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Feb 17, 2021

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@spockfish spockfish merged commit c50de1b into rpi-5.10.y Feb 17, 2021
spockfish pushed a commit that referenced this pull request Apr 8, 2021
commit 4d14c5c upstream

Calling btrfs_qgroup_reserve_meta_prealloc from
btrfs_delayed_inode_reserve_metadata can result in flushing delalloc
while holding a transaction and delayed node locks. This is deadlock
prone. In the past multiple commits:

 * ae5e070 ("btrfs: qgroup: don't try to wait flushing if we're
already holding a transaction")

 * 6f23277 ("btrfs: qgroup: don't commit transaction when we already
 hold the handle")

Tried to solve various aspects of this but this was always a
whack-a-mole game. Unfortunately those 2 fixes don't solve a deadlock
scenario involving btrfs_delayed_node::mutex. Namely, one thread
can call btrfs_dirty_inode as a result of reading a file and modifying
its atime:

  PID: 6963   TASK: ffff8c7f3f94c000  CPU: 2   COMMAND: "test"
  #0  __schedule at ffffffffa529e07d
  #1  schedule at ffffffffa529e4ff
  #2  schedule_timeout at ffffffffa52a1bdd
  #3  wait_for_completion at ffffffffa529eeea             <-- sleeps with delayed node mutex held
  #4  start_delalloc_inodes at ffffffffc0380db5
  #5  btrfs_start_delalloc_snapshot at ffffffffc0393836
  #6  try_flush_qgroup at ffffffffc03f04b2
  #7  __btrfs_qgroup_reserve_meta at ffffffffc03f5bb6     <-- tries to reserve space and starts delalloc inodes.
  #8  btrfs_delayed_update_inode at ffffffffc03e31aa      <-- acquires delayed node mutex
  #9  btrfs_update_inode at ffffffffc0385ba8
 #10  btrfs_dirty_inode at ffffffffc038627b               <-- TRANSACTIION OPENED
 raspberrypi#11  touch_atime at ffffffffa4cf0000
 raspberrypi#12  generic_file_read_iter at ffffffffa4c1f123
 raspberrypi#13  new_sync_read at ffffffffa4ccdc8a
 raspberrypi#14  vfs_read at ffffffffa4cd0849
 raspberrypi#15  ksys_read at ffffffffa4cd0bd1
 raspberrypi#16  do_syscall_64 at ffffffffa4a052eb
 raspberrypi#17  entry_SYSCALL_64_after_hwframe at ffffffffa540008c

This will cause an asynchronous work to flush the delalloc inodes to
happen which can try to acquire the same delayed_node mutex:

  PID: 455    TASK: ffff8c8085fa4000  CPU: 5   COMMAND: "kworker/u16:30"
  #0  __schedule at ffffffffa529e07d
  #1  schedule at ffffffffa529e4ff
  #2  schedule_preempt_disabled at ffffffffa529e80a
  #3  __mutex_lock at ffffffffa529fdcb                    <-- goes to sleep, never wakes up.
  #4  btrfs_delayed_update_inode at ffffffffc03e3143      <-- tries to acquire the mutex
  #5  btrfs_update_inode at ffffffffc0385ba8              <-- this is the same inode that pid 6963 is holding
  #6  cow_file_range_inline.constprop.78 at ffffffffc0386be7
  #7  cow_file_range at ffffffffc03879c1
  #8  btrfs_run_delalloc_range at ffffffffc038894c
  #9  writepage_delalloc at ffffffffc03a3c8f
 #10  __extent_writepage at ffffffffc03a4c01
 raspberrypi#11  extent_write_cache_pages at ffffffffc03a500b
 raspberrypi#12  extent_writepages at ffffffffc03a6de2
 raspberrypi#13  do_writepages at ffffffffa4c277eb
 raspberrypi#14  __filemap_fdatawrite_range at ffffffffa4c1e5bb
 raspberrypi#15  btrfs_run_delalloc_work at ffffffffc0380987         <-- starts running delayed nodes
 raspberrypi#16  normal_work_helper at ffffffffc03b706c
 raspberrypi#17  process_one_work at ffffffffa4aba4e4
 raspberrypi#18  worker_thread at ffffffffa4aba6fd
 raspberrypi#19  kthread at ffffffffa4ac0a3d
 raspberrypi#20  ret_from_fork at ffffffffa54001ff

To fully address those cases the complete fix is to never issue any
flushing while holding the transaction or the delayed node lock. This
patch achieves it by calling qgroup_reserve_meta directly which will
either succeed without flushing or will fail and return -EDQUOT. In the
latter case that return value is going to be propagated to
btrfs_dirty_inode which will fallback to start a new transaction. That's
fine as the majority of time we expect the inode will have
BTRFS_DELAYED_NODE_INODE_DIRTY flag set which will result in directly
copying the in-memory state.

Fixes: c53e965 ("btrfs: qgroup: try to flush qgroup space when we get -EDQUOT")
CC: [email protected] # 5.10+
Reviewed-by: Qu Wenruo <[email protected]>
Signed-off-by: Nikolay Borisov <[email protected]>
Signed-off-by: David Sterba <[email protected]>
[sudip: adjust context]
Signed-off-by: Sudip Mukherjee <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request Apr 8, 2021
commit ac0bbf5 upstream.

The digital input subdevice supports Comedi asynchronous commands that
read interrupt status information.  This uses 16-bit Comedi samples (of
which only the bottom 8 bits contain status information).  However, the
interrupt handler is calling `comedi_buf_write_samples()` with the
address of a 32-bit variable `unsigned int status`.  On a bigendian
machine, this will copy 2 bytes from the wrong end of the variable.  Fix
it by changing the type of the variable to `unsigned short`.

Fixes: a8c66b6 ("staging: comedi: addi_apci_1500: rewrite the subdevice support functions")
Cc: <[email protected]> #4.0+
Signed-off-by: Ian Abbott <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request Apr 19, 2021
commit 90bd070 upstream.

The following deadlock is detected:

  truncate -> setattr path is waiting for pending direct IO to be done (inode->i_dio_count become zero) with inode->i_rwsem held (down_write).

  PID: 14827  TASK: ffff881686a9af80  CPU: 20  COMMAND: "ora_p005_hrltd9"
   #0  __schedule at ffffffff818667cc
   #1  schedule at ffffffff81866de6
   #2  inode_dio_wait at ffffffff812a2d04
   #3  ocfs2_setattr at ffffffffc05f322e [ocfs2]
   #4  notify_change at ffffffff812a5a09
   #5  do_truncate at ffffffff812808f5
   #6  do_sys_ftruncate.constprop.18 at ffffffff81280cf2
   #7  sys_ftruncate at ffffffff81280d8e
   #8  do_syscall_64 at ffffffff81003949
   #9  entry_SYSCALL_64_after_hwframe at ffffffff81a001ad

dio completion path is going to complete one direct IO (decrement
inode->i_dio_count), but before that it hung at locking inode->i_rwsem:

   #0  __schedule+700 at ffffffff818667cc
   #1  schedule+54 at ffffffff81866de6
   #2  rwsem_down_write_failed+536 at ffffffff8186aa28
   #3  call_rwsem_down_write_failed+23 at ffffffff8185a1b7
   #4  down_write+45 at ffffffff81869c9d
   #5  ocfs2_dio_end_io_write+180 at ffffffffc05d5444 [ocfs2]
   #6  ocfs2_dio_end_io+85 at ffffffffc05d5a85 [ocfs2]
   #7  dio_complete+140 at ffffffff812c873c
   #8  dio_aio_complete_work+25 at ffffffff812c89f9
   #9  process_one_work+361 at ffffffff810b1889
  #10  worker_thread+77 at ffffffff810b233d
  raspberrypi#11  kthread+261 at ffffffff810b7fd5
  raspberrypi#12  ret_from_fork+62 at ffffffff81a0035e

Thus above forms ABBA deadlock.  The same deadlock was mentioned in
upstream commit 28f5a8a ("ocfs2: should wait dio before inode lock
in ocfs2_setattr()").  It seems that that commit only removed the
cluster lock (the victim of above dead lock) from the ABBA deadlock
party.

End-user visible effects: Process hang in truncate -> ocfs2_setattr path
and other processes hang at ocfs2_dio_end_io_write path.

This is to fix the deadlock itself.  It removes inode_lock() call from
dio completion path to remove the deadlock and add ip_alloc_sem lock in
setattr path to synchronize the inode modifications.

[[email protected]: remove the "had_alloc_lock" as suggested]
  Link: https://lkml.kernel.org/r/[email protected]

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Wengang Wang <[email protected]>
Reviewed-by: Joseph Qi <[email protected]>
Cc: Mark Fasheh <[email protected]>
Cc: Joel Becker <[email protected]>
Cc: Junxiao Bi <[email protected]>
Cc: Changwei Ge <[email protected]>
Cc: Gang He <[email protected]>
Cc: Jun Piao <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request May 19, 2021
commit 376565b upstream.

KMSAN complains that the vmci_use_ppn64() == false path in
vmci_dbell_register_notification_bitmap() left upper 32bits of
bitmap_set_msg.bitmap_ppn64 member uninitialized.

  =====================================================
  BUG: KMSAN: uninit-value in kmsan_check_memory+0xd/0x10
  CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.11.0-rc7+ #4
  Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 02/27/2020
  Call Trace:
   dump_stack+0x21c/0x280
   kmsan_report+0xfb/0x1e0
   kmsan_internal_check_memory+0x484/0x520
   kmsan_check_memory+0xd/0x10
   iowrite8_rep+0x86/0x380
   vmci_send_datagram+0x150/0x280
   vmci_dbell_register_notification_bitmap+0x133/0x1e0
   vmci_guest_probe_device+0xcab/0x1e70
   pci_device_probe+0xab3/0xe70
   really_probe+0xd16/0x24d0
   driver_probe_device+0x29d/0x3a0
   device_driver_attach+0x25a/0x490
   __driver_attach+0x78c/0x840
   bus_for_each_dev+0x210/0x340
   driver_attach+0x89/0xb0
   bus_add_driver+0x677/0xc40
   driver_register+0x485/0x8e0
   __pci_register_driver+0x1ff/0x350
   vmci_guest_init+0x3e/0x41
   vmci_drv_init+0x1d6/0x43f
   do_one_initcall+0x39c/0x9a0
   do_initcall_level+0x1d7/0x259
   do_initcalls+0x127/0x1cb
   do_basic_setup+0x33/0x36
   kernel_init_freeable+0x29a/0x3ed
   kernel_init+0x1f/0x840
   ret_from_fork+0x1f/0x30

  Local variable ----bitmap_set_msg@vmci_dbell_register_notification_bitmap created at:
   vmci_dbell_register_notification_bitmap+0x50/0x1e0
   vmci_dbell_register_notification_bitmap+0x50/0x1e0

  Bytes 28-31 of 32 are uninitialized
  Memory access of size 32 starts at ffff88810098f570
  =====================================================

Fixes: 83e2ec7 ("VMCI: doorbell implementation.")
Cc: <[email protected]>
Signed-off-by: Tetsuo Handa <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request May 19, 2021
commit b2192cf upstream.

KMSAN complains that vmci_check_host_caps() left the payload part of
check_msg uninitialized.

  =====================================================
  BUG: KMSAN: uninit-value in kmsan_check_memory+0xd/0x10
  CPU: 1 PID: 1 Comm: swapper/0 Tainted: G    B             5.11.0-rc7+ #4
  Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 02/27/2020
  Call Trace:
   dump_stack+0x21c/0x280
   kmsan_report+0xfb/0x1e0
   kmsan_internal_check_memory+0x202/0x520
   kmsan_check_memory+0xd/0x10
   iowrite8_rep+0x86/0x380
   vmci_guest_probe_device+0xf0b/0x1e70
   pci_device_probe+0xab3/0xe70
   really_probe+0xd16/0x24d0
   driver_probe_device+0x29d/0x3a0
   device_driver_attach+0x25a/0x490
   __driver_attach+0x78c/0x840
   bus_for_each_dev+0x210/0x340
   driver_attach+0x89/0xb0
   bus_add_driver+0x677/0xc40
   driver_register+0x485/0x8e0
   __pci_register_driver+0x1ff/0x350
   vmci_guest_init+0x3e/0x41
   vmci_drv_init+0x1d6/0x43f
   do_one_initcall+0x39c/0x9a0
   do_initcall_level+0x1d7/0x259
   do_initcalls+0x127/0x1cb
   do_basic_setup+0x33/0x36
   kernel_init_freeable+0x29a/0x3ed
   kernel_init+0x1f/0x840
   ret_from_fork+0x1f/0x30

  Uninit was created at:
   kmsan_internal_poison_shadow+0x5c/0xf0
   kmsan_slab_alloc+0x8d/0xe0
   kmem_cache_alloc+0x84f/0xe30
   vmci_guest_probe_device+0xd11/0x1e70
   pci_device_probe+0xab3/0xe70
   really_probe+0xd16/0x24d0
   driver_probe_device+0x29d/0x3a0
   device_driver_attach+0x25a/0x490
   __driver_attach+0x78c/0x840
   bus_for_each_dev+0x210/0x340
   driver_attach+0x89/0xb0
   bus_add_driver+0x677/0xc40
   driver_register+0x485/0x8e0
   __pci_register_driver+0x1ff/0x350
   vmci_guest_init+0x3e/0x41
   vmci_drv_init+0x1d6/0x43f
   do_one_initcall+0x39c/0x9a0
   do_initcall_level+0x1d7/0x259
   do_initcalls+0x127/0x1cb
   do_basic_setup+0x33/0x36
   kernel_init_freeable+0x29a/0x3ed
   kernel_init+0x1f/0x840
   ret_from_fork+0x1f/0x30

  Bytes 28-31 of 36 are uninitialized
  Memory access of size 36 starts at ffff8881675e5f00
  =====================================================

Fixes: 1f16643 ("VMCI: guest side driver implementation.")
Cc: <[email protected]>
Signed-off-by: Tetsuo Handa <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request May 19, 2021
[ Upstream commit b5332a9 ]

We are not changing anything in the TCP connection state so
we should not take a write_lock but rather a read lock.

This caused a deadlock when running nvmet-tcp and nvme-tcp
on the same system, where state_change callbacks on the
host and on the controller side have causal relationship
and made lockdep report on this with blktests:

================================
WARNING: inconsistent lock state
5.12.0-rc3 #1 Tainted: G          I
--------------------------------
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-R} usage.
nvme/1324 [HC0[0]:SC0[0]:HE1:SE1] takes:
ffff888363151000 (clock-AF_INET){++-?}-{2:2}, at: nvme_tcp_state_change+0x21/0x150 [nvme_tcp]
{IN-SOFTIRQ-W} state was registered at:
  __lock_acquire+0x79b/0x18d0
  lock_acquire+0x1ca/0x480
  _raw_write_lock_bh+0x39/0x80
  nvmet_tcp_state_change+0x21/0x170 [nvmet_tcp]
  tcp_fin+0x2a8/0x780
  tcp_data_queue+0xf94/0x1f20
  tcp_rcv_established+0x6ba/0x1f00
  tcp_v4_do_rcv+0x502/0x760
  tcp_v4_rcv+0x257e/0x3430
  ip_protocol_deliver_rcu+0x69/0x6a0
  ip_local_deliver_finish+0x1e2/0x2f0
  ip_local_deliver+0x1a2/0x420
  ip_rcv+0x4fb/0x6b0
  __netif_receive_skb_one_core+0x162/0x1b0
  process_backlog+0x1ff/0x770
  __napi_poll.constprop.0+0xa9/0x5c0
  net_rx_action+0x7b3/0xb30
  __do_softirq+0x1f0/0x940
  do_softirq+0xa1/0xd0
  __local_bh_enable_ip+0xd8/0x100
  ip_finish_output2+0x6b7/0x18a0
  __ip_queue_xmit+0x706/0x1aa0
  __tcp_transmit_skb+0x2068/0x2e20
  tcp_write_xmit+0xc9e/0x2bb0
  __tcp_push_pending_frames+0x92/0x310
  inet_shutdown+0x158/0x300
  __nvme_tcp_stop_queue+0x36/0x270 [nvme_tcp]
  nvme_tcp_stop_queue+0x87/0xb0 [nvme_tcp]
  nvme_tcp_teardown_admin_queue+0x69/0xe0 [nvme_tcp]
  nvme_do_delete_ctrl+0x100/0x10c [nvme_core]
  nvme_sysfs_delete.cold+0x8/0xd [nvme_core]
  kernfs_fop_write_iter+0x2c7/0x460
  new_sync_write+0x36c/0x610
  vfs_write+0x5c0/0x870
  ksys_write+0xf9/0x1d0
  do_syscall_64+0x33/0x40
  entry_SYSCALL_64_after_hwframe+0x44/0xae
irq event stamp: 10687
hardirqs last  enabled at (10687): [<ffffffff9ec376bd>] _raw_spin_unlock_irqrestore+0x2d/0x40
hardirqs last disabled at (10686): [<ffffffff9ec374d8>] _raw_spin_lock_irqsave+0x68/0x90
softirqs last  enabled at (10684): [<ffffffff9f000608>] __do_softirq+0x608/0x940
softirqs last disabled at (10649): [<ffffffff9cdedd31>] do_softirq+0xa1/0xd0

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(clock-AF_INET);
  <Interrupt>
    lock(clock-AF_INET);

 *** DEADLOCK ***

5 locks held by nvme/1324:
 #0: ffff8884a01fe470 (sb_writers#4){.+.+}-{0:0}, at: ksys_write+0xf9/0x1d0
 #1: ffff8886e435c090 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x216/0x460
 #2: ffff888104d90c38 (kn->active#255){++++}-{0:0}, at: kernfs_remove_self+0x22d/0x330
 #3: ffff8884634538d0 (&queue->queue_lock){+.+.}-{3:3}, at: nvme_tcp_stop_queue+0x52/0xb0 [nvme_tcp]
 #4: ffff888363150d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: inet_shutdown+0x59/0x300

stack backtrace:
CPU: 26 PID: 1324 Comm: nvme Tainted: G          I       5.12.0-rc3 #1
Hardware name: Dell Inc. PowerEdge R640/06NR82, BIOS 2.10.0 11/12/2020
Call Trace:
 dump_stack+0x93/0xc2
 mark_lock_irq.cold+0x2c/0xb3
 ? verify_lock_unused+0x390/0x390
 ? stack_trace_consume_entry+0x160/0x160
 ? lock_downgrade+0x100/0x100
 ? save_trace+0x88/0x5e0
 ? _raw_spin_unlock_irqrestore+0x2d/0x40
 mark_lock+0x530/0x1470
 ? mark_lock_irq+0x1d10/0x1d10
 ? enqueue_timer+0x660/0x660
 mark_usage+0x215/0x2a0
 __lock_acquire+0x79b/0x18d0
 ? tcp_schedule_loss_probe.part.0+0x38c/0x520
 lock_acquire+0x1ca/0x480
 ? nvme_tcp_state_change+0x21/0x150 [nvme_tcp]
 ? rcu_read_unlock+0x40/0x40
 ? tcp_mtu_probe+0x1ae0/0x1ae0
 ? kmalloc_reserve+0xa0/0xa0
 ? sysfs_file_ops+0x170/0x170
 _raw_read_lock+0x3d/0xa0
 ? nvme_tcp_state_change+0x21/0x150 [nvme_tcp]
 nvme_tcp_state_change+0x21/0x150 [nvme_tcp]
 ? sysfs_file_ops+0x170/0x170
 inet_shutdown+0x189/0x300
 __nvme_tcp_stop_queue+0x36/0x270 [nvme_tcp]
 nvme_tcp_stop_queue+0x87/0xb0 [nvme_tcp]
 nvme_tcp_teardown_admin_queue+0x69/0xe0 [nvme_tcp]
 nvme_do_delete_ctrl+0x100/0x10c [nvme_core]
 nvme_sysfs_delete.cold+0x8/0xd [nvme_core]
 kernfs_fop_write_iter+0x2c7/0x460
 new_sync_write+0x36c/0x610
 ? new_sync_read+0x600/0x600
 ? lock_acquire+0x1ca/0x480
 ? rcu_read_unlock+0x40/0x40
 ? lock_is_held_type+0x9a/0x110
 vfs_write+0x5c0/0x870
 ksys_write+0xf9/0x1d0
 ? __ia32_sys_read+0xa0/0xa0
 ? lockdep_hardirqs_on_prepare.part.0+0x198/0x340
 ? syscall_enter_from_user_mode+0x27/0x70
 do_syscall_64+0x33/0x40
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Fixes: 872d26a ("nvmet-tcp: add NVMe over TCP target driver")
Reported-by: Yi Zhang <[email protected]>
Signed-off-by: Sagi Grimberg <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request May 19, 2021
[ Upstream commit bbd6f0a ]

In bnxt_rx_pkt(), the RX buffers are expected to complete in order.
If the RX consumer index indicates an out of order buffer completion,
it means we are hitting a hardware bug and the driver will abort all
remaining RX packets and reset the RX ring.  The RX consumer index
that we pass to bnxt_discard_rx() is not correct.  We should be
passing the current index (tmp_raw_cons) instead of the old index
(raw_cons).  This bug can cause us to be at the wrong index when
trying to abort the next RX packet.  It can crash like this:

 #0 [ffff9bbcdf5c39a8] machine_kexec at ffffffff9b05e007
 #1 [ffff9bbcdf5c3a00] __crash_kexec at ffffffff9b111232
 #2 [ffff9bbcdf5c3ad0] panic at ffffffff9b07d61e
 #3 [ffff9bbcdf5c3b50] oops_end at ffffffff9b030978
 #4 [ffff9bbcdf5c3b78] no_context at ffffffff9b06aaf0
 #5 [ffff9bbcdf5c3bd8] __bad_area_nosemaphore at ffffffff9b06ae2e
 #6 [ffff9bbcdf5c3c28] bad_area_nosemaphore at ffffffff9b06af24
 #7 [ffff9bbcdf5c3c38] __do_page_fault at ffffffff9b06b67e
 #8 [ffff9bbcdf5c3cb0] do_page_fault at ffffffff9b06bb12
 #9 [ffff9bbcdf5c3ce0] page_fault at ffffffff9bc015c5
    [exception RIP: bnxt_rx_pkt+237]
    RIP: ffffffffc0259cdd  RSP: ffff9bbcdf5c3d98  RFLAGS: 00010213
    RAX: 000000005dd8097f  RBX: ffff9ba4cb11b7e0  RCX: ffffa923cf6e9000
    RDX: 0000000000000fff  RSI: 0000000000000627  RDI: 0000000000001000
    RBP: ffff9bbcdf5c3e60   R8: 0000000000420003   R9: 000000000000020d
    R10: ffffa923cf6ec138  R11: ffff9bbcdf5c3e83  R12: ffff9ba4d6f928c0
    R13: ffff9ba4cac28080  R14: ffff9ba4cb11b7f0  R15: ffff9ba4d5a30000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018

Fixes: a1b0e4e ("bnxt_en: Improve RX consumer index validity check.")
Reviewed-by: Pavan Chebbi <[email protected]>
Reviewed-by: Andy Gospodarek <[email protected]>
Signed-off-by: Michael Chan <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Jun 8, 2021
…xtent

[ Upstream commit 6416954 ]

When cloning an inline extent there are a few cases, such as when we have
an implicit hole at file offset 0, where we start a transaction while
holding a read lock on a leaf. Starting the transaction results in a call
to sb_start_intwrite(), which results in doing a read lock on a percpu
semaphore. Lockdep doesn't like this and complains about it:

  [46.580704] ======================================================
  [46.580752] WARNING: possible circular locking dependency detected
  [46.580799] 5.13.0-rc1 raspberrypi#28 Not tainted
  [46.580832] ------------------------------------------------------
  [46.580877] cloner/3835 is trying to acquire lock:
  [46.580918] c00000001301d638 (sb_internal#2){.+.+}-{0:0}, at: clone_copy_inline_extent+0xe4/0x5a0
  [46.581167]
  [46.581167] but task is already holding lock:
  [46.581217] c000000007fa2550 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x70/0x1d0
  [46.581293]
  [46.581293] which lock already depends on the new lock.
  [46.581293]
  [46.581351]
  [46.581351] the existing dependency chain (in reverse order) is:
  [46.581410]
  [46.581410] -> #1 (btrfs-tree-00){++++}-{3:3}:
  [46.581464]        down_read_nested+0x68/0x200
  [46.581536]        __btrfs_tree_read_lock+0x70/0x1d0
  [46.581577]        btrfs_read_lock_root_node+0x88/0x200
  [46.581623]        btrfs_search_slot+0x298/0xb70
  [46.581665]        btrfs_set_inode_index+0xfc/0x260
  [46.581708]        btrfs_new_inode+0x26c/0x950
  [46.581749]        btrfs_create+0xf4/0x2b0
  [46.581782]        lookup_open.isra.57+0x55c/0x6a0
  [46.581855]        path_openat+0x418/0xd20
  [46.581888]        do_filp_open+0x9c/0x130
  [46.581920]        do_sys_openat2+0x2ec/0x430
  [46.581961]        do_sys_open+0x90/0xc0
  [46.581993]        system_call_exception+0x3d4/0x410
  [46.582037]        system_call_common+0xec/0x278
  [46.582078]
  [46.582078] -> #0 (sb_internal#2){.+.+}-{0:0}:
  [46.582135]        __lock_acquire+0x1e90/0x2c50
  [46.582176]        lock_acquire+0x2b4/0x5b0
  [46.582263]        start_transaction+0x3cc/0x950
  [46.582308]        clone_copy_inline_extent+0xe4/0x5a0
  [46.582353]        btrfs_clone+0x5fc/0x880
  [46.582388]        btrfs_clone_files+0xd8/0x1c0
  [46.582434]        btrfs_remap_file_range+0x3d8/0x590
  [46.582481]        do_clone_file_range+0x10c/0x270
  [46.582558]        vfs_clone_file_range+0x1b0/0x310
  [46.582605]        ioctl_file_clone+0x90/0x130
  [46.582651]        do_vfs_ioctl+0x874/0x1ac0
  [46.582697]        sys_ioctl+0x6c/0x120
  [46.582733]        system_call_exception+0x3d4/0x410
  [46.582777]        system_call_common+0xec/0x278
  [46.582822]
  [46.582822] other info that might help us debug this:
  [46.582822]
  [46.582888]  Possible unsafe locking scenario:
  [46.582888]
  [46.582942]        CPU0                    CPU1
  [46.582984]        ----                    ----
  [46.583028]   lock(btrfs-tree-00);
  [46.583062]                                lock(sb_internal#2);
  [46.583119]                                lock(btrfs-tree-00);
  [46.583174]   lock(sb_internal#2);
  [46.583212]
  [46.583212]  *** DEADLOCK ***
  [46.583212]
  [46.583266] 6 locks held by cloner/3835:
  [46.583299]  #0: c00000001301d448 (sb_writers#12){.+.+}-{0:0}, at: ioctl_file_clone+0x90/0x130
  [46.583382]  #1: c00000000f6d3768 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}, at: lock_two_nondirectories+0x58/0xc0
  [46.583477]  #2: c00000000f6d72a8 (&sb->s_type->i_mutex_key#15/4){+.+.}-{3:3}, at: lock_two_nondirectories+0x9c/0xc0
  [46.583574]  #3: c00000000f6d7138 (&ei->i_mmap_lock){+.+.}-{3:3}, at: btrfs_remap_file_range+0xd0/0x590
  [46.583657]  #4: c00000000f6d35f8 (&ei->i_mmap_lock/1){+.+.}-{3:3}, at: btrfs_remap_file_range+0xe0/0x590
  [46.583743]  #5: c000000007fa2550 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x70/0x1d0
  [46.583828]
  [46.583828] stack backtrace:
  [46.583872] CPU: 1 PID: 3835 Comm: cloner Not tainted 5.13.0-rc1 raspberrypi#28
  [46.583931] Call Trace:
  [46.583955] [c0000000167c7200] [c000000000c1ee78] dump_stack+0xec/0x144 (unreliable)
  [46.584052] [c0000000167c7240] [c000000000274058] print_circular_bug.isra.32+0x3a8/0x400
  [46.584123] [c0000000167c72e0] [c0000000002741f4] check_noncircular+0x144/0x190
  [46.584191] [c0000000167c73b0] [c000000000278fc0] __lock_acquire+0x1e90/0x2c50
  [46.584259] [c0000000167c74f0] [c00000000027aa94] lock_acquire+0x2b4/0x5b0
  [46.584317] [c0000000167c75e0] [c000000000a0d6cc] start_transaction+0x3cc/0x950
  [46.584388] [c0000000167c7690] [c000000000af47a4] clone_copy_inline_extent+0xe4/0x5a0
  [46.584457] [c0000000167c77c0] [c000000000af525c] btrfs_clone+0x5fc/0x880
  [46.584514] [c0000000167c7990] [c000000000af5698] btrfs_clone_files+0xd8/0x1c0
  [46.584583] [c0000000167c7a00] [c000000000af5b58] btrfs_remap_file_range+0x3d8/0x590
  [46.584652] [c0000000167c7ae0] [c0000000005d81dc] do_clone_file_range+0x10c/0x270
  [46.584722] [c0000000167c7b40] [c0000000005d84f0] vfs_clone_file_range+0x1b0/0x310
  [46.584793] [c0000000167c7bb0] [c00000000058bf80] ioctl_file_clone+0x90/0x130
  [46.584861] [c0000000167c7c10] [c00000000058c894] do_vfs_ioctl+0x874/0x1ac0
  [46.584922] [c0000000167c7d10] [c00000000058db4c] sys_ioctl+0x6c/0x120
  [46.584978] [c0000000167c7d60] [c0000000000364a4] system_call_exception+0x3d4/0x410
  [46.585046] [c0000000167c7e10] [c00000000000d45c] system_call_common+0xec/0x278
  [46.585114] --- interrupt: c00 at 0x7ffff7e22990
  [46.585160] NIP:  00007ffff7e22990 LR: 00000001000010ec CTR: 0000000000000000
  [46.585224] REGS: c0000000167c7e80 TRAP: 0c00   Not tainted  (5.13.0-rc1)
  [46.585280] MSR:  800000000280f033 <SF,VEC,VSX,EE,PR,FP,ME,IR,DR,RI,LE>  CR: 28000244  XER: 00000000
  [46.585374] IRQMASK: 0
  [46.585374] GPR00: 0000000000000036 00007fffffffdec0 00007ffff7f17100 0000000000000004
  [46.585374] GPR04: 000000008020940d 00007fffffffdf40 0000000000000000 0000000000000000
  [46.585374] GPR08: 0000000000000004 0000000000000000 0000000000000000 0000000000000000
  [46.585374] GPR12: 0000000000000000 00007ffff7ffa940 0000000000000000 0000000000000000
  [46.585374] GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  [46.585374] GPR20: 0000000000000000 000000009123683e 00007fffffffdf40 0000000000000000
  [46.585374] GPR24: 0000000000000000 0000000000000000 0000000000000000 0000000000000004
  [46.585374] GPR28: 0000000100030260 0000000100030280 0000000000000003 000000000000005f
  [46.585919] NIP [00007ffff7e22990] 0x7ffff7e22990
  [46.585964] LR [00000001000010ec] 0x1000010ec
  [46.586010] --- interrupt: c00

This should be a false positive, as both locks are acquired in read mode.
Nevertheless, we don't need to hold a leaf locked when we start the
transaction, so just release the leaf (path) before starting it.

Reported-by: Ritesh Harjani <[email protected]>
Link: https://lore.kernel.org/linux-btrfs/20210513214404.xks77p566fglzgum@riteshh-domain/
Reviewed-by: Anand Jain <[email protected]>
Signed-off-by: Filipe Manana <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Jul 23, 2021
[ Upstream commit 2c48441 ]

lz4 compatible decompressor is simple.  The format is underspecified and
relies on EOF notification to determine when to stop.  Initramfs buffer
format[1] explicitly states that it can have arbitrary number of zero
padding.  Thus when operating without a fill function, be extra careful to
ensure that sizes less than 4, or apperantly empty chunksizes are treated
as EOF.

To test this I have created two cpio initrds, first a normal one,
main.cpio.  And second one with just a single /test-file with content
"second" second.cpio.  Then i compressed both of them with gzip, and with
lz4 -l.  Then I created a padding of 4 bytes (dd if=/dev/zero of=pad4 bs=1
count=4).  To create four testcase initrds:

 1) main.cpio.gzip + extra.cpio.gzip = pad0.gzip
 2) main.cpio.lz4  + extra.cpio.lz4 = pad0.lz4
 3) main.cpio.gzip + pad4 + extra.cpio.gzip = pad4.gzip
 4) main.cpio.lz4  + pad4 + extra.cpio.lz4 = pad4.lz4

The pad4 test-cases replicate the initrd load by grub, as it pads and
aligns every initrd it loads.

All of the above boot, however /test-file was not accessible in the initrd
for the testcase #4, as decoding in lz4 decompressor failed.  Also an
error message printed which usually is harmless.

Whith a patched kernel, all of the above testcases now pass, and
/test-file is accessible.

This fixes lz4 initrd decompress warning on every boot with grub.  And
more importantly this fixes inability to load multiple lz4 compressed
initrds with grub.  This patch has been shipping in Ubuntu kernels since
January 2021.

[1] ./Documentation/driver-api/early-userspace/buffer-format.rst

BugLink: https://bugs.launchpad.net/bugs/1835660
Link: https://lore.kernel.org/lkml/[email protected]/ # v0
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Dimitri John Ledkov <[email protected]>
Cc: Kyungsik Lee <[email protected]>
Cc: Yinghai Lu <[email protected]>
Cc: Bongkyu Kim <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Sven Schmidt <[email protected]>
Cc: Rajat Asthana <[email protected]>
Cc: Nick Terrell <[email protected]>
Cc: Gao Xiang <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Aug 27, 2021
commit 4385539 upstream.

The ordering of MSI-X enable in hardware is dysfunctional:

 1) MSI-X is disabled in the control register
 2) Various setup functions
 3) pci_msi_setup_msi_irqs() is invoked which ends up accessing
    the MSI-X table entries
 4) MSI-X is enabled and masked in the control register with the
    comment that enabling is required for some hardware to access
    the MSI-X table

Step #4 obviously contradicts #3. The history of this is an issue with the
NIU hardware. When #4 was introduced the table access actually happened in
msix_program_entries() which was invoked after enabling and masking MSI-X.

This was changed in commit d71d643 ("PCI/MSI: Kill redundant call of
irq_set_msi_desc() for MSI-X interrupts") which removed the table write
from msix_program_entries().

Interestingly enough nobody noticed and either NIU still works or it did
not get any testing with a kernel 3.19 or later.

Nevertheless this is inconsistent and there is no reason why MSI-X can't be
enabled and masked in the control register early on, i.e. move step #4
above to step #1. This preserves the NIU workaround and has no side effects
on other hardware.

Fixes: d71d643 ("PCI/MSI: Kill redundant call of irq_set_msi_desc() for MSI-X interrupts")
Signed-off-by: Thomas Gleixner <[email protected]>
Tested-by: Marc Zyngier <[email protected]>
Reviewed-by: Ashok Raj <[email protected]>
Reviewed-by: Marc Zyngier <[email protected]>
Acked-by: Bjorn Helgaas <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request Sep 10, 2021
commit 67069a1 upstream.

ASan reported a memory leak caused by info_linear not being deallocated.

The info_linear was allocated during in perf_event__synthesize_one_bpf_prog().

This patch adds the corresponding free() when bpf_prog_info_node
is freed in perf_env__purge_bpf().

  $ sudo ./perf record -- sleep 5
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.025 MB perf.data (8 samples) ]

  =================================================================
  ==297735==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 7688 byte(s) in 19 object(s) allocated from:
      #0 0x4f420f in malloc (/home/user/linux/tools/perf/perf+0x4f420f)
      #1 0xc06a74 in bpf_program__get_prog_info_linear /home/user/linux/tools/lib/bpf/libbpf.c:11113:16
      #2 0xb426fe in perf_event__synthesize_one_bpf_prog /home/user/linux/tools/perf/util/bpf-event.c:191:16
      #3 0xb42008 in perf_event__synthesize_bpf_events /home/user/linux/tools/perf/util/bpf-event.c:410:9
      #4 0x594596 in record__synthesize /home/user/linux/tools/perf/builtin-record.c:1490:8
      #5 0x58c9ac in __cmd_record /home/user/linux/tools/perf/builtin-record.c:1798:8
      #6 0x58990b in cmd_record /home/user/linux/tools/perf/builtin-record.c:2901:8
      #7 0x7b2a20 in run_builtin /home/user/linux/tools/perf/perf.c:313:11
      #8 0x7b12ff in handle_internal_command /home/user/linux/tools/perf/perf.c:365:8
      #9 0x7b2583 in run_argv /home/user/linux/tools/perf/perf.c:409:2
      #10 0x7b0d79 in main /home/user/linux/tools/perf/perf.c:539:3
      raspberrypi#11 0x7fa357ef6b74 in __libc_start_main /usr/src/debug/glibc-2.33-8.fc34.x86_64/csu/../csu/libc-start.c:332:16

Signed-off-by: Riccardo Mancini <[email protected]>
Acked-by: Ian Rogers <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Andrii Nakryiko <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: John Fastabend <[email protected]>
Cc: KP Singh <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Martin KaFai Lau <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Song Liu <[email protected]>
Cc: Yonghong Song <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Hanjun Guo <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request Sep 10, 2021
commit 41d5854 upstream.

I got several memory leak reports from Asan with a simple command.  It
was because VDSO is not released due to the refcount.  Like in
__dsos_addnew_id(), it should put the refcount after adding to the list.

  $ perf record true
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.030 MB perf.data (10 samples) ]

  =================================================================
  ==692599==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 439 byte(s) in 1 object(s) allocated from:
    #0 0x7fea52341037 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:154
    #1 0x559bce4aa8ee in dso__new_id util/dso.c:1256
    #2 0x559bce59245a in __machine__addnew_vdso util/vdso.c:132
    #3 0x559bce59245a in machine__findnew_vdso util/vdso.c:347
    #4 0x559bce50826c in map__new util/map.c:175
    #5 0x559bce503c92 in machine__process_mmap2_event util/machine.c:1787
    #6 0x559bce512f6b in machines__deliver_event util/session.c:1481
    #7 0x559bce515107 in perf_session__deliver_event util/session.c:1551
    #8 0x559bce51d4d2 in do_flush util/ordered-events.c:244
    #9 0x559bce51d4d2 in __ordered_events__flush util/ordered-events.c:323
    #10 0x559bce519bea in __perf_session__process_events util/session.c:2268
    raspberrypi#11 0x559bce519bea in perf_session__process_events util/session.c:2297
    raspberrypi#12 0x559bce2e7a52 in process_buildids /home/namhyung/project/linux/tools/perf/builtin-record.c:1017
    raspberrypi#13 0x559bce2e7a52 in record__finish_output /home/namhyung/project/linux/tools/perf/builtin-record.c:1234
    raspberrypi#14 0x559bce2ed4f6 in __cmd_record /home/namhyung/project/linux/tools/perf/builtin-record.c:2026
    raspberrypi#15 0x559bce2ed4f6 in cmd_record /home/namhyung/project/linux/tools/perf/builtin-record.c:2858
    raspberrypi#16 0x559bce422db4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
    raspberrypi#17 0x559bce2acac8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
    raspberrypi#18 0x559bce2acac8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
    raspberrypi#19 0x559bce2acac8 in main /home/namhyung/project/linux/tools/perf/perf.c:539
    raspberrypi#20 0x7fea51e76d09 in __libc_start_main ../csu/libc-start.c:308

  Indirect leak of 32 byte(s) in 1 object(s) allocated from:
    #0 0x7fea52341037 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:154
    #1 0x559bce520907 in nsinfo__copy util/namespaces.c:169
    #2 0x559bce50821b in map__new util/map.c:168
    #3 0x559bce503c92 in machine__process_mmap2_event util/machine.c:1787
    #4 0x559bce512f6b in machines__deliver_event util/session.c:1481
    #5 0x559bce515107 in perf_session__deliver_event util/session.c:1551
    #6 0x559bce51d4d2 in do_flush util/ordered-events.c:244
    #7 0x559bce51d4d2 in __ordered_events__flush util/ordered-events.c:323
    #8 0x559bce519bea in __perf_session__process_events util/session.c:2268
    #9 0x559bce519bea in perf_session__process_events util/session.c:2297
    #10 0x559bce2e7a52 in process_buildids /home/namhyung/project/linux/tools/perf/builtin-record.c:1017
    raspberrypi#11 0x559bce2e7a52 in record__finish_output /home/namhyung/project/linux/tools/perf/builtin-record.c:1234
    raspberrypi#12 0x559bce2ed4f6 in __cmd_record /home/namhyung/project/linux/tools/perf/builtin-record.c:2026
    raspberrypi#13 0x559bce2ed4f6 in cmd_record /home/namhyung/project/linux/tools/perf/builtin-record.c:2858
    raspberrypi#14 0x559bce422db4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
    raspberrypi#15 0x559bce2acac8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
    raspberrypi#16 0x559bce2acac8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
    raspberrypi#17 0x559bce2acac8 in main /home/namhyung/project/linux/tools/perf/perf.c:539
    raspberrypi#18 0x7fea51e76d09 in __libc_start_main ../csu/libc-start.c:308

  SUMMARY: AddressSanitizer: 471 byte(s) leaked in 2 allocation(s).

Signed-off-by: Namhyung Kim <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Hanjun Guo <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request Oct 14, 2021
commit 57f0ff0 upstream.

It's later supposed to be either a correct address or NULL. Without the
initialization, it may contain an undefined value which results in the
following segmentation fault:

  # perf top --sort comm -g --ignore-callees=do_idle

terminates with:

  #0  0x00007ffff56b7685 in __strlen_avx2 () from /lib64/libc.so.6
  #1  0x00007ffff55e3802 in strdup () from /lib64/libc.so.6
  #2  0x00005555558cb139 in hist_entry__init (callchain_size=<optimized out>, sample_self=true, template=0x7fffde7fb110, he=0x7fffd801c250) at util/hist.c:489
  #3  hist_entry__new (template=template@entry=0x7fffde7fb110, sample_self=sample_self@entry=true) at util/hist.c:564
  #4  0x00005555558cb4ba in hists__findnew_entry (hists=hists@entry=0x5555561d9e38, entry=entry@entry=0x7fffde7fb110, al=al@entry=0x7fffde7fb420,
      sample_self=sample_self@entry=true) at util/hist.c:657
  #5  0x00005555558cba1b in __hists__add_entry (hists=hists@entry=0x5555561d9e38, al=0x7fffde7fb420, sym_parent=<optimized out>, bi=bi@entry=0x0, mi=mi@entry=0x0,
      sample=sample@entry=0x7fffde7fb4b0, sample_self=true, ops=0x0, block_info=0x0) at util/hist.c:288
  #6  0x00005555558cbb70 in hists__add_entry (sample_self=true, sample=0x7fffde7fb4b0, mi=0x0, bi=0x0, sym_parent=<optimized out>, al=<optimized out>, hists=0x5555561d9e38)
      at util/hist.c:1056
  #7  iter_add_single_cumulative_entry (iter=0x7fffde7fb460, al=<optimized out>) at util/hist.c:1056
  #8  0x00005555558cc8a4 in hist_entry_iter__add (iter=iter@entry=0x7fffde7fb460, al=al@entry=0x7fffde7fb420, max_stack_depth=<optimized out>, arg=arg@entry=0x7fffffff7db0)
      at util/hist.c:1231
  #9  0x00005555557cdc9a in perf_event__process_sample (machine=<optimized out>, sample=0x7fffde7fb4b0, evsel=<optimized out>, event=<optimized out>, tool=0x7fffffff7db0)
      at builtin-top.c:842
  #10 deliver_event (qe=<optimized out>, qevent=<optimized out>) at builtin-top.c:1202
  raspberrypi#11 0x00005555558a9318 in do_flush (show_progress=false, oe=0x7fffffff80e0) at util/ordered-events.c:244
  raspberrypi#12 __ordered_events__flush (oe=oe@entry=0x7fffffff80e0, how=how@entry=OE_FLUSH__TOP, timestamp=timestamp@entry=0) at util/ordered-events.c:323
  raspberrypi#13 0x00005555558a9789 in __ordered_events__flush (timestamp=<optimized out>, how=<optimized out>, oe=<optimized out>) at util/ordered-events.c:339
  raspberrypi#14 ordered_events__flush (how=OE_FLUSH__TOP, oe=0x7fffffff80e0) at util/ordered-events.c:341
  raspberrypi#15 ordered_events__flush (oe=oe@entry=0x7fffffff80e0, how=how@entry=OE_FLUSH__TOP) at util/ordered-events.c:339
  raspberrypi#16 0x00005555557cd631 in process_thread (arg=0x7fffffff7db0) at builtin-top.c:1114
  raspberrypi#17 0x00007ffff7bb817a in start_thread () from /lib64/libpthread.so.0
  raspberrypi#18 0x00007ffff5656dc3 in clone () from /lib64/libc.so.6

If you look at the frame #2, the code is:

488	 if (he->srcline) {
489          he->srcline = strdup(he->srcline);
490          if (he->srcline == NULL)
491              goto err_rawdata;
492	 }

If he->srcline is not NULL (it is not NULL if it is uninitialized rubbish),
it gets strdupped and strdupping a rubbish random string causes the problem.

Also, if you look at the commit 1fb7d06, it adds the srcline property
into the struct, but not initializing it everywhere needed.

Committer notes:

Now I see, when using --ignore-callees=do_idle we end up here at line
2189 in add_callchain_ip():

2181         if (al.sym != NULL) {
2182                 if (perf_hpp_list.parent && !*parent &&
2183                     symbol__match_regex(al.sym, &parent_regex))
2184                         *parent = al.sym;
2185                 else if (have_ignore_callees && root_al &&
2186                   symbol__match_regex(al.sym, &ignore_callees_regex)) {
2187                         /* Treat this symbol as the root,
2188                            forgetting its callees. */
2189                         *root_al = al;
2190                         callchain_cursor_reset(cursor);
2191                 }
2192         }

And the al that doesn't have the ->srcline field initialized will be
copied to the root_al, so then, back to:

1211 int hist_entry_iter__add(struct hist_entry_iter *iter, struct addr_location *al,
1212                          int max_stack_depth, void *arg)
1213 {
1214         int err, err2;
1215         struct map *alm = NULL;
1216
1217         if (al)
1218                 alm = map__get(al->map);
1219
1220         err = sample__resolve_callchain(iter->sample, &callchain_cursor, &iter->parent,
1221                                         iter->evsel, al, max_stack_depth);
1222         if (err) {
1223                 map__put(alm);
1224                 return err;
1225         }
1226
1227         err = iter->ops->prepare_entry(iter, al);
1228         if (err)
1229                 goto out;
1230
1231         err = iter->ops->add_single_entry(iter, al);
1232         if (err)
1233                 goto out;
1234

That al at line 1221 is what hist_entry_iter__add() (called from
sample__resolve_callchain()) saw as 'root_al', and then:

        iter->ops->add_single_entry(iter, al);

will go on with al->srcline with a bogus value, I'll add the above
sequence to the cset and apply, thanks!

Signed-off-by: Michael Petlan <[email protected]>
CC: Milian Wolff <[email protected]>
Cc: Jiri Olsa <[email protected]>
Fixes: 1fb7d06 ("perf report Use srcline from callchain for hist entries")
Link: https //lore.kernel.org/r/[email protected]
Reported-by: Juri Lelli <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request Oct 14, 2021
[ Upstream commit 8f96a5b ]

We update the ctime/mtime of a block device when we remove it so that
blkid knows the device changed.  However we do this by re-opening the
block device and calling filp_update_time.  This is more correct because
it'll call the inode->i_op->update_time if it exists, but the block dev
inodes do not do this.  Instead call generic_update_time() on the
bd_inode in order to avoid the blkdev_open path and get rid of the
following lockdep splat:

======================================================
WARNING: possible circular locking dependency detected
5.14.0-rc2+ raspberrypi#406 Not tainted
------------------------------------------------------
losetup/11596 is trying to acquire lock:
ffff939640d2f538 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0

but task is already holding lock:
ffff939655510c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #4 (&lo->lo_mutex){+.+.}-{3:3}:
       __mutex_lock+0x7d/0x750
       lo_open+0x28/0x60 [loop]
       blkdev_get_whole+0x25/0xf0
       blkdev_get_by_dev.part.0+0x168/0x3c0
       blkdev_open+0xd2/0xe0
       do_dentry_open+0x161/0x390
       path_openat+0x3cc/0xa20
       do_filp_open+0x96/0x120
       do_sys_openat2+0x7b/0x130
       __x64_sys_openat+0x46/0x70
       do_syscall_64+0x38/0x90
       entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #3 (&disk->open_mutex){+.+.}-{3:3}:
       __mutex_lock+0x7d/0x750
       blkdev_get_by_dev.part.0+0x56/0x3c0
       blkdev_open+0xd2/0xe0
       do_dentry_open+0x161/0x390
       path_openat+0x3cc/0xa20
       do_filp_open+0x96/0x120
       file_open_name+0xc7/0x170
       filp_open+0x2c/0x50
       btrfs_scratch_superblocks.part.0+0x10f/0x170
       btrfs_rm_device.cold+0xe8/0xed
       btrfs_ioctl+0x2a31/0x2e70
       __x64_sys_ioctl+0x80/0xb0
       do_syscall_64+0x38/0x90
       entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #2 (sb_writers#12){.+.+}-{0:0}:
       lo_write_bvec+0xc2/0x240 [loop]
       loop_process_work+0x238/0xd00 [loop]
       process_one_work+0x26b/0x560
       worker_thread+0x55/0x3c0
       kthread+0x140/0x160
       ret_from_fork+0x1f/0x30

-> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
       process_one_work+0x245/0x560
       worker_thread+0x55/0x3c0
       kthread+0x140/0x160
       ret_from_fork+0x1f/0x30

-> #0 ((wq_completion)loop0){+.+.}-{0:0}:
       __lock_acquire+0x10ea/0x1d90
       lock_acquire+0xb5/0x2b0
       flush_workqueue+0x91/0x5e0
       drain_workqueue+0xa0/0x110
       destroy_workqueue+0x36/0x250
       __loop_clr_fd+0x9a/0x660 [loop]
       block_ioctl+0x3f/0x50
       __x64_sys_ioctl+0x80/0xb0
       do_syscall_64+0x38/0x90
       entry_SYSCALL_64_after_hwframe+0x44/0xae

other info that might help us debug this:

Chain exists of:
  (wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&lo->lo_mutex);
                               lock(&disk->open_mutex);
                               lock(&lo->lo_mutex);
  lock((wq_completion)loop0);

 *** DEADLOCK ***

1 lock held by losetup/11596:
 #0: ffff939655510c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]

stack backtrace:
CPU: 1 PID: 11596 Comm: losetup Not tainted 5.14.0-rc2+ raspberrypi#406
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
 dump_stack_lvl+0x57/0x72
 check_noncircular+0xcf/0xf0
 ? stack_trace_save+0x3b/0x50
 __lock_acquire+0x10ea/0x1d90
 lock_acquire+0xb5/0x2b0
 ? flush_workqueue+0x67/0x5e0
 ? lockdep_init_map_type+0x47/0x220
 flush_workqueue+0x91/0x5e0
 ? flush_workqueue+0x67/0x5e0
 ? verify_cpu+0xf0/0x100
 drain_workqueue+0xa0/0x110
 destroy_workqueue+0x36/0x250
 __loop_clr_fd+0x9a/0x660 [loop]
 ? blkdev_ioctl+0x8d/0x2a0
 block_ioctl+0x3f/0x50
 __x64_sys_ioctl+0x80/0xb0
 do_syscall_64+0x38/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reviewed-by: Anand Jain <[email protected]>
Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Oct 14, 2021
commit 57f0ff0 upstream.

It's later supposed to be either a correct address or NULL. Without the
initialization, it may contain an undefined value which results in the
following segmentation fault:

  # perf top --sort comm -g --ignore-callees=do_idle

terminates with:

  #0  0x00007ffff56b7685 in __strlen_avx2 () from /lib64/libc.so.6
  #1  0x00007ffff55e3802 in strdup () from /lib64/libc.so.6
  #2  0x00005555558cb139 in hist_entry__init (callchain_size=<optimized out>, sample_self=true, template=0x7fffde7fb110, he=0x7fffd801c250) at util/hist.c:489
  #3  hist_entry__new (template=template@entry=0x7fffde7fb110, sample_self=sample_self@entry=true) at util/hist.c:564
  #4  0x00005555558cb4ba in hists__findnew_entry (hists=hists@entry=0x5555561d9e38, entry=entry@entry=0x7fffde7fb110, al=al@entry=0x7fffde7fb420,
      sample_self=sample_self@entry=true) at util/hist.c:657
  #5  0x00005555558cba1b in __hists__add_entry (hists=hists@entry=0x5555561d9e38, al=0x7fffde7fb420, sym_parent=<optimized out>, bi=bi@entry=0x0, mi=mi@entry=0x0,
      sample=sample@entry=0x7fffde7fb4b0, sample_self=true, ops=0x0, block_info=0x0) at util/hist.c:288
  #6  0x00005555558cbb70 in hists__add_entry (sample_self=true, sample=0x7fffde7fb4b0, mi=0x0, bi=0x0, sym_parent=<optimized out>, al=<optimized out>, hists=0x5555561d9e38)
      at util/hist.c:1056
  #7  iter_add_single_cumulative_entry (iter=0x7fffde7fb460, al=<optimized out>) at util/hist.c:1056
  #8  0x00005555558cc8a4 in hist_entry_iter__add (iter=iter@entry=0x7fffde7fb460, al=al@entry=0x7fffde7fb420, max_stack_depth=<optimized out>, arg=arg@entry=0x7fffffff7db0)
      at util/hist.c:1231
  #9  0x00005555557cdc9a in perf_event__process_sample (machine=<optimized out>, sample=0x7fffde7fb4b0, evsel=<optimized out>, event=<optimized out>, tool=0x7fffffff7db0)
      at builtin-top.c:842
  #10 deliver_event (qe=<optimized out>, qevent=<optimized out>) at builtin-top.c:1202
  raspberrypi#11 0x00005555558a9318 in do_flush (show_progress=false, oe=0x7fffffff80e0) at util/ordered-events.c:244
  raspberrypi#12 __ordered_events__flush (oe=oe@entry=0x7fffffff80e0, how=how@entry=OE_FLUSH__TOP, timestamp=timestamp@entry=0) at util/ordered-events.c:323
  raspberrypi#13 0x00005555558a9789 in __ordered_events__flush (timestamp=<optimized out>, how=<optimized out>, oe=<optimized out>) at util/ordered-events.c:339
  raspberrypi#14 ordered_events__flush (how=OE_FLUSH__TOP, oe=0x7fffffff80e0) at util/ordered-events.c:341
  raspberrypi#15 ordered_events__flush (oe=oe@entry=0x7fffffff80e0, how=how@entry=OE_FLUSH__TOP) at util/ordered-events.c:339
  raspberrypi#16 0x00005555557cd631 in process_thread (arg=0x7fffffff7db0) at builtin-top.c:1114
  raspberrypi#17 0x00007ffff7bb817a in start_thread () from /lib64/libpthread.so.0
  raspberrypi#18 0x00007ffff5656dc3 in clone () from /lib64/libc.so.6

If you look at the frame #2, the code is:

488	 if (he->srcline) {
489          he->srcline = strdup(he->srcline);
490          if (he->srcline == NULL)
491              goto err_rawdata;
492	 }

If he->srcline is not NULL (it is not NULL if it is uninitialized rubbish),
it gets strdupped and strdupping a rubbish random string causes the problem.

Also, if you look at the commit 1fb7d06, it adds the srcline property
into the struct, but not initializing it everywhere needed.

Committer notes:

Now I see, when using --ignore-callees=do_idle we end up here at line
2189 in add_callchain_ip():

2181         if (al.sym != NULL) {
2182                 if (perf_hpp_list.parent && !*parent &&
2183                     symbol__match_regex(al.sym, &parent_regex))
2184                         *parent = al.sym;
2185                 else if (have_ignore_callees && root_al &&
2186                   symbol__match_regex(al.sym, &ignore_callees_regex)) {
2187                         /* Treat this symbol as the root,
2188                            forgetting its callees. */
2189                         *root_al = al;
2190                         callchain_cursor_reset(cursor);
2191                 }
2192         }

And the al that doesn't have the ->srcline field initialized will be
copied to the root_al, so then, back to:

1211 int hist_entry_iter__add(struct hist_entry_iter *iter, struct addr_location *al,
1212                          int max_stack_depth, void *arg)
1213 {
1214         int err, err2;
1215         struct map *alm = NULL;
1216
1217         if (al)
1218                 alm = map__get(al->map);
1219
1220         err = sample__resolve_callchain(iter->sample, &callchain_cursor, &iter->parent,
1221                                         iter->evsel, al, max_stack_depth);
1222         if (err) {
1223                 map__put(alm);
1224                 return err;
1225         }
1226
1227         err = iter->ops->prepare_entry(iter, al);
1228         if (err)
1229                 goto out;
1230
1231         err = iter->ops->add_single_entry(iter, al);
1232         if (err)
1233                 goto out;
1234

That al at line 1221 is what hist_entry_iter__add() (called from
sample__resolve_callchain()) saw as 'root_al', and then:

        iter->ops->add_single_entry(iter, al);

will go on with al->srcline with a bogus value, I'll add the above
sequence to the cset and apply, thanks!

Signed-off-by: Michael Petlan <[email protected]>
CC: Milian Wolff <[email protected]>
Cc: Jiri Olsa <[email protected]>
Fixes: 1fb7d06 ("perf report Use srcline from callchain for hist entries")
Link: https //lore.kernel.org/r/[email protected]
Reported-by: Juri Lelli <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request Oct 14, 2021
[ Upstream commit 8f96a5b ]

We update the ctime/mtime of a block device when we remove it so that
blkid knows the device changed.  However we do this by re-opening the
block device and calling filp_update_time.  This is more correct because
it'll call the inode->i_op->update_time if it exists, but the block dev
inodes do not do this.  Instead call generic_update_time() on the
bd_inode in order to avoid the blkdev_open path and get rid of the
following lockdep splat:

======================================================
WARNING: possible circular locking dependency detected
5.14.0-rc2+ raspberrypi#406 Not tainted
------------------------------------------------------
losetup/11596 is trying to acquire lock:
ffff939640d2f538 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0

but task is already holding lock:
ffff939655510c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #4 (&lo->lo_mutex){+.+.}-{3:3}:
       __mutex_lock+0x7d/0x750
       lo_open+0x28/0x60 [loop]
       blkdev_get_whole+0x25/0xf0
       blkdev_get_by_dev.part.0+0x168/0x3c0
       blkdev_open+0xd2/0xe0
       do_dentry_open+0x161/0x390
       path_openat+0x3cc/0xa20
       do_filp_open+0x96/0x120
       do_sys_openat2+0x7b/0x130
       __x64_sys_openat+0x46/0x70
       do_syscall_64+0x38/0x90
       entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #3 (&disk->open_mutex){+.+.}-{3:3}:
       __mutex_lock+0x7d/0x750
       blkdev_get_by_dev.part.0+0x56/0x3c0
       blkdev_open+0xd2/0xe0
       do_dentry_open+0x161/0x390
       path_openat+0x3cc/0xa20
       do_filp_open+0x96/0x120
       file_open_name+0xc7/0x170
       filp_open+0x2c/0x50
       btrfs_scratch_superblocks.part.0+0x10f/0x170
       btrfs_rm_device.cold+0xe8/0xed
       btrfs_ioctl+0x2a31/0x2e70
       __x64_sys_ioctl+0x80/0xb0
       do_syscall_64+0x38/0x90
       entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #2 (sb_writers#12){.+.+}-{0:0}:
       lo_write_bvec+0xc2/0x240 [loop]
       loop_process_work+0x238/0xd00 [loop]
       process_one_work+0x26b/0x560
       worker_thread+0x55/0x3c0
       kthread+0x140/0x160
       ret_from_fork+0x1f/0x30

-> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
       process_one_work+0x245/0x560
       worker_thread+0x55/0x3c0
       kthread+0x140/0x160
       ret_from_fork+0x1f/0x30

-> #0 ((wq_completion)loop0){+.+.}-{0:0}:
       __lock_acquire+0x10ea/0x1d90
       lock_acquire+0xb5/0x2b0
       flush_workqueue+0x91/0x5e0
       drain_workqueue+0xa0/0x110
       destroy_workqueue+0x36/0x250
       __loop_clr_fd+0x9a/0x660 [loop]
       block_ioctl+0x3f/0x50
       __x64_sys_ioctl+0x80/0xb0
       do_syscall_64+0x38/0x90
       entry_SYSCALL_64_after_hwframe+0x44/0xae

other info that might help us debug this:

Chain exists of:
  (wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&lo->lo_mutex);
                               lock(&disk->open_mutex);
                               lock(&lo->lo_mutex);
  lock((wq_completion)loop0);

 *** DEADLOCK ***

1 lock held by losetup/11596:
 #0: ffff939655510c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]

stack backtrace:
CPU: 1 PID: 11596 Comm: losetup Not tainted 5.14.0-rc2+ raspberrypi#406
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
 dump_stack_lvl+0x57/0x72
 check_noncircular+0xcf/0xf0
 ? stack_trace_save+0x3b/0x50
 __lock_acquire+0x10ea/0x1d90
 lock_acquire+0xb5/0x2b0
 ? flush_workqueue+0x67/0x5e0
 ? lockdep_init_map_type+0x47/0x220
 flush_workqueue+0x91/0x5e0
 ? flush_workqueue+0x67/0x5e0
 ? verify_cpu+0xf0/0x100
 drain_workqueue+0xa0/0x110
 destroy_workqueue+0x36/0x250
 __loop_clr_fd+0x9a/0x660 [loop]
 ? blkdev_ioctl+0x8d/0x2a0
 block_ioctl+0x3f/0x50
 __x64_sys_ioctl+0x80/0xb0
 do_syscall_64+0x38/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reviewed-by: Anand Jain <[email protected]>
Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Nov 24, 2021
[ Upstream commit 8ef9dc0 ]

We got the following lockdep splat while running fstests (specifically
btrfs/003 and btrfs/020 in a row) with the new rc.  This was uncovered
by 87579e9 ("loop: use worker per cgroup instead of kworker") which
converted loop to using workqueues, which comes with lockdep
annotations that don't exist with kworkers.  The lockdep splat is as
follows:

  WARNING: possible circular locking dependency detected
  5.14.0-rc2-custom+ raspberrypi#34 Not tainted
  ------------------------------------------------------
  losetup/156417 is trying to acquire lock:
  ffff9c7645b02d38 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x84/0x600

  but task is already holding lock:
  ffff9c7647395468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x650 [loop]

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #5 (&lo->lo_mutex){+.+.}-{3:3}:
	 __mutex_lock+0xba/0x7c0
	 lo_open+0x28/0x60 [loop]
	 blkdev_get_whole+0x28/0xf0
	 blkdev_get_by_dev.part.0+0x168/0x3c0
	 blkdev_open+0xd2/0xe0
	 do_dentry_open+0x163/0x3a0
	 path_openat+0x74d/0xa40
	 do_filp_open+0x9c/0x140
	 do_sys_openat2+0xb1/0x170
	 __x64_sys_openat+0x54/0x90
	 do_syscall_64+0x3b/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xae

  -> #4 (&disk->open_mutex){+.+.}-{3:3}:
	 __mutex_lock+0xba/0x7c0
	 blkdev_get_by_dev.part.0+0xd1/0x3c0
	 blkdev_get_by_path+0xc0/0xd0
	 btrfs_scan_one_device+0x52/0x1f0 [btrfs]
	 btrfs_control_ioctl+0xac/0x170 [btrfs]
	 __x64_sys_ioctl+0x83/0xb0
	 do_syscall_64+0x3b/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xae

  -> #3 (uuid_mutex){+.+.}-{3:3}:
	 __mutex_lock+0xba/0x7c0
	 btrfs_rm_device+0x48/0x6a0 [btrfs]
	 btrfs_ioctl+0x2d1c/0x3110 [btrfs]
	 __x64_sys_ioctl+0x83/0xb0
	 do_syscall_64+0x3b/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xae

  -> #2 (sb_writers#11){.+.+}-{0:0}:
	 lo_write_bvec+0x112/0x290 [loop]
	 loop_process_work+0x25f/0xcb0 [loop]
	 process_one_work+0x28f/0x5d0
	 worker_thread+0x55/0x3c0
	 kthread+0x140/0x170
	 ret_from_fork+0x22/0x30

  -> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
	 process_one_work+0x266/0x5d0
	 worker_thread+0x55/0x3c0
	 kthread+0x140/0x170
	 ret_from_fork+0x22/0x30

  -> #0 ((wq_completion)loop0){+.+.}-{0:0}:
	 __lock_acquire+0x1130/0x1dc0
	 lock_acquire+0xf5/0x320
	 flush_workqueue+0xae/0x600
	 drain_workqueue+0xa0/0x110
	 destroy_workqueue+0x36/0x250
	 __loop_clr_fd+0x9a/0x650 [loop]
	 lo_ioctl+0x29d/0x780 [loop]
	 block_ioctl+0x3f/0x50
	 __x64_sys_ioctl+0x83/0xb0
	 do_syscall_64+0x3b/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xae

  other info that might help us debug this:
  Chain exists of:
    (wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex
   Possible unsafe locking scenario:
	 CPU0                    CPU1
	 ----                    ----
    lock(&lo->lo_mutex);
				 lock(&disk->open_mutex);
				 lock(&lo->lo_mutex);
    lock((wq_completion)loop0);

   *** DEADLOCK ***
  1 lock held by losetup/156417:
   #0: ffff9c7647395468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x650 [loop]

  stack backtrace:
  CPU: 8 PID: 156417 Comm: losetup Not tainted 5.14.0-rc2-custom+ raspberrypi#34
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  Call Trace:
   dump_stack_lvl+0x57/0x72
   check_noncircular+0x10a/0x120
   __lock_acquire+0x1130/0x1dc0
   lock_acquire+0xf5/0x320
   ? flush_workqueue+0x84/0x600
   flush_workqueue+0xae/0x600
   ? flush_workqueue+0x84/0x600
   drain_workqueue+0xa0/0x110
   destroy_workqueue+0x36/0x250
   __loop_clr_fd+0x9a/0x650 [loop]
   lo_ioctl+0x29d/0x780 [loop]
   ? __lock_acquire+0x3a0/0x1dc0
   ? update_dl_rq_load_avg+0x152/0x360
   ? lock_is_held_type+0xa5/0x120
   ? find_held_lock.constprop.0+0x2b/0x80
   block_ioctl+0x3f/0x50
   __x64_sys_ioctl+0x83/0xb0
   do_syscall_64+0x3b/0x90
   entry_SYSCALL_64_after_hwframe+0x44/0xae
  RIP: 0033:0x7f645884de6b

Usually the uuid_mutex exists to protect the fs_devices that map
together all of the devices that match a specific uuid.  In rm_device
we're messing with the uuid of a device, so it makes sense to protect
that here.

However in doing that it pulls in a whole host of lockdep dependencies,
as we call mnt_may_write() on the sb before we grab the uuid_mutex, thus
we end up with the dependency chain under the uuid_mutex being added
under the normal sb write dependency chain, which causes problems with
loop devices.

We don't need the uuid mutex here however.  If we call
btrfs_scan_one_device() before we scratch the super block we will find
the fs_devices and not find the device itself and return EBUSY because
the fs_devices is open.  If we call it after the scratch happens it will
not appear to be a valid btrfs file system.

We do not need to worry about other fs_devices modifying operations here
because we're protected by the exclusive operations locking.

So drop the uuid_mutex here in order to fix the lockdep splat.

A more detailed explanation from the discussion:

We are worried about rm and scan racing with each other, before this
change we'll zero the device out under the UUID mutex so when scan does
run it'll make sure that it can go through the whole device scan thing
without rm messing with us.

We aren't worried if the scratch happens first, because the result is we
don't think this is a btrfs device and we bail out.

The only case we are concerned with is we scratch _after_ scan is able
to read the superblock and gets a seemingly valid super block, so lets
consider this case.

Scan will call device_list_add() with the device we're removing.  We'll
call find_fsid_with_metadata_uuid() and get our fs_devices for this
UUID.  At this point we lock the fs_devices->device_list_mutex.  This is
what protects us in this case, but we have two cases here.

1. We aren't to the device removal part of the RM.  We found our device,
   and device name matches our path, we go down and we set total_devices
   to our super number of devices, which doesn't affect anything because
   we haven't done the remove yet.

2. We are past the device removal part, which is protected by the
   device_list_mutex.  Scan doesn't find the device, it goes down and
   does the

   if (fs_devices->opened)
	   return -EBUSY;

   check and we bail out.

Nothing about this situation is ideal, but the lockdep splat is real,
and the fix is safe, tho admittedly a bit scary looking.

Reviewed-by: Anand Jain <[email protected]>
Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
[ copy more from the discussion ]
Signed-off-by: David Sterba <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Nov 24, 2021
[ Upstream commit f0caea8 ]

Olga reports seeing the following Oops when doing O_DIRECT writes to a
pNFS flexfiles server:

Oops: 0000 [#1] SMP PTI
CPU: 1 PID: 234186 Comm: kworker/u8:1 Not tainted 5.15.0-rc4+ #4
Hardware name: Red Hat KVM/RHEL-AV, BIOS 1.13.0-2.module+el8.3.0+7353+9de0a3cc 04/01/2014
Workqueue: nfsiod rpc_async_release [sunrpc]
RIP: 0010:nfs_mark_request_commit+0x12/0x30 [nfs]
Code: ff ff be 03 00 00 00 e8 ac 34 83 eb e9 29 ff ff
ff e8 22 bc d7 eb 66 90 0f 1f 44 00 00 48 85 f6 74 16 48 8b 42 10 48
8b 40 18 <48> 8b 40 18 48 85 c0 74 05 e9 70 fc 15 ec 48 89 d6 e9 68 ed
ff ff
RSP: 0018:ffffa82f0159fe00 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff8f3393141880 RCX: 0000000000000000
RDX: ffffa82f0159fe08 RSI: ffff8f3381252500 RDI: ffff8f3393141880
RBP: ffff8f33ac317c00 R08: 0000000000000000 R09: ffff8f3487724cb0
R10: 0000000000000008 R11: 0000000000000001 R12: 0000000000000001
R13: ffff8f3485bccee0 R14: ffff8f33ac317c10 R15: ffff8f33ac317cd8
FS:  0000000000000000(0000) GS:ffff8f34fbc80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000018 CR3: 0000000122120006 CR4: 0000000000770ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 nfs_direct_write_completion+0x13b/0x250 [nfs]
 rpc_free_task+0x39/0x60 [sunrpc]
 rpc_async_release+0x29/0x40 [sunrpc]
 process_one_work+0x1ce/0x370
 worker_thread+0x30/0x380
 ? process_one_work+0x370/0x370
 kthread+0x11a/0x140
 ? set_kthread_struct+0x40/0x40
 ret_from_fork+0x22/0x30

Reported-by: Olga Kornievskaia <[email protected]>
Fixes: 9c455a8 ("NFS/pNFS: Clean up pNFS commit operations")
Signed-off-by: Trond Myklebust <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Dec 8, 2021
[ Upstream commit 54659ca ]

when turning off a connection, lockdep complains with the
following warning (a modprobe has been done but the same
happens with a disconnection from NetworkManager,
it's enough to trigger a cfg80211_disconnect call):

[  682.855867] ======================================================
[  682.855877] WARNING: possible circular locking dependency detected
[  682.855887] 5.14.0-rc6+ raspberrypi#16 Tainted: G         C OE
[  682.855898] ------------------------------------------------------
[  682.855906] modprobe/1770 is trying to acquire lock:
[  682.855916] ffffb6d000332b00 (&pxmitpriv->lock){+.-.}-{2:2},
		at: rtw_free_stainfo+0x52/0x4a0 [r8723bs]
[  682.856073]
               but task is already holding lock:
[  682.856081] ffffb6d0003336a8 (&pstapriv->sta_hash_lock){+.-.}-{2:2},
		at: rtw_free_assoc_resources+0x48/0x110 [r8723bs]
[  682.856207]
               which lock already depends on the new lock.

[  682.856215]
               the existing dependency chain (in reverse order) is:
[  682.856223]
               -> #1 (&pstapriv->sta_hash_lock){+.-.}-{2:2}:
[  682.856247]        _raw_spin_lock_bh+0x34/0x40
[  682.856265]        rtw_get_stainfo+0x9a/0x110 [r8723bs]
[  682.856389]        rtw_xmit_classifier+0x27/0x130 [r8723bs]
[  682.856515]        rtw_xmitframe_enqueue+0xa/0x20 [r8723bs]
[  682.856642]        rtl8723bs_hal_xmit+0x3b/0xb0 [r8723bs]
[  682.856752]        rtw_xmit+0x4ef/0x890 [r8723bs]
[  682.856879]        _rtw_xmit_entry+0xba/0x350 [r8723bs]
[  682.856981]        dev_hard_start_xmit+0xee/0x320
[  682.856999]        sch_direct_xmit+0x8c/0x330
[  682.857014]        __dev_queue_xmit+0xba5/0xf00
[  682.857030]        packet_sendmsg+0x981/0x1b80
[  682.857047]        sock_sendmsg+0x5b/0x60
[  682.857060]        __sys_sendto+0xf1/0x160
[  682.857073]        __x64_sys_sendto+0x24/0x30
[  682.857087]        do_syscall_64+0x3a/0x80
[  682.857102]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[  682.857117]
               -> #0 (&pxmitpriv->lock){+.-.}-{2:2}:
[  682.857142]        __lock_acquire+0xfd9/0x1b50
[  682.857158]        lock_acquire+0xb4/0x2c0
[  682.857172]        _raw_spin_lock_bh+0x34/0x40
[  682.857185]        rtw_free_stainfo+0x52/0x4a0 [r8723bs]
[  682.857308]        rtw_free_assoc_resources+0x53/0x110 [r8723bs]
[  682.857415]        cfg80211_rtw_disconnect+0x4b/0x70 [r8723bs]
[  682.857522]        cfg80211_disconnect+0x12e/0x2f0 [cfg80211]
[  682.857759]        cfg80211_leave+0x2b/0x40 [cfg80211]
[  682.857961]        cfg80211_netdev_notifier_call+0xa9/0x560 [cfg80211]
[  682.858163]        raw_notifier_call_chain+0x41/0x50
[  682.858180]        __dev_close_many+0x62/0x100
[  682.858195]        dev_close_many+0x7d/0x120
[  682.858209]        unregister_netdevice_many+0x416/0x680
[  682.858225]        unregister_netdevice_queue+0xab/0xf0
[  682.858240]        unregister_netdev+0x18/0x20
[  682.858255]        rtw_unregister_netdevs+0x28/0x40 [r8723bs]
[  682.858360]        rtw_dev_remove+0x24/0xd0 [r8723bs]
[  682.858463]        sdio_bus_remove+0x31/0xd0 [mmc_core]
[  682.858532]        device_release_driver_internal+0xf7/0x1d0
[  682.858550]        driver_detach+0x47/0x90
[  682.858564]        bus_remove_driver+0x77/0xd0
[  682.858579]        rtw_drv_halt+0xc/0x678 [r8723bs]
[  682.858685]        __x64_sys_delete_module+0x13f/0x250
[  682.858699]        do_syscall_64+0x3a/0x80
[  682.858715]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[  682.858729]
               other info that might help us debug this:

[  682.858737]  Possible unsafe locking scenario:

[  682.858744]        CPU0                    CPU1
[  682.858751]        ----                    ----
[  682.858758]   lock(&pstapriv->sta_hash_lock);
[  682.858772]                                lock(&pxmitpriv->lock);
[  682.858786]                                lock(&pstapriv->sta_hash_lock);
[  682.858799]   lock(&pxmitpriv->lock);
[  682.858812]
                *** DEADLOCK ***

[  682.858820] 5 locks held by modprobe/1770:
[  682.858831]  #0: ffff8d870697d980 (&dev->mutex){....}-{3:3},
		at: device_release_driver_internal+0x1a/0x1d0
[  682.858869]  #1: ffffffffbdbbf1c8 (rtnl_mutex){+.+.}-{3:3},
		at: unregister_netdev+0xe/0x20
[  682.858906]  #2: ffff8d87054ee5e8 (&rdev->wiphy.mtx){+.+.}-{3:3},
		at: cfg80211_netdev_notifier_call+0x9e/0x560 [cfg80211]
[  682.859131]  #3: ffff8d870f2bc8f0 (&wdev->mtx){+.+.}-{3:3},
		at: cfg80211_leave+0x20/0x40 [cfg80211]
[  682.859354]  #4: ffffb6d0003336a8 (&pstapriv->sta_hash_lock){+.-.}-{2:2},
		at: rtw_free_assoc_resources+0x48/0x110 [r8723bs]
[  682.859482]
               stack backtrace:
[  682.859491] CPU: 1 PID: 1770 Comm: modprobe Tainted: G
		C OE     5.14.0-rc6+ raspberrypi#16
[  682.859507] Hardware name: LENOVO 80NR/Madrid, BIOS DACN25WW 08/20/2015
[  682.859517] Call Trace:
[  682.859531]  dump_stack_lvl+0x56/0x6f
[  682.859551]  check_noncircular+0xdb/0xf0
[  682.859579]  __lock_acquire+0xfd9/0x1b50
[  682.859606]  lock_acquire+0xb4/0x2c0
[  682.859623]  ? rtw_free_stainfo+0x52/0x4a0 [r8723bs]
[  682.859752]  ? mark_held_locks+0x48/0x70
[  682.859769]  ? rtw_free_stainfo+0x4a/0x4a0 [r8723bs]
[  682.859898]  _raw_spin_lock_bh+0x34/0x40
[  682.859914]  ? rtw_free_stainfo+0x52/0x4a0 [r8723bs]
[  682.860039]  rtw_free_stainfo+0x52/0x4a0 [r8723bs]
[  682.860171]  rtw_free_assoc_resources+0x53/0x110 [r8723bs]
[  682.860286]  cfg80211_rtw_disconnect+0x4b/0x70 [r8723bs]
[  682.860397]  cfg80211_disconnect+0x12e/0x2f0 [cfg80211]
[  682.860629]  cfg80211_leave+0x2b/0x40 [cfg80211]
[  682.860836]  cfg80211_netdev_notifier_call+0xa9/0x560 [cfg80211]
[  682.861048]  ? __lock_acquire+0x4dc/0x1b50
[  682.861070]  ? lock_is_held_type+0xa8/0x110
[  682.861089]  ? lock_is_held_type+0xa8/0x110
[  682.861104]  ? find_held_lock+0x2d/0x90
[  682.861120]  ? packet_notifier+0x173/0x300
[  682.861141]  ? lock_release+0xb3/0x250
[  682.861160]  ? packet_notifier+0x192/0x300
[  682.861184]  raw_notifier_call_chain+0x41/0x50
[  682.861205]  __dev_close_many+0x62/0x100
[  682.861224]  dev_close_many+0x7d/0x120
[  682.861245]  unregister_netdevice_many+0x416/0x680
[  682.861264]  ? find_held_lock+0x2d/0x90
[  682.861284]  unregister_netdevice_queue+0xab/0xf0
[  682.861306]  unregister_netdev+0x18/0x20
[  682.861325]  rtw_unregister_netdevs+0x28/0x40 [r8723bs]
[  682.861434]  rtw_dev_remove+0x24/0xd0 [r8723bs]
[  682.861542]  sdio_bus_remove+0x31/0xd0 [mmc_core]
[  682.861615]  device_release_driver_internal+0xf7/0x1d0
[  682.861637]  driver_detach+0x47/0x90
[  682.861656]  bus_remove_driver+0x77/0xd0
[  682.861674]  rtw_drv_halt+0xc/0x678 [r8723bs]
[  682.861782]  __x64_sys_delete_module+0x13f/0x250
[  682.861801]  ? lockdep_hardirqs_on_prepare+0xf3/0x170
[  682.861817]  ? syscall_enter_from_user_mode+0x20/0x70
[  682.861836]  do_syscall_64+0x3a/0x80
[  682.861855]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[  682.861873] RIP: 0033:0x7f6dbe85400b
[  682.861890] Code: 73 01 c3 48 8b 0d 6d 1e 0c 00 f7 d8 64 89
01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa
b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 3d
1e 0c 00 f7 d8 64 89 01 48
[  682.861906] RSP: 002b:00007ffe7a82f538 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
[  682.861923] RAX: ffffffffffffffda RBX: 000055a64693bd20 RCX: 00007f6dbe85400b
[  682.861935] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 000055a64693bd88
[  682.861946] RBP: 000055a64693bd20 R08: 0000000000000000 R09: 0000000000000000
[  682.861957] R10: 00007f6dbe8c7ac0 R11: 0000000000000206 R12: 000055a64693bd88
[  682.861967] R13: 0000000000000000 R14: 000055a64693bd88 R15: 00007ffe7a831848

This happens because when we enqueue a frame for
transmission we do it under xmit_priv lock, then calling
rtw_get_stainfo (needed for enqueuing) takes sta_hash_lock
and this leads to the following lock dependency:

xmit_priv->lock -> sta_hash_lock

Turning off a connection will bring to call
rtw_free_assoc_resources which will set up
the inverse dependency:

sta_hash_lock -> xmit_priv_lock

This could lead to a deadlock as lockdep complains.

Fix it by removing the xmit_priv->lock around
rtw_xmitframe_enqueue call inside rtl8723bs_hal_xmit
and put it in a smaller critical section inside
rtw_xmit_classifier, the only place where
xmit_priv data are actually accessed.

Replace spin_{lock,unlock}_bh(pxmitpriv->lock)
in other tx paths leading to rtw_xmitframe_enqueue
call with spin_{lock,unlock}_bh(psta->sleep_q.lock)
- it's not clear why accessing a sleep_q was protected
by a spinlock on xmitpriv->lock.

This way is avoided the same faulty lock nesting
order.

Extra changes in v2 by Hans de Goede:
-Lift the taking of the struct __queue.lock spinlock out of
 rtw_free_xmitframe_queue() into the callers this allows also
 protecting a bunch of related state in rtw_free_stainfo():
-Protect psta->sleepq_len on rtw_free_xmitframe_queue(&psta->sleep_q);
-Protect struct tx_servq.tx_pending and tx_servq.qcnt when
 calling rtw_free_xmitframe_queue(&tx_servq.sta_pending)
-This also allows moving the spin_lock_bh(&pxmitpriv->lock); to below
 the sleep_q free-ing code, avoiding another ABBA locking issue

CC: Larry Finger <[email protected]>
Co-developed-by: Hans de Goede <[email protected]>
Tested-on: Lenovo Ideapad MiiX 300-10IBY
Signed-off-by: Fabio Aiuto <[email protected]>
Signed-off-by: Hans de Goede <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Dec 23, 2021
commit f35838a upstream.

Line 1169 (#3) allocates a memory chunk for victim_name by kmalloc(),
but  when the function returns in line 1184 (#4) victim_name allocated
by line 1169 (#3) is not freed, which will lead to a memory leak.
There is a similar snippet of code in this function as allocating a memory
chunk for victim_name in line 1104 (#1) as well as releasing the memory
in line 1116 (#2).

We should kfree() victim_name when the return value of backref_in_log()
is less than zero and before the function returns in line 1184 (#4).

1057 static inline int __add_inode_ref(struct btrfs_trans_handle *trans,
1058 				  struct btrfs_root *root,
1059 				  struct btrfs_path *path,
1060 				  struct btrfs_root *log_root,
1061 				  struct btrfs_inode *dir,
1062 				  struct btrfs_inode *inode,
1063 				  u64 inode_objectid, u64 parent_objectid,
1064 				  u64 ref_index, char *name, int namelen,
1065 				  int *search_done)
1066 {

1104 	victim_name = kmalloc(victim_name_len, GFP_NOFS);
	// #1: kmalloc (victim_name-1)
1105 	if (!victim_name)
1106 		return -ENOMEM;

1112	ret = backref_in_log(log_root, &search_key,
1113			parent_objectid, victim_name,
1114			victim_name_len);
1115	if (ret < 0) {
1116		kfree(victim_name); // #2: kfree (victim_name-1)
1117		return ret;
1118	} else if (!ret) {

1169 	victim_name = kmalloc(victim_name_len, GFP_NOFS);
	// #3: kmalloc (victim_name-2)
1170 	if (!victim_name)
1171 		return -ENOMEM;

1180 	ret = backref_in_log(log_root, &search_key,
1181 			parent_objectid, victim_name,
1182 			victim_name_len);
1183 	if (ret < 0) {
1184 		return ret; // #4: missing kfree (victim_name-2)
1185 	} else if (!ret) {

1241 	return 0;
1242 }

Fixes: d3316c8 ("btrfs: Properly handle backref_in_log retval")
CC: [email protected] # 5.10+
Reviewed-by: Qu Wenruo <[email protected]>
Reviewed-by: Filipe Manana <[email protected]>
Signed-off-by: Jianglei Nie <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request Jan 27, 2022
commit 232796d upstream.

When enabling quotas, we attempt to commit a transaction while holding the
mutex fs_info->qgroup_ioctl_lock. This can result on a deadlock with other
quota operations such as:

- qgroup creation and deletion, ioctl BTRFS_IOC_QGROUP_CREATE;

- adding and removing qgroup relations, ioctl BTRFS_IOC_QGROUP_ASSIGN.

This is because these operations join a transaction and after that they
attempt to lock the mutex fs_info->qgroup_ioctl_lock. Acquiring that mutex
after joining or starting a transaction is a pattern followed everywhere
in qgroups, so the quota enablement operation is the one at fault here,
and should not commit a transaction while holding that mutex.

Fix this by making the transaction commit while not holding the mutex.
We are safe from two concurrent tasks trying to enable quotas because
we are serialized by the rw semaphore fs_info->subvol_sem at
btrfs_ioctl_quota_ctl(), which is the only call site for enabling
quotas.

When this deadlock happens, it produces a trace like the following:

  INFO: task syz-executor:25604 blocked for more than 143 seconds.
  Not tainted 5.15.0-rc6 #4
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  task:syz-executor state:D stack:24800 pid:25604 ppid: 24873 flags:0x00004004
  Call Trace:
  context_switch kernel/sched/core.c:4940 [inline]
  __schedule+0xcd9/0x2530 kernel/sched/core.c:6287
  schedule+0xd3/0x270 kernel/sched/core.c:6366
  btrfs_commit_transaction+0x994/0x2e90 fs/btrfs/transaction.c:2201
  btrfs_quota_enable+0x95c/0x1790 fs/btrfs/qgroup.c:1120
  btrfs_ioctl_quota_ctl fs/btrfs/ioctl.c:4229 [inline]
  btrfs_ioctl+0x637e/0x7b70 fs/btrfs/ioctl.c:5010
  vfs_ioctl fs/ioctl.c:51 [inline]
  __do_sys_ioctl fs/ioctl.c:874 [inline]
  __se_sys_ioctl fs/ioctl.c:860 [inline]
  __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
  do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
  entry_SYSCALL_64_after_hwframe+0x44/0xae
  RIP: 0033:0x7f86920b2c4d
  RSP: 002b:00007f868f61ac58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  RAX: ffffffffffffffda RBX: 00007f86921d90a0 RCX: 00007f86920b2c4d
  RDX: 0000000020005e40 RSI: 00000000c0109428 RDI: 0000000000000008
  RBP: 00007f869212bd80 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00007f86921d90a0
  R13: 00007fff6d233e4f R14: 00007fff6d233ff0 R15: 00007f868f61adc0
  INFO: task syz-executor:25628 blocked for more than 143 seconds.
  Not tainted 5.15.0-rc6 #4
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  task:syz-executor state:D stack:29080 pid:25628 ppid: 24873 flags:0x00004004
  Call Trace:
  context_switch kernel/sched/core.c:4940 [inline]
  __schedule+0xcd9/0x2530 kernel/sched/core.c:6287
  schedule+0xd3/0x270 kernel/sched/core.c:6366
  schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6425
  __mutex_lock_common kernel/locking/mutex.c:669 [inline]
  __mutex_lock+0xc96/0x1680 kernel/locking/mutex.c:729
  btrfs_remove_qgroup+0xb7/0x7d0 fs/btrfs/qgroup.c:1548
  btrfs_ioctl_qgroup_create fs/btrfs/ioctl.c:4333 [inline]
  btrfs_ioctl+0x683c/0x7b70 fs/btrfs/ioctl.c:5014
  vfs_ioctl fs/ioctl.c:51 [inline]
  __do_sys_ioctl fs/ioctl.c:874 [inline]
  __se_sys_ioctl fs/ioctl.c:860 [inline]
  __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
  do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
  entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported-by: Hao Sun <[email protected]>
Link: https://lore.kernel.org/linux-btrfs/CACkBjsZQF19bQ1C6=yetF3BvL10OSORpFUcWXTP6HErshDB4dQ@mail.gmail.com/
Fixes: 340f1aa ("btrfs: qgroups: Move transaction management inside btrfs_quota_enable/disable")
CC: [email protected] # 4.19
Reviewed-by: Qu Wenruo <[email protected]>
Signed-off-by: Filipe Manana <[email protected]>
Signed-off-by: David Sterba <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request Mar 21, 2022
[ Upstream commit 4cb9a99 ]

I saw the below splatting after the host suspended and resumed.

   WARNING: CPU: 0 PID: 2943 at kvm/arch/x86/kvm/../../../virt/kvm/kvm_main.c:5531 kvm_resume+0x2c/0x30 [kvm]
   CPU: 0 PID: 2943 Comm: step_after_susp Tainted: G        W IOE     5.17.0-rc3+ #4
   RIP: 0010:kvm_resume+0x2c/0x30 [kvm]
   Call Trace:
    <TASK>
    syscore_resume+0x90/0x340
    suspend_devices_and_enter+0xaee/0xe90
    pm_suspend.cold+0x36b/0x3c2
    state_store+0x82/0xf0
    kernfs_fop_write_iter+0x1b6/0x260
    new_sync_write+0x258/0x370
    vfs_write+0x33f/0x510
    ksys_write+0xc9/0x160
    do_syscall_64+0x3b/0xc0
    entry_SYSCALL_64_after_hwframe+0x44/0xae

lockdep_is_held() can return -1 when lockdep is disabled which triggers
this warning. Let's use lockdep_assert_not_held() which can detect
incorrect calls while holding a lock and it also avoids false negatives
when lockdep is disabled.

Signed-off-by: Wanpeng Li <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Apr 11, 2022
[ Upstream commit fe2640b ]

In remove_phb_dynamic() we use &phb->io_resource, after we've called
device_unregister(&host_bridge->dev). But the unregister may have freed
phb, because pcibios_free_controller_deferred() is the release function
for the host_bridge.

If there are no outstanding references when we call device_unregister()
then phb will be freed out from under us.

This has gone mainly unnoticed, but with slub_debug and page_poison
enabled it can lead to a crash:

  PID: 7574   TASK: c0000000d492cb80  CPU: 13  COMMAND: "drmgr"
   #0 [c0000000e4f075a0] crash_kexec at c00000000027d7dc
   #1 [c0000000e4f075d0] oops_end at c000000000029608
   #2 [c0000000e4f07650] __bad_page_fault at c0000000000904b4
   #3 [c0000000e4f076c0] do_bad_slb_fault at c00000000009a5a8
   #4 [c0000000e4f076f0] data_access_slb_common_virt at c000000000008b30
   Data SLB Access [380] exception frame:
   R0:  c000000000167250    R1:  c0000000e4f07a00    R2:  c000000002a46100
   R3:  c000000002b39ce8    R4:  00000000000000c0    R5:  00000000000000a9
   R6:  3894674d000000c0    R7:  0000000000000000    R8:  00000000000000ff
   R9:  0000000000000100    R10: 6b6b6b6b6b6b6b6b    R11: 0000000000008000
   R12: c00000000023da80    R13: c0000009ffd38b00    R14: 0000000000000000
   R15: 000000011c87f0f0    R16: 0000000000000006    R17: 0000000000000003
   R18: 0000000000000002    R19: 0000000000000004    R20: 0000000000000005
   R21: 000000011c87ede8    R22: 000000011c87c5a8    R23: 000000011c87d3a0
   R24: 0000000000000000    R25: 0000000000000001    R26: c0000000e4f07cc8
   R27: c00000004d1cc400    R28: c0080000031d00e8    R29: c00000004d23d800
   R30: c00000004d1d2400    R31: c00000004d1d2540
   NIP: c000000000167258    MSR: 8000000000009033    OR3: c000000000e9f474
   CTR: 0000000000000000    LR:  c000000000167250    XER: 0000000020040003
   CCR: 0000000024088420    MQ:  0000000000000000    DAR: 6b6b6b6b6b6b6ba3
   DSISR: c0000000e4f07920     Syscall Result: fffffffffffffff2
   [NIP  : release_resource+56]
   [LR   : release_resource+48]
   #5 [c0000000e4f07a00] release_resource at c000000000167258  (unreliable)
   #6 [c0000000e4f07a30] remove_phb_dynamic at c000000000105648
   #7 [c0000000e4f07ab0] dlpar_remove_slot at c0080000031a09e8 [rpadlpar_io]
   #8 [c0000000e4f07b50] remove_slot_store at c0080000031a0b9c [rpadlpar_io]
   #9 [c0000000e4f07be0] kobj_attr_store at c000000000817d8c
  #10 [c0000000e4f07c00] sysfs_kf_write at c00000000063e504
  raspberrypi#11 [c0000000e4f07c20] kernfs_fop_write_iter at c00000000063d868
  raspberrypi#12 [c0000000e4f07c70] new_sync_write at c00000000054339c
  raspberrypi#13 [c0000000e4f07d10] vfs_write at c000000000546624
  raspberrypi#14 [c0000000e4f07d60] ksys_write at c0000000005469f4
  raspberrypi#15 [c0000000e4f07db0] system_call_exception at c000000000030840
  raspberrypi#16 [c0000000e4f07e10] system_call_vectored_common at c00000000000c168

To avoid it, we can take a reference to the host_bridge->dev until we're
done using phb. Then when we drop the reference the phb will be freed.

Fixes: 2dd9c11 ("powerpc/pseries: use pci_host_bridge.release_fn() to kfree(phb)")
Reported-by: David Dai <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Tested-by: Sachin Sant <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Apr 11, 2022
[ Upstream commit 841aee4 ]

Put NVMe/TCP sockets in their own class to avoid some lockdep warnings.
Sockets created by nvme-tcp are not exposed to user-space, and will not
trigger certain code paths that the general socket API exposes.

Lockdep complains about a circular dependency between the socket and
filesystem locks, because setsockopt can trigger a page fault with a
socket lock held, but nvme-tcp sends requests on the socket while file
system locks are held.

  ======================================================
  WARNING: possible circular locking dependency detected
  5.15.0-rc3 #1 Not tainted
  ------------------------------------------------------
  fio/1496 is trying to acquire lock:
  (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendpage+0x23/0x80

  but task is already holding lock:
  (&xfs_dir_ilock_class/5){+.+.}-{3:3}, at: xfs_ilock+0xcf/0x290 [xfs]

  which lock already depends on the new lock.

  other info that might help us debug this:

  chain exists of:
   sk_lock-AF_INET --> sb_internal --> &xfs_dir_ilock_class/5

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&xfs_dir_ilock_class/5);
                                lock(sb_internal);
                                lock(&xfs_dir_ilock_class/5);
   lock(sk_lock-AF_INET);

  *** DEADLOCK ***

  6 locks held by fio/1496:
   #0: (sb_writers#13){.+.+}-{0:0}, at: path_openat+0x9fc/0xa20
   #1: (&inode->i_sb->s_type->i_mutex_dir_key){++++}-{3:3}, at: path_openat+0x296/0xa20
   #2: (sb_internal){.+.+}-{0:0}, at: xfs_trans_alloc_icreate+0x41/0xd0 [xfs]
   #3: (&xfs_dir_ilock_class/5){+.+.}-{3:3}, at: xfs_ilock+0xcf/0x290 [xfs]
   #4: (hctx->srcu){....}-{0:0}, at: hctx_lock+0x51/0xd0
   #5: (&queue->send_mutex){+.+.}-{3:3}, at: nvme_tcp_queue_rq+0x33e/0x380 [nvme_tcp]

This annotation lets lockdep analyze nvme-tcp controlled sockets
independently of what the user-space sockets API does.

Link: https://lore.kernel.org/linux-nvme/CAHj4cs9MDYLJ+q+2_GXUK9HxFizv2pxUryUR0toX974M040z7g@mail.gmail.com/

Signed-off-by: Chris Leech <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Apr 11, 2022
commit a80ced6 upstream.

As guest_irq is coming from KVM_IRQFD API call, it may trigger
crash in svm_update_pi_irte() due to out-of-bounds:

crash> bt
PID: 22218  TASK: ffff951a6ad74980  CPU: 73  COMMAND: "vcpu8"
 #0 [ffffb1ba6707fa40] machine_kexec at ffffffff8565b397
 #1 [ffffb1ba6707fa90] __crash_kexec at ffffffff85788a6d
 #2 [ffffb1ba6707fb58] crash_kexec at ffffffff8578995d
 #3 [ffffb1ba6707fb70] oops_end at ffffffff85623c0d
 #4 [ffffb1ba6707fb90] no_context at ffffffff856692c9
 #5 [ffffb1ba6707fbf8] exc_page_fault at ffffffff85f95b51
 #6 [ffffb1ba6707fc50] asm_exc_page_fault at ffffffff86000ace
    [exception RIP: svm_update_pi_irte+227]
    RIP: ffffffffc0761b53  RSP: ffffb1ba6707fd08  RFLAGS: 00010086
    RAX: ffffb1ba6707fd78  RBX: ffffb1ba66d91000  RCX: 0000000000000001
    RDX: 00003c803f63f1c0  RSI: 000000000000019a  RDI: ffffb1ba66db2ab8
    RBP: 000000000000019a   R8: 0000000000000040   R9: ffff94ca41b82200
    R10: ffffffffffffffcf  R11: 0000000000000001  R12: 0000000000000001
    R13: 0000000000000001  R14: ffffffffffffffcf  R15: 000000000000005f
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #7 [ffffb1ba6707fdb8] kvm_irq_routing_update at ffffffffc09f19a1 [kvm]
 #8 [ffffb1ba6707fde0] kvm_set_irq_routing at ffffffffc09f2133 [kvm]
 #9 [ffffb1ba6707fe18] kvm_vm_ioctl at ffffffffc09ef544 [kvm]
    RIP: 00007f143c36488b  RSP: 00007f143a4e04b8  RFLAGS: 00000246
    RAX: ffffffffffffffda  RBX: 00007f05780041d0  RCX: 00007f143c36488b
    RDX: 00007f05780041d0  RSI: 000000004008ae6a  RDI: 0000000000000020
    RBP: 00000000000004e8   R8: 0000000000000008   R9: 00007f05780041e0
    R10: 00007f0578004560  R11: 0000000000000246  R12: 00000000000004e0
    R13: 000000000000001a  R14: 00007f1424001c60  R15: 00007f0578003bc0
    ORIG_RAX: 0000000000000010  CS: 0033  SS: 002b

Vmx have been fix this in commit 3a8b067 (KVM: VMX: Do not BUG() on
out-of-bounds guest IRQ), so we can just copy source from that to fix
this.

Co-developed-by: Yi Liu <[email protected]>
Signed-off-by: Yi Liu <[email protected]>
Signed-off-by: Yi Wang <[email protected]>
Message-Id: <[email protected]>
Cc: [email protected]
Signed-off-by: Paolo Bonzini <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request Apr 19, 2022
[ Upstream commit 447c799 ]

Noticed the below warning while running a pytorch workload on vega10
GPUs. Change to trylock to avoid conflicts with already held reservation
locks.

[  +0.000003] WARNING: possible recursive locking detected
[  +0.000003] 5.13.0-kfd-rajneesh raspberrypi#1030 Not tainted
[  +0.000004] --------------------------------------------
[  +0.000002] python/4822 is trying to acquire lock:
[  +0.000004] ffff932cd9a259f8 (reservation_ww_class_mutex){+.+.}-{3:3},
at: amdgpu_bo_release_notify+0xc4/0x160 [amdgpu]
[  +0.000203]
              but task is already holding lock:
[  +0.000003] ffff932cbb7181f8 (reservation_ww_class_mutex){+.+.}-{3:3},
at: ttm_eu_reserve_buffers+0x270/0x470 [ttm]
[  +0.000017]
              other info that might help us debug this:
[  +0.000002]  Possible unsafe locking scenario:

[  +0.000003]        CPU0
[  +0.000002]        ----
[  +0.000002]   lock(reservation_ww_class_mutex);
[  +0.000004]   lock(reservation_ww_class_mutex);
[  +0.000003]
               *** DEADLOCK ***

[  +0.000002]  May be due to missing lock nesting notation

[  +0.000003] 7 locks held by python/4822:
[  +0.000003]  #0: ffff932c4ac028d0 (&process->mutex){+.+.}-{3:3}, at:
kfd_ioctl_map_memory_to_gpu+0x10b/0x320 [amdgpu]
[  +0.000232]  #1: ffff932c55e830a8 (&info->lock#2){+.+.}-{3:3}, at:
amdgpu_amdkfd_gpuvm_map_memory_to_gpu+0x64/0xf60 [amdgpu]
[  +0.000241]  #2: ffff932cc45b5e68 (&(*mem)->lock){+.+.}-{3:3}, at:
amdgpu_amdkfd_gpuvm_map_memory_to_gpu+0xdf/0xf60 [amdgpu]
[  +0.000236]  #3: ffffb2b35606fd28
(reservation_ww_class_acquire){+.+.}-{0:0}, at:
amdgpu_amdkfd_gpuvm_map_memory_to_gpu+0x232/0xf60 [amdgpu]
[  +0.000235]  #4: ffff932cbb7181f8
(reservation_ww_class_mutex){+.+.}-{3:3}, at:
ttm_eu_reserve_buffers+0x270/0x470 [ttm]
[  +0.000015]  #5: ffffffffc045f700 (*(sspp++)){....}-{0:0}, at:
drm_dev_enter+0x5/0xa0 [drm]
[  +0.000038]  #6: ffff932c52da7078 (&vm->eviction_lock){+.+.}-{3:3},
at: amdgpu_vm_bo_update_mapping+0xd5/0x4f0 [amdgpu]
[  +0.000195]
              stack backtrace:
[  +0.000003] CPU: 11 PID: 4822 Comm: python Not tainted
5.13.0-kfd-rajneesh raspberrypi#1030
[  +0.000005] Hardware name: GIGABYTE MZ01-CE0-00/MZ01-CE0-00, BIOS F02
08/29/2018
[  +0.000003] Call Trace:
[  +0.000003]  dump_stack+0x6d/0x89
[  +0.000010]  __lock_acquire+0xb93/0x1a90
[  +0.000009]  lock_acquire+0x25d/0x2d0
[  +0.000005]  ? amdgpu_bo_release_notify+0xc4/0x160 [amdgpu]
[  +0.000184]  ? lock_is_held_type+0xa2/0x110
[  +0.000006]  ? amdgpu_bo_release_notify+0xc4/0x160 [amdgpu]
[  +0.000184]  __ww_mutex_lock.constprop.17+0xca/0x1060
[  +0.000007]  ? amdgpu_bo_release_notify+0xc4/0x160 [amdgpu]
[  +0.000183]  ? lock_release+0x13f/0x270
[  +0.000005]  ? lock_is_held_type+0xa2/0x110
[  +0.000006]  ? amdgpu_bo_release_notify+0xc4/0x160 [amdgpu]
[  +0.000183]  amdgpu_bo_release_notify+0xc4/0x160 [amdgpu]
[  +0.000185]  ttm_bo_release+0x4c6/0x580 [ttm]
[  +0.000010]  amdgpu_bo_unref+0x1a/0x30 [amdgpu]
[  +0.000183]  amdgpu_vm_free_table+0x76/0xa0 [amdgpu]
[  +0.000189]  amdgpu_vm_free_pts+0xb8/0xf0 [amdgpu]
[  +0.000189]  amdgpu_vm_update_ptes+0x411/0x770 [amdgpu]
[  +0.000191]  amdgpu_vm_bo_update_mapping+0x324/0x4f0 [amdgpu]
[  +0.000191]  amdgpu_vm_bo_update+0x251/0x610 [amdgpu]
[  +0.000191]  update_gpuvm_pte+0xcc/0x290 [amdgpu]
[  +0.000229]  ? amdgpu_vm_bo_map+0xd7/0x130 [amdgpu]
[  +0.000190]  amdgpu_amdkfd_gpuvm_map_memory_to_gpu+0x912/0xf60
[amdgpu]
[  +0.000234]  kfd_ioctl_map_memory_to_gpu+0x182/0x320 [amdgpu]
[  +0.000218]  kfd_ioctl+0x2b9/0x600 [amdgpu]
[  +0.000216]  ? kfd_ioctl_unmap_memory_from_gpu+0x270/0x270 [amdgpu]
[  +0.000216]  ? lock_release+0x13f/0x270
[  +0.000006]  ? __fget_files+0x107/0x1e0
[  +0.000007]  __x64_sys_ioctl+0x8b/0xd0
[  +0.000007]  do_syscall_64+0x36/0x70
[  +0.000004]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[  +0.000007] RIP: 0033:0x7fbff90a7317
[  +0.000004] Code: b3 66 90 48 8b 05 71 4b 2d 00 64 c7 00 26 00 00 00
48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f
05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 41 4b 2d 00 f7 d8 64 89 01 48
[  +0.000005] RSP: 002b:00007fbe301fe648 EFLAGS: 00000246 ORIG_RAX:
0000000000000010
[  +0.000006] RAX: ffffffffffffffda RBX: 00007fbcc402d820 RCX:
00007fbff90a7317
[  +0.000003] RDX: 00007fbe301fe690 RSI: 00000000c0184b18 RDI:
0000000000000004
[  +0.000003] RBP: 00007fbe301fe690 R08: 0000000000000000 R09:
00007fbcc402d880
[  +0.000003] R10: 0000000002001000 R11: 0000000000000246 R12:
00000000c0184b18
[  +0.000003] R13: 0000000000000004 R14: 00007fbf689593a0 R15:
00007fbcc402d820

Cc: Christian König <[email protected]>
Cc: Felix Kuehling <[email protected]>
Cc: Alex Deucher <[email protected]>

Reviewed-by: Christian König <[email protected]>
Reviewed-by: Felix Kuehling <[email protected]>
Signed-off-by: Rajneesh Bhardwaj <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Aug 6, 2024
[ Upstream commit 59a931c ]

If the driver uses a page pool, it creates a page pool with
page_pool_create().
The reference count of page pool is 1 as default.
A page pool will be destroyed only when a reference count reaches 0.
page_pool_destroy() is used to destroy page pool, it decreases a
reference count.
When a page pool is destroyed, ->disconnect() is called, which is
mem_allocator_disconnect().
This function internally acquires mutex_lock().

If the driver uses XDP, it registers a memory model with
xdp_rxq_info_reg_mem_model().
The xdp_rxq_info_reg_mem_model() internally increases a page pool
reference count if a memory model is a page pool.
Now the reference count is 2.

To destroy a page pool, the driver should call both page_pool_destroy()
and xdp_unreg_mem_model().
The xdp_unreg_mem_model() internally calls page_pool_destroy().
Only page_pool_destroy() decreases a reference count.

If a driver calls page_pool_destroy() then xdp_unreg_mem_model(), we
will face an invalid wait context warning.
Because xdp_unreg_mem_model() calls page_pool_destroy() with
rcu_read_lock().
The page_pool_destroy() internally acquires mutex_lock().

Splat looks like:
=============================
[ BUG: Invalid wait context ]
6.10.0-rc6+ #4 Tainted: G W
-----------------------------
ethtool/1806 is trying to lock:
ffffffff90387b90 (mem_id_lock){+.+.}-{4:4}, at: mem_allocator_disconnect+0x73/0x150
other info that might help us debug this:
context-{5:5}
3 locks held by ethtool/1806:
stack backtrace:
CPU: 0 PID: 1806 Comm: ethtool Tainted: G W 6.10.0-rc6+ #4 f916f41f172891c800f2fed
Hardware name: ASUS System Product Name/PRIME Z690-P D4, BIOS 0603 11/01/2021
Call Trace:
<TASK>
dump_stack_lvl+0x7e/0xc0
__lock_acquire+0x1681/0x4de0
? _printk+0x64/0xe0
? __pfx_mark_lock.part.0+0x10/0x10
? __pfx___lock_acquire+0x10/0x10
lock_acquire+0x1b3/0x580
? mem_allocator_disconnect+0x73/0x150
? __wake_up_klogd.part.0+0x16/0xc0
? __pfx_lock_acquire+0x10/0x10
? dump_stack_lvl+0x91/0xc0
__mutex_lock+0x15c/0x1690
? mem_allocator_disconnect+0x73/0x150
? __pfx_prb_read_valid+0x10/0x10
? mem_allocator_disconnect+0x73/0x150
? __pfx_llist_add_batch+0x10/0x10
? console_unlock+0x193/0x1b0
? lockdep_hardirqs_on+0xbe/0x140
? __pfx___mutex_lock+0x10/0x10
? tick_nohz_tick_stopped+0x16/0x90
? __irq_work_queue_local+0x1e5/0x330
? irq_work_queue+0x39/0x50
? __wake_up_klogd.part.0+0x79/0xc0
? mem_allocator_disconnect+0x73/0x150
mem_allocator_disconnect+0x73/0x150
? __pfx_mem_allocator_disconnect+0x10/0x10
? mark_held_locks+0xa5/0xf0
? rcu_is_watching+0x11/0xb0
page_pool_release+0x36e/0x6d0
page_pool_destroy+0xd7/0x440
xdp_unreg_mem_model+0x1a7/0x2a0
? __pfx_xdp_unreg_mem_model+0x10/0x10
? kfree+0x125/0x370
? bnxt_free_ring.isra.0+0x2eb/0x500
? bnxt_free_mem+0x5ac/0x2500
xdp_rxq_info_unreg+0x4a/0xd0
bnxt_free_mem+0x1356/0x2500
bnxt_close_nic+0xf0/0x3b0
? __pfx_bnxt_close_nic+0x10/0x10
? ethnl_parse_bit+0x2c6/0x6d0
? __pfx___nla_validate_parse+0x10/0x10
? __pfx_ethnl_parse_bit+0x10/0x10
bnxt_set_features+0x2a8/0x3e0
__netdev_update_features+0x4dc/0x1370
? ethnl_parse_bitset+0x4ff/0x750
? __pfx_ethnl_parse_bitset+0x10/0x10
? __pfx___netdev_update_features+0x10/0x10
? mark_held_locks+0xa5/0xf0
? _raw_spin_unlock_irqrestore+0x42/0x70
? __pm_runtime_resume+0x7d/0x110
ethnl_set_features+0x32d/0xa20

To fix this problem, it uses rhashtable_lookup_fast() instead of
rhashtable_lookup() with rcu_read_lock().
Using xa without rcu_read_lock() here is safe.
xa is freed by __xdp_mem_allocator_rcu_free() and this is called by
call_rcu() of mem_xa_remove().
The mem_xa_remove() is called by page_pool_destroy() if a reference
count reaches 0.
The xa is already protected by the reference count mechanism well in the
control plane.
So removing rcu_read_lock() for page_pool_destroy() is safe.

Fixes: c3f812c ("page_pool: do not release pool until inflight == 0.")
Signed-off-by: Taehee Yoo <[email protected]>
Reviewed-by: Jakub Kicinski <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Aug 24, 2024
[ Upstream commit 86a41ea ]

When l2tp tunnels use a socket provided by userspace, we can hit
lockdep splats like the below when data is transmitted through another
(unrelated) userspace socket which then gets routed over l2tp.

This issue was previously discussed here:
https://lore.kernel.org/netdev/[email protected]/

The solution is to have lockdep treat socket locks of l2tp tunnel
sockets separately than those of standard INET sockets. To do so, use
a different lockdep subclass where lock nesting is possible.

  ============================================
  WARNING: possible recursive locking detected
  6.10.0+ raspberrypi#34 Not tainted
  --------------------------------------------
  iperf3/771 is trying to acquire lock:
  ffff8881027601d8 (slock-AF_INET/1){+.-.}-{2:2}, at: l2tp_xmit_skb+0x243/0x9d0

  but task is already holding lock:
  ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(slock-AF_INET/1);
    lock(slock-AF_INET/1);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  10 locks held by iperf3/771:
   #0: ffff888102650258 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x1a/0x40
   #1: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0
   #2: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130
   #3: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x28b/0x9f0
   #4: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0xf9/0x260
   #5: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10
   #6: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0
   #7: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130
   #8: ffffffff822ac1e0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0xcc/0x1450
   #9: ffff888101f33258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2){+...}-{2:2}, at: __dev_queue_xmit+0x513/0x1450

  stack backtrace:
  CPU: 2 UID: 0 PID: 771 Comm: iperf3 Not tainted 6.10.0+ raspberrypi#34
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
  Call Trace:
   <IRQ>
   dump_stack_lvl+0x69/0xa0
   dump_stack+0xc/0x20
   __lock_acquire+0x135d/0x2600
   ? srso_alias_return_thunk+0x5/0xfbef5
   lock_acquire+0xc4/0x2a0
   ? l2tp_xmit_skb+0x243/0x9d0
   ? __skb_checksum+0xa3/0x540
   _raw_spin_lock_nested+0x35/0x50
   ? l2tp_xmit_skb+0x243/0x9d0
   l2tp_xmit_skb+0x243/0x9d0
   l2tp_eth_dev_xmit+0x3c/0xc0
   dev_hard_start_xmit+0x11e/0x420
   sch_direct_xmit+0xc3/0x640
   __dev_queue_xmit+0x61c/0x1450
   ? ip_finish_output2+0xf4c/0x1130
   ip_finish_output2+0x6b6/0x1130
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __ip_finish_output+0x217/0x380
   ? srso_alias_return_thunk+0x5/0xfbef5
   __ip_finish_output+0x217/0x380
   ip_output+0x99/0x120
   __ip_queue_xmit+0xae4/0xbc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? tcp_options_write.constprop.0+0xcb/0x3e0
   ip_queue_xmit+0x34/0x40
   __tcp_transmit_skb+0x1625/0x1890
   __tcp_send_ack+0x1b8/0x340
   tcp_send_ack+0x23/0x30
   __tcp_ack_snd_check+0xa8/0x530
   ? srso_alias_return_thunk+0x5/0xfbef5
   tcp_rcv_established+0x412/0xd70
   tcp_v4_do_rcv+0x299/0x420
   tcp_v4_rcv+0x1991/0x1e10
   ip_protocol_deliver_rcu+0x50/0x220
   ip_local_deliver_finish+0x158/0x260
   ip_local_deliver+0xc8/0xe0
   ip_rcv+0xe5/0x1d0
   ? __pfx_ip_rcv+0x10/0x10
   __netif_receive_skb_one_core+0xce/0xe0
   ? process_backlog+0x28b/0x9f0
   __netif_receive_skb+0x34/0xd0
   ? process_backlog+0x28b/0x9f0
   process_backlog+0x2cb/0x9f0
   __napi_poll.constprop.0+0x61/0x280
   net_rx_action+0x332/0x670
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? find_held_lock+0x2b/0x80
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   handle_softirqs+0xda/0x480
   ? __dev_queue_xmit+0xa2c/0x1450
   do_softirq+0xa1/0xd0
   </IRQ>
   <TASK>
   __local_bh_enable_ip+0xc8/0xe0
   ? __dev_queue_xmit+0xa2c/0x1450
   __dev_queue_xmit+0xa48/0x1450
   ? ip_finish_output2+0xf4c/0x1130
   ip_finish_output2+0x6b6/0x1130
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __ip_finish_output+0x217/0x380
   ? srso_alias_return_thunk+0x5/0xfbef5
   __ip_finish_output+0x217/0x380
   ip_output+0x99/0x120
   __ip_queue_xmit+0xae4/0xbc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? tcp_options_write.constprop.0+0xcb/0x3e0
   ip_queue_xmit+0x34/0x40
   __tcp_transmit_skb+0x1625/0x1890
   tcp_write_xmit+0x766/0x2fb0
   ? __entry_text_end+0x102ba9/0x102bad
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __might_fault+0x74/0xc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   __tcp_push_pending_frames+0x56/0x190
   tcp_push+0x117/0x310
   tcp_sendmsg_locked+0x14c1/0x1740
   tcp_sendmsg+0x28/0x40
   inet_sendmsg+0x5d/0x90
   sock_write_iter+0x242/0x2b0
   vfs_write+0x68d/0x800
   ? __pfx_sock_write_iter+0x10/0x10
   ksys_write+0xc8/0xf0
   __x64_sys_write+0x3d/0x50
   x64_sys_call+0xfaf/0x1f50
   do_syscall_64+0x6d/0x140
   entry_SYSCALL_64_after_hwframe+0x76/0x7e
  RIP: 0033:0x7f4d143af992
  Code: c3 8b 07 85 c0 75 24 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> e9 01 cc ff ff 41 54 b8 02 00 00 0
  RSP: 002b:00007ffd65032058 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
  RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f4d143af992
  RDX: 0000000000000025 RSI: 00007f4d143f3bcc RDI: 0000000000000005
  RBP: 00007f4d143f2b28 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4d143f3bcc
  R13: 0000000000000005 R14: 0000000000000000 R15: 00007ffd650323f0
   </TASK>

Fixes: 0b2c597 ("l2tp: close all race conditions in l2tp_tunnel_register()")
Suggested-by: Eric Dumazet <[email protected]>
Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=6acef9e0a4d1f46c83d4
CC: [email protected]
CC: [email protected]
Signed-off-by: James Chapman <[email protected]>
Signed-off-by: Tom Parkin <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Sep 10, 2024
[ Upstream commit b313a8c ]

Lockdep reported a warning in Linux version 6.6:

[  414.344659] ================================
[  414.345155] WARNING: inconsistent lock state
[  414.345658] 6.6.0-07439-gba2303cacfda #6 Not tainted
[  414.346221] --------------------------------
[  414.346712] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
[  414.347545] kworker/u10:3/1152 [HC0[0]:SC0[0]:HE0:SE1] takes:
[  414.349245] ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0
[  414.351204] {IN-SOFTIRQ-W} state was registered at:
[  414.351751]   lock_acquire+0x18d/0x460
[  414.352218]   _raw_spin_lock_irqsave+0x39/0x60
[  414.352769]   __wake_up_common_lock+0x22/0x60
[  414.353289]   sbitmap_queue_wake_up+0x375/0x4f0
[  414.353829]   sbitmap_queue_clear+0xdd/0x270
[  414.354338]   blk_mq_put_tag+0xdf/0x170
[  414.354807]   __blk_mq_free_request+0x381/0x4d0
[  414.355335]   blk_mq_free_request+0x28b/0x3e0
[  414.355847]   __blk_mq_end_request+0x242/0xc30
[  414.356367]   scsi_end_request+0x2c1/0x830
[  414.345155] WARNING: inconsistent lock state
[  414.345658] 6.6.0-07439-gba2303cacfda #6 Not tainted
[  414.346221] --------------------------------
[  414.346712] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
[  414.347545] kworker/u10:3/1152 [HC0[0]:SC0[0]:HE0:SE1] takes:
[  414.349245] ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0
[  414.351204] {IN-SOFTIRQ-W} state was registered at:
[  414.351751]   lock_acquire+0x18d/0x460
[  414.352218]   _raw_spin_lock_irqsave+0x39/0x60
[  414.352769]   __wake_up_common_lock+0x22/0x60
[  414.353289]   sbitmap_queue_wake_up+0x375/0x4f0
[  414.353829]   sbitmap_queue_clear+0xdd/0x270
[  414.354338]   blk_mq_put_tag+0xdf/0x170
[  414.354807]   __blk_mq_free_request+0x381/0x4d0
[  414.355335]   blk_mq_free_request+0x28b/0x3e0
[  414.355847]   __blk_mq_end_request+0x242/0xc30
[  414.356367]   scsi_end_request+0x2c1/0x830
[  414.356863]   scsi_io_completion+0x177/0x1610
[  414.357379]   scsi_complete+0x12f/0x260
[  414.357856]   blk_complete_reqs+0xba/0xf0
[  414.358338]   __do_softirq+0x1b0/0x7a2
[  414.358796]   irq_exit_rcu+0x14b/0x1a0
[  414.359262]   sysvec_call_function_single+0xaf/0xc0
[  414.359828]   asm_sysvec_call_function_single+0x1a/0x20
[  414.360426]   default_idle+0x1e/0x30
[  414.360873]   default_idle_call+0x9b/0x1f0
[  414.361390]   do_idle+0x2d2/0x3e0
[  414.361819]   cpu_startup_entry+0x55/0x60
[  414.362314]   start_secondary+0x235/0x2b0
[  414.362809]   secondary_startup_64_no_verify+0x18f/0x19b
[  414.363413] irq event stamp: 428794
[  414.363825] hardirqs last  enabled at (428793): [<ffffffff816bfd1c>] ktime_get+0x1dc/0x200
[  414.364694] hardirqs last disabled at (428794): [<ffffffff85470177>] _raw_spin_lock_irq+0x47/0x50
[  414.365629] softirqs last  enabled at (428444): [<ffffffff85474780>] __do_softirq+0x540/0x7a2
[  414.366522] softirqs last disabled at (428419): [<ffffffff813f65ab>] irq_exit_rcu+0x14b/0x1a0
[  414.367425]
               other info that might help us debug this:
[  414.368194]  Possible unsafe locking scenario:
[  414.368900]        CPU0
[  414.369225]        ----
[  414.369548]   lock(&sbq->ws[i].wait);
[  414.370000]   <Interrupt>
[  414.370342]     lock(&sbq->ws[i].wait);
[  414.370802]
                *** DEADLOCK ***
[  414.371569] 5 locks held by kworker/u10:3/1152:
[  414.372088]  #0: ffff88810130e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x357/0x13f0
[  414.373180]  #1: ffff88810201fdb8 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x3a3/0x13f0
[  414.374384]  #2: ffffffff86ffbdc0 (rcu_read_lock){....}-{1:2}, at: blk_mq_run_hw_queue+0x637/0xa00
[  414.375342]  #3: ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0
[  414.376377]  #4: ffff888106205a08 (&hctx->dispatch_wait_lock){+.-.}-{2:2}, at: blk_mq_dispatch_rq_list+0x1337/0x1ee0
[  414.378607]
               stack backtrace:
[  414.379177] CPU: 0 PID: 1152 Comm: kworker/u10:3 Not tainted 6.6.0-07439-gba2303cacfda #6
[  414.380032] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[  414.381177] Workqueue: writeback wb_workfn (flush-253:0)
[  414.381805] Call Trace:
[  414.382136]  <TASK>
[  414.382429]  dump_stack_lvl+0x91/0xf0
[  414.382884]  mark_lock_irq+0xb3b/0x1260
[  414.383367]  ? __pfx_mark_lock_irq+0x10/0x10
[  414.383889]  ? stack_trace_save+0x8e/0xc0
[  414.384373]  ? __pfx_stack_trace_save+0x10/0x10
[  414.384903]  ? graph_lock+0xcf/0x410
[  414.385350]  ? save_trace+0x3d/0xc70
[  414.385808]  mark_lock.part.20+0x56d/0xa90
[  414.386317]  mark_held_locks+0xb0/0x110
[  414.386791]  ? __pfx_do_raw_spin_lock+0x10/0x10
[  414.387320]  lockdep_hardirqs_on_prepare+0x297/0x3f0
[  414.387901]  ? _raw_spin_unlock_irq+0x28/0x50
[  414.388422]  trace_hardirqs_on+0x58/0x100
[  414.388917]  _raw_spin_unlock_irq+0x28/0x50
[  414.389422]  __blk_mq_tag_busy+0x1d6/0x2a0
[  414.389920]  __blk_mq_get_driver_tag+0x761/0x9f0
[  414.390899]  blk_mq_dispatch_rq_list+0x1780/0x1ee0
[  414.391473]  ? __pfx_blk_mq_dispatch_rq_list+0x10/0x10
[  414.392070]  ? sbitmap_get+0x2b8/0x450
[  414.392533]  ? __blk_mq_get_driver_tag+0x210/0x9f0
[  414.393095]  __blk_mq_sched_dispatch_requests+0xd99/0x1690
[  414.393730]  ? elv_attempt_insert_merge+0x1b1/0x420
[  414.394302]  ? __pfx___blk_mq_sched_dispatch_requests+0x10/0x10
[  414.394970]  ? lock_acquire+0x18d/0x460
[  414.395456]  ? blk_mq_run_hw_queue+0x637/0xa00
[  414.395986]  ? __pfx_lock_acquire+0x10/0x10
[  414.396499]  blk_mq_sched_dispatch_requests+0x109/0x190
[  414.397100]  blk_mq_run_hw_queue+0x66e/0xa00
[  414.397616]  blk_mq_flush_plug_list.part.17+0x614/0x2030
[  414.398244]  ? __pfx_blk_mq_flush_plug_list.part.17+0x10/0x10
[  414.398897]  ? writeback_sb_inodes+0x241/0xcc0
[  414.399429]  blk_mq_flush_plug_list+0x65/0x80
[  414.399957]  __blk_flush_plug+0x2f1/0x530
[  414.400458]  ? __pfx___blk_flush_plug+0x10/0x10
[  414.400999]  blk_finish_plug+0x59/0xa0
[  414.401467]  wb_writeback+0x7cc/0x920
[  414.401935]  ? __pfx_wb_writeback+0x10/0x10
[  414.402442]  ? mark_held_locks+0xb0/0x110
[  414.402931]  ? __pfx_do_raw_spin_lock+0x10/0x10
[  414.403462]  ? lockdep_hardirqs_on_prepare+0x297/0x3f0
[  414.404062]  wb_workfn+0x2b3/0xcf0
[  414.404500]  ? __pfx_wb_workfn+0x10/0x10
[  414.404989]  process_scheduled_works+0x432/0x13f0
[  414.405546]  ? __pfx_process_scheduled_works+0x10/0x10
[  414.406139]  ? do_raw_spin_lock+0x101/0x2a0
[  414.406641]  ? assign_work+0x19b/0x240
[  414.407106]  ? lock_is_held_type+0x9d/0x110
[  414.407604]  worker_thread+0x6f2/0x1160
[  414.408075]  ? __kthread_parkme+0x62/0x210
[  414.408572]  ? lockdep_hardirqs_on_prepare+0x297/0x3f0
[  414.409168]  ? __kthread_parkme+0x13c/0x210
[  414.409678]  ? __pfx_worker_thread+0x10/0x10
[  414.410191]  kthread+0x33c/0x440
[  414.410602]  ? __pfx_kthread+0x10/0x10
[  414.411068]  ret_from_fork+0x4d/0x80
[  414.411526]  ? __pfx_kthread+0x10/0x10
[  414.411993]  ret_from_fork_asm+0x1b/0x30
[  414.412489]  </TASK>

When interrupt is turned on while a lock holding by spin_lock_irq it
throws a warning because of potential deadlock.

blk_mq_prep_dispatch_rq
 blk_mq_get_driver_tag
  __blk_mq_get_driver_tag
   __blk_mq_alloc_driver_tag
    blk_mq_tag_busy -> tag is already busy
    // failed to get driver tag
 blk_mq_mark_tag_wait
  spin_lock_irq(&wq->lock) -> lock A (&sbq->ws[i].wait)
  __add_wait_queue(wq, wait) -> wait queue active
  blk_mq_get_driver_tag
  __blk_mq_tag_busy
-> 1) tag must be idle, which means there can't be inflight IO
   spin_lock_irq(&tags->lock) -> lock B (hctx->tags)
   spin_unlock_irq(&tags->lock) -> unlock B, turn on interrupt accidentally
-> 2) context must be preempt by IO interrupt to trigger deadlock.

As shown above, the deadlock is not possible in theory, but the warning
still need to be fixed.

Fix it by using spin_lock_irqsave to get lockB instead of spin_lock_irq.

Fixes: 4f1731d ("blk-mq: fix potential io hang by wrong 'wake_batch'")
Signed-off-by: Li Lingfeng <[email protected]>
Reviewed-by: Ming Lei <[email protected]>
Reviewed-by: Yu Kuai <[email protected]>
Reviewed-by: Bart Van Assche <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Sep 15, 2024
[ Upstream commit c3a5e3e ]

When using cachefiles, lockdep may emit something similar to the circular
locking dependency notice below.  The problem appears to stem from the
following:

 (1) Cachefiles manipulates xattrs on the files in its cache when called
     from ->writepages().

 (2) The setxattr() and removexattr() system call handlers get the name
     (and value) from userspace after taking the sb_writers lock, putting
     accesses of the vma->vm_lock and mm->mmap_lock inside of that.

 (3) The afs filesystem uses a per-inode lock to prevent multiple
     revalidation RPCs and in writeback vs truncate to prevent parallel
     operations from deadlocking against the server on one side and local
     page locks on the other.

Fix this by moving the getting of the name and value in {get,remove}xattr()
outside of the sb_writers lock.  This also has the minor benefits that we
don't need to reget these in the event of a retry and we never try to take
the sb_writers lock in the event we can't pull the name and value into the
kernel.

Alternative approaches that might fix this include moving the dispatch of a
write to the cache off to a workqueue or trying to do without the
validation lock in afs.  Note that this might also affect other filesystems
that use netfslib and/or cachefiles.

 ======================================================
 WARNING: possible circular locking dependency detected
 6.10.0-build2+ raspberrypi#956 Not tainted
 ------------------------------------------------------
 fsstress/6050 is trying to acquire lock:
 ffff888138fd82f0 (mapping.invalidate_lock#3){++++}-{3:3}, at: filemap_fault+0x26e/0x8b0

 but task is already holding lock:
 ffff888113f26d18 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x165/0x250

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #4 (&vma->vm_lock->lock){++++}-{3:3}:
        __lock_acquire+0xaf0/0xd80
        lock_acquire.part.0+0x103/0x280
        down_write+0x3b/0x50
        vma_start_write+0x6b/0xa0
        vma_link+0xcc/0x140
        insert_vm_struct+0xb7/0xf0
        alloc_bprm+0x2c1/0x390
        kernel_execve+0x65/0x1a0
        call_usermodehelper_exec_async+0x14d/0x190
        ret_from_fork+0x24/0x40
        ret_from_fork_asm+0x1a/0x30

 -> #3 (&mm->mmap_lock){++++}-{3:3}:
        __lock_acquire+0xaf0/0xd80
        lock_acquire.part.0+0x103/0x280
        __might_fault+0x7c/0xb0
        strncpy_from_user+0x25/0x160
        removexattr+0x7f/0x100
        __do_sys_fremovexattr+0x7e/0xb0
        do_syscall_64+0x9f/0x100
        entry_SYSCALL_64_after_hwframe+0x76/0x7e

 -> #2 (sb_writers#14){.+.+}-{0:0}:
        __lock_acquire+0xaf0/0xd80
        lock_acquire.part.0+0x103/0x280
        percpu_down_read+0x3c/0x90
        vfs_iocb_iter_write+0xe9/0x1d0
        __cachefiles_write+0x367/0x430
        cachefiles_issue_write+0x299/0x2f0
        netfs_advance_write+0x117/0x140
        netfs_write_folio.isra.0+0x5ca/0x6e0
        netfs_writepages+0x230/0x2f0
        afs_writepages+0x4d/0x70
        do_writepages+0x1e8/0x3e0
        filemap_fdatawrite_wbc+0x84/0xa0
        __filemap_fdatawrite_range+0xa8/0xf0
        file_write_and_wait_range+0x59/0x90
        afs_release+0x10f/0x270
        __fput+0x25f/0x3d0
        __do_sys_close+0x43/0x70
        do_syscall_64+0x9f/0x100
        entry_SYSCALL_64_after_hwframe+0x76/0x7e

 -> #1 (&vnode->validate_lock){++++}-{3:3}:
        __lock_acquire+0xaf0/0xd80
        lock_acquire.part.0+0x103/0x280
        down_read+0x95/0x200
        afs_writepages+0x37/0x70
        do_writepages+0x1e8/0x3e0
        filemap_fdatawrite_wbc+0x84/0xa0
        filemap_invalidate_inode+0x167/0x1e0
        netfs_unbuffered_write_iter+0x1bd/0x2d0
        vfs_write+0x22e/0x320
        ksys_write+0xbc/0x130
        do_syscall_64+0x9f/0x100
        entry_SYSCALL_64_after_hwframe+0x76/0x7e

 -> #0 (mapping.invalidate_lock#3){++++}-{3:3}:
        check_noncircular+0x119/0x160
        check_prev_add+0x195/0x430
        __lock_acquire+0xaf0/0xd80
        lock_acquire.part.0+0x103/0x280
        down_read+0x95/0x200
        filemap_fault+0x26e/0x8b0
        __do_fault+0x57/0xd0
        do_pte_missing+0x23b/0x320
        __handle_mm_fault+0x2d4/0x320
        handle_mm_fault+0x14f/0x260
        do_user_addr_fault+0x2a2/0x500
        exc_page_fault+0x71/0x90
        asm_exc_page_fault+0x22/0x30

 other info that might help us debug this:

 Chain exists of:
   mapping.invalidate_lock#3 --> &mm->mmap_lock --> &vma->vm_lock->lock

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   rlock(&vma->vm_lock->lock);
                                lock(&mm->mmap_lock);
                                lock(&vma->vm_lock->lock);
   rlock(mapping.invalidate_lock#3);

  *** DEADLOCK ***

 1 lock held by fsstress/6050:
  #0: ffff888113f26d18 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x165/0x250

 stack backtrace:
 CPU: 0 PID: 6050 Comm: fsstress Not tainted 6.10.0-build2+ raspberrypi#956
 Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
 Call Trace:
  <TASK>
  dump_stack_lvl+0x57/0x80
  check_noncircular+0x119/0x160
  ? queued_spin_lock_slowpath+0x4be/0x510
  ? __pfx_check_noncircular+0x10/0x10
  ? __pfx_queued_spin_lock_slowpath+0x10/0x10
  ? mark_lock+0x47/0x160
  ? init_chain_block+0x9c/0xc0
  ? add_chain_block+0x84/0xf0
  check_prev_add+0x195/0x430
  __lock_acquire+0xaf0/0xd80
  ? __pfx___lock_acquire+0x10/0x10
  ? __lock_release.isra.0+0x13b/0x230
  lock_acquire.part.0+0x103/0x280
  ? filemap_fault+0x26e/0x8b0
  ? __pfx_lock_acquire.part.0+0x10/0x10
  ? rcu_is_watching+0x34/0x60
  ? lock_acquire+0xd7/0x120
  down_read+0x95/0x200
  ? filemap_fault+0x26e/0x8b0
  ? __pfx_down_read+0x10/0x10
  ? __filemap_get_folio+0x25/0x1a0
  filemap_fault+0x26e/0x8b0
  ? __pfx_filemap_fault+0x10/0x10
  ? find_held_lock+0x7c/0x90
  ? __pfx___lock_release.isra.0+0x10/0x10
  ? __pte_offset_map+0x99/0x110
  __do_fault+0x57/0xd0
  do_pte_missing+0x23b/0x320
  __handle_mm_fault+0x2d4/0x320
  ? __pfx___handle_mm_fault+0x10/0x10
  handle_mm_fault+0x14f/0x260
  do_user_addr_fault+0x2a2/0x500
  exc_page_fault+0x71/0x90
  asm_exc_page_fault+0x22/0x30

Signed-off-by: David Howells <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
cc: Alexander Viro <[email protected]>
cc: Christian Brauner <[email protected]>
cc: Jan Kara <[email protected]>
cc: Jeff Layton <[email protected]>
cc: Gao Xiang <[email protected]>
cc: Matthew Wilcox <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
[brauner: fix minor issues]
Signed-off-by: Christian Brauner <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Oct 5, 2024
[ Upstream commit 89a906d ]

Floating point instructions in userspace can crash some arm kernels
built with clang/LLD 17.0.6:

    BUG: unsupported FP instruction in kernel mode
    FPEXC == 0xc0000780
    Internal error: Oops - undefined instruction: 0 [#1] ARM
    CPU: 0 PID: 196 Comm: vfp-reproducer Not tainted 6.10.0 #1
    Hardware name: BCM2835
    PC is at vfp_support_entry+0xc8/0x2cc
    LR is at do_undefinstr+0xa8/0x250
    pc : [<c0101d50>]    lr : [<c010a80c>]    psr: a0000013
    sp : dc8d1f68  ip : 60000013  fp : bedea19c
    r10: ec532b17  r9 : 00000010  r8 : 0044766c
    r7 : c0000780  r6 : ec532b17  r5 : c1c13800  r4 : dc8d1fb0
    r3 : c10072c4  r2 : c0101c88  r1 : ec532b17  r0 : 0044766c
    Flags: NzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
    Control: 00c5387d  Table: 0251c008  DAC: 00000051
    Register r0 information: non-paged memory
    Register r1 information: vmalloc memory
    Register r2 information: non-slab/vmalloc memory
    Register r3 information: non-slab/vmalloc memory
    Register r4 information: 2-page vmalloc region
    Register r5 information: slab kmalloc-cg-2k
    Register r6 information: vmalloc memory
    Register r7 information: non-slab/vmalloc memory
    Register r8 information: non-paged memory
    Register r9 information: zero-size pointer
    Register r10 information: vmalloc memory
    Register r11 information: non-paged memory
    Register r12 information: non-paged memory
    Process vfp-reproducer (pid: 196, stack limit = 0x61aaaf8b)
    Stack: (0xdc8d1f68 to 0xdc8d2000)
    1f60:                   0000081f b6f69300 0000000f c10073f4 c10072c4 dc8d1fb0
    1f80: ec532b17 0c532b17 0044766c b6f9ccd8 00000000 c010a80c 00447670 60000010
    1fa0: ffffffff c1c13800 00c5387d c0100f10 b6f68af8 00448fc0 00000000 bedea188
    1fc0: bedea314 00000001 00448ebc b6f9d000 00447608 b6f9ccd8 00000000 bedea19c
    1fe0: bede9198 bedea188 b6e1061c 0044766c 60000010 ffffffff 00000000 00000000
    Call trace:
    [<c0101d50>] (vfp_support_entry) from [<c010a80c>] (do_undefinstr+0xa8/0x250)
    [<c010a80c>] (do_undefinstr) from [<c0100f10>] (__und_usr+0x70/0x80)
    Exception stack(0xdc8d1fb0 to 0xdc8d1ff8)
    1fa0:                                     b6f68af8 00448fc0 00000000 bedea188
    1fc0: bedea314 00000001 00448ebc b6f9d000 00447608 b6f9ccd8 00000000 bedea19c
    1fe0: bede9198 bedea188 b6e1061c 0044766c 60000010 ffffffff
    Code: 0a000061 e3877202 e594003c e3a09010 (eef16a10)
    ---[ end trace 0000000000000000 ]---
    Kernel panic - not syncing: Fatal exception in interrupt
    ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---

This is a minimal userspace reproducer on a Raspberry Pi Zero W:

    #include <stdio.h>
    #include <math.h>

    int main(void)
    {
            double v = 1.0;
            printf("%fn", NAN + *(volatile double *)&v);
            return 0;
    }

Another way to consistently trigger the oops is:

    calvin@raspberry-pi-zero-w ~$ python -c "import json"

The bug reproduces only when the kernel is built with DYNAMIC_DEBUG=n,
because the pr_debug() calls act as barriers even when not activated.

This is the output from the same kernel source built with the same
compiler and DYNAMIC_DEBUG=y, where the userspace reproducer works as
expected:

    VFP: bounce: trigger ec532b17 fpexc c0000780
    VFP: emulate: INST=0xee377b06 SCR=0x00000000
    VFP: bounce: trigger eef1fa10 fpexc c0000780
    VFP: emulate: INST=0xeeb40b40 SCR=0x00000000
    VFP: raising exceptions 30000000

    calvin@raspberry-pi-zero-w ~$ ./vfp-reproducer
    nan

Crudely grepping for vmsr/vmrs instructions in the otherwise nearly
idential text for vfp_support_entry() makes the problem obvious:

    vmlinux.llvm.good [0xc0101cb8] <+48>:  vmrs   r7, fpexc
    vmlinux.llvm.good [0xc0101cd8] <+80>:  vmsr   fpexc, r0
    vmlinux.llvm.good [0xc0101d20] <+152>: vmsr   fpexc, r7
    vmlinux.llvm.good [0xc0101d38] <+176>: vmrs   r4, fpexc
    vmlinux.llvm.good [0xc0101d6c] <+228>: vmrs   r0, fpscr
    vmlinux.llvm.good [0xc0101dc4] <+316>: vmsr   fpexc, r0
    vmlinux.llvm.good [0xc0101dc8] <+320>: vmrs   r0, fpsid
    vmlinux.llvm.good [0xc0101dcc] <+324>: vmrs   r6, fpscr
    vmlinux.llvm.good [0xc0101e10] <+392>: vmrs   r10, fpinst
    vmlinux.llvm.good [0xc0101eb8] <+560>: vmrs   r10, fpinst2

    vmlinux.llvm.bad  [0xc0101cb8] <+48>:  vmrs   r7, fpexc
    vmlinux.llvm.bad  [0xc0101cd8] <+80>:  vmsr   fpexc, r0
    vmlinux.llvm.bad  [0xc0101d20] <+152>: vmsr   fpexc, r7
    vmlinux.llvm.bad  [0xc0101d30] <+168>: vmrs   r0, fpscr
    vmlinux.llvm.bad  [0xc0101d50] <+200>: vmrs   r6, fpscr  <== BOOM!
    vmlinux.llvm.bad  [0xc0101d6c] <+228>: vmsr   fpexc, r0
    vmlinux.llvm.bad  [0xc0101d70] <+232>: vmrs   r0, fpsid
    vmlinux.llvm.bad  [0xc0101da4] <+284>: vmrs   r10, fpinst
    vmlinux.llvm.bad  [0xc0101df8] <+368>: vmrs   r4, fpexc
    vmlinux.llvm.bad  [0xc0101e5c] <+468>: vmrs   r10, fpinst2

I think LLVM's reordering is valid as the code is currently written: the
compiler doesn't know the instructions have side effects in hardware.

Fix by using "asm volatile" in fmxr() and fmrx(), so they cannot be
reordered with respect to each other. The original compiler now produces
working kernels on my hardware with DYNAMIC_DEBUG=n.

This is the relevant piece of the diff of the vfp_support_entry() text,
from the original oopsing kernel to a working kernel with this patch:

         vmrs r0, fpscr
         tst r0, raspberrypi#4096
         bne 0xc0101d48
         tst r0, #458752
         beq 0xc0101ecc
         orr r7, r7, #536870912
         ldr r0, [r4, #0x3c]
         mov r9, raspberrypi#16
        -vmrs r6, fpscr
         orr r9, r9, #251658240
         add r0, r0, #4
         str r0, [r4, #0x3c]
         mvn r0, raspberrypi#159
         sub r0, r0, #-1207959552
         and r0, r7, r0
         vmsr fpexc, r0
         vmrs r0, fpsid
        +vmrs r6, fpscr
         and r0, r0, #983040
         cmp r0, #65536
         bne 0xc0101d88

Fixes: 4708fb0 ("ARM: vfp: Reimplement VFP exception entry in C code")
Signed-off-by: Calvin Owens <[email protected]>
Signed-off-by: Russell King (Oracle) <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Oct 5, 2024
commit 44d1745 upstream.

Use a dedicated mutex to guard kvm_usage_count to fix a potential deadlock
on x86 due to a chain of locks and SRCU synchronizations.  Translating the
below lockdep splat, CPU1 #6 will wait on CPU0 #1, CPU0 #8 will wait on
CPU2 #3, and CPU2 #7 will wait on CPU1 #4 (if there's a writer, due to the
fairness of r/w semaphores).

    CPU0                     CPU1                     CPU2
1   lock(&kvm->slots_lock);
2                                                     lock(&vcpu->mutex);
3                                                     lock(&kvm->srcu);
4                            lock(cpu_hotplug_lock);
5                            lock(kvm_lock);
6                            lock(&kvm->slots_lock);
7                                                     lock(cpu_hotplug_lock);
8   sync(&kvm->srcu);

Note, there are likely more potential deadlocks in KVM x86, e.g. the same
pattern of taking cpu_hotplug_lock outside of kvm_lock likely exists with
__kvmclock_cpufreq_notifier():

  cpuhp_cpufreq_online()
  |
  -> cpufreq_online()
     |
     -> cpufreq_gov_performance_limits()
        |
        -> __cpufreq_driver_target()
           |
           -> __target_index()
              |
              -> cpufreq_freq_transition_begin()
                 |
                 -> cpufreq_notify_transition()
                    |
                    -> ... __kvmclock_cpufreq_notifier()

But, actually triggering such deadlocks is beyond rare due to the
combination of dependencies and timings involved.  E.g. the cpufreq
notifier is only used on older CPUs without a constant TSC, mucking with
the NX hugepage mitigation while VMs are running is very uncommon, and
doing so while also onlining/offlining a CPU (necessary to generate
contention on cpu_hotplug_lock) would be even more unusual.

The most robust solution to the general cpu_hotplug_lock issue is likely
to switch vm_list to be an RCU-protected list, e.g. so that x86's cpufreq
notifier doesn't to take kvm_lock.  For now, settle for fixing the most
blatant deadlock, as switching to an RCU-protected list is a much more
involved change, but add a comment in locking.rst to call out that care
needs to be taken when walking holding kvm_lock and walking vm_list.

  ======================================================
  WARNING: possible circular locking dependency detected
  6.10.0-smp--c257535a0c9d-pip raspberrypi#330 Tainted: G S         O
  ------------------------------------------------------
  tee/35048 is trying to acquire lock:
  ff6a80eced71e0a8 (&kvm->slots_lock){+.+.}-{3:3}, at: set_nx_huge_pages+0x179/0x1e0 [kvm]

  but task is already holding lock:
  ffffffffc07abb08 (kvm_lock){+.+.}-{3:3}, at: set_nx_huge_pages+0x14a/0x1e0 [kvm]

  which lock already depends on the new lock.

   the existing dependency chain (in reverse order) is:

  -> #3 (kvm_lock){+.+.}-{3:3}:
         __mutex_lock+0x6a/0xb40
         mutex_lock_nested+0x1f/0x30
         kvm_dev_ioctl+0x4fb/0xe50 [kvm]
         __se_sys_ioctl+0x7b/0xd0
         __x64_sys_ioctl+0x21/0x30
         x64_sys_call+0x15d0/0x2e60
         do_syscall_64+0x83/0x160
         entry_SYSCALL_64_after_hwframe+0x76/0x7e

  -> #2 (cpu_hotplug_lock){++++}-{0:0}:
         cpus_read_lock+0x2e/0xb0
         static_key_slow_inc+0x16/0x30
         kvm_lapic_set_base+0x6a/0x1c0 [kvm]
         kvm_set_apic_base+0x8f/0xe0 [kvm]
         kvm_set_msr_common+0x9ae/0xf80 [kvm]
         vmx_set_msr+0xa54/0xbe0 [kvm_intel]
         __kvm_set_msr+0xb6/0x1a0 [kvm]
         kvm_arch_vcpu_ioctl+0xeca/0x10c0 [kvm]
         kvm_vcpu_ioctl+0x485/0x5b0 [kvm]
         __se_sys_ioctl+0x7b/0xd0
         __x64_sys_ioctl+0x21/0x30
         x64_sys_call+0x15d0/0x2e60
         do_syscall_64+0x83/0x160
         entry_SYSCALL_64_after_hwframe+0x76/0x7e

  -> #1 (&kvm->srcu){.+.+}-{0:0}:
         __synchronize_srcu+0x44/0x1a0
         synchronize_srcu_expedited+0x21/0x30
         kvm_swap_active_memslots+0x110/0x1c0 [kvm]
         kvm_set_memslot+0x360/0x620 [kvm]
         __kvm_set_memory_region+0x27b/0x300 [kvm]
         kvm_vm_ioctl_set_memory_region+0x43/0x60 [kvm]
         kvm_vm_ioctl+0x295/0x650 [kvm]
         __se_sys_ioctl+0x7b/0xd0
         __x64_sys_ioctl+0x21/0x30
         x64_sys_call+0x15d0/0x2e60
         do_syscall_64+0x83/0x160
         entry_SYSCALL_64_after_hwframe+0x76/0x7e

  -> #0 (&kvm->slots_lock){+.+.}-{3:3}:
         __lock_acquire+0x15ef/0x2e30
         lock_acquire+0xe0/0x260
         __mutex_lock+0x6a/0xb40
         mutex_lock_nested+0x1f/0x30
         set_nx_huge_pages+0x179/0x1e0 [kvm]
         param_attr_store+0x93/0x100
         module_attr_store+0x22/0x40
         sysfs_kf_write+0x81/0xb0
         kernfs_fop_write_iter+0x133/0x1d0
         vfs_write+0x28d/0x380
         ksys_write+0x70/0xe0
         __x64_sys_write+0x1f/0x30
         x64_sys_call+0x281b/0x2e60
         do_syscall_64+0x83/0x160
         entry_SYSCALL_64_after_hwframe+0x76/0x7e

Cc: Chao Gao <[email protected]>
Fixes: 0bf5049 ("KVM: Drop kvm_count_lock and instead protect kvm_usage_count with kvm_lock")
Cc: [email protected]
Reviewed-by: Kai Huang <[email protected]>
Acked-by: Kai Huang <[email protected]>
Tested-by: Farrah Chen <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
Message-ID: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request Oct 11, 2024
commit ac01c8c upstream.

AddressSanitizer found a use-after-free bug in the symbol code which
manifested as 'perf top' segfaulting.

  ==1238389==ERROR: AddressSanitizer: heap-use-after-free on address 0x60b00c48844b at pc 0x5650d8035961 bp 0x7f751aaecc90 sp 0x7f751aaecc80
  READ of size 1 at 0x60b00c48844b thread T193
      #0 0x5650d8035960 in _sort__sym_cmp util/sort.c:310
      #1 0x5650d8043744 in hist_entry__cmp util/hist.c:1286
      #2 0x5650d8043951 in hists__findnew_entry util/hist.c:614
      #3 0x5650d804568f in __hists__add_entry util/hist.c:754
      #4 0x5650d8045bf9 in hists__add_entry util/hist.c:772
      #5 0x5650d8045df1 in iter_add_single_normal_entry util/hist.c:997
      #6 0x5650d8043326 in hist_entry_iter__add util/hist.c:1242
      #7 0x5650d7ceeefe in perf_event__process_sample /home/matt/src/linux/tools/perf/builtin-top.c:845
      #8 0x5650d7ceeefe in deliver_event /home/matt/src/linux/tools/perf/builtin-top.c:1208
      #9 0x5650d7fdb51b in do_flush util/ordered-events.c:245
      #10 0x5650d7fdb51b in __ordered_events__flush util/ordered-events.c:324
      raspberrypi#11 0x5650d7ced743 in process_thread /home/matt/src/linux/tools/perf/builtin-top.c:1120
      raspberrypi#12 0x7f757ef1f133 in start_thread nptl/pthread_create.c:442
      raspberrypi#13 0x7f757ef9f7db in clone3 ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

When updating hist maps it's also necessary to update the hist symbol
reference because the old one gets freed in map__put().

While this bug was probably introduced with 5c24b67 ("perf
tools: Replace map->referenced & maps->removed_maps with map->refcnt"),
the symbol objects were leaked until c087e94 ("perf machine:
Fix refcount usage when processing PERF_RECORD_KSYMBOL") was merged so
the bug was masked.

Fixes: c087e94 ("perf machine: Fix refcount usage when processing PERF_RECORD_KSYMBOL")
Reported-by: Yunzhao Li <[email protected]>
Signed-off-by: Matt Fleming (Cloudflare) <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: [email protected]
Cc: Namhyung Kim <[email protected]>
Cc: Riccardo Mancini <[email protected]>
Cc: [email protected] # v5.13+
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request Oct 11, 2024
commit 9af2efe upstream.

The fields in the hist_entry are filled on-demand which means they only
have meaningful values when relevant sort keys are used.

So if neither of 'dso' nor 'sym' sort keys are used, the map/symbols in
the hist entry can be garbage.  So it shouldn't access it
unconditionally.

I got a segfault, when I wanted to see cgroup profiles.

  $ sudo perf record -a --all-cgroups --synth=cgroup true

  $ sudo perf report -s cgroup

  Program received signal SIGSEGV, Segmentation fault.
  0x00005555557a8d90 in map__dso (map=0x0) at util/map.h:48
  48		return RC_CHK_ACCESS(map)->dso;
  (gdb) bt
  #0  0x00005555557a8d90 in map__dso (map=0x0) at util/map.h:48
  #1  0x00005555557aa39b in map__load (map=0x0) at util/map.c:344
  #2  0x00005555557aa592 in map__find_symbol (map=0x0, addr=140736115941088) at util/map.c:385
  #3  0x00005555557ef000 in hists__findnew_entry (hists=0x555556039d60, entry=0x7fffffffa4c0, al=0x7fffffffa8c0, sample_self=true)
      at util/hist.c:644
  #4  0x00005555557ef61c in __hists__add_entry (hists=0x555556039d60, al=0x7fffffffa8c0, sym_parent=0x0, bi=0x0, mi=0x0, ki=0x0,
      block_info=0x0, sample=0x7fffffffaa90, sample_self=true, ops=0x0) at util/hist.c:761
  #5  0x00005555557ef71f in hists__add_entry (hists=0x555556039d60, al=0x7fffffffa8c0, sym_parent=0x0, bi=0x0, mi=0x0, ki=0x0,
      sample=0x7fffffffaa90, sample_self=true) at util/hist.c:779
  #6  0x00005555557f00fb in iter_add_single_normal_entry (iter=0x7fffffffa900, al=0x7fffffffa8c0) at util/hist.c:1015
  #7  0x00005555557f09a7 in hist_entry_iter__add (iter=0x7fffffffa900, al=0x7fffffffa8c0, max_stack_depth=127, arg=0x7fffffffbce0)
      at util/hist.c:1260
  #8  0x00005555555ba7ce in process_sample_event (tool=0x7fffffffbce0, event=0x7ffff7c14128, sample=0x7fffffffaa90, evsel=0x555556039ad0,
      machine=0x5555560388e8) at builtin-report.c:334
  #9  0x00005555557b30c8 in evlist__deliver_sample (evlist=0x555556039010, tool=0x7fffffffbce0, event=0x7ffff7c14128,
      sample=0x7fffffffaa90, evsel=0x555556039ad0, machine=0x5555560388e8) at util/session.c:1232
  #10 0x00005555557b32bc in machines__deliver_event (machines=0x5555560388e8, evlist=0x555556039010, event=0x7ffff7c14128,
      sample=0x7fffffffaa90, tool=0x7fffffffbce0, file_offset=110888, file_path=0x555556038ff0 "perf.data") at util/session.c:1271
  raspberrypi#11 0x00005555557b3848 in perf_session__deliver_event (session=0x5555560386d0, event=0x7ffff7c14128, tool=0x7fffffffbce0,
      file_offset=110888, file_path=0x555556038ff0 "perf.data") at util/session.c:1354
  raspberrypi#12 0x00005555557affaf in ordered_events__deliver_event (oe=0x555556038e60, event=0x555556135aa0) at util/session.c:132
  raspberrypi#13 0x00005555557bb605 in do_flush (oe=0x555556038e60, show_progress=false) at util/ordered-events.c:245
  raspberrypi#14 0x00005555557bb95c in __ordered_events__flush (oe=0x555556038e60, how=OE_FLUSH__ROUND, timestamp=0) at util/ordered-events.c:324
  raspberrypi#15 0x00005555557bba46 in ordered_events__flush (oe=0x555556038e60, how=OE_FLUSH__ROUND) at util/ordered-events.c:342
  raspberrypi#16 0x00005555557b1b3b in perf_event__process_finished_round (tool=0x7fffffffbce0, event=0x7ffff7c15bb8, oe=0x555556038e60)
      at util/session.c:780
  raspberrypi#17 0x00005555557b3b27 in perf_session__process_user_event (session=0x5555560386d0, event=0x7ffff7c15bb8, file_offset=117688,
      file_path=0x555556038ff0 "perf.data") at util/session.c:1406

As you can see the entry->ms.map was NULL even if he->ms.map has a
value.  This is because 'sym' sort key is not given, so it cannot assume
whether he->ms.sym and entry->ms.sym is the same.  I only checked the
'sym' sort key here as it implies 'dso' behavior (so maps are the same).

Fixes: ac01c8c ("perf hist: Update hist symbol when updating maps")
Signed-off-by: Namhyung Kim <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Matt Fleming <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request Oct 18, 2024
…tion to perf_sched__replay()

[ Upstream commit c690786 ]

The start_work_mutex and work_done_wait_mutex are used only for the
'perf sched replay'. Put their initialization in perf_sched__replay () to
reduce unnecessary actions in other commands.

Simple functional testing:

  # perf sched record perf bench sched messaging
  # Running 'sched/messaging' benchmark:
  # 20 sender and receiver processes per group
  # 10 groups == 400 processes run

       Total time: 0.197 [sec]
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 14.952 MB perf.data (134165 samples) ]

  # perf sched replay
  run measurement overhead: 108 nsecs
  sleep measurement overhead: 65658 nsecs
  the run test took 999991 nsecs
  the sleep test took 1079324 nsecs
  nr_run_events:        42378
  nr_sleep_events:      43102
  nr_wakeup_events:     31852
  target-less wakeups:  17
  multi-target wakeups: 712
  task      0 (             swapper:         0), nr_events: 10451
  task      1 (             swapper:         1), nr_events: 3
  task      2 (             swapper:         2), nr_events: 1
  <SNIP>
  task    717 (     sched-messaging:     74483), nr_events: 152
  task    718 (     sched-messaging:     74484), nr_events: 1944
  task    719 (     sched-messaging:     74485), nr_events: 73
  task    720 (     sched-messaging:     74486), nr_events: 163
  task    721 (     sched-messaging:     74487), nr_events: 942
  task    722 (     sched-messaging:     74488), nr_events: 78
  task    723 (     sched-messaging:     74489), nr_events: 1090
  ------------------------------------------------------------
  #1  : 1366.507, ravg: 1366.51, cpu: 7682.70 / 7682.70
  #2  : 1410.072, ravg: 1370.86, cpu: 7723.88 / 7686.82
  #3  : 1396.296, ravg: 1373.41, cpu: 7568.20 / 7674.96
  #4  : 1381.019, ravg: 1374.17, cpu: 7531.81 / 7660.64
  #5  : 1393.826, ravg: 1376.13, cpu: 7725.25 / 7667.11
  #6  : 1401.581, ravg: 1378.68, cpu: 7594.82 / 7659.88
  #7  : 1381.337, ravg: 1378.94, cpu: 7371.22 / 7631.01
  #8  : 1373.842, ravg: 1378.43, cpu: 7894.92 / 7657.40
  #9  : 1364.697, ravg: 1377.06, cpu: 7324.91 / 7624.15
  #10 : 1363.613, ravg: 1375.72, cpu: 7209.55 / 7582.69
  # echo $?
  0

Signed-off-by: Yang Jihong <[email protected]>
Signed-off-by: Namhyung Kim <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Stable-dep-of: 1a5efc9 ("libsubcmd: Don't free the usage string")
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Oct 18, 2024
…f_sched__{lat|map|replay}()

[ Upstream commit bd2cdf2 ]

The curr_pid and cpu_last_switched are used only for the
'perf sched replay/latency/map'. Put their initialization in
perf_sched__{lat|map|replay () to reduce unnecessary actions in other
commands.

Simple functional testing:

  # perf sched record perf bench sched messaging
  # Running 'sched/messaging' benchmark:
  # 20 sender and receiver processes per group
  # 10 groups == 400 processes run

       Total time: 0.209 [sec]
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 16.456 MB perf.data (147907 samples) ]

  # perf sched lat

   -------------------------------------------------------------------------------------------------------------------------------------------
    Task                  |   Runtime ms  | Switches | Avg delay ms    | Max delay ms    | Max delay start           | Max delay end          |
   -------------------------------------------------------------------------------------------------------------------------------------------
    sched-messaging:(401) |   2990.699 ms |    38705 | avg:   0.661 ms | max:  67.046 ms | max start: 456532.624830 s | max end: 456532.691876 s
    qemu-system-x86:(7)   |    179.764 ms |     2191 | avg:   0.152 ms | max:  21.857 ms | max start: 456532.576434 s | max end: 456532.598291 s
    sshd:48125            |      0.522 ms |        2 | avg:   0.037 ms | max:   0.046 ms | max start: 456532.514610 s | max end: 456532.514656 s
  <SNIP>
    ksoftirqd/11:82       |      0.063 ms |        1 | avg:   0.005 ms | max:   0.005 ms | max start: 456532.769366 s | max end: 456532.769371 s
    kworker/9:0-mm_:34624 |      0.233 ms |       20 | avg:   0.004 ms | max:   0.007 ms | max start: 456532.690804 s | max end: 456532.690812 s
    migration/13:93       |      0.000 ms |        1 | avg:   0.004 ms | max:   0.004 ms | max start: 456532.512669 s | max end: 456532.512674 s
   -----------------------------------------------------------------------------------------------------------------
    TOTAL:                |   3180.750 ms |    41368 |
   ---------------------------------------------------

  # echo $?
  0

  # perf sched map
    *A0                                                               456532.510141 secs A0 => migration/0:15
    *.                                                                456532.510171 secs .  => swapper:0
     .  *B0                                                           456532.510261 secs B0 => migration/1:21
     .  *.                                                            456532.510279 secs
  <SNIP>
     L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7 *L7  .   .   .   .    456532.785979 secs
     L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7 *L7  .   .   .    456532.786054 secs
     L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7 *L7  .   .    456532.786127 secs
     L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7 *L7  .    456532.786197 secs
     L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7 *L7   456532.786270 secs
  # echo $?
  0

  # perf sched replay
  run measurement overhead: 108 nsecs
  sleep measurement overhead: 66473 nsecs
  the run test took 1000002 nsecs
  the sleep test took 1082686 nsecs
  nr_run_events:        49334
  nr_sleep_events:      50054
  nr_wakeup_events:     34701
  target-less wakeups:  165
  multi-target wakeups: 766
  task      0 (             swapper:         0), nr_events: 15419
  task      1 (             swapper:         1), nr_events: 1
  task      2 (             swapper:         2), nr_events: 1
  <SNIP>
  task    715 (     sched-messaging:    110248), nr_events: 1438
  task    716 (     sched-messaging:    110249), nr_events: 512
  task    717 (     sched-messaging:    110250), nr_events: 500
  task    718 (     sched-messaging:    110251), nr_events: 537
  task    719 (     sched-messaging:    110252), nr_events: 823
  ------------------------------------------------------------
  #1  : 1325.288, ravg: 1325.29, cpu: 7823.35 / 7823.35
  #2  : 1363.606, ravg: 1329.12, cpu: 7655.53 / 7806.56
  #3  : 1349.494, ravg: 1331.16, cpu: 7544.80 / 7780.39
  #4  : 1311.488, ravg: 1329.19, cpu: 7495.13 / 7751.86
  #5  : 1309.902, ravg: 1327.26, cpu: 7266.65 / 7703.34
  #6  : 1309.535, ravg: 1325.49, cpu: 7843.86 / 7717.39
  #7  : 1316.482, ravg: 1324.59, cpu: 7854.41 / 7731.09
  #8  : 1366.604, ravg: 1328.79, cpu: 7955.81 / 7753.57
  #9  : 1326.286, ravg: 1328.54, cpu: 7466.86 / 7724.90
  #10 : 1356.653, ravg: 1331.35, cpu: 7566.60 / 7709.07
  # echo $?
  0

Signed-off-by: Yang Jihong <[email protected]>
Signed-off-by: Namhyung Kim <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Stable-dep-of: 1a5efc9 ("libsubcmd: Don't free the usage string")
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Oct 18, 2024
[ Upstream commit d1bc560 ]

Add nested locking with I_MUTEX_XATTR subclass to avoid lockdep warning
while handling xattr inode on file open syscall at ext4_xattr_inode_iget.

Backtrace
EXT4-fs (loop0): Ignoring removed oldalloc option
======================================================
WARNING: possible circular locking dependency detected
5.10.0-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor543/2794 is trying to acquire lock:
ffff8880215e1a48 (&ea_inode->i_rwsem#7/1){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:782 [inline]
ffff8880215e1a48 (&ea_inode->i_rwsem#7/1){+.+.}-{3:3}, at: ext4_xattr_inode_iget+0x42a/0x5c0 fs/ext4/xattr.c:425

but task is already holding lock:
ffff8880215e3278 (&ei->i_data_sem/3){++++}-{3:3}, at: ext4_setattr+0x136d/0x19c0 fs/ext4/inode.c:5559

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&ei->i_data_sem/3){++++}-{3:3}:
       lock_acquire+0x197/0x480 kernel/locking/lockdep.c:5566
       down_write+0x93/0x180 kernel/locking/rwsem.c:1564
       ext4_update_i_disksize fs/ext4/ext4.h:3267 [inline]
       ext4_xattr_inode_write fs/ext4/xattr.c:1390 [inline]
       ext4_xattr_inode_lookup_create fs/ext4/xattr.c:1538 [inline]
       ext4_xattr_set_entry+0x331a/0x3d80 fs/ext4/xattr.c:1662
       ext4_xattr_ibody_set+0x124/0x390 fs/ext4/xattr.c:2228
       ext4_xattr_set_handle+0xc27/0x14e0 fs/ext4/xattr.c:2385
       ext4_xattr_set+0x219/0x390 fs/ext4/xattr.c:2498
       ext4_xattr_user_set+0xc9/0xf0 fs/ext4/xattr_user.c:40
       __vfs_setxattr+0x404/0x450 fs/xattr.c:177
       __vfs_setxattr_noperm+0x11d/0x4f0 fs/xattr.c:208
       __vfs_setxattr_locked+0x1f9/0x210 fs/xattr.c:266
       vfs_setxattr+0x112/0x2c0 fs/xattr.c:283
       setxattr+0x1db/0x3e0 fs/xattr.c:548
       path_setxattr+0x15a/0x240 fs/xattr.c:567
       __do_sys_setxattr fs/xattr.c:582 [inline]
       __se_sys_setxattr fs/xattr.c:578 [inline]
       __x64_sys_setxattr+0xc5/0xe0 fs/xattr.c:578
       do_syscall_64+0x6d/0xa0 arch/x86/entry/common.c:62
       entry_SYSCALL_64_after_hwframe+0x61/0xcb

-> #0 (&ea_inode->i_rwsem#7/1){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:2988 [inline]
       check_prevs_add kernel/locking/lockdep.c:3113 [inline]
       validate_chain+0x1695/0x58f0 kernel/locking/lockdep.c:3729
       __lock_acquire+0x12fd/0x20d0 kernel/locking/lockdep.c:4955
       lock_acquire+0x197/0x480 kernel/locking/lockdep.c:5566
       down_write+0x93/0x180 kernel/locking/rwsem.c:1564
       inode_lock include/linux/fs.h:782 [inline]
       ext4_xattr_inode_iget+0x42a/0x5c0 fs/ext4/xattr.c:425
       ext4_xattr_inode_get+0x138/0x410 fs/ext4/xattr.c:485
       ext4_xattr_move_to_block fs/ext4/xattr.c:2580 [inline]
       ext4_xattr_make_inode_space fs/ext4/xattr.c:2682 [inline]
       ext4_expand_extra_isize_ea+0xe70/0x1bb0 fs/ext4/xattr.c:2774
       __ext4_expand_extra_isize+0x304/0x3f0 fs/ext4/inode.c:5898
       ext4_try_to_expand_extra_isize fs/ext4/inode.c:5941 [inline]
       __ext4_mark_inode_dirty+0x591/0x810 fs/ext4/inode.c:6018
       ext4_setattr+0x1400/0x19c0 fs/ext4/inode.c:5562
       notify_change+0xbb6/0xe60 fs/attr.c:435
       do_truncate+0x1de/0x2c0 fs/open.c:64
       handle_truncate fs/namei.c:2970 [inline]
       do_open fs/namei.c:3311 [inline]
       path_openat+0x29f3/0x3290 fs/namei.c:3425
       do_filp_open+0x20b/0x450 fs/namei.c:3452
       do_sys_openat2+0x124/0x460 fs/open.c:1207
       do_sys_open fs/open.c:1223 [inline]
       __do_sys_open fs/open.c:1231 [inline]
       __se_sys_open fs/open.c:1227 [inline]
       __x64_sys_open+0x221/0x270 fs/open.c:1227
       do_syscall_64+0x6d/0xa0 arch/x86/entry/common.c:62
       entry_SYSCALL_64_after_hwframe+0x61/0xcb

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ei->i_data_sem/3);
                               lock(&ea_inode->i_rwsem#7/1);
                               lock(&ei->i_data_sem/3);
  lock(&ea_inode->i_rwsem#7/1);

 *** DEADLOCK ***

5 locks held by syz-executor543/2794:
 #0: ffff888026fbc448 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x4a/0x2a0 fs/namespace.c:365
 #1: ffff8880215e3488 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: inode_lock include/linux/fs.h:782 [inline]
 #1: ffff8880215e3488 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: do_truncate+0x1cf/0x2c0 fs/open.c:62
 #2: ffff8880215e3310 (&ei->i_mmap_sem){++++}-{3:3}, at: ext4_setattr+0xec4/0x19c0 fs/ext4/inode.c:5519
 #3: ffff8880215e3278 (&ei->i_data_sem/3){++++}-{3:3}, at: ext4_setattr+0x136d/0x19c0 fs/ext4/inode.c:5559
 #4: ffff8880215e30c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:162 [inline]
 #4: ffff8880215e30c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:5938 [inline]
 #4: ffff8880215e30c8 (&ei->xattr_sem){++++}-{3:3}, at: __ext4_mark_inode_dirty+0x4fb/0x810 fs/ext4/inode.c:6018

stack backtrace:
CPU: 1 PID: 2794 Comm: syz-executor543 Not tainted 5.10.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x177/0x211 lib/dump_stack.c:118
 print_circular_bug+0x146/0x1b0 kernel/locking/lockdep.c:2002
 check_noncircular+0x2cc/0x390 kernel/locking/lockdep.c:2123
 check_prev_add kernel/locking/lockdep.c:2988 [inline]
 check_prevs_add kernel/locking/lockdep.c:3113 [inline]
 validate_chain+0x1695/0x58f0 kernel/locking/lockdep.c:3729
 __lock_acquire+0x12fd/0x20d0 kernel/locking/lockdep.c:4955
 lock_acquire+0x197/0x480 kernel/locking/lockdep.c:5566
 down_write+0x93/0x180 kernel/locking/rwsem.c:1564
 inode_lock include/linux/fs.h:782 [inline]
 ext4_xattr_inode_iget+0x42a/0x5c0 fs/ext4/xattr.c:425
 ext4_xattr_inode_get+0x138/0x410 fs/ext4/xattr.c:485
 ext4_xattr_move_to_block fs/ext4/xattr.c:2580 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2682 [inline]
 ext4_expand_extra_isize_ea+0xe70/0x1bb0 fs/ext4/xattr.c:2774
 __ext4_expand_extra_isize+0x304/0x3f0 fs/ext4/inode.c:5898
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5941 [inline]
 __ext4_mark_inode_dirty+0x591/0x810 fs/ext4/inode.c:6018
 ext4_setattr+0x1400/0x19c0 fs/ext4/inode.c:5562
 notify_change+0xbb6/0xe60 fs/attr.c:435
 do_truncate+0x1de/0x2c0 fs/open.c:64
 handle_truncate fs/namei.c:2970 [inline]
 do_open fs/namei.c:3311 [inline]
 path_openat+0x29f3/0x3290 fs/namei.c:3425
 do_filp_open+0x20b/0x450 fs/namei.c:3452
 do_sys_openat2+0x124/0x460 fs/open.c:1207
 do_sys_open fs/open.c:1223 [inline]
 __do_sys_open fs/open.c:1231 [inline]
 __se_sys_open fs/open.c:1227 [inline]
 __x64_sys_open+0x221/0x270 fs/open.c:1227
 do_syscall_64+0x6d/0xa0 arch/x86/entry/common.c:62
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f0cde4ea229
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 18 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd81d1c978 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0030656c69662f30 RCX: 00007f0cde4ea229
RDX: 0000000000000089 RSI: 00000000000a0a00 RDI: 00000000200001c0
RBP: 2f30656c69662f2e R08: 0000000000208000 R09: 0000000000208000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd81d1c9c0
R13: 00007ffd81d1ca00 R14: 0000000000080000 R15: 0000000000000003
EXT4-fs error (device loop0): ext4_expand_extra_isize_ea:2730: inode raspberrypi#13: comm syz-executor543: corrupted in-inode xattr

Signed-off-by: Wojciech Gładysz <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Oct 18, 2024
[ Upstream commit a848c29 ]

On the node of an NFS client, some files saved in the mountpoint of the
NFS server were copied to another location of the same NFS server.
Accidentally, the nfs42_complete_copies() got a NULL-pointer dereference
crash with the following syslog:

[232064.838881] NFSv4: state recovery failed for open file nfs/pvc-12b5200d-cd0f-46a3-b9f0-af8f4fe0ef64.qcow2, error = -116
[232064.839360] NFSv4: state recovery failed for open file nfs/pvc-12b5200d-cd0f-46a3-b9f0-af8f4fe0ef64.qcow2, error = -116
[232066.588183] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000058
[232066.588586] Mem abort info:
[232066.588701]   ESR = 0x0000000096000007
[232066.588862]   EC = 0x25: DABT (current EL), IL = 32 bits
[232066.589084]   SET = 0, FnV = 0
[232066.589216]   EA = 0, S1PTW = 0
[232066.589340]   FSC = 0x07: level 3 translation fault
[232066.589559] Data abort info:
[232066.589683]   ISV = 0, ISS = 0x00000007
[232066.589842]   CM = 0, WnR = 0
[232066.589967] user pgtable: 64k pages, 48-bit VAs, pgdp=00002000956ff400
[232066.590231] [0000000000000058] pgd=08001100ae100003, p4d=08001100ae100003, pud=08001100ae100003, pmd=08001100b3c00003, pte=0000000000000000
[232066.590757] Internal error: Oops: 96000007 [#1] SMP
[232066.590958] Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm vhost_net vhost vhost_iotlb tap tun ipt_rpfilter xt_multiport ip_set_hash_ip ip_set_hash_net xfrm_interface xfrm6_tunnel tunnel4 tunnel6 esp4 ah4 wireguard libcurve25519_generic veth xt_addrtype xt_set nf_conntrack_netlink ip_set_hash_ipportnet ip_set_hash_ipportip ip_set_bitmap_port ip_set_hash_ipport dummy ip_set ip_vs_sh ip_vs_wrr ip_vs_rr ip_vs iptable_filter sch_ingress nfnetlink_cttimeout vport_gre ip_gre ip_tunnel gre vport_geneve geneve vport_vxlan vxlan ip6_udp_tunnel udp_tunnel openvswitch nf_conncount dm_round_robin dm_service_time dm_multipath xt_nat xt_MASQUERADE nft_chain_nat nf_nat xt_mark xt_conntrack xt_comment nft_compat nft_counter nf_tables nfnetlink ocfs2 ocfs2_nodemanager ocfs2_stackglue iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ipmi_ssif nbd overlay 8021q garp mrp bonding tls rfkill sunrpc ext4 mbcache jbd2
[232066.591052]  vfat fat cas_cache cas_disk ses enclosure scsi_transport_sas sg acpi_ipmi ipmi_si ipmi_devintf ipmi_msghandler ip_tables vfio_pci vfio_pci_core vfio_virqfd vfio_iommu_type1 vfio dm_mirror dm_region_hash dm_log dm_mod nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 br_netfilter bridge stp llc fuse xfs libcrc32c ast drm_vram_helper qla2xxx drm_kms_helper syscopyarea crct10dif_ce sysfillrect ghash_ce sysimgblt sha2_ce fb_sys_fops cec sha256_arm64 sha1_ce drm_ttm_helper ttm nvme_fc igb sbsa_gwdt nvme_fabrics drm nvme_core i2c_algo_bit i40e scsi_transport_fc megaraid_sas aes_neon_bs
[232066.596953] CPU: 6 PID: 4124696 Comm: 10.253.166.125- Kdump: loaded Not tainted 5.15.131-9.cl9_ocfs2.aarch64 #1
[232066.597356] Hardware name: Great Wall .\x93\x8e...RF6260 V5/GWMSSE2GL1T, BIOS T656FBE_V3.0.18 2024-01-06
[232066.597721] pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[232066.598034] pc : nfs4_reclaim_open_state+0x220/0x800 [nfsv4]
[232066.598327] lr : nfs4_reclaim_open_state+0x12c/0x800 [nfsv4]
[232066.598595] sp : ffff8000f568fc70
[232066.598731] x29: ffff8000f568fc70 x28: 0000000000001000 x27: ffff21003db33000
[232066.599030] x26: ffff800005521ae0 x25: ffff0100f98fa3f0 x24: 0000000000000001
[232066.599319] x23: ffff800009920008 x22: ffff21003db33040 x21: ffff21003db33050
[232066.599628] x20: ffff410172fe9e40 x19: ffff410172fe9e00 x18: 0000000000000000
[232066.599914] x17: 0000000000000000 x16: 0000000000000004 x15: 0000000000000000
[232066.600195] x14: 0000000000000000 x13: ffff800008e685a8 x12: 00000000eac0c6e6
[232066.600498] x11: 0000000000000000 x10: 0000000000000008 x9 : ffff8000054e5828
[232066.600784] x8 : 00000000ffffffbf x7 : 0000000000000001 x6 : 000000000a9eb14a
[232066.601062] x5 : 0000000000000000 x4 : ffff70ff8a14a800 x3 : 0000000000000058
[232066.601348] x2 : 0000000000000001 x1 : 54dce46366daa6c6 x0 : 0000000000000000
[232066.601636] Call trace:
[232066.601749]  nfs4_reclaim_open_state+0x220/0x800 [nfsv4]
[232066.601998]  nfs4_do_reclaim+0x1b8/0x28c [nfsv4]
[232066.602218]  nfs4_state_manager+0x928/0x10f0 [nfsv4]
[232066.602455]  nfs4_run_state_manager+0x78/0x1b0 [nfsv4]
[232066.602690]  kthread+0x110/0x114
[232066.602830]  ret_from_fork+0x10/0x20
[232066.602985] Code: 1400000d f9403f20 f9402e61 91016003 (f9402c00)
[232066.603284] SMP: stopping secondary CPUs
[232066.606936] Starting crashdump kernel...
[232066.607146] Bye!

Analysing the vmcore, we know that nfs4_copy_state listed by destination
nfs_server->ss_copies was added by the field copies in handle_async_copy(),
and we found a waiting copy process with the stack as:
PID: 3511963  TASK: ffff710028b47e00  CPU: 0   COMMAND: "cp"
 #0 [ffff8001116ef740] __switch_to at ffff8000081b92f4
 #1 [ffff8001116ef760] __schedule at ffff800008dd0650
 #2 [ffff8001116ef7c0] schedule at ffff800008dd0a00
 #3 [ffff8001116ef7e0] schedule_timeout at ffff800008dd6aa0
 #4 [ffff8001116ef860] __wait_for_common at ffff800008dd166c
 #5 [ffff8001116ef8e0] wait_for_completion_interruptible at ffff800008dd1898
 #6 [ffff8001116ef8f0] handle_async_copy at ffff8000055142f4 [nfsv4]
 #7 [ffff8001116ef970] _nfs42_proc_copy at ffff8000055147c8 [nfsv4]
 #8 [ffff8001116efa80] nfs42_proc_copy at ffff800005514cf0 [nfsv4]
 #9 [ffff8001116efc50] __nfs4_copy_file_range.constprop.0 at ffff8000054ed694 [nfsv4]

The NULL-pointer dereference was due to nfs42_complete_copies() listed
the nfs_server->ss_copies by the field ss_copies of nfs4_copy_state.
So the nfs4_copy_state address ffff0100f98fa3f0 was offset by 0x10 and
the data accessed through this pointer was also incorrect. Generally,
the ordered list nfs4_state_owner->so_states indicate open(O_RDWR) or
open(O_WRITE) states are reclaimed firstly by nfs4_reclaim_open_state().
When destination state reclaim is failed with NFS_STATE_RECOVERY_FAILED
and copies are not deleted in nfs_server->ss_copies, the source state
may be passed to the nfs42_complete_copies() process earlier, resulting
in this crash scene finally. To solve this issue, we add a list_head
nfs_server->ss_src_copies for a server-to-server copy specially.

Fixes: 0e65a32 ("NFS: handle source server reboot")
Signed-off-by: Yanjun Zhang <[email protected]>
Reviewed-by: Trond Myklebust <[email protected]>
Signed-off-by: Anna Schumaker <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Oct 30, 2024
commit 348a198 upstream.

Luis has been reporting an assert failure when freeing an inode
cluster during inode inactivation for a while. The assert looks
like:

 XFS: Assertion failed: bp->b_flags & XBF_DONE, file: fs/xfs/xfs_trans_buf.c, line: 241
 ------------[ cut here ]------------
 kernel BUG at fs/xfs/xfs_message.c:102!
 Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
 CPU: 4 PID: 73 Comm: kworker/4:1 Not tainted 6.10.0-rc1 #4
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
 Workqueue: xfs-inodegc/loop5 xfs_inodegc_worker [xfs]
 RIP: 0010:assfail (fs/xfs/xfs_message.c:102) xfs
 RSP: 0018:ffff88810188f7f0 EFLAGS: 00010202
 RAX: 0000000000000000 RBX: ffff88816e748250 RCX: 1ffffffff844b0e7
 RDX: 0000000000000004 RSI: ffff88810188f558 RDI: ffffffffc2431fa0
 RBP: 1ffff11020311f01 R08: 0000000042431f9f R09: ffffed1020311e9b
 R10: ffff88810188f4df R11: ffffffffac725d70 R12: ffff88817a3f4000
 R13: ffff88812182f000 R14: ffff88810188f998 R15: ffffffffc2423f80
 FS:  0000000000000000(0000) GS:ffff8881c8400000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 000055fe9d0f109c CR3: 000000014426c002 CR4: 0000000000770ef0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400
 PKRU: 55555554
 Call Trace:
  <TASK>
 xfs_trans_read_buf_map (fs/xfs/xfs_trans_buf.c:241 (discriminator 1)) xfs
 xfs_imap_to_bp (fs/xfs/xfs_trans.h:210 fs/xfs/libxfs/xfs_inode_buf.c:138) xfs
 xfs_inode_item_precommit (fs/xfs/xfs_inode_item.c:145) xfs
 xfs_trans_run_precommits (fs/xfs/xfs_trans.c:931) xfs
 __xfs_trans_commit (fs/xfs/xfs_trans.c:966) xfs
 xfs_inactive_ifree (fs/xfs/xfs_inode.c:1811) xfs
 xfs_inactive (fs/xfs/xfs_inode.c:2013) xfs
 xfs_inodegc_worker (fs/xfs/xfs_icache.c:1841 fs/xfs/xfs_icache.c:1886) xfs
 process_one_work (kernel/workqueue.c:3231)
 worker_thread (kernel/workqueue.c:3306 (discriminator 2) kernel/workqueue.c:3393 (discriminator 2))
 kthread (kernel/kthread.c:389)
 ret_from_fork (arch/x86/kernel/process.c:147)
 ret_from_fork_asm (arch/x86/entry/entry_64.S:257)
  </TASK>

And occurs when the the inode precommit handlers is attempt to look
up the inode cluster buffer to attach the inode for writeback.

The trail of logic that I can reconstruct is as follows.

	1. the inode is clean when inodegc runs, so it is not
	   attached to a cluster buffer when precommit runs.

	2. #1 implies the inode cluster buffer may be clean and not
	   pinned by dirty inodes when inodegc runs.

	3. #2 implies that the inode cluster buffer can be reclaimed
	   by memory pressure at any time.

	4. The assert failure implies that the cluster buffer was
	   attached to the transaction, but not marked done. It had
	   been accessed earlier in the transaction, but not marked
	   done.

	5. #4 implies the cluster buffer has been invalidated (i.e.
	   marked stale).

	6. #5 implies that the inode cluster buffer was instantiated
	   uninitialised in the transaction in xfs_ifree_cluster(),
	   which only instantiates the buffers to invalidate them
	   and never marks them as done.

Given factors 1-3, this issue is highly dependent on timing and
environmental factors. Hence the issue can be very difficult to
reproduce in some situations, but highly reliable in others. Luis
has an environment where it can be reproduced easily by g/531 but,
OTOH, I've reproduced it only once in ~2000 cycles of g/531.

I think the fix is to have xfs_ifree_cluster() set the XBF_DONE flag
on the cluster buffers, even though they may not be initialised. The
reasons why I think this is safe are:

	1. A buffer cache lookup hit on a XBF_STALE buffer will
	   clear the XBF_DONE flag. Hence all future users of the
	   buffer know they have to re-initialise the contents
	   before use and mark it done themselves.

	2. xfs_trans_binval() sets the XFS_BLI_STALE flag, which
	   means the buffer remains locked until the journal commit
	   completes and the buffer is unpinned. Hence once marked
	   XBF_STALE/XFS_BLI_STALE by xfs_ifree_cluster(), the only
	   context that can access the freed buffer is the currently
	   running transaction.

	3. #2 implies that future buffer lookups in the currently
	   running transaction will hit the transaction match code
	   and not the buffer cache. Hence XBF_STALE and
	   XFS_BLI_STALE will not be cleared unless the transaction
	   initialises and logs the buffer with valid contents
	   again. At which point, the buffer will be marked marked
	   XBF_DONE again, so having XBF_DONE already set on the
	   stale buffer is a moot point.

	4. #2 also implies that any concurrent access to that
	   cluster buffer will block waiting on the buffer lock
	   until the inode cluster has been fully freed and is no
	   longer an active inode cluster buffer.

	5. #4 + #1 means that any future user of the disk range of
	   that buffer will always see the range of disk blocks
	   covered by the cluster buffer as not done, and hence must
	   initialise the contents themselves.

	6. Setting XBF_DONE in xfs_ifree_cluster() then means the
	   unlinked inode precommit code will see a XBF_DONE buffer
	   from the transaction match as it expects. It can then
	   attach the stale but newly dirtied inode to the stale
	   but newly dirtied cluster buffer without unexpected
	   failures. The stale buffer will then sail through the
	   journal and do the right thing with the attached stale
	   inode during unpin.

Hence the fix is just one line of extra code. The explanation of
why we have to set XBF_DONE in xfs_ifree_cluster, OTOH, is long and
complex....

Fixes: 82842fe ("xfs: fix AGF vs inode cluster buffer deadlock")
Signed-off-by: Dave Chinner <[email protected]>
Tested-by: Luis Chamberlain <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Darrick J. Wong <[email protected]>
Signed-off-by: Chandan Babu R <[email protected]>
Signed-off-by: Catherine Hoang <[email protected]>
Acked-by: Darrick J. Wong <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request Oct 30, 2024
commit 3d04139 upstream.

Syzkaller reported a lockdep splat:

  ============================================
  WARNING: possible recursive locking detected
  6.11.0-rc6-syzkaller-00019-g67784a74e258 #0 Not tainted
  --------------------------------------------
  syz-executor364/5113 is trying to acquire lock:
  ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
  ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328

  but task is already holding lock:
  ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
  ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(k-slock-AF_INET);
    lock(k-slock-AF_INET);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  7 locks held by syz-executor364/5113:
   #0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline]
   #0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0x153/0x1b10 net/mptcp/protocol.c:1806
   #1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline]
   #1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg_fastopen+0x11f/0x530 net/mptcp/protocol.c:1727
   #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
   #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
   #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x5f/0x1b80 net/ipv4/ip_output.c:470
   #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
   #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
   #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x45f/0x1390 net/ipv4/ip_output.c:228
   #4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
   #4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x33b/0x15b0 net/core/dev.c:6104
   #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
   #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
   #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0x230/0x5f0 net/ipv4/ip_input.c:232
   #6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
   #6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328

  stack backtrace:
  CPU: 0 UID: 0 PID: 5113 Comm: syz-executor364 Not tainted 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
  Call Trace:
   <IRQ>
   __dump_stack lib/dump_stack.c:93 [inline]
   dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
   check_deadlock kernel/locking/lockdep.c:3061 [inline]
   validate_chain+0x15d3/0x5900 kernel/locking/lockdep.c:3855
   __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142
   lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
   __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
   _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
   spin_lock include/linux/spinlock.h:351 [inline]
   sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328
   mptcp_sk_clone_init+0x32/0x13c0 net/mptcp/protocol.c:3279
   subflow_syn_recv_sock+0x931/0x1920 net/mptcp/subflow.c:874
   tcp_check_req+0xfe4/0x1a20 net/ipv4/tcp_minisocks.c:853
   tcp_v4_rcv+0x1c3e/0x37f0 net/ipv4/tcp_ipv4.c:2267
   ip_protocol_deliver_rcu+0x22e/0x440 net/ipv4/ip_input.c:205
   ip_local_deliver_finish+0x341/0x5f0 net/ipv4/ip_input.c:233
   NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314
   NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314
   __netif_receive_skb_one_core net/core/dev.c:5661 [inline]
   __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5775
   process_backlog+0x662/0x15b0 net/core/dev.c:6108
   __napi_poll+0xcb/0x490 net/core/dev.c:6772
   napi_poll net/core/dev.c:6841 [inline]
   net_rx_action+0x89b/0x1240 net/core/dev.c:6963
   handle_softirqs+0x2c4/0x970 kernel/softirq.c:554
   do_softirq+0x11b/0x1e0 kernel/softirq.c:455
   </IRQ>
   <TASK>
   __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382
   local_bh_enable include/linux/bottom_half.h:33 [inline]
   rcu_read_unlock_bh include/linux/rcupdate.h:908 [inline]
   __dev_queue_xmit+0x1763/0x3e90 net/core/dev.c:4450
   dev_queue_xmit include/linux/netdevice.h:3105 [inline]
   neigh_hh_output include/net/neighbour.h:526 [inline]
   neigh_output include/net/neighbour.h:540 [inline]
   ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:235
   ip_local_out net/ipv4/ip_output.c:129 [inline]
   __ip_queue_xmit+0x118c/0x1b80 net/ipv4/ip_output.c:535
   __tcp_transmit_skb+0x2544/0x3b30 net/ipv4/tcp_output.c:1466
   tcp_rcv_synsent_state_process net/ipv4/tcp_input.c:6542 [inline]
   tcp_rcv_state_process+0x2c32/0x4570 net/ipv4/tcp_input.c:6729
   tcp_v4_do_rcv+0x77d/0xc70 net/ipv4/tcp_ipv4.c:1934
   sk_backlog_rcv include/net/sock.h:1111 [inline]
   __release_sock+0x214/0x350 net/core/sock.c:3004
   release_sock+0x61/0x1f0 net/core/sock.c:3558
   mptcp_sendmsg_fastopen+0x1ad/0x530 net/mptcp/protocol.c:1733
   mptcp_sendmsg+0x1884/0x1b10 net/mptcp/protocol.c:1812
   sock_sendmsg_nosec net/socket.c:730 [inline]
   __sock_sendmsg+0x1a6/0x270 net/socket.c:745
   ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597
   ___sys_sendmsg net/socket.c:2651 [inline]
   __sys_sendmmsg+0x3b2/0x740 net/socket.c:2737
   __do_sys_sendmmsg net/socket.c:2766 [inline]
   __se_sys_sendmmsg net/socket.c:2763 [inline]
   __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763
   do_syscall_x64 arch/x86/entry/common.c:52 [inline]
   do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
  RIP: 0033:0x7f04fb13a6b9
  Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 01 1a 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
  RSP: 002b:00007ffd651f42d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
  RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f04fb13a6b9
  RDX: 0000000000000001 RSI: 0000000020000d00 RDI: 0000000000000004
  RBP: 00007ffd651f4310 R08: 0000000000000001 R09: 0000000000000001
  R10: 0000000020000080 R11: 0000000000000246 R12: 00000000000f4240
  R13: 00007f04fb187449 R14: 00007ffd651f42f4 R15: 00007ffd651f4300
   </TASK>

As noted by Cong Wang, the splat is false positive, but the code
path leading to the report is an unexpected one: a client is
attempting an MPC handshake towards the in-kernel listener created
by the in-kernel PM for a port based signal endpoint.

Such connection will be never accepted; many of them can make the
listener queue full and preventing the creation of MPJ subflow via
such listener - its intended role.

Explicitly detect this scenario at initial-syn time and drop the
incoming MPC request.

Fixes: 1729cf1 ("mptcp: create the listening socket for new port")
Cc: [email protected]
Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=f4aacdfef2c6a6529c3e
Cc: Cong Wang <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>
Reviewed-by: Matthieu Baerts (NGI0) <[email protected]>
Reviewed-by: Mat Martineau <[email protected]>
Signed-off-by: Matthieu Baerts (NGI0) <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
[ Conflicts in mib.[ch], because commit 6982826 ("mptcp: fallback
  to TCP after SYN+MPC drops"), and commit 27069e7 ("mptcp: disable
  active MPTCP in case of blackhole") are linked to new features, not
  available in this version. Resolving the conflicts is easy, simply
  adding the new lines declaring the new "endpoint attempt" MIB entry. ]
Signed-off-by: Matthieu Baerts (NGI0) <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request Jan 4, 2025
[ Upstream commit fd7b4f9 ]

When CONFIG_KASAN_SW_TAGS and CONFIG_KASAN_STACK are enabled, the
object_is_on_stack() function may produce incorrect results due to the
presence of tags in the obj pointer, while the stack pointer does not have
tags.  This discrepancy can lead to incorrect stack object detection and
subsequently trigger warnings if CONFIG_DEBUG_OBJECTS is also enabled.

Example of the warning:

ODEBUG: object 3eff800082ea7bb0 is NOT on stack ffff800082ea0000, but annotated.
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1 at lib/debugobjects.c:557 __debug_object_init+0x330/0x364
Modules linked in:
CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.0-rc5 #4
Hardware name: linux,dummy-virt (DT)
pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __debug_object_init+0x330/0x364
lr : __debug_object_init+0x330/0x364
sp : ffff800082ea7b40
x29: ffff800082ea7b40 x28: 98ff0000c0164518 x27: 98ff0000c0164534
x26: ffff800082d93ec8 x25: 0000000000000001 x24: 1cff0000c00172a0
x23: 0000000000000000 x22: ffff800082d93ed0 x21: ffff800081a24418
x20: 3eff800082ea7bb0 x19: efff800000000000 x18: 0000000000000000
x17: 00000000000000ff x16: 0000000000000047 x15: 206b63617473206e
x14: 0000000000000018 x13: ffff800082ea7780 x12: 0ffff800082ea78e
x11: 0ffff800082ea790 x10: 0ffff800082ea79d x9 : 34d77febe173e800
x8 : 34d77febe173e800 x7 : 0000000000000001 x6 : 0000000000000001
x5 : feff800082ea74b8 x4 : ffff800082870a90 x3 : ffff80008018d3c4
x2 : 0000000000000001 x1 : ffff800082858810 x0 : 0000000000000050
Call trace:
 __debug_object_init+0x330/0x364
 debug_object_init_on_stack+0x30/0x3c
 schedule_hrtimeout_range_clock+0xac/0x26c
 schedule_hrtimeout+0x1c/0x30
 wait_task_inactive+0x1d4/0x25c
 kthread_bind_mask+0x28/0x98
 init_rescuer+0x1e8/0x280
 workqueue_init+0x1a0/0x3cc
 kernel_init_freeable+0x118/0x200
 kernel_init+0x28/0x1f0
 ret_from_fork+0x10/0x20
---[ end trace 0000000000000000 ]---
ODEBUG: object 3eff800082ea7bb0 is NOT on stack ffff800082ea0000, but annotated.
------------[ cut here ]------------

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Qun-Wei Lin <[email protected]>
Cc: Andrew Yang <[email protected]>
Cc: AngeloGioacchino Del Regno <[email protected]>
Cc: Casper Li <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Chinwen Chang <[email protected]>
Cc: Kent Overstreet <[email protected]>
Cc: Matthias Brugger <[email protected]>
Cc: Pasha Tatashin <[email protected]>
Cc: Shakeel Butt <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
[ Resolve line conflicts ]
Signed-off-by: Wenshan Lan <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Jan 10, 2025
…nt message

commit cddc76b upstream.

Address a bug in the kernel that triggers a "sleeping function called from
invalid context" warning when /sys/kernel/debug/kmemleak is printed under
specific conditions:
- CONFIG_PREEMPT_RT=y
- Set SELinux as the LSM for the system
- Set kptr_restrict to 1
- kmemleak buffer contains at least one item

BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 136, name: cat
preempt_count: 1, expected: 0
RCU nest depth: 2, expected: 2
6 locks held by cat/136:
 #0: ffff32e64bcbf950 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb8/0xe30
 #1: ffffafe6aaa9dea0 (scan_mutex){+.+.}-{3:3}, at: kmemleak_seq_start+0x34/0x128
 #3: ffff32e6546b1cd0 (&object->lock){....}-{2:2}, at: kmemleak_seq_show+0x3c/0x1e0
 #4: ffffafe6aa8d8560 (rcu_read_lock){....}-{1:2}, at: has_ns_capability_noaudit+0x8/0x1b0
 #5: ffffafe6aabbc0f8 (notif_lock){+.+.}-{2:2}, at: avc_compute_av+0xc4/0x3d0
irq event stamp: 136660
hardirqs last  enabled at (136659): [<ffffafe6a80fd7a0>] _raw_spin_unlock_irqrestore+0xa8/0xd8
hardirqs last disabled at (136660): [<ffffafe6a80fd85c>] _raw_spin_lock_irqsave+0x8c/0xb0
softirqs last  enabled at (0): [<ffffafe6a5d50b28>] copy_process+0x11d8/0x3df8
softirqs last disabled at (0): [<0000000000000000>] 0x0
Preemption disabled at:
[<ffffafe6a6598a4c>] kmemleak_seq_show+0x3c/0x1e0
CPU: 1 UID: 0 PID: 136 Comm: cat Tainted: G            E      6.11.0-rt7+ raspberrypi#34
Tainted: [E]=UNSIGNED_MODULE
Hardware name: linux,dummy-virt (DT)
Call trace:
 dump_backtrace+0xa0/0x128
 show_stack+0x1c/0x30
 dump_stack_lvl+0xe8/0x198
 dump_stack+0x18/0x20
 rt_spin_lock+0x8c/0x1a8
 avc_perm_nonode+0xa0/0x150
 cred_has_capability.isra.0+0x118/0x218
 selinux_capable+0x50/0x80
 security_capable+0x7c/0xd0
 has_ns_capability_noaudit+0x94/0x1b0
 has_capability_noaudit+0x20/0x30
 restricted_pointer+0x21c/0x4b0
 pointer+0x298/0x760
 vsnprintf+0x330/0xf70
 seq_printf+0x178/0x218
 print_unreferenced+0x1a4/0x2d0
 kmemleak_seq_show+0xd0/0x1e0
 seq_read_iter+0x354/0xe30
 seq_read+0x250/0x378
 full_proxy_read+0xd8/0x148
 vfs_read+0x190/0x918
 ksys_read+0xf0/0x1e0
 __arm64_sys_read+0x70/0xa8
 invoke_syscall.constprop.0+0xd4/0x1d8
 el0_svc+0x50/0x158
 el0t_64_sync+0x17c/0x180

%pS and %pK, in the same back trace line, are redundant, and %pS can void
%pK service in certain contexts.

%pS alone already provides the necessary information, and if it cannot
resolve the symbol, it falls back to printing the raw address voiding
the original intent behind the %pK.

Additionally, %pK requires a privilege check CAP_SYSLOG enforced through
the LSM, which can trigger a "sleeping function called from invalid
context" warning under RT_PREEMPT kernels when the check occurs in an
atomic context. This issue may also affect other LSMs.

This change avoids the unnecessary privilege check and resolves the
sleeping function warning without any loss of information.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 3a6f33d ("mm/kmemleak: use %pK to display kernel pointers in backtrace")
Signed-off-by: Alessandro Carminati <[email protected]>
Acked-by: Sebastian Andrzej Siewior <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
Cc: Clément Léger <[email protected]>
Cc: Alessandro Carminati <[email protected]>
Cc: Eric Chanudet <[email protected]>
Cc: Gabriele Paoloni <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Thomas Weißschuh <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request Jan 10, 2025
…le_direct_reclaim()

commit 6aaced5 upstream.

The task sometimes continues looping in throttle_direct_reclaim() because
allow_direct_reclaim(pgdat) keeps returning false.

 #0 [ffff80002cb6f8d0] __switch_to at ffff8000080095ac
 #1 [ffff80002cb6f900] __schedule at ffff800008abbd1c
 #2 [ffff80002cb6f990] schedule at ffff800008abc50c
 #3 [ffff80002cb6f9b0] throttle_direct_reclaim at ffff800008273550
 #4 [ffff80002cb6fa20] try_to_free_pages at ffff800008277b68
 #5 [ffff80002cb6fae0] __alloc_pages_nodemask at ffff8000082c4660
 #6 [ffff80002cb6fc50] alloc_pages_vma at ffff8000082e4a98
 #7 [ffff80002cb6fca0] do_anonymous_page at ffff80000829f5a8
 #8 [ffff80002cb6fce0] __handle_mm_fault at ffff8000082a5974
 #9 [ffff80002cb6fd90] handle_mm_fault at ffff8000082a5bd4

At this point, the pgdat contains the following two zones:

        NODE: 4  ZONE: 0  ADDR: ffff00817fffe540  NAME: "DMA32"
          SIZE: 20480  MIN/LOW/HIGH: 11/28/45
          VM_STAT:
                NR_FREE_PAGES: 359
        NR_ZONE_INACTIVE_ANON: 18813
          NR_ZONE_ACTIVE_ANON: 0
        NR_ZONE_INACTIVE_FILE: 50
          NR_ZONE_ACTIVE_FILE: 0
          NR_ZONE_UNEVICTABLE: 0
        NR_ZONE_WRITE_PENDING: 0
                     NR_MLOCK: 0
                    NR_BOUNCE: 0
                   NR_ZSPAGES: 0
            NR_FREE_CMA_PAGES: 0

        NODE: 4  ZONE: 1  ADDR: ffff00817fffec00  NAME: "Normal"
          SIZE: 8454144  PRESENT: 98304  MIN/LOW/HIGH: 68/166/264
          VM_STAT:
                NR_FREE_PAGES: 146
        NR_ZONE_INACTIVE_ANON: 94668
          NR_ZONE_ACTIVE_ANON: 3
        NR_ZONE_INACTIVE_FILE: 735
          NR_ZONE_ACTIVE_FILE: 78
          NR_ZONE_UNEVICTABLE: 0
        NR_ZONE_WRITE_PENDING: 0
                     NR_MLOCK: 0
                    NR_BOUNCE: 0
                   NR_ZSPAGES: 0
            NR_FREE_CMA_PAGES: 0

In allow_direct_reclaim(), while processing ZONE_DMA32, the sum of
inactive/active file-backed pages calculated in zone_reclaimable_pages()
based on the result of zone_page_state_snapshot() is zero.

Additionally, since this system lacks swap, the calculation of inactive/
active anonymous pages is skipped.

        crash> p nr_swap_pages
        nr_swap_pages = $1937 = {
          counter = 0
        }

As a result, ZONE_DMA32 is deemed unreclaimable and skipped, moving on to
the processing of the next zone, ZONE_NORMAL, despite ZONE_DMA32 having
free pages significantly exceeding the high watermark.

The problem is that the pgdat->kswapd_failures hasn't been incremented.

        crash> px ((struct pglist_data *) 0xffff00817fffe540)->kswapd_failures
        $1935 = 0x0

This is because the node deemed balanced.  The node balancing logic in
balance_pgdat() evaluates all zones collectively.  If one or more zones
(e.g., ZONE_DMA32) have enough free pages to meet their watermarks, the
entire node is deemed balanced.  This causes balance_pgdat() to exit early
before incrementing the kswapd_failures, as it considers the overall
memory state acceptable, even though some zones (like ZONE_NORMAL) remain
under significant pressure.


The patch ensures that zone_reclaimable_pages() includes free pages
(NR_FREE_PAGES) in its calculation when no other reclaimable pages are
available (e.g., file-backed or anonymous pages).  This change prevents
zones like ZONE_DMA32, which have sufficient free pages, from being
mistakenly deemed unreclaimable.  By doing so, the patch ensures proper
node balancing, avoids masking pressure on other zones like ZONE_NORMAL,
and prevents infinite loops in throttle_direct_reclaim() caused by
allow_direct_reclaim(pgdat) repeatedly returning false.


The kernel hangs due to a task stuck in throttle_direct_reclaim(), caused
by a node being incorrectly deemed balanced despite pressure in certain
zones, such as ZONE_NORMAL.  This issue arises from
zone_reclaimable_pages() returning 0 for zones without reclaimable file-
backed or anonymous pages, causing zones like ZONE_DMA32 with sufficient
free pages to be skipped.

The lack of swap or reclaimable pages results in ZONE_DMA32 being ignored
during reclaim, masking pressure in other zones.  Consequently,
pgdat->kswapd_failures remains 0 in balance_pgdat(), preventing fallback
mechanisms in allow_direct_reclaim() from being triggered, leading to an
infinite loop in throttle_direct_reclaim().

This patch modifies zone_reclaimable_pages() to account for free pages
(NR_FREE_PAGES) when no other reclaimable pages exist.  This ensures zones
with sufficient free pages are not skipped, enabling proper balancing and
reclaim behavior.

[[email protected]: coding-style cleanups]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 5a1c84b ("mm: remove reclaim and compaction retry approximations")
Signed-off-by: Seiji Nishikawa <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request Jan 26, 2025
[ Upstream commit 2c36880 ]

Attempt to enable IPsec packet offload in tunnel mode in debug kernel
generates the following kernel panic, which is happening due to two
issues:
1. In SA add section, the should be _bh() variant when marking SA mode.
2. There is not needed flush_workqueue in SA delete routine. It is not
needed as at this stage as it is removed from SADB and the running work
will be canceled later in SA free.

 =====================================================
 WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
 6.12.0+ #4 Not tainted
 -----------------------------------------------------
 charon/1337 [HC0[0]:SC0[4]:HE1:SE0] is trying to acquire:
 ffff88810f365020 (&xa->xa_lock#24){+.+.}-{3:3}, at: mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]

 and this task is already holding:
 ffff88813e0f0d48 (&x->lock){+.-.}-{3:3}, at: xfrm_state_delete+0x16/0x30
 which would create a new lock dependency:
  (&x->lock){+.-.}-{3:3} -> (&xa->xa_lock#24){+.+.}-{3:3}

 but this new dependency connects a SOFTIRQ-irq-safe lock:
  (&x->lock){+.-.}-{3:3}

 ... which became SOFTIRQ-irq-safe at:
   lock_acquire+0x1be/0x520
   _raw_spin_lock_bh+0x34/0x40
   xfrm_timer_handler+0x91/0xd70
   __hrtimer_run_queues+0x1dd/0xa60
   hrtimer_run_softirq+0x146/0x2e0
   handle_softirqs+0x266/0x860
   irq_exit_rcu+0x115/0x1a0
   sysvec_apic_timer_interrupt+0x6e/0x90
   asm_sysvec_apic_timer_interrupt+0x16/0x20
   default_idle+0x13/0x20
   default_idle_call+0x67/0xa0
   do_idle+0x2da/0x320
   cpu_startup_entry+0x50/0x60
   start_secondary+0x213/0x2a0
   common_startup_64+0x129/0x138

 to a SOFTIRQ-irq-unsafe lock:
  (&xa->xa_lock#24){+.+.}-{3:3}

 ... which became SOFTIRQ-irq-unsafe at:
 ...
   lock_acquire+0x1be/0x520
   _raw_spin_lock+0x2c/0x40
   xa_set_mark+0x70/0x110
   mlx5e_xfrm_add_state+0xe48/0x2290 [mlx5_core]
   xfrm_dev_state_add+0x3bb/0xd70
   xfrm_add_sa+0x2451/0x4a90
   xfrm_user_rcv_msg+0x493/0x880
   netlink_rcv_skb+0x12e/0x380
   xfrm_netlink_rcv+0x6d/0x90
   netlink_unicast+0x42f/0x740
   netlink_sendmsg+0x745/0xbe0
   __sock_sendmsg+0xc5/0x190
   __sys_sendto+0x1fe/0x2c0
   __x64_sys_sendto+0xdc/0x1b0
   do_syscall_64+0x6d/0x140
   entry_SYSCALL_64_after_hwframe+0x4b/0x53

 other info that might help us debug this:

  Possible interrupt unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&xa->xa_lock#24);
                                local_irq_disable();
                                lock(&x->lock);
                                lock(&xa->xa_lock#24);
   <Interrupt>
     lock(&x->lock);

  *** DEADLOCK ***

 2 locks held by charon/1337:
  #0: ffffffff87f8f858 (&net->xfrm.xfrm_cfg_mutex){+.+.}-{4:4}, at: xfrm_netlink_rcv+0x5e/0x90
  #1: ffff88813e0f0d48 (&x->lock){+.-.}-{3:3}, at: xfrm_state_delete+0x16/0x30

 the dependencies between SOFTIRQ-irq-safe lock and the holding lock:
 -> (&x->lock){+.-.}-{3:3} ops: 29 {
    HARDIRQ-ON-W at:
                     lock_acquire+0x1be/0x520
                     _raw_spin_lock_bh+0x34/0x40
                     xfrm_alloc_spi+0xc0/0xe60
                     xfrm_alloc_userspi+0x5f6/0xbc0
                     xfrm_user_rcv_msg+0x493/0x880
                     netlink_rcv_skb+0x12e/0x380
                     xfrm_netlink_rcv+0x6d/0x90
                     netlink_unicast+0x42f/0x740
                     netlink_sendmsg+0x745/0xbe0
                     __sock_sendmsg+0xc5/0x190
                     __sys_sendto+0x1fe/0x2c0
                     __x64_sys_sendto+0xdc/0x1b0
                     do_syscall_64+0x6d/0x140
                     entry_SYSCALL_64_after_hwframe+0x4b/0x53
    IN-SOFTIRQ-W at:
                     lock_acquire+0x1be/0x520
                     _raw_spin_lock_bh+0x34/0x40
                     xfrm_timer_handler+0x91/0xd70
                     __hrtimer_run_queues+0x1dd/0xa60
                     hrtimer_run_softirq+0x146/0x2e0
                     handle_softirqs+0x266/0x860
                     irq_exit_rcu+0x115/0x1a0
                     sysvec_apic_timer_interrupt+0x6e/0x90
                     asm_sysvec_apic_timer_interrupt+0x16/0x20
                     default_idle+0x13/0x20
                     default_idle_call+0x67/0xa0
                     do_idle+0x2da/0x320
                     cpu_startup_entry+0x50/0x60
                     start_secondary+0x213/0x2a0
                     common_startup_64+0x129/0x138
    INITIAL USE at:
                    lock_acquire+0x1be/0x520
                    _raw_spin_lock_bh+0x34/0x40
                    xfrm_alloc_spi+0xc0/0xe60
                    xfrm_alloc_userspi+0x5f6/0xbc0
                    xfrm_user_rcv_msg+0x493/0x880
                    netlink_rcv_skb+0x12e/0x380
                    xfrm_netlink_rcv+0x6d/0x90
                    netlink_unicast+0x42f/0x740
                    netlink_sendmsg+0x745/0xbe0
                    __sock_sendmsg+0xc5/0x190
                    __sys_sendto+0x1fe/0x2c0
                    __x64_sys_sendto+0xdc/0x1b0
                    do_syscall_64+0x6d/0x140
                    entry_SYSCALL_64_after_hwframe+0x4b/0x53
  }
  ... key      at: [<ffffffff87f9cd20>] __key.18+0x0/0x40

 the dependencies between the lock to be acquired
  and SOFTIRQ-irq-unsafe lock:
 -> (&xa->xa_lock#24){+.+.}-{3:3} ops: 9 {
    HARDIRQ-ON-W at:
                     lock_acquire+0x1be/0x520
                     _raw_spin_lock_bh+0x34/0x40
                     mlx5e_xfrm_add_state+0xc5b/0x2290 [mlx5_core]
                     xfrm_dev_state_add+0x3bb/0xd70
                     xfrm_add_sa+0x2451/0x4a90
                     xfrm_user_rcv_msg+0x493/0x880
                     netlink_rcv_skb+0x12e/0x380
                     xfrm_netlink_rcv+0x6d/0x90
                     netlink_unicast+0x42f/0x740
                     netlink_sendmsg+0x745/0xbe0
                     __sock_sendmsg+0xc5/0x190
                     __sys_sendto+0x1fe/0x2c0
                     __x64_sys_sendto+0xdc/0x1b0
                     do_syscall_64+0x6d/0x140
                     entry_SYSCALL_64_after_hwframe+0x4b/0x53
    SOFTIRQ-ON-W at:
                     lock_acquire+0x1be/0x520
                     _raw_spin_lock+0x2c/0x40
                     xa_set_mark+0x70/0x110
                     mlx5e_xfrm_add_state+0xe48/0x2290 [mlx5_core]
                     xfrm_dev_state_add+0x3bb/0xd70
                     xfrm_add_sa+0x2451/0x4a90
                     xfrm_user_rcv_msg+0x493/0x880
                     netlink_rcv_skb+0x12e/0x380
                     xfrm_netlink_rcv+0x6d/0x90
                     netlink_unicast+0x42f/0x740
                     netlink_sendmsg+0x745/0xbe0
                     __sock_sendmsg+0xc5/0x190
                     __sys_sendto+0x1fe/0x2c0
                     __x64_sys_sendto+0xdc/0x1b0
                     do_syscall_64+0x6d/0x140
                     entry_SYSCALL_64_after_hwframe+0x4b/0x53
    INITIAL USE at:
                    lock_acquire+0x1be/0x520
                    _raw_spin_lock_bh+0x34/0x40
                    mlx5e_xfrm_add_state+0xc5b/0x2290 [mlx5_core]
                    xfrm_dev_state_add+0x3bb/0xd70
                    xfrm_add_sa+0x2451/0x4a90
                    xfrm_user_rcv_msg+0x493/0x880
                    netlink_rcv_skb+0x12e/0x380
                    xfrm_netlink_rcv+0x6d/0x90
                    netlink_unicast+0x42f/0x740
                    netlink_sendmsg+0x745/0xbe0
                    __sock_sendmsg+0xc5/0x190
                    __sys_sendto+0x1fe/0x2c0
                    __x64_sys_sendto+0xdc/0x1b0
                    do_syscall_64+0x6d/0x140
                    entry_SYSCALL_64_after_hwframe+0x4b/0x53
  }
  ... key      at: [<ffffffffa078ff60>] __key.48+0x0/0xfffffffffff210a0 [mlx5_core]
  ... acquired at:
    __lock_acquire+0x30a0/0x5040
    lock_acquire+0x1be/0x520
    _raw_spin_lock_bh+0x34/0x40
    mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]
    xfrm_dev_state_delete+0x90/0x160
    __xfrm_state_delete+0x662/0xae0
    xfrm_state_delete+0x1e/0x30
    xfrm_del_sa+0x1c2/0x340
    xfrm_user_rcv_msg+0x493/0x880
    netlink_rcv_skb+0x12e/0x380
    xfrm_netlink_rcv+0x6d/0x90
    netlink_unicast+0x42f/0x740
    netlink_sendmsg+0x745/0xbe0
    __sock_sendmsg+0xc5/0x190
    __sys_sendto+0x1fe/0x2c0
    __x64_sys_sendto+0xdc/0x1b0
    do_syscall_64+0x6d/0x140
    entry_SYSCALL_64_after_hwframe+0x4b/0x53

 stack backtrace:
 CPU: 7 UID: 0 PID: 1337 Comm: charon Not tainted 6.12.0+ #4
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
 Call Trace:
  <TASK>
  dump_stack_lvl+0x74/0xd0
  check_irq_usage+0x12e8/0x1d90
  ? print_shortest_lock_dependencies_backwards+0x1b0/0x1b0
  ? check_chain_key+0x1bb/0x4c0
  ? __lockdep_reset_lock+0x180/0x180
  ? check_path.constprop.0+0x24/0x50
  ? mark_lock+0x108/0x2fb0
  ? print_circular_bug+0x9b0/0x9b0
  ? mark_lock+0x108/0x2fb0
  ? print_usage_bug.part.0+0x670/0x670
  ? check_prev_add+0x1c4/0x2310
  check_prev_add+0x1c4/0x2310
  __lock_acquire+0x30a0/0x5040
  ? lockdep_set_lock_cmp_fn+0x190/0x190
  ? lockdep_set_lock_cmp_fn+0x190/0x190
  lock_acquire+0x1be/0x520
  ? mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]
  ? lockdep_hardirqs_on_prepare+0x400/0x400
  ? __xfrm_state_delete+0x5f0/0xae0
  ? lock_downgrade+0x6b0/0x6b0
  _raw_spin_lock_bh+0x34/0x40
  ? mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]
  mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]
  xfrm_dev_state_delete+0x90/0x160
  __xfrm_state_delete+0x662/0xae0
  xfrm_state_delete+0x1e/0x30
  xfrm_del_sa+0x1c2/0x340
  ? xfrm_get_sa+0x250/0x250
  ? check_chain_key+0x1bb/0x4c0
  xfrm_user_rcv_msg+0x493/0x880
  ? copy_sec_ctx+0x270/0x270
  ? check_chain_key+0x1bb/0x4c0
  ? lockdep_set_lock_cmp_fn+0x190/0x190
  ? lockdep_set_lock_cmp_fn+0x190/0x190
  netlink_rcv_skb+0x12e/0x380
  ? copy_sec_ctx+0x270/0x270
  ? netlink_ack+0xd90/0xd90
  ? netlink_deliver_tap+0xcd/0xb60
  xfrm_netlink_rcv+0x6d/0x90
  netlink_unicast+0x42f/0x740
  ? netlink_attachskb+0x730/0x730
  ? lock_acquire+0x1be/0x520
  netlink_sendmsg+0x745/0xbe0
  ? netlink_unicast+0x740/0x740
  ? __might_fault+0xbb/0x170
  ? netlink_unicast+0x740/0x740
  __sock_sendmsg+0xc5/0x190
  ? fdget+0x163/0x1d0
  __sys_sendto+0x1fe/0x2c0
  ? __x64_sys_getpeername+0xb0/0xb0
  ? do_user_addr_fault+0x856/0xe30
  ? lock_acquire+0x1be/0x520
  ? __task_pid_nr_ns+0x117/0x410
  ? lock_downgrade+0x6b0/0x6b0
  __x64_sys_sendto+0xdc/0x1b0
  ? lockdep_hardirqs_on_prepare+0x284/0x400
  do_syscall_64+0x6d/0x140
  entry_SYSCALL_64_after_hwframe+0x4b/0x53
 RIP: 0033:0x7f7d31291ba4
 Code: 7d e8 89 4d d4 e8 4c 42 f7 ff 44 8b 4d d0 4c 8b 45 c8 89 c3 44 8b 55 d4 8b 7d e8 b8 2c 00 00 00 48 8b 55 d8 48 8b 75 e0 0f 05 <48> 3d 00 f0 ff ff 77 34 89 df 48 89 45 e8 e8 99 42 f7 ff 48 8b 45
 RSP: 002b:00007f7d2ccd94f0 EFLAGS: 00000297 ORIG_RAX: 000000000000002c
 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f7d31291ba4
 RDX: 0000000000000028 RSI: 00007f7d2ccd96a0 RDI: 000000000000000a
 RBP: 00007f7d2ccd9530 R08: 00007f7d2ccd9598 R09: 000000000000000c
 R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000028
 R13: 00007f7d2ccd9598 R14: 00007f7d2ccd96a0 R15: 00000000000000e1
  </TASK>

Fixes: 4c24272 ("net/mlx5e: Listen to ARP events to update IPsec L2 headers in tunnel mode")
Signed-off-by: Leon Romanovsky <[email protected]>
Signed-off-by: Tariq Toukan <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Jan 26, 2025
commit 9860370 upstream.

irq_chip functions may be called in raw spinlock context. Therefore, we
must also use a raw spinlock for our own internal locking.

This fixes the following lockdep splat:

[    5.349336] =============================
[    5.353349] [ BUG: Invalid wait context ]
[    5.357361] 6.13.0-rc5+ raspberrypi#69 Tainted: G        W
[    5.363031] -----------------------------
[    5.367045] kworker/u17:1/44 is trying to lock:
[    5.371587] ffffff88018b02c0 (&chip->gpio_lock){....}-{3:3}, at: xgpio_irq_unmask (drivers/gpio/gpio-xilinx.c:433 (discriminator 8))
[    5.380079] other info that might help us debug this:
[    5.385138] context-{5:5}
[    5.387762] 5 locks held by kworker/u17:1/44:
[    5.392123] #0: ffffff8800014958 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work (kernel/workqueue.c:3204)
[    5.402260] #1: ffffffc082fcbdd8 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work (kernel/workqueue.c:3205)
[    5.411528] #2: ffffff880172c900 (&dev->mutex){....}-{4:4}, at: __device_attach (drivers/base/dd.c:1006)
[    5.419929] #3: ffffff88039c8268 (request_class#2){+.+.}-{4:4}, at: __setup_irq (kernel/irq/internals.h:156 kernel/irq/manage.c:1596)
[    5.428331] #4: ffffff88039c80c8 (lock_class#2){....}-{2:2}, at: __setup_irq (kernel/irq/manage.c:1614)
[    5.436472] stack backtrace:
[    5.439359] CPU: 2 UID: 0 PID: 44 Comm: kworker/u17:1 Tainted: G        W          6.13.0-rc5+ raspberrypi#69
[    5.448690] Tainted: [W]=WARN
[    5.451656] Hardware name: xlnx,zynqmp (DT)
[    5.455845] Workqueue: events_unbound deferred_probe_work_func
[    5.461699] Call trace:
[    5.464147] show_stack+0x18/0x24 C
[    5.467821] dump_stack_lvl (lib/dump_stack.c:123)
[    5.471501] dump_stack (lib/dump_stack.c:130)
[    5.474824] __lock_acquire (kernel/locking/lockdep.c:4828 kernel/locking/lockdep.c:4898 kernel/locking/lockdep.c:5176)
[    5.478758] lock_acquire (arch/arm64/include/asm/percpu.h:40 kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851 kernel/locking/lockdep.c:5814)
[    5.482429] _raw_spin_lock_irqsave (include/linux/spinlock_api_smp.h:111 kernel/locking/spinlock.c:162)
[    5.486797] xgpio_irq_unmask (drivers/gpio/gpio-xilinx.c:433 (discriminator 8))
[    5.490737] irq_enable (kernel/irq/internals.h:236 kernel/irq/chip.c:170 kernel/irq/chip.c:439 kernel/irq/chip.c:432 kernel/irq/chip.c:345)
[    5.494060] __irq_startup (kernel/irq/internals.h:241 kernel/irq/chip.c:180 kernel/irq/chip.c:250)
[    5.497645] irq_startup (kernel/irq/chip.c:270)
[    5.501143] __setup_irq (kernel/irq/manage.c:1807)
[    5.504728] request_threaded_irq (kernel/irq/manage.c:2208)

Fixes: a32c7ca ("gpio: gpio-xilinx: Add interrupt support")
Signed-off-by: Sean Anderson <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Bartosz Golaszewski <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request Feb 13, 2025
[ Upstream commit c7b87ce ]

libtraceevent parses and returns an array of argument fields, sometimes
larger than RAW_SYSCALL_ARGS_NUM (6) because it includes "__syscall_nr",
idx will traverse to index 6 (7th element) whereas sc->fmt->arg holds 6
elements max, creating an out-of-bounds access. This runtime error is
found by UBsan. The error message:

  $ sudo UBSAN_OPTIONS=print_stacktrace=1 ./perf trace -a --max-events=1
  builtin-trace.c:1966:35: runtime error: index 6 out of bounds for type 'syscall_arg_fmt [6]'
    #0 0x5c04956be5fe in syscall__alloc_arg_fmts /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:1966
    #1 0x5c04956c0510 in trace__read_syscall_info /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:2110
    #2 0x5c04956c372b in trace__syscall_info /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:2436
    #3 0x5c04956d2f39 in trace__init_syscalls_bpf_prog_array_maps /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:3897
    #4 0x5c04956d6d25 in trace__run /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:4335
    #5 0x5c04956e112e in cmd_trace /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:5502
    #6 0x5c04956eda7d in run_builtin /home/howard/hw/linux-perf/tools/perf/perf.c:351
    #7 0x5c04956ee0a8 in handle_internal_command /home/howard/hw/linux-perf/tools/perf/perf.c:404
    #8 0x5c04956ee37f in run_argv /home/howard/hw/linux-perf/tools/perf/perf.c:448
    #9 0x5c04956ee8e9 in main /home/howard/hw/linux-perf/tools/perf/perf.c:556
    #10 0x79eb3622a3b7 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
    raspberrypi#11 0x79eb3622a47a in __libc_start_main_impl ../csu/libc-start.c:360
    raspberrypi#12 0x5c04955422d4 in _start (/home/howard/hw/linux-perf/tools/perf/perf+0x4e02d4) (BuildId: 5b6cab2d59e96a4341741765ad6914a4d784dbc6)

     0.000 ( 0.014 ms): Chrome_ChildIO/117244 write(fd: 238, buf: !, count: 1)                                      = 1

Fixes: 5e58fcf ("perf trace: Allow allocating sc->arg_fmt even without the syscall tracepoint")
Signed-off-by: Howard Chu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Namhyung Kim <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Feb 13, 2025
commit c6ef3a7 upstream.

If the uvc_status_init() function fails to allocate the int_urb, it will
free the dev->status pointer but doesn't reset the pointer to NULL. This
results in the kfree() call in uvc_status_cleanup() trying to
double-free the memory. Fix it by resetting the dev->status pointer to
NULL after freeing it.

Fixes: a31a405 ("V4L/DVB:usbvideo:don't use part of buffer for USB transfer #4")
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Laurent Pinchart <[email protected]>
Reviewed by: Ricardo Ribalda <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request Apr 28, 2025
…ate_pagetables'

[ Upstream commit fddc450 ]

This commit addresses a circular locking dependency in the
svm_range_cpu_invalidate_pagetables function. The function previously
held a lock while determining whether to perform an unmap or eviction
operation, which could lead to deadlocks.

Fixes the below:

[  223.418794] ======================================================
[  223.418820] WARNING: possible circular locking dependency detected
[  223.418845] 6.12.0-amdstaging-drm-next-lol-050225 raspberrypi#14 Tainted: G     U     OE
[  223.418869] ------------------------------------------------------
[  223.418889] kfdtest/3939 is trying to acquire lock:
[  223.418906] ffff8957552eae38 (&dqm->lock_hidden){+.+.}-{3:3}, at: evict_process_queues_cpsch+0x43/0x210 [amdgpu]
[  223.419302]
               but task is already holding lock:
[  223.419303] ffff8957556b83b0 (&prange->lock){+.+.}-{3:3}, at: svm_range_cpu_invalidate_pagetables+0x9d/0x850 [amdgpu]
[  223.419447] Console: switching to colour dummy device 80x25
[  223.419477] [IGT] amd_basic: executing
[  223.419599]
               which lock already depends on the new lock.

[  223.419611]
               the existing dependency chain (in reverse order) is:
[  223.419621]
               -> #2 (&prange->lock){+.+.}-{3:3}:
[  223.419636]        __mutex_lock+0x85/0xe20
[  223.419647]        mutex_lock_nested+0x1b/0x30
[  223.419656]        svm_range_validate_and_map+0x2f1/0x15b0 [amdgpu]
[  223.419954]        svm_range_set_attr+0xe8c/0x1710 [amdgpu]
[  223.420236]        svm_ioctl+0x46/0x50 [amdgpu]
[  223.420503]        kfd_ioctl_svm+0x50/0x90 [amdgpu]
[  223.420763]        kfd_ioctl+0x409/0x6d0 [amdgpu]
[  223.421024]        __x64_sys_ioctl+0x95/0xd0
[  223.421036]        x64_sys_call+0x1205/0x20d0
[  223.421047]        do_syscall_64+0x87/0x140
[  223.421056]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  223.421068]
               -> #1 (reservation_ww_class_mutex){+.+.}-{3:3}:
[  223.421084]        __ww_mutex_lock.constprop.0+0xab/0x1560
[  223.421095]        ww_mutex_lock+0x2b/0x90
[  223.421103]        amdgpu_amdkfd_alloc_gtt_mem+0xcc/0x2b0 [amdgpu]
[  223.421361]        add_queue_mes+0x3bc/0x440 [amdgpu]
[  223.421623]        unhalt_cpsch+0x1ae/0x240 [amdgpu]
[  223.421888]        kgd2kfd_start_sched+0x5e/0xd0 [amdgpu]
[  223.422148]        amdgpu_amdkfd_start_sched+0x3d/0x50 [amdgpu]
[  223.422414]        amdgpu_gfx_enforce_isolation_handler+0x132/0x270 [amdgpu]
[  223.422662]        process_one_work+0x21e/0x680
[  223.422673]        worker_thread+0x190/0x330
[  223.422682]        kthread+0xe7/0x120
[  223.422690]        ret_from_fork+0x3c/0x60
[  223.422699]        ret_from_fork_asm+0x1a/0x30
[  223.422708]
               -> #0 (&dqm->lock_hidden){+.+.}-{3:3}:
[  223.422723]        __lock_acquire+0x16f4/0x2810
[  223.422734]        lock_acquire+0xd1/0x300
[  223.422742]        __mutex_lock+0x85/0xe20
[  223.422751]        mutex_lock_nested+0x1b/0x30
[  223.422760]        evict_process_queues_cpsch+0x43/0x210 [amdgpu]
[  223.423025]        kfd_process_evict_queues+0x8a/0x1d0 [amdgpu]
[  223.423285]        kgd2kfd_quiesce_mm+0x43/0x90 [amdgpu]
[  223.423540]        svm_range_cpu_invalidate_pagetables+0x4a7/0x850 [amdgpu]
[  223.423807]        __mmu_notifier_invalidate_range_start+0x1f5/0x250
[  223.423819]        copy_page_range+0x1e94/0x1ea0
[  223.423829]        copy_process+0x172f/0x2ad0
[  223.423839]        kernel_clone+0x9c/0x3f0
[  223.423847]        __do_sys_clone+0x66/0x90
[  223.423856]        __x64_sys_clone+0x25/0x30
[  223.423864]        x64_sys_call+0x1d7c/0x20d0
[  223.423872]        do_syscall_64+0x87/0x140
[  223.423880]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  223.423891]
               other info that might help us debug this:

[  223.423903] Chain exists of:
                 &dqm->lock_hidden --> reservation_ww_class_mutex --> &prange->lock

[  223.423926]  Possible unsafe locking scenario:

[  223.423935]        CPU0                    CPU1
[  223.423942]        ----                    ----
[  223.423949]   lock(&prange->lock);
[  223.423958]                                lock(reservation_ww_class_mutex);
[  223.423970]                                lock(&prange->lock);
[  223.423981]   lock(&dqm->lock_hidden);
[  223.423990]
                *** DEADLOCK ***

[  223.423999] 5 locks held by kfdtest/3939:
[  223.424006]  #0: ffffffffb82b4fc0 (dup_mmap_sem){.+.+}-{0:0}, at: copy_process+0x1387/0x2ad0
[  223.424026]  #1: ffff89575eda81b0 (&mm->mmap_lock){++++}-{3:3}, at: copy_process+0x13a8/0x2ad0
[  223.424046]  #2: ffff89575edaf3b0 (&mm->mmap_lock/1){+.+.}-{3:3}, at: copy_process+0x13e4/0x2ad0
[  223.424066]  #3: ffffffffb82e76e0 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at: copy_page_range+0x1cea/0x1ea0
[  223.424088]  #4: ffff8957556b83b0 (&prange->lock){+.+.}-{3:3}, at: svm_range_cpu_invalidate_pagetables+0x9d/0x850 [amdgpu]
[  223.424365]
               stack backtrace:
[  223.424374] CPU: 0 UID: 0 PID: 3939 Comm: kfdtest Tainted: G     U     OE      6.12.0-amdstaging-drm-next-lol-050225 raspberrypi#14
[  223.424392] Tainted: [U]=USER, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
[  223.424401] Hardware name: Gigabyte Technology Co., Ltd. X570 AORUS PRO WIFI/X570 AORUS PRO WIFI, BIOS F36a 02/16/2022
[  223.424416] Call Trace:
[  223.424423]  <TASK>
[  223.424430]  dump_stack_lvl+0x9b/0xf0
[  223.424441]  dump_stack+0x10/0x20
[  223.424449]  print_circular_bug+0x275/0x350
[  223.424460]  check_noncircular+0x157/0x170
[  223.424469]  ? __bfs+0xfd/0x2c0
[  223.424481]  __lock_acquire+0x16f4/0x2810
[  223.424490]  ? srso_return_thunk+0x5/0x5f
[  223.424505]  lock_acquire+0xd1/0x300
[  223.424514]  ? evict_process_queues_cpsch+0x43/0x210 [amdgpu]
[  223.424783]  __mutex_lock+0x85/0xe20
[  223.424792]  ? evict_process_queues_cpsch+0x43/0x210 [amdgpu]
[  223.425058]  ? srso_return_thunk+0x5/0x5f
[  223.425067]  ? mark_held_locks+0x54/0x90
[  223.425076]  ? evict_process_queues_cpsch+0x43/0x210 [amdgpu]
[  223.425339]  ? srso_return_thunk+0x5/0x5f
[  223.425350]  mutex_lock_nested+0x1b/0x30
[  223.425358]  ? mutex_lock_nested+0x1b/0x30
[  223.425367]  evict_process_queues_cpsch+0x43/0x210 [amdgpu]
[  223.425631]  kfd_process_evict_queues+0x8a/0x1d0 [amdgpu]
[  223.425893]  kgd2kfd_quiesce_mm+0x43/0x90 [amdgpu]
[  223.426156]  svm_range_cpu_invalidate_pagetables+0x4a7/0x850 [amdgpu]
[  223.426423]  ? srso_return_thunk+0x5/0x5f
[  223.426436]  __mmu_notifier_invalidate_range_start+0x1f5/0x250
[  223.426450]  copy_page_range+0x1e94/0x1ea0
[  223.426461]  ? srso_return_thunk+0x5/0x5f
[  223.426474]  ? srso_return_thunk+0x5/0x5f
[  223.426484]  ? lock_acquire+0xd1/0x300
[  223.426494]  ? copy_process+0x1718/0x2ad0
[  223.426502]  ? srso_return_thunk+0x5/0x5f
[  223.426510]  ? sched_clock_noinstr+0x9/0x10
[  223.426519]  ? local_clock_noinstr+0xe/0xc0
[  223.426528]  ? copy_process+0x1718/0x2ad0
[  223.426537]  ? srso_return_thunk+0x5/0x5f
[  223.426550]  copy_process+0x172f/0x2ad0
[  223.426569]  kernel_clone+0x9c/0x3f0
[  223.426577]  ? __schedule+0x4c9/0x1b00
[  223.426586]  ? srso_return_thunk+0x5/0x5f
[  223.426594]  ? sched_clock_noinstr+0x9/0x10
[  223.426602]  ? srso_return_thunk+0x5/0x5f
[  223.426610]  ? local_clock_noinstr+0xe/0xc0
[  223.426619]  ? schedule+0x107/0x1a0
[  223.426629]  __do_sys_clone+0x66/0x90
[  223.426643]  __x64_sys_clone+0x25/0x30
[  223.426652]  x64_sys_call+0x1d7c/0x20d0
[  223.426661]  do_syscall_64+0x87/0x140
[  223.426671]  ? srso_return_thunk+0x5/0x5f
[  223.426679]  ? common_nsleep+0x44/0x50
[  223.426690]  ? srso_return_thunk+0x5/0x5f
[  223.426698]  ? trace_hardirqs_off+0x52/0xd0
[  223.426709]  ? srso_return_thunk+0x5/0x5f
[  223.426717]  ? syscall_exit_to_user_mode+0xcc/0x200
[  223.426727]  ? srso_return_thunk+0x5/0x5f
[  223.426736]  ? do_syscall_64+0x93/0x140
[  223.426748]  ? srso_return_thunk+0x5/0x5f
[  223.426756]  ? up_write+0x1c/0x1e0
[  223.426765]  ? srso_return_thunk+0x5/0x5f
[  223.426775]  ? srso_return_thunk+0x5/0x5f
[  223.426783]  ? trace_hardirqs_off+0x52/0xd0
[  223.426792]  ? srso_return_thunk+0x5/0x5f
[  223.426800]  ? syscall_exit_to_user_mode+0xcc/0x200
[  223.426810]  ? srso_return_thunk+0x5/0x5f
[  223.426818]  ? do_syscall_64+0x93/0x140
[  223.426826]  ? syscall_exit_to_user_mode+0xcc/0x200
[  223.426836]  ? srso_return_thunk+0x5/0x5f
[  223.426844]  ? do_syscall_64+0x93/0x140
[  223.426853]  ? srso_return_thunk+0x5/0x5f
[  223.426861]  ? irqentry_exit+0x6b/0x90
[  223.426869]  ? srso_return_thunk+0x5/0x5f
[  223.426877]  ? exc_page_fault+0xa7/0x2c0
[  223.426888]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  223.426898] RIP: 0033:0x7f46758eab57
[  223.426906] Code: ba 04 00 f3 0f 1e fa 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 41 41 89 c0 85 c0 75 2c 64 48 8b 04 25 10 00
[  223.426930] RSP: 002b:00007fff5c3e5188 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
[  223.426943] RAX: ffffffffffffffda RBX: 00007f4675f8c040 RCX: 00007f46758eab57
[  223.426954] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
[  223.426965] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
[  223.426975] R10: 00007f4675e81a50 R11: 0000000000000246 R12: 0000000000000001
[  223.426986] R13: 00007fff5c3e5470 R14: 00007fff5c3e53e0 R15: 00007fff5c3e5410
[  223.427004]  </TASK>

v2: To resolve this issue, the allocation of the process context buffer
(`proc_ctx_bo`) has been moved from the `add_queue_mes` function to the
`pqm_create_queue` function. This change ensures that the buffer is
allocated only when the first queue for a process is created and only if
the Micro Engine Scheduler (MES) is enabled. (Felix)

v3: Fix typo s/Memory Execution Scheduler (MES)/Micro Engine Scheduler
in commit message. (Lijo)

Fixes: 438b39a ("drm/amdkfd: pause autosuspend when creating pdd")
Cc: Jesse Zhang <[email protected]>
Cc: Yunxiang Li <[email protected]>
Cc: Philip Yang <[email protected]>
Cc: Alex Sierra <[email protected]>
Cc: Felix Kuehling <[email protected]>
Cc: Christian König <[email protected]>
Cc: Alex Deucher <[email protected]>
Signed-off-by: Srinivasan Shanmugam <[email protected]>
Reviewed-by: Felix Kuehling <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Apr 28, 2025
…cal section

[ Upstream commit 85b2b9c ]

A circular lock dependency splat has been seen involving down_trylock():

  ======================================================
  WARNING: possible circular locking dependency detected
  6.12.0-41.el10.s390x+debug
  ------------------------------------------------------
  dd/32479 is trying to acquire lock:
  0015a20accd0d4f8 ((console_sem).lock){-.-.}-{2:2}, at: down_trylock+0x26/0x90

  but task is already holding lock:
  000000017e461698 (&zone->lock){-.-.}-{2:2}, at: rmqueue_bulk+0xac/0x8f0

  the existing dependency chain (in reverse order) is:
  -> #4 (&zone->lock){-.-.}-{2:2}:
  -> #3 (hrtimer_bases.lock){-.-.}-{2:2}:
  -> #2 (&rq->__lock){-.-.}-{2:2}:
  -> #1 (&p->pi_lock){-.-.}-{2:2}:
  -> #0 ((console_sem).lock){-.-.}-{2:2}:

The console_sem -> pi_lock dependency is due to calling try_to_wake_up()
while holding the console_sem raw_spinlock. This dependency can be broken
by using wake_q to do the wakeup instead of calling try_to_wake_up()
under the console_sem lock. This will also make the semaphore's
raw_spinlock become a terminal lock without taking any further locks
underneath it.

The hrtimer_bases.lock is a raw_spinlock while zone->lock is a
spinlock. The hrtimer_bases.lock -> zone->lock dependency happens via
the debug_objects_fill_pool() helper function in the debugobjects code.

  -> #4 (&zone->lock){-.-.}-{2:2}:
         __lock_acquire+0xe86/0x1cc0
         lock_acquire.part.0+0x258/0x630
         lock_acquire+0xb8/0xe0
         _raw_spin_lock_irqsave+0xb4/0x120
         rmqueue_bulk+0xac/0x8f0
         __rmqueue_pcplist+0x580/0x830
         rmqueue_pcplist+0xfc/0x470
         rmqueue.isra.0+0xdec/0x11b0
         get_page_from_freelist+0x2ee/0xeb0
         __alloc_pages_noprof+0x2c2/0x520
         alloc_pages_mpol_noprof+0x1fc/0x4d0
         alloc_pages_noprof+0x8c/0xe0
         allocate_slab+0x320/0x460
         ___slab_alloc+0xa58/0x12b0
         __slab_alloc.isra.0+0x42/0x60
         kmem_cache_alloc_noprof+0x304/0x350
         fill_pool+0xf6/0x450
         debug_object_activate+0xfe/0x360
         enqueue_hrtimer+0x34/0x190
         __run_hrtimer+0x3c8/0x4c0
         __hrtimer_run_queues+0x1b2/0x260
         hrtimer_interrupt+0x316/0x760
         do_IRQ+0x9a/0xe0
         do_irq_async+0xf6/0x160

Normally a raw_spinlock to spinlock dependency is not legitimate
and will be warned if CONFIG_PROVE_RAW_LOCK_NESTING is enabled,
but debug_objects_fill_pool() is an exception as it explicitly
allows this dependency for non-PREEMPT_RT kernel without causing
PROVE_RAW_LOCK_NESTING lockdep splat. As a result, this dependency is
legitimate and not a bug.

Anyway, semaphore is the only locking primitive left that is still
using try_to_wake_up() to do wakeup inside critical section, all the
other locking primitives had been migrated to use wake_q to do wakeup
outside of the critical section. It is also possible that there are
other circular locking dependencies involving printk/console_sem or
other existing/new semaphores lurking somewhere which may show up in
the future. Let just do the migration now to wake_q to avoid headache
like this.

Reported-by: [email protected]
Signed-off-by: Waiman Long <[email protected]>
Signed-off-by: Boqun Feng <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Apr 28, 2025
[ Upstream commit 053f3ff ]

v2:
- Created a single error handling unlock and exit in veth_pool_store
- Greatly expanded commit message with previous explanatory-only text

Summary: Use rtnl_mutex to synchronize veth_pool_store with itself,
ibmveth_close and ibmveth_open, preventing multiple calls in a row to
napi_disable.

Background: Two (or more) threads could call veth_pool_store through
writing to /sys/devices/vio/30000002/pool*/*. You can do this easily
with a little shell script. This causes a hang.

I configured LOCKDEP, compiled ibmveth.c with DEBUG, and built a new
kernel. I ran this test again and saw:

    Setting pool0/active to 0
    Setting pool1/active to 1
    [   73.911067][ T4365] ibmveth 30000002 eth0: close starting
    Setting pool1/active to 1
    Setting pool1/active to 0
    [   73.911367][ T4366] ibmveth 30000002 eth0: close starting
    [   73.916056][ T4365] ibmveth 30000002 eth0: close complete
    [   73.916064][ T4365] ibmveth 30000002 eth0: open starting
    [  110.808564][  T712] systemd-journald[712]: Sent WATCHDOG=1 notification.
    [  230.808495][  T712] systemd-journald[712]: Sent WATCHDOG=1 notification.
    [  243.683786][  T123] INFO: task stress.sh:4365 blocked for more than 122 seconds.
    [  243.683827][  T123]       Not tainted 6.14.0-01103-g2df0c02dab82-dirty #8
    [  243.683833][  T123] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
    [  243.683838][  T123] task:stress.sh       state:D stack:28096 pid:4365  tgid:4365  ppid:4364   task_flags:0x400040 flags:0x00042000
    [  243.683852][  T123] Call Trace:
    [  243.683857][  T123] [c00000000c38f690] [0000000000000001] 0x1 (unreliable)
    [  243.683868][  T123] [c00000000c38f840] [c00000000001f908] __switch_to+0x318/0x4e0
    [  243.683878][  T123] [c00000000c38f8a0] [c000000001549a70] __schedule+0x500/0x12a0
    [  243.683888][  T123] [c00000000c38f9a0] [c00000000154a878] schedule+0x68/0x210
    [  243.683896][  T123] [c00000000c38f9d0] [c00000000154ac80] schedule_preempt_disabled+0x30/0x50
    [  243.683904][  T123] [c00000000c38fa00] [c00000000154dbb0] __mutex_lock+0x730/0x10f0
    [  243.683913][  T123] [c00000000c38fb10] [c000000001154d40] napi_enable+0x30/0x60
    [  243.683921][  T123] [c00000000c38fb40] [c000000000f4ae94] ibmveth_open+0x68/0x5dc
    [  243.683928][  T123] [c00000000c38fbe0] [c000000000f4aa20] veth_pool_store+0x220/0x270
    [  243.683936][  T123] [c00000000c38fc70] [c000000000826278] sysfs_kf_write+0x68/0xb0
    [  243.683944][  T123] [c00000000c38fcb0] [c0000000008240b8] kernfs_fop_write_iter+0x198/0x2d0
    [  243.683951][  T123] [c00000000c38fd00] [c00000000071b9ac] vfs_write+0x34c/0x650
    [  243.683958][  T123] [c00000000c38fdc0] [c00000000071bea8] ksys_write+0x88/0x150
    [  243.683966][  T123] [c00000000c38fe10] [c0000000000317f4] system_call_exception+0x124/0x340
    [  243.683973][  T123] [c00000000c38fe50] [c00000000000d05c] system_call_vectored_common+0x15c/0x2ec
    ...
    [  243.684087][  T123] Showing all locks held in the system:
    [  243.684095][  T123] 1 lock held by khungtaskd/123:
    [  243.684099][  T123]  #0: c00000000278e370 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x50/0x248
    [  243.684114][  T123] 4 locks held by stress.sh/4365:
    [  243.684119][  T123]  #0: c00000003a4cd3f8 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x88/0x150
    [  243.684132][  T123]  #1: c000000041aea888 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x154/0x2d0
    [  243.684143][  T123]  #2: c0000000366fb9a8 (kn->active#64){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x160/0x2d0
    [  243.684155][  T123]  #3: c000000035ff4cb8 (&dev->lock){+.+.}-{3:3}, at: napi_enable+0x30/0x60
    [  243.684166][  T123] 5 locks held by stress.sh/4366:
    [  243.684170][  T123]  #0: c00000003a4cd3f8 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x88/0x150
    [  243.684183][  T123]  #1: c00000000aee2288 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x154/0x2d0
    [  243.684194][  T123]  #2: c0000000366f4ba8 (kn->active#64){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x160/0x2d0
    [  243.684205][  T123]  #3: c000000035ff4cb8 (&dev->lock){+.+.}-{3:3}, at: napi_disable+0x30/0x60
    [  243.684216][  T123]  #4: c0000003ff9bbf18 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x138/0x12a0

From the ibmveth debug, two threads are calling veth_pool_store, which
calls ibmveth_close and ibmveth_open. Here's the sequence:

  T4365             T4366
  ----------------- ----------------- ---------
  veth_pool_store   veth_pool_store
                    ibmveth_close
  ibmveth_close
  napi_disable
                    napi_disable
  ibmveth_open
  napi_enable                         <- HANG

ibmveth_close calls napi_disable at the top and ibmveth_open calls
napi_enable at the top.

https://docs.kernel.org/networking/napi.html]] says

  The control APIs are not idempotent. Control API calls are safe
  against concurrent use of datapath APIs but an incorrect sequence of
  control API calls may result in crashes, deadlocks, or race
  conditions. For example, calling napi_disable() multiple times in a
  row will deadlock.

In the normal open and close paths, rtnl_mutex is acquired to prevent
other callers. This is missing from veth_pool_store. Use rtnl_mutex in
veth_pool_store fixes these hangs.

Signed-off-by: Dave Marquardt <[email protected]>
Fixes: 860f242 ("[PATCH] ibmveth change buffer pools dynamically")
Reviewed-by: Nick Child <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Apr 28, 2025
[ Upstream commit b61e69b ]

syzbot report a deadlock in diFree. [1]

When calling "ioctl$LOOP_SET_STATUS64", the offset value passed in is 4,
which does not match the mounted loop device, causing the mapping of the
mounted loop device to be invalidated.

When creating the directory and creating the inode of iag in diReadSpecial(),
read the page of fixed disk inode (AIT) in raw mode in read_metapage(), the
metapage data it returns is corrupted, which causes the nlink value of 0 to be
assigned to the iag inode when executing copy_from_dinode(), which ultimately
causes a deadlock when entering diFree().

To avoid this, first check the nlink value of dinode before setting iag inode.

[1]
WARNING: possible recursive locking detected
6.12.0-rc7-syzkaller-00212-g4a5df3796467 #0 Not tainted
--------------------------------------------
syz-executor301/5309 is trying to acquire lock:
ffff888044548920 (&(imap->im_aglock[index])){+.+.}-{3:3}, at: diFree+0x37c/0x2fb0 fs/jfs/jfs_imap.c:889

but task is already holding lock:
ffff888044548920 (&(imap->im_aglock[index])){+.+.}-{3:3}, at: diAlloc+0x1b6/0x1630

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&(imap->im_aglock[index]));
  lock(&(imap->im_aglock[index]));

 *** DEADLOCK ***

 May be due to missing lock nesting notation

5 locks held by syz-executor301/5309:
 #0: ffff8880422a4420 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515
 #1: ffff88804755b390 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:850 [inline]
 #1: ffff88804755b390 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: filename_create+0x260/0x540 fs/namei.c:4026
 #2: ffff888044548920 (&(imap->im_aglock[index])){+.+.}-{3:3}, at: diAlloc+0x1b6/0x1630
 #3: ffff888044548890 (&imap->im_freelock){+.+.}-{3:3}, at: diNewIAG fs/jfs/jfs_imap.c:2460 [inline]
 #3: ffff888044548890 (&imap->im_freelock){+.+.}-{3:3}, at: diAllocExt fs/jfs/jfs_imap.c:1905 [inline]
 #3: ffff888044548890 (&imap->im_freelock){+.+.}-{3:3}, at: diAllocAG+0x4b7/0x1e50 fs/jfs/jfs_imap.c:1669
 #4: ffff88804755a618 (&jfs_ip->rdwrlock/1){++++}-{3:3}, at: diNewIAG fs/jfs/jfs_imap.c:2477 [inline]
 #4: ffff88804755a618 (&jfs_ip->rdwrlock/1){++++}-{3:3}, at: diAllocExt fs/jfs/jfs_imap.c:1905 [inline]
 #4: ffff88804755a618 (&jfs_ip->rdwrlock/1){++++}-{3:3}, at: diAllocAG+0x869/0x1e50 fs/jfs/jfs_imap.c:1669

stack backtrace:
CPU: 0 UID: 0 PID: 5309 Comm: syz-executor301 Not tainted 6.12.0-rc7-syzkaller-00212-g4a5df3796467 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_deadlock_bug+0x483/0x620 kernel/locking/lockdep.c:3037
 check_deadlock kernel/locking/lockdep.c:3089 [inline]
 validate_chain+0x15e2/0x5920 kernel/locking/lockdep.c:3891
 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
 __mutex_lock_common kernel/locking/mutex.c:608 [inline]
 __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
 diFree+0x37c/0x2fb0 fs/jfs/jfs_imap.c:889
 jfs_evict_inode+0x32d/0x440 fs/jfs/inode.c:156
 evict+0x4e8/0x9b0 fs/inode.c:725
 diFreeSpecial fs/jfs/jfs_imap.c:552 [inline]
 duplicateIXtree+0x3c6/0x550 fs/jfs/jfs_imap.c:3022
 diNewIAG fs/jfs/jfs_imap.c:2597 [inline]
 diAllocExt fs/jfs/jfs_imap.c:1905 [inline]
 diAllocAG+0x17dc/0x1e50 fs/jfs/jfs_imap.c:1669
 diAlloc+0x1d2/0x1630 fs/jfs/jfs_imap.c:1590
 ialloc+0x8f/0x900 fs/jfs/jfs_inode.c:56
 jfs_mkdir+0x1c5/0xba0 fs/jfs/namei.c:225
 vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4257
 do_mkdirat+0x264/0x3a0 fs/namei.c:4280
 __do_sys_mkdirat fs/namei.c:4295 [inline]
 __se_sys_mkdirat fs/namei.c:4293 [inline]
 __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4293
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=355da3b3a74881008e8f
Signed-off-by: Edward Adam Davis <[email protected]>
Signed-off-by: Dave Kleikamp <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
spockfish pushed a commit that referenced this pull request Apr 28, 2025
commit 93ae6e6 upstream.

We have recently seen report of lockdep circular lock dependency warnings
on platforms like Skylake and Kabylake:

 ======================================================
 WARNING: possible circular locking dependency detected
 6.14.0-rc6-CI_DRM_16276-gca2c04fe76e8+ #1 Not tainted
 ------------------------------------------------------
 swapper/0/1 is trying to acquire lock:
 ffffffff8360ee48 (iommu_probe_device_lock){+.+.}-{3:3},
   at: iommu_probe_device+0x1d/0x70

 but task is already holding lock:
 ffff888102c7efa8 (&device->physical_node_lock){+.+.}-{3:3},
   at: intel_iommu_init+0xe75/0x11f0

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #6 (&device->physical_node_lock){+.+.}-{3:3}:
        __mutex_lock+0xb4/0xe40
        mutex_lock_nested+0x1b/0x30
        intel_iommu_init+0xe75/0x11f0
        pci_iommu_init+0x13/0x70
        do_one_initcall+0x62/0x3f0
        kernel_init_freeable+0x3da/0x6a0
        kernel_init+0x1b/0x200
        ret_from_fork+0x44/0x70
        ret_from_fork_asm+0x1a/0x30

 -> #5 (dmar_global_lock){++++}-{3:3}:
        down_read+0x43/0x1d0
        enable_drhd_fault_handling+0x21/0x110
        cpuhp_invoke_callback+0x4c6/0x870
        cpuhp_issue_call+0xbf/0x1f0
        __cpuhp_setup_state_cpuslocked+0x111/0x320
        __cpuhp_setup_state+0xb0/0x220
        irq_remap_enable_fault_handling+0x3f/0xa0
        apic_intr_mode_init+0x5c/0x110
        x86_late_time_init+0x24/0x40
        start_kernel+0x895/0xbd0
        x86_64_start_reservations+0x18/0x30
        x86_64_start_kernel+0xbf/0x110
        common_startup_64+0x13e/0x141

 -> #4 (cpuhp_state_mutex){+.+.}-{3:3}:
        __mutex_lock+0xb4/0xe40
        mutex_lock_nested+0x1b/0x30
        __cpuhp_setup_state_cpuslocked+0x67/0x320
        __cpuhp_setup_state+0xb0/0x220
        page_alloc_init_cpuhp+0x2d/0x60
        mm_core_init+0x18/0x2c0
        start_kernel+0x576/0xbd0
        x86_64_start_reservations+0x18/0x30
        x86_64_start_kernel+0xbf/0x110
        common_startup_64+0x13e/0x141

 -> #3 (cpu_hotplug_lock){++++}-{0:0}:
        __cpuhp_state_add_instance+0x4f/0x220
        iova_domain_init_rcaches+0x214/0x280
        iommu_setup_dma_ops+0x1a4/0x710
        iommu_device_register+0x17d/0x260
        intel_iommu_init+0xda4/0x11f0
        pci_iommu_init+0x13/0x70
        do_one_initcall+0x62/0x3f0
        kernel_init_freeable+0x3da/0x6a0
        kernel_init+0x1b/0x200
        ret_from_fork+0x44/0x70
        ret_from_fork_asm+0x1a/0x30

 -> #2 (&domain->iova_cookie->mutex){+.+.}-{3:3}:
        __mutex_lock+0xb4/0xe40
        mutex_lock_nested+0x1b/0x30
        iommu_setup_dma_ops+0x16b/0x710
        iommu_device_register+0x17d/0x260
        intel_iommu_init+0xda4/0x11f0
        pci_iommu_init+0x13/0x70
        do_one_initcall+0x62/0x3f0
        kernel_init_freeable+0x3da/0x6a0
        kernel_init+0x1b/0x200
        ret_from_fork+0x44/0x70
        ret_from_fork_asm+0x1a/0x30

 -> #1 (&group->mutex){+.+.}-{3:3}:
        __mutex_lock+0xb4/0xe40
        mutex_lock_nested+0x1b/0x30
        __iommu_probe_device+0x24c/0x4e0
        probe_iommu_group+0x2b/0x50
        bus_for_each_dev+0x7d/0xe0
        iommu_device_register+0xe1/0x260
        intel_iommu_init+0xda4/0x11f0
        pci_iommu_init+0x13/0x70
        do_one_initcall+0x62/0x3f0
        kernel_init_freeable+0x3da/0x6a0
        kernel_init+0x1b/0x200
        ret_from_fork+0x44/0x70
        ret_from_fork_asm+0x1a/0x30

 -> #0 (iommu_probe_device_lock){+.+.}-{3:3}:
        __lock_acquire+0x1637/0x2810
        lock_acquire+0xc9/0x300
        __mutex_lock+0xb4/0xe40
        mutex_lock_nested+0x1b/0x30
        iommu_probe_device+0x1d/0x70
        intel_iommu_init+0xe90/0x11f0
        pci_iommu_init+0x13/0x70
        do_one_initcall+0x62/0x3f0
        kernel_init_freeable+0x3da/0x6a0
        kernel_init+0x1b/0x200
        ret_from_fork+0x44/0x70
        ret_from_fork_asm+0x1a/0x30

 other info that might help us debug this:

 Chain exists of:
   iommu_probe_device_lock --> dmar_global_lock -->
     &device->physical_node_lock

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&device->physical_node_lock);
                                lock(dmar_global_lock);
                                lock(&device->physical_node_lock);
   lock(iommu_probe_device_lock);

  *** DEADLOCK ***

This driver uses a global lock to protect the list of enumerated DMA
remapping units. It is necessary due to the driver's support for dynamic
addition and removal of remapping units at runtime.

Two distinct code paths require iteration over this remapping unit list:

- Device registration and probing: the driver iterates the list to
  register each remapping unit with the upper layer IOMMU framework
  and subsequently probe the devices managed by that unit.
- Global configuration: Upper layer components may also iterate the list
  to apply configuration changes.

The lock acquisition order between these two code paths was reversed. This
caused lockdep warnings, indicating a risk of deadlock. Fix this warning
by releasing the global lock before invoking upper layer interfaces for
device registration.

Fixes: b150654 ("iommu/vt-d: Fix suspicious RCU usage")
Closes: https://lore.kernel.org/linux-iommu/SJ1PR11MB612953431F94F18C954C4A9CB9D32@SJ1PR11MB6129.namprd11.prod.outlook.com/
Tested-by: Chaitanya Kumar Borah <[email protected]>
Cc: [email protected]
Signed-off-by: Lu Baolu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Joerg Roedel <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request Apr 28, 2025
commit 2ccd42b upstream.

If we finds a vq without a name in our input array in
virtio_ccw_find_vqs(), we treat it as "non-existing" and set the vq pointer
to NULL; we will not call virtio_ccw_setup_vq() to allocate/setup a vq.

Consequently, we create only a queue if it actually exists (name != NULL)
and assign an incremental queue index to each such existing queue.

However, in virtio_ccw_register_adapter_ind()->get_airq_indicator() we
will not ignore these "non-existing queues", but instead assign an airq
indicator to them.

Besides never releasing them in virtio_ccw_drop_indicators() (because
there is no virtqueue), the bigger issue seems to be that there will be a
disagreement between the device and the Linux guest about the airq
indicator to be used for notifying a queue, because the indicator bit
for adapter I/O interrupt is derived from the queue index.

The virtio spec states under "Setting Up Two-Stage Queue Indicators":

	... indicator contains the guest address of an area wherein the
	indicators for the devices are contained, starting at bit_nr, one
	bit per virtqueue of the device.

And further in "Notification via Adapter I/O Interrupts":

	For notifying the driver of virtqueue buffers, the device sets the
	bit in the guest-provided indicator area at the corresponding
	offset.

For example, QEMU uses in virtio_ccw_notify() the queue index (passed as
"vector") to select the relevant indicator bit. If a queue does not exist,
it does not have a corresponding indicator bit assigned, because it
effectively doesn't have a queue index.

Using a virtio-balloon-ccw device under QEMU with free-page-hinting
disabled ("free-page-hint=off") but free-page-reporting enabled
("free-page-reporting=on") will result in free page reporting
not working as expected: in the virtio_balloon driver, we'll be stuck
forever in virtballoon_free_page_report()->wait_event(), because the
waitqueue will not be woken up as the notification from the device is
lost: it would use the wrong indicator bit.

Free page reporting stops working and we get splats (when configured to
detect hung wqs) like:

 INFO: task kworker/1:3:463 blocked for more than 61 seconds.
       Not tainted 6.14.0 #4
 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
 task:kworker/1:3 [...]
 Workqueue: events page_reporting_process
 Call Trace:
  [<000002f404e6dfb2>] __schedule+0x402/0x1640
  [<000002f404e6f22e>] schedule+0x3e/0xe0
  [<000002f3846a88fa>] virtballoon_free_page_report+0xaa/0x110 [virtio_balloon]
  [<000002f40435c8a4>] page_reporting_process+0x2e4/0x740
  [<000002f403fd3ee2>] process_one_work+0x1c2/0x400
  [<000002f403fd4b96>] worker_thread+0x296/0x420
  [<000002f403fe10b4>] kthread+0x124/0x290
  [<000002f403f4e0dc>] __ret_from_fork+0x3c/0x60
  [<000002f404e77272>] ret_from_fork+0xa/0x38

There was recently a discussion [1] whether the "holes" should be
treated differently again, effectively assigning also non-existing
queues a queue index: that should also fix the issue, but requires other
workarounds to not break existing setups.

Let's fix it without affecting existing setups for now by properly ignoring
the non-existing queues, so the indicator bits will match the queue
indexes.

[1] https://lore.kernel.org/all/[email protected]/

Fixes: a229989 ("virtio: don't allocate vqs when names[i] = NULL")
Reported-by: Chandra Merla <[email protected]>
Cc: [email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Tested-by: Thomas Huth <[email protected]>
Reviewed-by: Thomas Huth <[email protected]>
Reviewed-by: Cornelia Huck <[email protected]>
Acked-by: Michael S. Tsirkin <[email protected]>
Acked-by: Christian Borntraeger <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Heiko Carstens <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request Apr 28, 2025
commit 366e77c upstream.

Commit 7da55c2 ("drm/amd/display: Remove incorrect FP context
start") removes the FP context protection of dml2_create(), and it said
"All the DC_FP_START/END should be used before call anything from DML2".

However, dml2_validate()/dml21_validate() are not protected from their
callers, causing such errors:

 do_fpu invoked from kernel context![#1]:
 CPU: 10 UID: 0 PID: 331 Comm: kworker/10:1H Not tainted 6.14.0-rc6+ #4
 Workqueue: events_highpri dm_irq_work_func [amdgpu]
 pc ffff800003191eb0 ra ffff800003191e60 tp 9000000107a94000 sp 9000000107a975b0
 a0 9000000140ce4910 a1 0000000000000000 a2 9000000140ce49b0 a3 9000000140ce49a8
 a4 9000000140ce49a8 a5 0000000100000000 a6 0000000000000001 a7 9000000107a97660
 t0 ffff800003790000 t1 9000000140ce5000 t2 0000000000000001 t3 0000000000000000
 t4 0000000000000004 t5 0000000000000000 t6 0000000000000000 t7 0000000000000000
 t8 0000000100000000 u0 ffff8000031a3b9c s9 9000000130bc0000 s0 9000000132400000
 s1 9000000140ec0000 s2 9000000132400000 s3 9000000140ce0000 s4 90000000057f8b88
 s5 9000000140ec0000 s6 9000000140ce4910 s7 0000000000000001 s8 9000000130d45010
 ra: ffff800003191e60 dml21_map_dc_state_into_dml_display_cfg+0x40/0x1140 [amdgpu]
   ERA: ffff800003191eb0 dml21_map_dc_state_into_dml_display_cfg+0x90/0x1140 [amdgpu]
  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  PRMD: 00000004 (PPLV0 +PIE -PWE)
  EUEN: 00000000 (-FPE -SXE -ASXE -BTE)
  ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
 ESTAT: 000f0000 [FPD] (IS= ECode=15 EsubCode=0)
  PRID: 0014d010 (Loongson-64bit, Loongson-3C6000/S)
 Process kworker/10:1H (pid: 331, threadinfo=000000007bf9ddb0, task=00000000cc4ab9f3)
 Stack : 0000000100000000 0000043800000780 0000000100000001 0000000100000001
         0000000000000000 0000078000000000 0000000000000438 0000078000000000
         0000000000000438 0000078000000000 0000000000000438 0000000100000000
         0000000100000000 0000000100000000 0000000100000000 0000000100000000
         0000000000000001 9000000140ec0000 9000000132400000 9000000132400000
         ffff800003408000 ffff800003408000 9000000132400000 9000000140ce0000
         9000000140ce0000 ffff800003193850 0000000000000001 9000000140ec0000
         9000000132400000 9000000140ec0860 9000000140ec0738 0000000000000001
         90000001405e8000 9000000130bc0000 9000000140ec02a8 ffff8000031b5db8
         0000000000000000 0000043800000780 0000000000000003 ffff8000031b79cc
         ...
 Call Trace:
 [<ffff800003191eb0>] dml21_map_dc_state_into_dml_display_cfg+0x90/0x1140 [amdgpu]
 [<ffff80000319384c>] dml21_validate+0xcc/0x520 [amdgpu]
 [<ffff8000031b8948>] dc_validate_global_state+0x2e8/0x460 [amdgpu]
 [<ffff800002e94034>] create_validate_stream_for_sink+0x3d4/0x420 [amdgpu]
 [<ffff800002e940e4>] amdgpu_dm_connector_mode_valid+0x64/0x240 [amdgpu]
 [<900000000441d6b8>] drm_connector_mode_valid+0x38/0x80
 [<900000000441d824>] __drm_helper_update_and_validate+0x124/0x3e0
 [<900000000441ddc0>] drm_helper_probe_single_connector_modes+0x2e0/0x620
 [<90000000044050dc>] drm_client_modeset_probe+0x23c/0x1780
 [<9000000004420384>] __drm_fb_helper_initial_config_and_unlock+0x44/0x5a0
 [<9000000004403acc>] drm_client_dev_hotplug+0xcc/0x140
 [<ffff800002e9ab50>] handle_hpd_irq_helper+0x1b0/0x1e0 [amdgpu]
 [<90000000038f5da0>] process_one_work+0x160/0x300
 [<90000000038f6718>] worker_thread+0x318/0x440
 [<9000000003901b8c>] kthread+0x12c/0x220
 [<90000000038b1484>] ret_from_kernel_thread+0x8/0xa4

Unfortunately, protecting dml2_validate()/dml21_validate() out of DML2
causes "sleeping function called from invalid context", so protect them
with DC_FP_START() and DC_FP_END() inside.

Fixes: 7da55c2 ("drm/amd/display: Remove incorrect FP context start")
Cc: [email protected]
Signed-off-by: Huacai Chen <[email protected]>
Tested-by: Dongyan Qian <[email protected]>
Reviewed-by: Aurabindo Pillai <[email protected]>
Tested-by: Daniel Wheeler <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request May 21, 2025
commit be6e843 upstream.

When migrating a THP, concurrent access to the PMD migration entry during
a deferred split scan can lead to an invalid address access, as
illustrated below.  To prevent this invalid access, it is necessary to
check the PMD migration entry and return early.  In this context, there is
no need to use pmd_to_swp_entry and pfn_swap_entry_to_page to verify the
equality of the target folio.  Since the PMD migration entry is locked, it
cannot be served as the target.

Mailing list discussion and explanation from Hugh Dickins: "An anon_vma
lookup points to a location which may contain the folio of interest, but
might instead contain another folio: and weeding out those other folios is
precisely what the "folio != pmd_folio((*pmd)" check (and the "risk of
replacing the wrong folio" comment a few lines above it) is for."

BUG: unable to handle page fault for address: ffffea60001db008
CPU: 0 UID: 0 PID: 2199114 Comm: tee Not tainted 6.14.0+ #4 NONE
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:split_huge_pmd_locked+0x3b5/0x2b60
Call Trace:
<TASK>
try_to_migrate_one+0x28c/0x3730
rmap_walk_anon+0x4f6/0x770
unmap_folio+0x196/0x1f0
split_huge_page_to_list_to_order+0x9f6/0x1560
deferred_split_scan+0xac5/0x12a0
shrinker_debugfs_scan_write+0x376/0x470
full_proxy_write+0x15c/0x220
vfs_write+0x2fc/0xcb0
ksys_write+0x146/0x250
do_syscall_64+0x6a/0x120
entry_SYSCALL_64_after_hwframe+0x76/0x7e

The bug is found by syzkaller on an internal kernel, then confirmed on
upstream.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lore.kernel.org/all/[email protected]/
Link: https://lore.kernel.org/all/[email protected]/
Fixes: 84c3fc4 ("mm: thp: check pmd migration entry in common path")
Signed-off-by: Gavin Guo <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Acked-by: Hugh Dickins <[email protected]>
Acked-by: Zi Yan <[email protected]>
Reviewed-by: Gavin Shan <[email protected]>
Cc: Florent Revest <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Miaohe Lin <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
spockfish pushed a commit that referenced this pull request May 24, 2025
commit 78ab4be upstream.

A warning on driver removal started occurring after commit 9dd05df
("net: warn if NAPI instance wasn't shut down"). Disable tx napi before
deleting it in mt76_dma_cleanup().

 WARNING: CPU: 4 PID: 18828 at net/core/dev.c:7288 __netif_napi_del_locked+0xf0/0x100
 CPU: 4 UID: 0 PID: 18828 Comm: modprobe Not tainted 6.15.0-rc4 #4 PREEMPT(lazy)
 Hardware name: ASUS System Product Name/PRIME X670E-PRO WIFI, BIOS 3035 09/05/2024
 RIP: 0010:__netif_napi_del_locked+0xf0/0x100
 Call Trace:
 <TASK>
 mt76_dma_cleanup+0x54/0x2f0 [mt76]
 mt7921_pci_remove+0xd5/0x190 [mt7921e]
 pci_device_remove+0x47/0xc0
 device_release_driver_internal+0x19e/0x200
 driver_detach+0x48/0x90
 bus_remove_driver+0x6d/0xf0
 pci_unregister_driver+0x2e/0xb0
 __do_sys_delete_module.isra.0+0x197/0x2e0
 do_syscall_64+0x7b/0x160
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Tested with mt7921e but the same pattern can be actually applied to other
mt76 drivers calling mt76_dma_cleanup() during removal. Tx napi is enabled
in their *_dma_init() functions and only toggled off and on again inside
their suspend/resume/reset paths. So it should be okay to disable tx
napi in such a generic way.

Found by Linux Verification Center (linuxtesting.org).

Fixes: 2ac515a ("mt76: mt76x02: use napi polling for tx cleanup")
Cc: [email protected]
Signed-off-by: Fedor Pchelkin <[email protected]>
Tested-by: Ming Yen Hsieh <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Felix Fietkau <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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