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Merged
merged 1 commit into from
Nov 25, 2024

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@gvrose8192 gvrose8192 commented Nov 25, 2024

Commit

jira VULN-6743
cve CVE-2023-5178
commit-author Sagi Grimberg <[email protected]>
commit d920abd1e7c4884f9ecd0749d1921b7ab19ddfbd

From Alon:
"Due to a logical bug in the NVMe-oF/TCP subsystem in the Linux kernel, a malicious user can cause a UAF and a double free, which may lead to RCE (may also lead to an LPE in case the attacker already has local privileges)."

Hence, when a queue initialization fails after the ahash requests are allocated, it is guaranteed that the queue removal async work will be called, hence leave the deallocation to the queue removal.

Also, be extra careful not to continue processing the socket, so set queue rcv_state to NVMET_TCP_RECV_ERR upon a socket error.

	Cc: [email protected]
	Reported-by: Alon Zahavi <[email protected]>
	Tested-by: Alon Zahavi <[email protected]>
	Signed-off-by: Sagi Grimberg <[email protected]>
	Reviewed-by: Christoph Hellwig <[email protected]>
	Reviewed-by: Chaitanya Kulkarni <[email protected]>
	Signed-off-by: Keith Busch <[email protected]>
(cherry picked from commit d920abd1e7c4884f9ecd0749d1921b7ab19ddfbd)
	Signed-off-by: Greg Rose <[email protected]>

BUILD

Builds:
`kABI check will be skipped
/home/g.v.rose/prj/kernel-build-tmp
  CLEAN   .
  CLEAN   arch/x86/entry/vdso
  CLEAN   arch/x86/kernel/cpu
  CLEAN   arch/x86/kernel
  CLEAN   arch/x86/purgatory
  CLEAN   arch/x86/realmode/rm
  CLEAN   arch/x86/lib
  CLEAN   certs
  CLEAN   drivers/firmware/efi/libstub
  CLEAN   drivers/gpu/drm/radeon
  CLEAN   drivers/scsi
  CLEAN   drivers/tty/vt
  CLEAN   drivers/video/logo
  CLEAN   kernel/debug/kdb
  CLEAN   kernel
  CLEAN   lib/raid6
  CLEAN   lib
  CLEAN   net/wireless
  CLEAN   security/selinux
  CLEAN   usr
  CLEAN   arch/x86/boot/compressed
  CLEAN   arch/x86/boot
  CLEAN   arch/x86/tools
  CLEAN   .tmp_versions
  CLEAN   scripts/basic
  CLEAN   scripts/genksyms
  CLEAN   scripts/kconfig
  CLEAN   scripts/mod
  CLEAN   scripts/selinux/genheaders
  CLEAN   scripts/selinux/mdp
  CLEAN   scripts
  CLEAN   include/config usr/include include/generated arch/x86/include/generated
  CLEAN   .config .config.old .version Module.symvers
[TIMER]{MRPROPER}: 14s
x86_64 architecture detected, copying config
'configs/kernel-4.18.0-x86_64.config' -> '.config'
Setting Local Version for build
CONFIG_LOCALVERSION="-debug-branch"
Making olddefconfig
  HOSTCC  scripts/basic/fixdep
  HOSTCC  scripts/kconfig/conf.o
  YACC    scripts/kconfig/zconf.tab.c
  LEX     scripts/kconfig/zconf.lex.c
  HOSTCC  scripts/kconfig/zconf.tab.o
  HOSTLD  scripts/kconfig/conf
scripts/kconfig/conf  --olddefconfig Kconfig

[SNIP]

  INSTALL sound/x86/snd-hdmi-lpe-audio.ko
  INSTALL virt/lib/irqbypass.ko
  DEPMOD  4.18.0-debug-branch+
[TIMER]{MODULES}: 44s
Making Install
sh ./arch/x86/boot/install.sh 4.18.0-debug-branch+ arch/x86/boot/bzImage \
        System.map "/boot"
[TIMER]{INSTALL}: 12s
Checking kABI
kABI check skipped
Setting Default Kernel to /boot/vmlinuz-4.18.0-debug-branch+ and Index to 0
Hopefully Grub2.0 took everything ... rebooting after time metrices
[TIMER]{MRPROPER}: 14s
[TIMER]{BUILD}: 2022s
[TIMER]{MODULES}: 44s
[TIMER]{INSTALL}: 12s
[TIMER]{TOTAL} 2097s
Rebooting in 10 seconds
`

As noted the KABI check is skipped due to RT kernel.

Boots and runs:
[g.v.rose@rocky8-6-lts-rt kernel-build-tmp]$ uname -a Linux rocky8-6-lts-rt 4.18.0-debug-branch+ #2 SMP PREEMPT_RT Mon Nov 25 11:42:47 EST 2024 x86_64 x86_64 x86_64 GNU/Linux

Passes kernel selftests with no notable error differences.
kernel-selftests-before.log
kernel-selftests-after.log

Passed kernel selftests with lockdep and kmemleak enabled:
kernel-selftests-ldpon.log

The kernel selftests run with lockdep / kmemleak / stress do not finish. The same is true for the RT kernel without this change so it is unrelated. The lockdep enabled kernel just won't run selftests on RT with stress enabled.

jira VULN-6743
cve CVE-2023-5178
commit-author Sagi Grimberg <[email protected]>
commit d920abd

From Alon:
"Due to a logical bug in the NVMe-oF/TCP subsystem in the Linux kernel,
a malicious user can cause a UAF and a double free, which may lead to
RCE (may also lead to an LPE in case the attacker already has local
privileges)."

Hence, when a queue initialization fails after the ahash requests are
allocated, it is guaranteed that the queue removal async work will be
called, hence leave the deallocation to the queue removal.

Also, be extra careful not to continue processing the socket, so set
queue rcv_state to NVMET_TCP_RECV_ERR upon a socket error.

	Cc: [email protected]
	Reported-by: Alon Zahavi <[email protected]>
	Tested-by: Alon Zahavi <[email protected]>
	Signed-off-by: Sagi Grimberg <[email protected]>
	Reviewed-by: Christoph Hellwig <[email protected]>
	Reviewed-by: Chaitanya Kulkarni <[email protected]>
	Signed-off-by: Keith Busch <[email protected]>
(cherry picked from commit d920abd)
	Signed-off-by: Greg Rose <[email protected]>
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:shipit:

@gvrose8192 gvrose8192 merged commit f2e90fe into ciqlts8_6-rt Nov 25, 2024
@gvrose8192 gvrose8192 deleted the gvrose_ciqlts8_6-rt branch November 25, 2024 21:00
PlaidCat added a commit that referenced this pull request Dec 16, 2024
jira LE-2157
Rebuild_History Non-Buildable kernel-5.14.0-503.15.1.el9_5
commit-author Jamie Bainbridge <[email protected]>
commit a699781

A sysfs reader can race with a device reset or removal, attempting to
read device state when the device is not actually present. eg:

     [exception RIP: qed_get_current_link+17]
  #8 [ffffb9e4f2907c48] qede_get_link_ksettings at ffffffffc07a994a [qede]
  #9 [ffffb9e4f2907cd8] __rh_call_get_link_ksettings at ffffffff992b01a3
 #10 [ffffb9e4f2907d38] __ethtool_get_link_ksettings at ffffffff992b04e4
 #11 [ffffb9e4f2907d90] duplex_show at ffffffff99260300
 #12 [ffffb9e4f2907e38] dev_attr_show at ffffffff9905a01c
 #13 [ffffb9e4f2907e50] sysfs_kf_seq_show at ffffffff98e0145b
 #14 [ffffb9e4f2907e68] seq_read at ffffffff98d902e3
 #15 [ffffb9e4f2907ec8] vfs_read at ffffffff98d657d1
 #16 [ffffb9e4f2907f00] ksys_read at ffffffff98d65c3f
 #17 [ffffb9e4f2907f38] do_syscall_64 at ffffffff98a052fb

 crash> struct net_device.state ffff9a9d21336000
    state = 5,

state 5 is __LINK_STATE_START (0b1) and __LINK_STATE_NOCARRIER (0b100).
The device is not present, note lack of __LINK_STATE_PRESENT (0b10).

This is the same sort of panic as observed in commit 4224cfd
("net-sysfs: add check for netdevice being present to speed_show").

There are many other callers of __ethtool_get_link_ksettings() which
don't have a device presence check.

Move this check into ethtool to protect all callers.

Fixes: d519e17 ("net: export device speed and duplex via sysfs")
Fixes: 4224cfd ("net-sysfs: add check for netdevice being present to speed_show")
	Signed-off-by: Jamie Bainbridge <[email protected]>
Link: https://patch.msgid.link/8bae218864beaa44ed01628140475b9bf641c5b0.1724393671.git.jamie.bainbridge@gmail.com
	Signed-off-by: Jakub Kicinski <[email protected]>
(cherry picked from commit a699781)
	Signed-off-by: Jonathan Maple <[email protected]>
PlaidCat added a commit that referenced this pull request Dec 17, 2024
jira LE-2169
Rebuild_History Non-Buildable kernel-4.18.0-553.27.1.el8_10
commit-author Jamie Bainbridge <[email protected]>
commit a699781

A sysfs reader can race with a device reset or removal, attempting to
read device state when the device is not actually present. eg:

     [exception RIP: qed_get_current_link+17]
  #8 [ffffb9e4f2907c48] qede_get_link_ksettings at ffffffffc07a994a [qede]
  #9 [ffffb9e4f2907cd8] __rh_call_get_link_ksettings at ffffffff992b01a3
 #10 [ffffb9e4f2907d38] __ethtool_get_link_ksettings at ffffffff992b04e4
 #11 [ffffb9e4f2907d90] duplex_show at ffffffff99260300
 #12 [ffffb9e4f2907e38] dev_attr_show at ffffffff9905a01c
 #13 [ffffb9e4f2907e50] sysfs_kf_seq_show at ffffffff98e0145b
 #14 [ffffb9e4f2907e68] seq_read at ffffffff98d902e3
 #15 [ffffb9e4f2907ec8] vfs_read at ffffffff98d657d1
 #16 [ffffb9e4f2907f00] ksys_read at ffffffff98d65c3f
 #17 [ffffb9e4f2907f38] do_syscall_64 at ffffffff98a052fb

 crash> struct net_device.state ffff9a9d21336000
    state = 5,

state 5 is __LINK_STATE_START (0b1) and __LINK_STATE_NOCARRIER (0b100).
The device is not present, note lack of __LINK_STATE_PRESENT (0b10).

This is the same sort of panic as observed in commit 4224cfd
("net-sysfs: add check for netdevice being present to speed_show").

There are many other callers of __ethtool_get_link_ksettings() which
don't have a device presence check.

Move this check into ethtool to protect all callers.

Fixes: d519e17 ("net: export device speed and duplex via sysfs")
Fixes: 4224cfd ("net-sysfs: add check for netdevice being present to speed_show")
	Signed-off-by: Jamie Bainbridge <[email protected]>
Link: https://patch.msgid.link/8bae218864beaa44ed01628140475b9bf641c5b0.1724393671.git.jamie.bainbridge@gmail.com
	Signed-off-by: Jakub Kicinski <[email protected]>
(cherry picked from commit a699781)
	Signed-off-by: Jonathan Maple <[email protected]>
pvts-mat pushed a commit to pvts-mat/kernel-src-tree that referenced this pull request Jan 14, 2025
jira LE-1907
Rebuild_History Non-Buildable kernel-rt-5.14.0-284.30.1.rt14.315.el9_2
commit-author Stefan Assmann <[email protected]>
commit 4e264be

When a system with E810 with existing VFs gets rebooted the following
hang may be observed.

 Pid 1 is hung in iavf_remove(), part of a network driver:
 PID: 1        TASK: ffff965400e5a340  CPU: 24   COMMAND: "systemd-shutdow"
  #0 [ffffaad04005fa50] __schedule at ffffffff8b3239cb
  ctrliq#1 [ffffaad04005fae8] schedule at ffffffff8b323e2d
  ctrliq#2 [ffffaad04005fb00] schedule_hrtimeout_range_clock at ffffffff8b32cebc
  ctrliq#3 [ffffaad04005fb80] usleep_range_state at ffffffff8b32c930
  ctrliq#4 [ffffaad04005fbb0] iavf_remove at ffffffffc12b9b4c [iavf]
  ctrliq#5 [ffffaad04005fbf0] pci_device_remove at ffffffff8add7513
  ctrliq#6 [ffffaad04005fc10] device_release_driver_internal at ffffffff8af08baa
  ctrliq#7 [ffffaad04005fc40] pci_stop_bus_device at ffffffff8adcc5fc
  ctrliq#8 [ffffaad04005fc60] pci_stop_and_remove_bus_device at ffffffff8adcc81e
  ctrliq#9 [ffffaad04005fc70] pci_iov_remove_virtfn at ffffffff8adf9429
 ctrliq#10 [ffffaad04005fca8] sriov_disable at ffffffff8adf98e4
 ctrliq#11 [ffffaad04005fcc8] ice_free_vfs at ffffffffc04bb2c8 [ice]
 ctrliq#12 [ffffaad04005fd10] ice_remove at ffffffffc04778fe [ice]
 ctrliq#13 [ffffaad04005fd38] ice_shutdown at ffffffffc0477946 [ice]
 ctrliq#14 [ffffaad04005fd50] pci_device_shutdown at ffffffff8add58f1
 ctrliq#15 [ffffaad04005fd70] device_shutdown at ffffffff8af05386
 ctrliq#16 [ffffaad04005fd98] kernel_restart at ffffffff8a92a870
 ctrliq#17 [ffffaad04005fda8] __do_sys_reboot at ffffffff8a92abd6
 ctrliq#18 [ffffaad04005fee0] do_syscall_64 at ffffffff8b317159
 ctrliq#19 [ffffaad04005ff08] __context_tracking_enter at ffffffff8b31b6fc
 ctrliq#20 [ffffaad04005ff18] syscall_exit_to_user_mode at ffffffff8b31b50d
 ctrliq#21 [ffffaad04005ff28] do_syscall_64 at ffffffff8b317169
 ctrliq#22 [ffffaad04005ff50] entry_SYSCALL_64_after_hwframe at ffffffff8b40009b
     RIP: 00007f1baa5c13d7  RSP: 00007fffbcc55a98  RFLAGS: 00000202
     RAX: ffffffffffffffda  RBX: 0000000000000000  RCX: 00007f1baa5c13d7
     RDX: 0000000001234567  RSI: 0000000028121969  RDI: 00000000fee1dead
     RBP: 00007fffbcc55ca0   R8: 0000000000000000   R9: 00007fffbcc54e90
     R10: 00007fffbcc55050  R11: 0000000000000202  R12: 0000000000000005
     R13: 0000000000000000  R14: 00007fffbcc55af0  R15: 0000000000000000
     ORIG_RAX: 00000000000000a9  CS: 0033  SS: 002b

During reboot all drivers PM shutdown callbacks are invoked.
In iavf_shutdown() the adapter state is changed to __IAVF_REMOVE.
In ice_shutdown() the call chain above is executed, which at some point
calls iavf_remove(). However iavf_remove() expects the VF to be in one
of the states __IAVF_RUNNING, __IAVF_DOWN or __IAVF_INIT_FAILED. If
that's not the case it sleeps forever.
So if iavf_shutdown() gets invoked before iavf_remove() the system will
hang indefinitely because the adapter is already in state __IAVF_REMOVE.

Fix this by returning from iavf_remove() if the state is __IAVF_REMOVE,
as we already went through iavf_shutdown().

Fixes: 9745780 ("iavf: Add waiting so the port is initialized in remove")
Fixes: a841733 ("iavf: Fix race condition between iavf_shutdown and iavf_remove")
	Reported-by: Marius Cornea <[email protected]>
	Signed-off-by: Stefan Assmann <[email protected]>
	Reviewed-by: Michal Kubiak <[email protected]>
	Tested-by: Rafal Romanowski <[email protected]>
	Signed-off-by: Tony Nguyen <[email protected]>
(cherry picked from commit 4e264be)
	Signed-off-by: Jonathan Maple <[email protected]>
pvts-mat pushed a commit to pvts-mat/kernel-src-tree that referenced this pull request Jan 14, 2025
jira LE-1907
Rebuild_History Non-Buildable kernel-rt-5.14.0-284.30.1.rt14.315.el9_2
commit-author Eelco Chaudron <[email protected]>
commit de9df6c

Currently, the per cpu upcall counters are allocated after the vport is
created and inserted into the system. This could lead to the datapath
accessing the counters before they are allocated resulting in a kernel
Oops.

Here is an example:

  PID: 59693    TASK: ffff0005f4f51500  CPU: 0    COMMAND: "ovs-vswitchd"
   #0 [ffff80000a39b5b0] __switch_to at ffffb70f0629f2f4
   ctrliq#1 [ffff80000a39b5d0] __schedule at ffffb70f0629f5cc
   ctrliq#2 [ffff80000a39b650] preempt_schedule_common at ffffb70f0629fa60
   ctrliq#3 [ffff80000a39b670] dynamic_might_resched at ffffb70f0629fb58
   ctrliq#4 [ffff80000a39b680] mutex_lock_killable at ffffb70f062a1388
   ctrliq#5 [ffff80000a39b6a0] pcpu_alloc at ffffb70f0594460c
   ctrliq#6 [ffff80000a39b750] __alloc_percpu_gfp at ffffb70f05944e68
   ctrliq#7 [ffff80000a39b760] ovs_vport_cmd_new at ffffb70ee6961b90 [openvswitch]
   ...

  PID: 58682    TASK: ffff0005b2f0bf00  CPU: 0    COMMAND: "kworker/0:3"
   #0 [ffff80000a5d2f40] machine_kexec at ffffb70f056a0758
   ctrliq#1 [ffff80000a5d2f70] __crash_kexec at ffffb70f057e2994
   ctrliq#2 [ffff80000a5d3100] crash_kexec at ffffb70f057e2ad8
   ctrliq#3 [ffff80000a5d3120] die at ffffb70f0628234c
   ctrliq#4 [ffff80000a5d31e0] die_kernel_fault at ffffb70f062828a8
   ctrliq#5 [ffff80000a5d3210] __do_kernel_fault at ffffb70f056a31f4
   ctrliq#6 [ffff80000a5d3240] do_bad_area at ffffb70f056a32a4
   ctrliq#7 [ffff80000a5d3260] do_translation_fault at ffffb70f062a9710
   ctrliq#8 [ffff80000a5d3270] do_mem_abort at ffffb70f056a2f74
   ctrliq#9 [ffff80000a5d32a0] el1_abort at ffffb70f06297dac
  ctrliq#10 [ffff80000a5d32d0] el1h_64_sync_handler at ffffb70f06299b24
  ctrliq#11 [ffff80000a5d3410] el1h_64_sync at ffffb70f056812dc
  ctrliq#12 [ffff80000a5d3430] ovs_dp_upcall at ffffb70ee6963c84 [openvswitch]
  ctrliq#13 [ffff80000a5d3470] ovs_dp_process_packet at ffffb70ee6963fdc [openvswitch]
  ctrliq#14 [ffff80000a5d34f0] ovs_vport_receive at ffffb70ee6972c78 [openvswitch]
  ctrliq#15 [ffff80000a5d36f0] netdev_port_receive at ffffb70ee6973948 [openvswitch]
  ctrliq#16 [ffff80000a5d3720] netdev_frame_hook at ffffb70ee6973a28 [openvswitch]
  ctrliq#17 [ffff80000a5d3730] __netif_receive_skb_core.constprop.0 at ffffb70f06079f90

We moved the per cpu upcall counter allocation to the existing vport
alloc and free functions to solve this.

Fixes: 95637d9 ("net: openvswitch: release vport resources on failure")
Fixes: 1933ea3 ("net: openvswitch: Add support to count upcall packets")
	Signed-off-by: Eelco Chaudron <[email protected]>
	Reviewed-by: Simon Horman <[email protected]>
	Acked-by: Aaron Conole <[email protected]>
	Signed-off-by: David S. Miller <[email protected]>
(cherry picked from commit de9df6c)
	Signed-off-by: Jonathan Maple <[email protected]>
github-actions bot pushed a commit to bmastbergen/kernel-src-tree that referenced this pull request Apr 4, 2025
…ge_order()

Patch series "mm: MM owner tracking for large folios (!hugetlb) +
CONFIG_NO_PAGE_MAPCOUNT", v3.

Let's add an "easy" way to decide -- without false positives, without
page-mapcounts and without page table/rmap scanning -- whether a large
folio is "certainly mapped exclusively" into a single MM, or whether it
"maybe mapped shared" into multiple MMs.

Use that information to implement Copy-on-Write reuse, to convert
folio_likely_mapped_shared() to folio_maybe_mapped_share(), and to
introduce a kernel config option that lets us not use+maintain per-page
mapcounts in large folios anymore.

The bigger picture was presented at LSF/MM [1].

This series is effectively a follow-up on my early work [2], which
implemented a more precise, but also more complicated, way to identify
whether a large folio is "mapped shared" into multiple MMs or "mapped
exclusively" into a single MM.


1 Patch Organization
====================

Patch #1 -> ctrliq#6: make more room in order-1 folios, so we have two
                "unsigned long" available for our purposes

Patch ctrliq#7 -> ctrliq#11: preparations

Patch ctrliq#12: MM owner tracking for large folios

Patch ctrliq#13: COW reuse for PTE-mapped anon THP

Patch ctrliq#14: folio_maybe_mapped_shared()

Patch ctrliq#15 -> ctrliq#20: introduce and implement CONFIG_NO_PAGE_MAPCOUNT


2 MM owner tracking
===================

We assign each MM a unique ID ("MM ID"), to be able to squeeze more
information in our folios.  On 32bit we use 15-bit IDs, on 64bit we use
31-bit IDs.

For each large folios, we now store two MM-ID+mapcount ("slot")
combinations:
* mm0_id + mm0_mapcount
* mm1_id + mm1_mapcount

On 32bit, we use a 16-bit per-MM mapcount, on 64bit an ordinary 32bit
mapcount.  This way, we require 2x "unsigned long" on 32bit and 64bit for
both slots.

Paired with the large mapcount, we can reliably identify whether one of
these MMs is the current owner (-> owns all mappings) or even holds all
folio references (-> owns all mappings, and all references are from
mappings).

As long as only two MMs map folio pages at a time, we can reliably and
precisely identify whether a large folio is "mapped shared" or "mapped
exclusively".

Any additional MM that starts mapping the folio while there are no free
slots becomes an "untracked MM".  If one such "untracked MM" is the last
one mapping a folio exclusively, we will not detect the folio as "mapped
exclusively" but instead as "maybe mapped shared".  (exception: only a
single mapping remains)

So that's where the approach gets imprecise.

For now, we use a bit-spinlock to sync the large mapcount + slots, and
make sure we do keep the machinery fast, to not degrade (un)map
performance drastically: for example, we make sure to only use a single
atomic (when grabbing the bit-spinlock), like we would already perform
when updating the large mapcount.


3 CONFIG_NO_PAGE_MAPCOUNT
=========================

patch ctrliq#15 -> ctrliq#20 spell out and document what exactly is affected when not
maintaining the per-page mapcounts in large folios anymore.

Most importantly, as we cannot maintain folio->_nr_pages_mapped anymore
when (un)mapping pages, we'll account a complete folio as mapped if a
single page is mapped.  In addition, we'll not detect partially mapped
anonymous folios as such in all cases yet.

Likely less relevant changes include that we might now under-estimate the
USS (Unique Set Size) of a process, but never over-estimate it.

The goal is to make CONFIG_NO_PAGE_MAPCOUNT the default at some point, to
then slowly make it the only option, as we learn about real-life impacts
and possible ways to mitigate them.


4 Performance
=============

Detailed performance numbers were included in v1 [3], and not that much
changed between v1 and v2.

I did plenty of measurements on different systems in the meantime, that
all revealed slightly different results.

The pte-mapped-folio micro-benchmarks [4] are fairly sensitive to code
layout changes on some systems.  Especially the fork() benchmark started
being more-shaky-than-before on recent kernels for some reason.

In summary, with my micro-benchmarks:

* Small folios are not impacted.

* CoW performance seems to be mostly unchanged across all folios sizes.

* CoW reuse performance of large folios now matches CoW reuse
  performance of small folios, because we now actually implement the CoW
  reuse optimization.  On an Intel Xeon Silver 4210R I measured a ~65%
  reduction in runtime, on an arm64 system I measured ~54% reduction.

* munmap() performance improves with CONFIG_NO_PAGE_MAPCOUNT.  I saw
  double-digit % reduction (up to ~30% on an Intel Xeon Silver 4210R and
  up to ~70% on an AmpereOne A192-32X) with larger folios.  The larger the
  folios, the larger the performance improvement.

* munmao() performance very slightly (couple percent) degrades without
  CONFIG_NO_PAGE_MAPCOUNT for smaller folios.  For larger folios, there
  seems to be no change at all.

* fork() performance improves with CONFIG_NO_PAGE_MAPCOUNT.  I saw
  double-digit % reduction (up to ~20% on an Intel Xeon Silver 4210R and
  up to ~10% on an AmpereOne A192-32X) with larger folios.  The larger the
  folios, the larger the performance improvement.

* While fork() performance without CONFIG_NO_PAGE_MAPCOUNT seems to be
  almost unchanged on some systems, I saw some degradation for smaller
  folios on the AmpereOne A192-32X.  I did not investigate the details
  yet, but I suspect code layout changes or suboptimal code placement /
  inlining.

I'm not to worried about the fork() micro-benchmarks for smaller folios
given how shaky the results are lately and by how much we improved fork()
performance recently.

I also ran case-anon-cow-rand and case-anon-cow-seq part of
vm-scalability, to assess the scalability and the impact of the
bit-spinlock.  My measurements on a two 2-socket 10-core Intel Xeon Silver
4210R CPU revealed no significant changes.

Similarly, running these benchmarks with 2 MiB THPs enabled on the
AmpereOne A192-32X with 192 cores, I got < 1% difference with < 1% stdev,
which is nice.

So far, I did not get my hands on a similarly large system with multiple
sockets.

I found no other fitting scalability benchmarks that seem to really hammer
on concurrent mapping/unmapping of large folio pages like
case-anon-cow-seq does.


5 Concerns
==========

5.1 Bit spinlock
----------------

I'm not quite happy about the bit-spinlock, but so far it does not seem to
affect scalability in my measurements.

If it ever becomes a problem we could either investigate improving the
locking, or simply stopping the MM tracking once there are "too many
mappings" and simply assume that the folio is "mapped shared" until it was
freed.

This would be similar (but slightly different) to the "0,1,2,stopped"
counting idea Willy had at some point.  Adding that logic to "stop
tracking" adds more code to the hot path, so I avoided that for now.


5.2 folio_maybe_mapped_shared()
-------------------------------

I documented the change from folio_likely_mapped_shared() to
folio_maybe_mapped_shared() quite extensively.  If we run into surprises,
I have some ideas on how to resolve them.  For now, I think we should be
fine.


5.3 Added code to map/unmap hot path
------------------------------------

So far, it looks like the added code on the rmap hot path does not really
seem to matter much in the bigger picture.  I'd like to further reduce it
(and possibly improve fork() performance further), but I don't easily see
how right now.  Well, and I am out of puff 🙂

Having that said, alternatives I considered (e.g., per-MM per-folio
mapcount) would add a lot more overhead to these hot paths.


6 Future Work
=============

6.1 Large mapcount
------------------

It would be very handy if the large mapcount would count how often folio
pages are actually mapped into page tables: a PMD on x86-64 would count
512 times.  Calculating the average per-page mapcount will be easy, and
remapping (PMD->PTE) folios would get even faster.

That would also remove the need for the entire mapcount (except for
PMD-sized folios for memory statistics reasons ...), and allow for mapping
folios larger than PMDs (e.g., 4 MiB) easily.

We likely would also have to take the same number of folio references to
make our folio_mapcount() == folio_ref_count() work, and we'd want to be
able to avoid mapcount+refcount overflows: this could already become an
issue with pte-mapped PUD-sized folios (fsdax).

One approach we discussed in the THP cabal meeting is (1) extending the
mapcount for large folios to 64bit (at least on 64bit systems) and (2)
keeping the refcount at 32bit, but (3) having exactly one reference if the
the mapcount != 0.

It should be doable, but there are some corner cases to consider on the
unmap path; it is something that I will be looking into next.


6.2 hugetlb
-----------

I'd love to make use of the same tracking also for hugetlb.

The real problem is PMD table sharing: getting a page mapped by MM X and
unmapped by MM Y will not work.  With mshare, that problem should not
exist (all mapping/unmapping will be routed through the mshare MM).

[1] https://lwn.net/Articles/974223/
[2] https://lore.kernel.org/linux-mm/[email protected]/T/
[3] https://lkml.kernel.org/r/[email protected]
[4] https://gitlab.com/davidhildenbrand/scratchspace/-/raw/main/pte-mapped-folio-benchmarks.c


This patch (of 20):

Let's factor it out into a simple helper function.  This helper will also
come in handy when working with code where we know that our folio is
large.

Maybe in the future we'll have the order readily available for small and
large folios; in that case, folio_large_order() would simply translate to
folio_order().

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Reviewed-by: Lance Yang <[email protected]>
Reviewed-by: Kirill A. Shutemov <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Andy Lutomirks^H^Hski <[email protected]>
Cc: Borislav Betkov <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Liam Howlett <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Cc: Matthew Wilcow (Oracle) <[email protected]>
Cc: Michal Koutn <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: tejun heo <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Zefan Li <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Kemotaha pushed a commit to ctrliq/kernel-pkg-fork that referenced this pull request Apr 7, 2025
[ Upstream commit 1626e5e ]

While performing the rq locking dance in dispatch_to_local_dsq(), we may
trigger the following lock imbalance condition, in particular when
multiple tasks are rapidly changing CPU affinity (i.e., running a
`stress-ng --race-sched 0`):

[   13.413579] =====================================
[   13.413660] WARNING: bad unlock balance detected!
[   13.413729] 6.13.0-virtme ctrliq#15 Not tainted
[   13.413792] -------------------------------------
[   13.413859] kworker/1:1/80 is trying to release lock (&rq->__lock) at:
[   13.413954] [<ffffffff873c6c48>] dispatch_to_local_dsq+0x108/0x1a0
[   13.414111] but there are no more locks to release!
[   13.414176]
[   13.414176] other info that might help us debug this:
[   13.414258] 1 lock held by kworker/1:1/80:
[   13.414318]  #0: ffff8b66feb41698 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x20/0x90
[   13.414612]
[   13.414612] stack backtrace:
[   13.415255] CPU: 1 UID: 0 PID: 80 Comm: kworker/1:1 Not tainted 6.13.0-virtme ctrliq#15
[   13.415505] Workqueue:  0x0 (events)
[   13.415567] Sched_ext: dsp_local_on (enabled+all), task: runnable_at=-2ms
[   13.415570] Call Trace:
[   13.415700]  <TASK>
[   13.415744]  dump_stack_lvl+0x78/0xe0
[   13.415806]  ? dispatch_to_local_dsq+0x108/0x1a0
[   13.415884]  print_unlock_imbalance_bug+0x11b/0x130
[   13.415965]  ? dispatch_to_local_dsq+0x108/0x1a0
[   13.416226]  lock_release+0x231/0x2c0
[   13.416326]  _raw_spin_unlock+0x1b/0x40
[   13.416422]  dispatch_to_local_dsq+0x108/0x1a0
[   13.416554]  flush_dispatch_buf+0x199/0x1d0
[   13.416652]  balance_one+0x194/0x370
[   13.416751]  balance_scx+0x61/0x1e0
[   13.416848]  prev_balance+0x43/0xb0
[   13.416947]  __pick_next_task+0x6b/0x1b0
[   13.417052]  __schedule+0x20d/0x1740

This happens because dispatch_to_local_dsq() is racing with
dispatch_dequeue() and, when the latter wins, we incorrectly assume that
the task has been moved to dst_rq.

Fix by properly tracking the currently locked rq.

Fixes: 4d3ca89 ("sched_ext: Refactor consume_remote_task()")
Signed-off-by: Andrea Righi <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
bmastbergen pushed a commit to bmastbergen/kernel-src-tree that referenced this pull request Apr 25, 2025
jira LE-1907
Rebuild_History Non-Buildable kernel-5.14.0-284.30.1.el9_2
commit-author Stefan Assmann <[email protected]>
commit 4e264be

When a system with E810 with existing VFs gets rebooted the following
hang may be observed.

 Pid 1 is hung in iavf_remove(), part of a network driver:
 PID: 1        TASK: ffff965400e5a340  CPU: 24   COMMAND: "systemd-shutdow"
  #0 [ffffaad04005fa50] __schedule at ffffffff8b3239cb
  #1 [ffffaad04005fae8] schedule at ffffffff8b323e2d
  #2 [ffffaad04005fb00] schedule_hrtimeout_range_clock at ffffffff8b32cebc
  #3 [ffffaad04005fb80] usleep_range_state at ffffffff8b32c930
  #4 [ffffaad04005fbb0] iavf_remove at ffffffffc12b9b4c [iavf]
  ctrliq#5 [ffffaad04005fbf0] pci_device_remove at ffffffff8add7513
  ctrliq#6 [ffffaad04005fc10] device_release_driver_internal at ffffffff8af08baa
  ctrliq#7 [ffffaad04005fc40] pci_stop_bus_device at ffffffff8adcc5fc
  ctrliq#8 [ffffaad04005fc60] pci_stop_and_remove_bus_device at ffffffff8adcc81e
  ctrliq#9 [ffffaad04005fc70] pci_iov_remove_virtfn at ffffffff8adf9429
 ctrliq#10 [ffffaad04005fca8] sriov_disable at ffffffff8adf98e4
 ctrliq#11 [ffffaad04005fcc8] ice_free_vfs at ffffffffc04bb2c8 [ice]
 ctrliq#12 [ffffaad04005fd10] ice_remove at ffffffffc04778fe [ice]
 ctrliq#13 [ffffaad04005fd38] ice_shutdown at ffffffffc0477946 [ice]
 ctrliq#14 [ffffaad04005fd50] pci_device_shutdown at ffffffff8add58f1
 ctrliq#15 [ffffaad04005fd70] device_shutdown at ffffffff8af05386
 ctrliq#16 [ffffaad04005fd98] kernel_restart at ffffffff8a92a870
 ctrliq#17 [ffffaad04005fda8] __do_sys_reboot at ffffffff8a92abd6
 ctrliq#18 [ffffaad04005fee0] do_syscall_64 at ffffffff8b317159
 ctrliq#19 [ffffaad04005ff08] __context_tracking_enter at ffffffff8b31b6fc
 ctrliq#20 [ffffaad04005ff18] syscall_exit_to_user_mode at ffffffff8b31b50d
 ctrliq#21 [ffffaad04005ff28] do_syscall_64 at ffffffff8b317169
 ctrliq#22 [ffffaad04005ff50] entry_SYSCALL_64_after_hwframe at ffffffff8b40009b
     RIP: 00007f1baa5c13d7  RSP: 00007fffbcc55a98  RFLAGS: 00000202
     RAX: ffffffffffffffda  RBX: 0000000000000000  RCX: 00007f1baa5c13d7
     RDX: 0000000001234567  RSI: 0000000028121969  RDI: 00000000fee1dead
     RBP: 00007fffbcc55ca0   R8: 0000000000000000   R9: 00007fffbcc54e90
     R10: 00007fffbcc55050  R11: 0000000000000202  R12: 0000000000000005
     R13: 0000000000000000  R14: 00007fffbcc55af0  R15: 0000000000000000
     ORIG_RAX: 00000000000000a9  CS: 0033  SS: 002b

During reboot all drivers PM shutdown callbacks are invoked.
In iavf_shutdown() the adapter state is changed to __IAVF_REMOVE.
In ice_shutdown() the call chain above is executed, which at some point
calls iavf_remove(). However iavf_remove() expects the VF to be in one
of the states __IAVF_RUNNING, __IAVF_DOWN or __IAVF_INIT_FAILED. If
that's not the case it sleeps forever.
So if iavf_shutdown() gets invoked before iavf_remove() the system will
hang indefinitely because the adapter is already in state __IAVF_REMOVE.

Fix this by returning from iavf_remove() if the state is __IAVF_REMOVE,
as we already went through iavf_shutdown().

Fixes: 9745780 ("iavf: Add waiting so the port is initialized in remove")
Fixes: a841733 ("iavf: Fix race condition between iavf_shutdown and iavf_remove")
	Reported-by: Marius Cornea <[email protected]>
	Signed-off-by: Stefan Assmann <[email protected]>
	Reviewed-by: Michal Kubiak <[email protected]>
	Tested-by: Rafal Romanowski <[email protected]>
	Signed-off-by: Tony Nguyen <[email protected]>
(cherry picked from commit 4e264be)
	Signed-off-by: Jonathan Maple <[email protected]>
bmastbergen pushed a commit to bmastbergen/kernel-src-tree that referenced this pull request Apr 25, 2025
jira LE-1907
Rebuild_History Non-Buildable kernel-5.14.0-284.30.1.el9_2
commit-author Eelco Chaudron <[email protected]>
commit de9df6c

Currently, the per cpu upcall counters are allocated after the vport is
created and inserted into the system. This could lead to the datapath
accessing the counters before they are allocated resulting in a kernel
Oops.

Here is an example:

  PID: 59693    TASK: ffff0005f4f51500  CPU: 0    COMMAND: "ovs-vswitchd"
   #0 [ffff80000a39b5b0] __switch_to at ffffb70f0629f2f4
   #1 [ffff80000a39b5d0] __schedule at ffffb70f0629f5cc
   #2 [ffff80000a39b650] preempt_schedule_common at ffffb70f0629fa60
   #3 [ffff80000a39b670] dynamic_might_resched at ffffb70f0629fb58
   #4 [ffff80000a39b680] mutex_lock_killable at ffffb70f062a1388
   ctrliq#5 [ffff80000a39b6a0] pcpu_alloc at ffffb70f0594460c
   ctrliq#6 [ffff80000a39b750] __alloc_percpu_gfp at ffffb70f05944e68
   ctrliq#7 [ffff80000a39b760] ovs_vport_cmd_new at ffffb70ee6961b90 [openvswitch]
   ...

  PID: 58682    TASK: ffff0005b2f0bf00  CPU: 0    COMMAND: "kworker/0:3"
   #0 [ffff80000a5d2f40] machine_kexec at ffffb70f056a0758
   #1 [ffff80000a5d2f70] __crash_kexec at ffffb70f057e2994
   #2 [ffff80000a5d3100] crash_kexec at ffffb70f057e2ad8
   #3 [ffff80000a5d3120] die at ffffb70f0628234c
   #4 [ffff80000a5d31e0] die_kernel_fault at ffffb70f062828a8
   ctrliq#5 [ffff80000a5d3210] __do_kernel_fault at ffffb70f056a31f4
   ctrliq#6 [ffff80000a5d3240] do_bad_area at ffffb70f056a32a4
   ctrliq#7 [ffff80000a5d3260] do_translation_fault at ffffb70f062a9710
   ctrliq#8 [ffff80000a5d3270] do_mem_abort at ffffb70f056a2f74
   ctrliq#9 [ffff80000a5d32a0] el1_abort at ffffb70f06297dac
  ctrliq#10 [ffff80000a5d32d0] el1h_64_sync_handler at ffffb70f06299b24
  ctrliq#11 [ffff80000a5d3410] el1h_64_sync at ffffb70f056812dc
  ctrliq#12 [ffff80000a5d3430] ovs_dp_upcall at ffffb70ee6963c84 [openvswitch]
  ctrliq#13 [ffff80000a5d3470] ovs_dp_process_packet at ffffb70ee6963fdc [openvswitch]
  ctrliq#14 [ffff80000a5d34f0] ovs_vport_receive at ffffb70ee6972c78 [openvswitch]
  ctrliq#15 [ffff80000a5d36f0] netdev_port_receive at ffffb70ee6973948 [openvswitch]
  ctrliq#16 [ffff80000a5d3720] netdev_frame_hook at ffffb70ee6973a28 [openvswitch]
  ctrliq#17 [ffff80000a5d3730] __netif_receive_skb_core.constprop.0 at ffffb70f06079f90

We moved the per cpu upcall counter allocation to the existing vport
alloc and free functions to solve this.

Fixes: 95637d9 ("net: openvswitch: release vport resources on failure")
Fixes: 1933ea3 ("net: openvswitch: Add support to count upcall packets")
	Signed-off-by: Eelco Chaudron <[email protected]>
	Reviewed-by: Simon Horman <[email protected]>
	Acked-by: Aaron Conole <[email protected]>
	Signed-off-by: David S. Miller <[email protected]>
(cherry picked from commit de9df6c)
	Signed-off-by: Jonathan Maple <[email protected]>
github-actions bot pushed a commit that referenced this pull request May 23, 2025
JIRA: https://issues.redhat.com/browse/RHEL-83380
CVE: CVE-2024-50301

commit 4a74da0
Author: Chen Ridong <[email protected]>
Date:   Tue Oct 8 12:46:39 2024 +0000

    security/keys: fix slab-out-of-bounds in key_task_permission

    KASAN reports an out of bounds read:
    BUG: KASAN: slab-out-of-bounds in __kuid_val include/linux/uidgid.h:36
    BUG: KASAN: slab-out-of-bounds in uid_eq include/linux/uidgid.h:63 [inline]
    BUG: KASAN: slab-out-of-bounds in key_task_permission+0x394/0x410
    security/keys/permission.c:54
    Read of size 4 at addr ffff88813c3ab618 by task stress-ng/4362

    CPU: 2 PID: 4362 Comm: stress-ng Not tainted 5.10.0-14930-gafbffd6c3ede #15
    Call Trace:
     __dump_stack lib/dump_stack.c:82 [inline]
     dump_stack+0x107/0x167 lib/dump_stack.c:123
     print_address_description.constprop.0+0x19/0x170 mm/kasan/report.c:400
     __kasan_report.cold+0x6c/0x84 mm/kasan/report.c:560
     kasan_report+0x3a/0x50 mm/kasan/report.c:585
     __kuid_val include/linux/uidgid.h:36 [inline]
     uid_eq include/linux/uidgid.h:63 [inline]
     key_task_permission+0x394/0x410 security/keys/permission.c:54
     search_nested_keyrings+0x90e/0xe90 security/keys/keyring.c:793

    This issue was also reported by syzbot.

    It can be reproduced by following these steps(more details [1]):
    1. Obtain more than 32 inputs that have similar hashes, which ends with the
       pattern '0xxxxxxxe6'.
    2. Reboot and add the keys obtained in step 1.

    The reproducer demonstrates how this issue happened:
    1. In the search_nested_keyrings function, when it iterates through the
       slots in a node(below tag ascend_to_node), if the slot pointer is meta
       and node->back_pointer != NULL(it means a root), it will proceed to
       descend_to_node. However, there is an exception. If node is the root,
       and one of the slots points to a shortcut, it will be treated as a
       keyring.
    2. Whether the ptr is keyring decided by keyring_ptr_is_keyring function.
       However, KEYRING_PTR_SUBTYPE is 0x2UL, the same as
       ASSOC_ARRAY_PTR_SUBTYPE_MASK.
    3. When 32 keys with the similar hashes are added to the tree, the ROOT
       has keys with hashes that are not similar (e.g. slot 0) and it splits
       NODE A without using a shortcut. When NODE A is filled with keys that
       all hashes are xxe6, the keys are similar, NODE A will split with a
       shortcut. Finally, it forms the tree as shown below, where slot 6 points
       to a shortcut.

                          NODE A
                  +------>+---+
          ROOT    |       | 0 | xxe6
          +---+   |       +---+
     xxxx | 0 | shortcut  :   : xxe6
          +---+   |       +---+
     xxe6 :   :   |       |   | xxe6
          +---+   |       +---+
          | 6 |---+       :   : xxe6
          +---+           +---+
     xxe6 :   :           | f | xxe6
          +---+           +---+
     xxe6 | f |
          +---+

    4. As mentioned above, If a slot(slot 6) of the root points to a shortcut,
       it may be mistakenly transferred to a key*, leading to a read
       out-of-bounds read.

    To fix this issue, one should jump to descend_to_node if the ptr is a
    shortcut, regardless of whether the node is root or not.

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

    [jarkko: tweaked the commit message a bit to have an appropriate closes
     tag.]
    Fixes: b2a4df2 ("KEYS: Expand the capacity of a keyring")
    Reported-by: [email protected]
    Closes: https://lore.kernel.org/all/[email protected]/T/
    Signed-off-by: Chen Ridong <[email protected]>
    Reviewed-by: Jarkko Sakkinen <[email protected]>
    Signed-off-by: Jarkko Sakkinen <[email protected]>

Signed-off-by: CKI Backport Bot <[email protected]>
github-actions bot pushed a commit that referenced this pull request May 23, 2025
…ask_permission

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/6573

JIRA: https://issues.redhat.com/browse/RHEL-83380
CVE: CVE-2024-50301

```
commit 4a74da0
Author: Chen Ridong <[email protected]>
Date:   Tue Oct 8 12:46:39 2024 +0000

    security/keys: fix slab-out-of-bounds in key_task_permission

    KASAN reports an out of bounds read:
    BUG: KASAN: slab-out-of-bounds in __kuid_val include/linux/uidgid.h:36
    BUG: KASAN: slab-out-of-bounds in uid_eq include/linux/uidgid.h:63 [inline]
    BUG: KASAN: slab-out-of-bounds in key_task_permission+0x394/0x410
    security/keys/permission.c:54
    Read of size 4 at addr ffff88813c3ab618 by task stress-ng/4362

    CPU: 2 PID: 4362 Comm: stress-ng Not tainted 5.10.0-14930-gafbffd6c3ede #15
    Call Trace:
     __dump_stack lib/dump_stack.c:82 [inline]
     dump_stack+0x107/0x167 lib/dump_stack.c:123
     print_address_description.constprop.0+0x19/0x170 mm/kasan/report.c:400
     __kasan_report.cold+0x6c/0x84 mm/kasan/report.c:560
     kasan_report+0x3a/0x50 mm/kasan/report.c:585
     __kuid_val include/linux/uidgid.h:36 [inline]
     uid_eq include/linux/uidgid.h:63 [inline]
     key_task_permission+0x394/0x410 security/keys/permission.c:54
     search_nested_keyrings+0x90e/0xe90 security/keys/keyring.c:793

    This issue was also reported by syzbot.

    It can be reproduced by following these steps(more details [1]):
    1. Obtain more than 32 inputs that have similar hashes, which ends with the
       pattern '0xxxxxxxe6'.
    2. Reboot and add the keys obtained in step 1.

    The reproducer demonstrates how this issue happened:
    1. In the search_nested_keyrings function, when it iterates through the
       slots in a node(below tag ascend_to_node), if the slot pointer is meta
       and node->back_pointer != NULL(it means a root), it will proceed to
       descend_to_node. However, there is an exception. If node is the root,
       and one of the slots points to a shortcut, it will be treated as a
       keyring.
    2. Whether the ptr is keyring decided by keyring_ptr_is_keyring function.
       However, KEYRING_PTR_SUBTYPE is 0x2UL, the same as
       ASSOC_ARRAY_PTR_SUBTYPE_MASK.
    3. When 32 keys with the similar hashes are added to the tree, the ROOT
       has keys with hashes that are not similar (e.g. slot 0) and it splits
       NODE A without using a shortcut. When NODE A is filled with keys that
       all hashes are xxe6, the keys are similar, NODE A will split with a
       shortcut. Finally, it forms the tree as shown below, where slot 6 points
       to a shortcut.

                          NODE A
                  +------>+---+
          ROOT    |       | 0 | xxe6
          +---+   |       +---+
     xxxx | 0 | shortcut  :   : xxe6
          +---+   |       +---+
     xxe6 :   :   |       |   | xxe6
          +---+   |       +---+
          | 6 |---+       :   : xxe6
          +---+           +---+
     xxe6 :   :           | f | xxe6
          +---+           +---+
     xxe6 | f |
          +---+

    4. As mentioned above, If a slot(slot 6) of the root points to a shortcut,
       it may be mistakenly transferred to a key*, leading to a read
       out-of-bounds read.

    To fix this issue, one should jump to descend_to_node if the ptr is a
    shortcut, regardless of whether the node is root or not.

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

    [jarkko: tweaked the commit message a bit to have an appropriate closes
     tag.]
    Fixes: b2a4df2 ("KEYS: Expand the capacity of a keyring")
    Reported-by: [email protected]
    Closes: https://lore.kernel.org/all/[email protected]/T/
    Signed-off-by: Chen Ridong <[email protected]>
    Reviewed-by: Jarkko Sakkinen <[email protected]>
    Signed-off-by: Jarkko Sakkinen <[email protected]>```

Signed-off-by: CKI Backport Bot <[email protected]>

---

<small>Created 2025-03-13 09:38 UTC by backporter - [KWF FAQ](https://red.ht/kernel_workflow_doc) - [Slack #team-kernel-workflow](https://redhat-internal.slack.com/archives/C04LRUPMJQ5) - [Source](https://gitlab.com/cki-project/kernel-workflow/-/blob/main/webhook/utils/backporter.py) - [Documentation](https://gitlab.com/cki-project/kernel-workflow/-/blob/main/docs/README.backporter.md) - [Report an issue](https://gitlab.com/cki-project/kernel-workflow/-/issues/new?issue%5Btitle%5D=backporter%20webhook%20issue)</small>

Approved-by: David Howells <[email protected]>
Approved-by: Eric Sandeen <[email protected]>
Approved-by: CKI KWF Bot <[email protected]>

Merged-by: Augusto Caringi <[email protected]>
github-actions bot pushed a commit that referenced this pull request May 28, 2025
ACPICA commit 1c28da2242783579d59767617121035dafba18c3

This was originally done in NetBSD:
NetBSD/src@b69d1ac
and is the correct alternative to the smattering of `memcpy`s I
previously contributed to this repository.

This also sidesteps the newly strict checks added in UBSAN:
llvm/llvm-project@7926744

Before this change we see the following UBSAN stack trace in Fuchsia:

  #0    0x000021afcfdeca5e in acpi_rs_get_address_common(struct acpi_resource*, union aml_resource*) ../../third_party/acpica/source/components/resources/rsaddr.c:329 <platform-bus-x86.so>+0x6aca5e
  #1.2  0x000021982bc4af3c in ubsan_get_stack_trace() compiler-rt/lib/ubsan/ubsan_diag.cpp:41 <libclang_rt.asan.so>+0x41f3c
  #1.1  0x000021982bc4af3c in maybe_print_stack_trace() compiler-rt/lib/ubsan/ubsan_diag.cpp:51 <libclang_rt.asan.so>+0x41f3c
  #1    0x000021982bc4af3c in ~scoped_report() compiler-rt/lib/ubsan/ubsan_diag.cpp:395 <libclang_rt.asan.so>+0x41f3c
  #2    0x000021982bc4bb6f in handletype_mismatch_impl() compiler-rt/lib/ubsan/ubsan_handlers.cpp:137 <libclang_rt.asan.so>+0x42b6f
  #3    0x000021982bc4b723 in __ubsan_handle_type_mismatch_v1 compiler-rt/lib/ubsan/ubsan_handlers.cpp:142 <libclang_rt.asan.so>+0x42723
  #4    0x000021afcfdeca5e in acpi_rs_get_address_common(struct acpi_resource*, union aml_resource*) ../../third_party/acpica/source/components/resources/rsaddr.c:329 <platform-bus-x86.so>+0x6aca5e
  #5    0x000021afcfdf2089 in acpi_rs_convert_aml_to_resource(struct acpi_resource*, union aml_resource*, struct acpi_rsconvert_info*) ../../third_party/acpica/source/components/resources/rsmisc.c:355 <platform-bus-x86.so>+0x6b2089
  #6    0x000021afcfded169 in acpi_rs_convert_aml_to_resources(u8*, u32, u32, u8, void**) ../../third_party/acpica/source/components/resources/rslist.c:137 <platform-bus-x86.so>+0x6ad169
  #7    0x000021afcfe2d24a in acpi_ut_walk_aml_resources(struct acpi_walk_state*, u8*, acpi_size, acpi_walk_aml_callback, void**) ../../third_party/acpica/source/components/utilities/utresrc.c:237 <platform-bus-x86.so>+0x6ed24a
  #8    0x000021afcfde66b7 in acpi_rs_create_resource_list(union acpi_operand_object*, struct acpi_buffer*) ../../third_party/acpica/source/components/resources/rscreate.c:199 <platform-bus-x86.so>+0x6a66b7
  #9    0x000021afcfdf6979 in acpi_rs_get_method_data(acpi_handle, const char*, struct acpi_buffer*) ../../third_party/acpica/source/components/resources/rsutils.c:770 <platform-bus-x86.so>+0x6b6979
  #10   0x000021afcfdf708f in acpi_walk_resources(acpi_handle, char*, acpi_walk_resource_callback, void*) ../../third_party/acpica/source/components/resources/rsxface.c:731 <platform-bus-x86.so>+0x6b708f
  #11   0x000021afcfa95dcf in acpi::acpi_impl::walk_resources(acpi::acpi_impl*, acpi_handle, const char*, acpi::Acpi::resources_callable) ../../src/devices/board/lib/acpi/acpi-impl.cc:41 <platform-bus-x86.so>+0x355dcf
  #12   0x000021afcfaa8278 in acpi::device_builder::gather_resources(acpi::device_builder*, acpi::Acpi*, fidl::any_arena&, acpi::Manager*, acpi::device_builder::gather_resources_callback) ../../src/devices/board/lib/acpi/device-builder.cc:84 <platform-bus-x86.so>+0x368278
  #13   0x000021afcfbddb87 in acpi::Manager::configure_discovered_devices(acpi::Manager*) ../../src/devices/board/lib/acpi/manager.cc:75 <platform-bus-x86.so>+0x49db87
  #14   0x000021afcf99091d in publish_acpi_devices(acpi::Manager*, zx_device_t*, zx_device_t*) ../../src/devices/board/drivers/x86/acpi-nswalk.cc:95 <platform-bus-x86.so>+0x25091d
  #15   0x000021afcf9c1d4e in x86::X86::do_init(x86::X86*) ../../src/devices/board/drivers/x86/x86.cc:60 <platform-bus-x86.so>+0x281d4e
  #16   0x000021afcf9e33ad in λ(x86::X86::ddk_init::(anon class)*) ../../src/devices/board/drivers/x86/x86.cc:77 <platform-bus-x86.so>+0x2a33ad
  #17   0x000021afcf9e313e in fit::internal::target<(lambda at../../src/devices/board/drivers/x86/x86.cc:76:19), false, false, std::__2::allocator<std::byte>, void>::invoke(void*) ../../sdk/lib/fit/include/lib/fit/internal/function.h:183 <platform-bus-x86.so>+0x2a313e
  #18   0x000021afcfbab4c7 in fit::internal::function_base<16UL, false, void(), std::__2::allocator<std::byte>>::invoke(const fit::internal::function_base<16UL, false, void (), std::__2::allocator<std::byte> >*) ../../sdk/lib/fit/include/lib/fit/internal/function.h:522 <platform-bus-x86.so>+0x46b4c7
  #19   0x000021afcfbab342 in fit::function_impl<16UL, false, void(), std::__2::allocator<std::byte>>::operator()(const fit::function_impl<16UL, false, void (), std::__2::allocator<std::byte> >*) ../../sdk/lib/fit/include/lib/fit/function.h:315 <platform-bus-x86.so>+0x46b342
  #20   0x000021afcfcd98c3 in async::internal::retained_task::Handler(async_dispatcher_t*, async_task_t*, zx_status_t) ../../sdk/lib/async/task.cc:24 <platform-bus-x86.so>+0x5998c3
  #21   0x00002290f9924616 in λ(const driver_runtime::Dispatcher::post_task::(anon class)*, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, zx_status_t) ../../src/devices/bin/driver_runtime/dispatcher.cc:789 <libdriver_runtime.so>+0x10a616
  #22   0x00002290f9924323 in fit::internal::target<(lambda at../../src/devices/bin/driver_runtime/dispatcher.cc:788:7), true, false, std::__2::allocator<std::byte>, void, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request>>, int>::invoke(void*, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, int) ../../sdk/lib/fit/include/lib/fit/internal/function.h:128 <libdriver_runtime.so>+0x10a323
  #23   0x00002290f9904b76 in fit::internal::function_base<24UL, true, void(std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request>>, int), std::__2::allocator<std::byte>>::invoke(const fit::internal::function_base<24UL, true, void (std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, int), std::__2::allocator<std::byte> >*, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, int) ../../sdk/lib/fit/include/lib/fit/internal/function.h:522 <libdriver_runtime.so>+0xeab76
  #24   0x00002290f9904831 in fit::callback_impl<24UL, true, void(std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request>>, int), std::__2::allocator<std::byte>>::operator()(fit::callback_impl<24UL, true, void (std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, int), std::__2::allocator<std::byte> >*, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, int) ../../sdk/lib/fit/include/lib/fit/function.h:471 <libdriver_runtime.so>+0xea831
  #25   0x00002290f98d5adc in driver_runtime::callback_request::Call(driver_runtime::callback_request*, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, zx_status_t) ../../src/devices/bin/driver_runtime/callback_request.h:74 <libdriver_runtime.so>+0xbbadc
  #26   0x00002290f98e1e58 in driver_runtime::Dispatcher::dispatch_callback(driver_runtime::Dispatcher*, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >) ../../src/devices/bin/driver_runtime/dispatcher.cc:1248 <libdriver_runtime.so>+0xc7e58
  #27   0x00002290f98e4159 in driver_runtime::Dispatcher::dispatch_callbacks(driver_runtime::Dispatcher*, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>) ../../src/devices/bin/driver_runtime/dispatcher.cc:1308 <libdriver_runtime.so>+0xca159
  #28   0x00002290f9918414 in λ(const driver_runtime::Dispatcher::create_with_adder::(anon class)*, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>) ../../src/devices/bin/driver_runtime/dispatcher.cc:353 <libdriver_runtime.so>+0xfe414
  #29   0x00002290f991812d in fit::internal::target<(lambda at../../src/devices/bin/driver_runtime/dispatcher.cc:351:7), true, false, std::__2::allocator<std::byte>, void, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter>>, fbl::ref_ptr<driver_runtime::Dispatcher>>::invoke(void*, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>) ../../sdk/lib/fit/include/lib/fit/internal/function.h:128 <libdriver_runtime.so>+0xfe12d
  #30   0x00002290f9906fc7 in fit::internal::function_base<8UL, true, void(std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter>>, fbl::ref_ptr<driver_runtime::Dispatcher>), std::__2::allocator<std::byte>>::invoke(const fit::internal::function_base<8UL, true, void (std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>), std::__2::allocator<std::byte> >*, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>) ../../sdk/lib/fit/include/lib/fit/internal/function.h:522 <libdriver_runtime.so>+0xecfc7
  #31   0x00002290f9906c66 in fit::function_impl<8UL, true, void(std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter>>, fbl::ref_ptr<driver_runtime::Dispatcher>), std::__2::allocator<std::byte>>::operator()(const fit::function_impl<8UL, true, void (std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>), std::__2::allocator<std::byte> >*, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>) ../../sdk/lib/fit/include/lib/fit/function.h:315 <libdriver_runtime.so>+0xecc66
  #32   0x00002290f98e73d9 in driver_runtime::Dispatcher::event_waiter::invoke_callback(driver_runtime::Dispatcher::event_waiter*, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>) ../../src/devices/bin/driver_runtime/dispatcher.h:543 <libdriver_runtime.so>+0xcd3d9
  #33   0x00002290f98e700d in driver_runtime::Dispatcher::event_waiter::handle_event(std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, async_dispatcher_t*, async::wait_base*, zx_status_t, zx_packet_signal_t const*) ../../src/devices/bin/driver_runtime/dispatcher.cc:1442 <libdriver_runtime.so>+0xcd00d
  #34   0x00002290f9918983 in async_loop_owned_event_handler<driver_runtime::Dispatcher::event_waiter>::handle_event(async_loop_owned_event_handler<driver_runtime::Dispatcher::event_waiter>*, async_dispatcher_t*, async::wait_base*, zx_status_t, zx_packet_signal_t const*) ../../src/devices/bin/driver_runtime/async_loop_owned_event_handler.h:59 <libdriver_runtime.so>+0xfe983
  #35   0x00002290f9918b9e in async::wait_method<async_loop_owned_event_handler<driver_runtime::Dispatcher::event_waiter>, &async_loop_owned_event_handler<driver_runtime::Dispatcher::event_waiter>::handle_event>::call_handler(async_dispatcher_t*, async_wait_t*, zx_status_t, zx_packet_signal_t const*) ../../sdk/lib/async/include/lib/async/cpp/wait.h:201 <libdriver_runtime.so>+0xfeb9e
  #36   0x00002290f99bf509 in async_loop_dispatch_wait(async_loop_t*, async_wait_t*, zx_status_t, zx_packet_signal_t const*) ../../sdk/lib/async-loop/loop.c:394 <libdriver_runtime.so>+0x1a5509
  #37   0x00002290f99b9958 in async_loop_run_once(async_loop_t*, zx_time_t) ../../sdk/lib/async-loop/loop.c:343 <libdriver_runtime.so>+0x19f958
  #38   0x00002290f99b9247 in async_loop_run(async_loop_t*, zx_time_t, _Bool) ../../sdk/lib/async-loop/loop.c:301 <libdriver_runtime.so>+0x19f247
  #39   0x00002290f99ba962 in async_loop_run_thread(void*) ../../sdk/lib/async-loop/loop.c:860 <libdriver_runtime.so>+0x1a0962
  #40   0x000041afd176ef30 in start_c11(void*) ../../zircon/third_party/ulib/musl/pthread/pthread_create.c:63 <libc.so>+0x84f30
  #41   0x000041afd18a448d in thread_trampoline(uintptr_t, uintptr_t) ../../zircon/system/ulib/runtime/thread.cc:100 <libc.so>+0x1ba48d

Link: acpica/acpica@1c28da22
Signed-off-by: Rafael J. Wysocki <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Tamir Duberstein <[email protected]>
[ rjw: Pick up the tag from Tamir ]
Signed-off-by: Rafael J. Wysocki <[email protected]>
github-actions bot pushed a commit that referenced this pull request May 30, 2025
[ Upstream commit 88f7f56 ]

When a bio with REQ_PREFLUSH is submitted to dm, __send_empty_flush()
generates a flush_bio with REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC,
which causes the flush_bio to be throttled by wbt_wait().

An example from v5.4, similar problem also exists in upstream:

    crash> bt 2091206
    PID: 2091206  TASK: ffff2050df92a300  CPU: 109  COMMAND: "kworker/u260:0"
     #0 [ffff800084a2f7f0] __switch_to at ffff80004008aeb8
     #1 [ffff800084a2f820] __schedule at ffff800040bfa0c4
     #2 [ffff800084a2f880] schedule at ffff800040bfa4b4
     #3 [ffff800084a2f8a0] io_schedule at ffff800040bfa9c4
     #4 [ffff800084a2f8c0] rq_qos_wait at ffff8000405925bc
     #5 [ffff800084a2f940] wbt_wait at ffff8000405bb3a0
     #6 [ffff800084a2f9a0] __rq_qos_throttle at ffff800040592254
     #7 [ffff800084a2f9c0] blk_mq_make_request at ffff80004057cf38
     #8 [ffff800084a2fa60] generic_make_request at ffff800040570138
     #9 [ffff800084a2fae0] submit_bio at ffff8000405703b4
    #10 [ffff800084a2fb50] xlog_write_iclog at ffff800001280834 [xfs]
    #11 [ffff800084a2fbb0] xlog_sync at ffff800001280c3c [xfs]
    #12 [ffff800084a2fbf0] xlog_state_release_iclog at ffff800001280df4 [xfs]
    #13 [ffff800084a2fc10] xlog_write at ffff80000128203c [xfs]
    #14 [ffff800084a2fcd0] xlog_cil_push at ffff8000012846dc [xfs]
    #15 [ffff800084a2fda0] xlog_cil_push_work at ffff800001284a2c [xfs]
    #16 [ffff800084a2fdb0] process_one_work at ffff800040111d08
    #17 [ffff800084a2fe00] worker_thread at ffff8000401121cc
    #18 [ffff800084a2fe70] kthread at ffff800040118de4

After commit 2def284 ("xfs: don't allow log IO to be throttled"),
the metadata submitted by xlog_write_iclog() should not be throttled.
But due to the existence of the dm layer, throttling flush_bio indirectly
causes the metadata bio to be throttled.

Fix this by conditionally adding REQ_IDLE to flush_bio.bi_opf, which makes
wbt_should_throttle() return false to avoid wbt_wait().

Signed-off-by: Jinliang Zheng <[email protected]>
Reviewed-by: Tianxiang Peng <[email protected]>
Reviewed-by: Hao Peng <[email protected]>
Signed-off-by: Mikulas Patocka <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
github-actions bot pushed a commit that referenced this pull request Jun 4, 2025
JIRA: https://issues.redhat.com/browse/RHEL-92762
Upstream Status: kernel/git/torvalds/linux.git

commit 88f7f56
Author: Jinliang Zheng <[email protected]>
Date:   Thu Feb 20 19:20:14 2025 +0800

    dm: fix unconditional IO throttle caused by REQ_PREFLUSH

    When a bio with REQ_PREFLUSH is submitted to dm, __send_empty_flush()
    generates a flush_bio with REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC,
    which causes the flush_bio to be throttled by wbt_wait().

    An example from v5.4, similar problem also exists in upstream:

        crash> bt 2091206
        PID: 2091206  TASK: ffff2050df92a300  CPU: 109  COMMAND: "kworker/u260:0"
         #0 [ffff800084a2f7f0] __switch_to at ffff80004008aeb8
         #1 [ffff800084a2f820] __schedule at ffff800040bfa0c4
         #2 [ffff800084a2f880] schedule at ffff800040bfa4b4
         #3 [ffff800084a2f8a0] io_schedule at ffff800040bfa9c4
         #4 [ffff800084a2f8c0] rq_qos_wait at ffff8000405925bc
         #5 [ffff800084a2f940] wbt_wait at ffff8000405bb3a0
         #6 [ffff800084a2f9a0] __rq_qos_throttle at ffff800040592254
         #7 [ffff800084a2f9c0] blk_mq_make_request at ffff80004057cf38
         #8 [ffff800084a2fa60] generic_make_request at ffff800040570138
         #9 [ffff800084a2fae0] submit_bio at ffff8000405703b4
        #10 [ffff800084a2fb50] xlog_write_iclog at ffff800001280834 [xfs]
        #11 [ffff800084a2fbb0] xlog_sync at ffff800001280c3c [xfs]
        #12 [ffff800084a2fbf0] xlog_state_release_iclog at ffff800001280df4 [xfs]
        #13 [ffff800084a2fc10] xlog_write at ffff80000128203c [xfs]
        #14 [ffff800084a2fcd0] xlog_cil_push at ffff8000012846dc [xfs]
        #15 [ffff800084a2fda0] xlog_cil_push_work at ffff800001284a2c [xfs]
        #16 [ffff800084a2fdb0] process_one_work at ffff800040111d08
        #17 [ffff800084a2fe00] worker_thread at ffff8000401121cc
        #18 [ffff800084a2fe70] kthread at ffff800040118de4

    After commit 2def284 ("xfs: don't allow log IO to be throttled"),
    the metadata submitted by xlog_write_iclog() should not be throttled.
    But due to the existence of the dm layer, throttling flush_bio indirectly
    causes the metadata bio to be throttled.

    Fix this by conditionally adding REQ_IDLE to flush_bio.bi_opf, which makes
    wbt_should_throttle() return false to avoid wbt_wait().

    Signed-off-by: Jinliang Zheng <[email protected]>
    Reviewed-by: Tianxiang Peng <[email protected]>
    Reviewed-by: Hao Peng <[email protected]>
    Signed-off-by: Mikulas Patocka <[email protected]>

Signed-off-by: Benjamin Marzinski <[email protected]>
github-actions bot pushed a commit that referenced this pull request Jun 5, 2025
JIRA: https://issues.redhat.com/browse/RHEL-92761
Upstream Status: kernel/git/torvalds/linux.git

commit 88f7f56
Author: Jinliang Zheng <[email protected]>
Date:   Thu Feb 20 19:20:14 2025 +0800

    dm: fix unconditional IO throttle caused by REQ_PREFLUSH

    When a bio with REQ_PREFLUSH is submitted to dm, __send_empty_flush()
    generates a flush_bio with REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC,
    which causes the flush_bio to be throttled by wbt_wait().

    An example from v5.4, similar problem also exists in upstream:

        crash> bt 2091206
        PID: 2091206  TASK: ffff2050df92a300  CPU: 109  COMMAND: "kworker/u260:0"
         #0 [ffff800084a2f7f0] __switch_to at ffff80004008aeb8
         #1 [ffff800084a2f820] __schedule at ffff800040bfa0c4
         #2 [ffff800084a2f880] schedule at ffff800040bfa4b4
         #3 [ffff800084a2f8a0] io_schedule at ffff800040bfa9c4
         #4 [ffff800084a2f8c0] rq_qos_wait at ffff8000405925bc
         #5 [ffff800084a2f940] wbt_wait at ffff8000405bb3a0
         #6 [ffff800084a2f9a0] __rq_qos_throttle at ffff800040592254
         #7 [ffff800084a2f9c0] blk_mq_make_request at ffff80004057cf38
         #8 [ffff800084a2fa60] generic_make_request at ffff800040570138
         #9 [ffff800084a2fae0] submit_bio at ffff8000405703b4
        #10 [ffff800084a2fb50] xlog_write_iclog at ffff800001280834 [xfs]
        #11 [ffff800084a2fbb0] xlog_sync at ffff800001280c3c [xfs]
        #12 [ffff800084a2fbf0] xlog_state_release_iclog at ffff800001280df4 [xfs]
        #13 [ffff800084a2fc10] xlog_write at ffff80000128203c [xfs]
        #14 [ffff800084a2fcd0] xlog_cil_push at ffff8000012846dc [xfs]
        #15 [ffff800084a2fda0] xlog_cil_push_work at ffff800001284a2c [xfs]
        #16 [ffff800084a2fdb0] process_one_work at ffff800040111d08
        #17 [ffff800084a2fe00] worker_thread at ffff8000401121cc
        #18 [ffff800084a2fe70] kthread at ffff800040118de4

    After commit 2def284 ("xfs: don't allow log IO to be throttled"),
    the metadata submitted by xlog_write_iclog() should not be throttled.
    But due to the existence of the dm layer, throttling flush_bio indirectly
    causes the metadata bio to be throttled.

    Fix this by conditionally adding REQ_IDLE to flush_bio.bi_opf, which makes
    wbt_should_throttle() return false to avoid wbt_wait().

    Signed-off-by: Jinliang Zheng <[email protected]>
    Reviewed-by: Tianxiang Peng <[email protected]>
    Reviewed-by: Hao Peng <[email protected]>
    Signed-off-by: Mikulas Patocka <[email protected]>

Signed-off-by: Benjamin Marzinski <[email protected]>
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