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Background

Some of the kernel functions in the unmount path are not traceable which makes it harder to debug busy unmounts.

Problem

To help with diagnosing busy unmounts we should allow tracing of mnt_add_count() and do_umount() in bpftrace probes.

Solution

Augment these functions with noinline and __noclone (disables the "-fipa-sra" compilation optimization to keep the compiler from optimizing the function signatures).

Testing Done

Confirm these function symbols are traceable:

delphix@ip-10-110-220-172:~$ sudo bpftrace -l '*mnt_add_count'
kprobe:mnt_add_count
delphix@ip-10-110-220-172:~$ sudo bpftrace -l '*do_umount'
kprobe:do_umount

Also used them with a bpftrace script that watches mnt_add_count calls that decrement the mount reference after a busy unmount occurred.

@don-brady don-brady merged commit 94bae91 into delphix:6.0/stage Dec 9, 2022
@don-brady don-brady deleted the dlpx-83701-gcp branch December 9, 2022 23:19
delphix-devops-bot pushed a commit that referenced this pull request Mar 4, 2023
BugLink: https://bugs.launchpad.net/bugs/2002347

[ Upstream commit 5dd7caf ]

In __unregister_kprobe_top(), if the currently unregistered probe has
post_handler but other child probes of the aggrprobe do not have
post_handler, the post_handler of the aggrprobe is cleared. If this is
a ftrace-based probe, there is a problem. In later calls to
disarm_kprobe(), we will use kprobe_ftrace_ops because post_handler is
NULL. But we're armed with kprobe_ipmodify_ops. This triggers a WARN in
__disarm_kprobe_ftrace() and may even cause use-after-free:

  Failed to disarm kprobe-ftrace at kernel_clone+0x0/0x3c0 (error -2)
  WARNING: CPU: 5 PID: 137 at kernel/kprobes.c:1135 __disarm_kprobe_ftrace.isra.21+0xcf/0xe0
  Modules linked in: testKprobe_007(-)
  CPU: 5 PID: 137 Comm: rmmod Not tainted 6.1.0-rc4-dirty #18
  [...]
  Call Trace:
   <TASK>
   __disable_kprobe+0xcd/0xe0
   __unregister_kprobe_top+0x12/0x150
   ? mutex_lock+0xe/0x30
   unregister_kprobes.part.23+0x31/0xa0
   unregister_kprobe+0x32/0x40
   __x64_sys_delete_module+0x15e/0x260
   ? do_user_addr_fault+0x2cd/0x6b0
   do_syscall_64+0x3a/0x90
   entry_SYSCALL_64_after_hwframe+0x63/0xcd
   [...]

For the kprobe-on-ftrace case, we keep the post_handler setting to
identify this aggrprobe armed with kprobe_ipmodify_ops. This way we
can disarm it correctly.

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

Fixes: 0bc11ed ("kprobes: Allow kprobes coexist with livepatch")
Reported-by: Zhao Gongyi <[email protected]>
Suggested-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Li Huafei <[email protected]>
Acked-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Kamal Mostafa <[email protected]>
Signed-off-by: Stefan Bader <[email protected]>
delphix-devops-bot pushed a commit that referenced this pull request Mar 4, 2023
…g the sock

BugLink: https://bugs.launchpad.net/bugs/2003914

[ Upstream commit 3cf7203 ]

There is a race condition in vxlan that when deleting a vxlan device
during receiving packets, there is a possibility that the sock is
released after getting vxlan_sock vs from sk_user_data. Then in
later vxlan_ecn_decapsulate(), vxlan_get_sk_family() we will got
NULL pointer dereference. e.g.

   #0 [ffffa25ec6978a38] machine_kexec at ffffffff8c669757
   #1 [ffffa25ec6978a90] __crash_kexec at ffffffff8c7c0a4d
   #2 [ffffa25ec6978b58] crash_kexec at ffffffff8c7c1c48
   #3 [ffffa25ec6978b60] oops_end at ffffffff8c627f2b
   #4 [ffffa25ec6978b80] page_fault_oops at ffffffff8c678fcb
   #5 [ffffa25ec6978bd8] exc_page_fault at ffffffff8d109542
   #6 [ffffa25ec6978c00] asm_exc_page_fault at ffffffff8d200b62
      [exception RIP: vxlan_ecn_decapsulate+0x3b]
      RIP: ffffffffc1014e7b  RSP: ffffa25ec6978cb0  RFLAGS: 00010246
      RAX: 0000000000000008  RBX: ffff8aa000888000  RCX: 0000000000000000
      RDX: 000000000000000e  RSI: ffff8a9fc7ab803e  RDI: ffff8a9fd1168700
      RBP: ffff8a9fc7ab803e   R8: 0000000000700000   R9: 00000000000010ae
      R10: ffff8a9fcb748980  R11: 0000000000000000  R12: ffff8a9fd1168700
      R13: ffff8aa000888000  R14: 00000000002a0000  R15: 00000000000010ae
      ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
   #7 [ffffa25ec6978ce8] vxlan_rcv at ffffffffc10189cd [vxlan]
   #8 [ffffa25ec6978d90] udp_queue_rcv_one_skb at ffffffff8cfb6507
   #9 [ffffa25ec6978dc0] udp_unicast_rcv_skb at ffffffff8cfb6e45
  #10 [ffffa25ec6978dc8] __udp4_lib_rcv at ffffffff8cfb8807
  #11 [ffffa25ec6978e20] ip_protocol_deliver_rcu at ffffffff8cf76951
  #12 [ffffa25ec6978e48] ip_local_deliver at ffffffff8cf76bde
  #13 [ffffa25ec6978ea0] __netif_receive_skb_one_core at ffffffff8cecde9b
  #14 [ffffa25ec6978ec8] process_backlog at ffffffff8cece139
  #15 [ffffa25ec6978f00] __napi_poll at ffffffff8ceced1a
  #16 [ffffa25ec6978f28] net_rx_action at ffffffff8cecf1f3
  #17 [ffffa25ec6978fa0] __softirqentry_text_start at ffffffff8d4000ca
  #18 [ffffa25ec6978ff0] do_softirq at ffffffff8c6fbdc3

Reproducer: https://github.com/Mellanox/ovs-tests/blob/master/test-ovs-vxlan-remove-tunnel-during-traffic.sh

Fix this by waiting for all sk_user_data reader to finish before
releasing the sock.

Reported-by: Jianlin Shi <[email protected]>
Suggested-by: Jakub Sitnicki <[email protected]>
Fixes: 6a93cc9 ("udp-tunnel: Add a few more UDP tunnel APIs")
Signed-off-by: Hangbin Liu <[email protected]>
Reviewed-by: Jiri Pirko <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Kamal Mostafa <[email protected]>
Signed-off-by: Stefan Bader <[email protected]>
delphix-devops-bot pushed a commit that referenced this pull request Mar 4, 2023
BugLink: https://bugs.launchpad.net/bugs/2003914

[ Upstream commit b6702a9 ]

syzkaller reported use-after-free with the stack trace like below [1]:

[   38.960489][    C3] ==================================================================
[   38.963216][    C3] BUG: KASAN: use-after-free in ar5523_cmd_tx_cb+0x220/0x240
[   38.964950][    C3] Read of size 8 at addr ffff888048e03450 by task swapper/3/0
[   38.966363][    C3]
[   38.967053][    C3] CPU: 3 PID: 0 Comm: swapper/3 Not tainted 6.0.0-09039-ga6afa4199d3d-dirty #18
[   38.968464][    C3] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014
[   38.969959][    C3] Call Trace:
[   38.970841][    C3]  <IRQ>
[   38.971663][    C3]  dump_stack_lvl+0xfc/0x174
[   38.972620][    C3]  print_report.cold+0x2c3/0x752
[   38.973626][    C3]  ? ar5523_cmd_tx_cb+0x220/0x240
[   38.974644][    C3]  kasan_report+0xb1/0x1d0
[   38.975720][    C3]  ? ar5523_cmd_tx_cb+0x220/0x240
[   38.976831][    C3]  ar5523_cmd_tx_cb+0x220/0x240
[   38.978412][    C3]  __usb_hcd_giveback_urb+0x353/0x5b0
[   38.979755][    C3]  usb_hcd_giveback_urb+0x385/0x430
[   38.981266][    C3]  dummy_timer+0x140c/0x34e0
[   38.982925][    C3]  ? notifier_call_chain+0xb5/0x1e0
[   38.984761][    C3]  ? rcu_read_lock_sched_held+0xb/0x60
[   38.986242][    C3]  ? lock_release+0x51c/0x790
[   38.987323][    C3]  ? _raw_read_unlock_irqrestore+0x37/0x70
[   38.988483][    C3]  ? __wake_up_common_lock+0xde/0x130
[   38.989621][    C3]  ? reacquire_held_locks+0x4a0/0x4a0
[   38.990777][    C3]  ? lock_acquire+0x472/0x550
[   38.991919][    C3]  ? rcu_read_lock_sched_held+0xb/0x60
[   38.993138][    C3]  ? lock_acquire+0x472/0x550
[   38.994890][    C3]  ? dummy_urb_enqueue+0x860/0x860
[   38.996266][    C3]  ? do_raw_spin_unlock+0x16f/0x230
[   38.997670][    C3]  ? dummy_urb_enqueue+0x860/0x860
[   38.999116][    C3]  call_timer_fn+0x1a0/0x6a0
[   39.000668][    C3]  ? add_timer_on+0x4a0/0x4a0
[   39.002137][    C3]  ? reacquire_held_locks+0x4a0/0x4a0
[   39.003809][    C3]  ? __next_timer_interrupt+0x226/0x2a0
[   39.005509][    C3]  __run_timers.part.0+0x69a/0xac0
[   39.007025][    C3]  ? dummy_urb_enqueue+0x860/0x860
[   39.008716][    C3]  ? call_timer_fn+0x6a0/0x6a0
[   39.010254][    C3]  ? cpuacct_percpu_seq_show+0x10/0x10
[   39.011795][    C3]  ? kvm_sched_clock_read+0x14/0x40
[   39.013277][    C3]  ? sched_clock_cpu+0x69/0x2b0
[   39.014724][    C3]  run_timer_softirq+0xb6/0x1d0
[   39.016196][    C3]  __do_softirq+0x1d2/0x9be
[   39.017616][    C3]  __irq_exit_rcu+0xeb/0x190
[   39.019004][    C3]  irq_exit_rcu+0x5/0x20
[   39.020361][    C3]  sysvec_apic_timer_interrupt+0x8f/0xb0
[   39.021965][    C3]  </IRQ>
[   39.023237][    C3]  <TASK>

In ar5523_probe(), ar5523_host_available() calls ar5523_cmd() as below
(there are other functions which finally call ar5523_cmd()):

ar5523_probe()
-> ar5523_host_available()
   -> ar5523_cmd_read()
      -> ar5523_cmd()

If ar5523_cmd() timed out, then ar5523_host_available() failed and
ar5523_probe() freed the device structure.  So, ar5523_cmd_tx_cb()
might touch the freed structure.

This patch fixes this issue by canceling in-flight tx cmd if submitted
urb timed out.

Link: https://syzkaller.appspot.com/bug?id=9e12b2d54300842b71bdd18b54971385ff0d0d3a [1]
Reported-by: [email protected]
Signed-off-by: Shigeru Yoshida <[email protected]>
Signed-off-by: Kalle Valo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Kamal Mostafa <[email protected]>
Signed-off-by: Stefan Bader <[email protected]>
delphix-devops-bot pushed a commit that referenced this pull request Mar 4, 2023
BugLink: https://bugs.launchpad.net/bugs/2003914

[ Upstream commit 031af50 ]

The inline assembly for arm64's cmpxchg_double*() implementations use a
+Q constraint to hazard against other accesses to the memory location
being exchanged. However, the pointer passed to the constraint is a
pointer to unsigned long, and thus the hazard only applies to the first
8 bytes of the location.

GCC can take advantage of this, assuming that other portions of the
location are unchanged, leading to a number of potential problems.

This is similar to what we fixed back in commit:

  fee960b ("arm64: xchg: hazard against entire exchange variable")

... but we forgot to adjust cmpxchg_double*() similarly at the same
time.

The same problem applies, as demonstrated with the following test:

| struct big {
|         u64 lo, hi;
| } __aligned(128);
|
| unsigned long foo(struct big *b)
| {
|         u64 hi_old, hi_new;
|
|         hi_old = b->hi;
|         cmpxchg_double_local(&b->lo, &b->hi, 0x12, 0x34, 0x56, 0x78);
|         hi_new = b->hi;
|
|         return hi_old ^ hi_new;
| }

... which GCC 12.1.0 compiles as:

| 0000000000000000 <foo>:
|    0:   d503233f        paciasp
|    4:   aa0003e4        mov     x4, x0
|    8:   1400000e        b       40 <foo+0x40>
|    c:   d2800240        mov     x0, #0x12                       // #18
|   10:   d2800681        mov     x1, #0x34                       // #52
|   14:   aa0003e5        mov     x5, x0
|   18:   aa0103e6        mov     x6, x1
|   1c:   d2800ac2        mov     x2, #0x56                       // #86
|   20:   d2800f03        mov     x3, #0x78                       // #120
|   24:   48207c82        casp    x0, x1, x2, x3, [x4]
|   28:   ca050000        eor     x0, x0, x5
|   2c:   ca060021        eor     x1, x1, x6
|   30:   aa010000        orr     x0, x0, x1
|   34:   d2800000        mov     x0, #0x0                        // #0    <--- BANG
|   38:   d50323bf        autiasp
|   3c:   d65f03c0        ret
|   40:   d2800240        mov     x0, #0x12                       // #18
|   44:   d2800681        mov     x1, #0x34                       // #52
|   48:   d2800ac2        mov     x2, #0x56                       // #86
|   4c:   d2800f03        mov     x3, #0x78                       // #120
|   50:   f9800091        prfm    pstl1strm, [x4]
|   54:   c87f1885        ldxp    x5, x6, [x4]
|   58:   ca0000a5        eor     x5, x5, x0
|   5c:   ca0100c6        eor     x6, x6, x1
|   60:   aa0600a6        orr     x6, x5, x6
|   64:   b5000066        cbnz    x6, 70 <foo+0x70>
|   68:   c8250c82        stxp    w5, x2, x3, [x4]
|   6c:   35ffff45        cbnz    w5, 54 <foo+0x54>
|   70:   d2800000        mov     x0, #0x0                        // #0     <--- BANG
|   74:   d50323bf        autiasp
|   78:   d65f03c0        ret

Notice that at the lines with "BANG" comments, GCC has assumed that the
higher 8 bytes are unchanged by the cmpxchg_double() call, and that
`hi_old ^ hi_new` can be reduced to a constant zero, for both LSE and
LL/SC versions of cmpxchg_double().

This patch fixes the issue by passing a pointer to __uint128_t into the
+Q constraint, ensuring that the compiler hazards against the entire 16
bytes being modified.

With this change, GCC 12.1.0 compiles the above test as:

| 0000000000000000 <foo>:
|    0:   f9400407        ldr     x7, [x0, #8]
|    4:   d503233f        paciasp
|    8:   aa0003e4        mov     x4, x0
|    c:   1400000f        b       48 <foo+0x48>
|   10:   d2800240        mov     x0, #0x12                       // #18
|   14:   d2800681        mov     x1, #0x34                       // #52
|   18:   aa0003e5        mov     x5, x0
|   1c:   aa0103e6        mov     x6, x1
|   20:   d2800ac2        mov     x2, #0x56                       // #86
|   24:   d2800f03        mov     x3, #0x78                       // #120
|   28:   48207c82        casp    x0, x1, x2, x3, [x4]
|   2c:   ca050000        eor     x0, x0, x5
|   30:   ca060021        eor     x1, x1, x6
|   34:   aa010000        orr     x0, x0, x1
|   38:   f9400480        ldr     x0, [x4, #8]
|   3c:   d50323bf        autiasp
|   40:   ca0000e0        eor     x0, x7, x0
|   44:   d65f03c0        ret
|   48:   d2800240        mov     x0, #0x12                       // #18
|   4c:   d2800681        mov     x1, #0x34                       // #52
|   50:   d2800ac2        mov     x2, #0x56                       // #86
|   54:   d2800f03        mov     x3, #0x78                       // #120
|   58:   f9800091        prfm    pstl1strm, [x4]
|   5c:   c87f1885        ldxp    x5, x6, [x4]
|   60:   ca0000a5        eor     x5, x5, x0
|   64:   ca0100c6        eor     x6, x6, x1
|   68:   aa0600a6        orr     x6, x5, x6
|   6c:   b5000066        cbnz    x6, 78 <foo+0x78>
|   70:   c8250c82        stxp    w5, x2, x3, [x4]
|   74:   35ffff45        cbnz    w5, 5c <foo+0x5c>
|   78:   f9400480        ldr     x0, [x4, #8]
|   7c:   d50323bf        autiasp
|   80:   ca0000e0        eor     x0, x7, x0
|   84:   d65f03c0        ret

... sampling the high 8 bytes before and after the cmpxchg, and
performing an EOR, as we'd expect.

For backporting, I've tested this atop linux-4.9.y with GCC 5.5.0. Note
that linux-4.9.y is oldest currently supported stable release, and
mandates GCC 5.1+. Unfortunately I couldn't get a GCC 5.1 binary to run
on my machines due to library incompatibilities.

I've also used a standalone test to check that we can use a __uint128_t
pointer in a +Q constraint at least as far back as GCC 4.8.5 and LLVM
3.9.1.

Fixes: 5284e1b ("arm64: xchg: Implement cmpxchg_double")
Fixes: e9a4b79 ("arm64: cmpxchg_dbl: patch in lse instructions when supported by the CPU")
Reported-by: Boqun Feng <[email protected]>
Link: https://lore.kernel.org/lkml/Y6DEfQXymYVgL3oJ@boqun-archlinux/
Reported-by: Peter Zijlstra <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]/
Signed-off-by: Mark Rutland <[email protected]>
Cc: [email protected]
Cc: Arnd Bergmann <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Steve Capper <[email protected]>
Cc: Will Deacon <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Kamal Mostafa <[email protected]>
Signed-off-by: Stefan Bader <[email protected]>
delphix-devops-bot pushed a commit that referenced this pull request Aug 23, 2023
BugLink: https://bugs.launchpad.net/bugs/2023230

[ Upstream 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]
  #5 [ffffaad04005fbf0] pci_device_remove at ffffffff8add7513
  #6 [ffffaad04005fc10] device_release_driver_internal at ffffffff8af08baa
  #7 [ffffaad04005fc40] pci_stop_bus_device at ffffffff8adcc5fc
  #8 [ffffaad04005fc60] pci_stop_and_remove_bus_device at ffffffff8adcc81e
  #9 [ffffaad04005fc70] pci_iov_remove_virtfn at ffffffff8adf9429
 #10 [ffffaad04005fca8] sriov_disable at ffffffff8adf98e4
 #11 [ffffaad04005fcc8] ice_free_vfs at ffffffffc04bb2c8 [ice]
 #12 [ffffaad04005fd10] ice_remove at ffffffffc04778fe [ice]
 #13 [ffffaad04005fd38] ice_shutdown at ffffffffc0477946 [ice]
 #14 [ffffaad04005fd50] pci_device_shutdown at ffffffff8add58f1
 #15 [ffffaad04005fd70] device_shutdown at ffffffff8af05386
 #16 [ffffaad04005fd98] kernel_restart at ffffffff8a92a870
 #17 [ffffaad04005fda8] __do_sys_reboot at ffffffff8a92abd6
 #18 [ffffaad04005fee0] do_syscall_64 at ffffffff8b317159
 #19 [ffffaad04005ff08] __context_tracking_enter at ffffffff8b31b6fc
 #20 [ffffaad04005ff18] syscall_exit_to_user_mode at ffffffff8b31b50d
 #21 [ffffaad04005ff28] do_syscall_64 at ffffffff8b317169
 #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]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Kamal Mostafa <[email protected]>
Signed-off-by: Luke Nowakowski-Krijger <[email protected]>
delphix-devops-bot pushed a commit that referenced this pull request Dec 18, 2024
…the Crashkernel Scenario

BugLink: https://bugs.launchpad.net/bugs/2086242

[ Upstream commit 4058c39 ]

The issue is that before entering the crash kernel, the DWC USB controller
did not perform operations such as resetting the interrupt mask bits.
After entering the crash kernel,before the USB interrupt handler
registration was completed while loading the DWC USB driver,an GINTSTS_SOF
interrupt was received.This triggered the misroute_irq process within the
GIC handling framework,ultimately leading to the misrouting of the
interrupt,causing it to be handled by the wrong interrupt handler
and resulting in the issue.

Summary:In a scenario where the kernel triggers a panic and enters
the crash kernel,it is necessary to ensure that the interrupt mask
bit is not enabled before the interrupt registration is complete.
If an interrupt reaches the CPU at this moment,it will certainly
not be handled correctly,especially in cases where this interrupt
is reported frequently.

Please refer to the Crashkernel dmesg information as follows
(the message on line 3 was added before devm_request_irq is
called by the dwc2_driver_probe function):
[    5.866837][    T1] dwc2 JMIC0010:01: supply vusb_d not found, using dummy regulator
[    5.874588][    T1] dwc2 JMIC0010:01: supply vusb_a not found, using dummy regulator
[    5.882335][    T1] dwc2 JMIC0010:01: before devm_request_irq  irq: [71], gintmsk[0xf300080e], gintsts[0x04200009]
[    5.892686][    C0] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.10.0-jmnd1.2_RC #18
[    5.900327][    C0] Hardware name: CMSS HyperCard4-25G/HyperCard4-25G, BIOS 1.6.4 Jul  8 2024
[    5.908836][    C0] Call trace:
[    5.911965][    C0]  dump_backtrace+0x0/0x1f0
[    5.916308][    C0]  show_stack+0x20/0x30
[    5.920304][    C0]  dump_stack+0xd8/0x140
[    5.924387][    C0]  pcie_xxx_handler+0x3c/0x1d8
[    5.930121][    C0]  __handle_irq_event_percpu+0x64/0x1e0
[    5.935506][    C0]  handle_irq_event+0x80/0x1d0
[    5.940109][    C0]  try_one_irq+0x138/0x174
[    5.944365][    C0]  misrouted_irq+0x134/0x140
[    5.948795][    C0]  note_interrupt+0x1d0/0x30c
[    5.953311][    C0]  handle_irq_event+0x13c/0x1d0
[    5.958001][    C0]  handle_fasteoi_irq+0xd4/0x260
[    5.962779][    C0]  __handle_domain_irq+0x88/0xf0
[    5.967555][    C0]  gic_handle_irq+0x9c/0x2f0
[    5.971985][    C0]  el1_irq+0xb8/0x140
[    5.975807][    C0]  __setup_irq+0x3dc/0x7cc
[    5.980064][    C0]  request_threaded_irq+0xf4/0x1b4
[    5.985015][    C0]  devm_request_threaded_irq+0x80/0x100
[    5.990400][    C0]  dwc2_driver_probe+0x1b8/0x6b0
[    5.995178][    C0]  platform_drv_probe+0x5c/0xb0
[    5.999868][    C0]  really_probe+0xf8/0x51c
[    6.004125][    C0]  driver_probe_device+0xfc/0x170
[    6.008989][    C0]  device_driver_attach+0xc8/0xd0
[    6.013853][    C0]  __driver_attach+0xe8/0x1b0
[    6.018369][    C0]  bus_for_each_dev+0x7c/0xdc
[    6.022886][    C0]  driver_attach+0x2c/0x3c
[    6.027143][    C0]  bus_add_driver+0xdc/0x240
[    6.031573][    C0]  driver_register+0x80/0x13c
[    6.036090][    C0]  __platform_driver_register+0x50/0x5c
[    6.041476][    C0]  dwc2_platform_driver_init+0x24/0x30
[    6.046774][    C0]  do_one_initcall+0x50/0x25c
[    6.051291][    C0]  do_initcall_level+0xe4/0xfc
[    6.055894][    C0]  do_initcalls+0x80/0xa4
[    6.060064][    C0]  kernel_init_freeable+0x198/0x240
[    6.065102][    C0]  kernel_init+0x1c/0x12c

Signed-off-by: Shawn Shao <[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]>
Signed-off-by: Koichiro Den <[email protected]>
Signed-off-by: Roxana Nicolescu <[email protected]>
delphix-devops-bot pushed a commit that referenced this pull request Feb 7, 2025
BugLink: https://bugs.launchpad.net/bugs/2076435

commit be346c1 upstream.

The code in ocfs2_dio_end_io_write() estimates number of necessary
transaction credits using ocfs2_calc_extend_credits().  This however does
not take into account that the IO could be arbitrarily large and can
contain arbitrary number of extents.

Extent tree manipulations do often extend the current transaction but not
in all of the cases.  For example if we have only single block extents in
the tree, ocfs2_mark_extent_written() will end up calling
ocfs2_replace_extent_rec() all the time and we will never extend the
current transaction and eventually exhaust all the transaction credits if
the IO contains many single block extents.  Once that happens a
WARN_ON(jbd2_handle_buffer_credits(handle) <= 0) is triggered in
jbd2_journal_dirty_metadata() and subsequently OCFS2 aborts in response to
this error.  This was actually triggered by one of our customers on a
heavily fragmented OCFS2 filesystem.

To fix the issue make sure the transaction always has enough credits for
one extent insert before each call of ocfs2_mark_extent_written().

Heming Zhao said:

------
PANIC: "Kernel panic - not syncing: OCFS2: (device dm-1): panic forced after error"

PID: xxx  TASK: xxxx  CPU: 5  COMMAND: "SubmitThread-CA"
  #0 machine_kexec at ffffffff8c069932
  #1 __crash_kexec at ffffffff8c1338fa
  #2 panic at ffffffff8c1d69b9
  #3 ocfs2_handle_error at ffffffffc0c86c0c [ocfs2]
  #4 __ocfs2_abort at ffffffffc0c88387 [ocfs2]
  #5 ocfs2_journal_dirty at ffffffffc0c51e98 [ocfs2]
  #6 ocfs2_split_extent at ffffffffc0c27ea3 [ocfs2]
  #7 ocfs2_change_extent_flag at ffffffffc0c28053 [ocfs2]
  #8 ocfs2_mark_extent_written at ffffffffc0c28347 [ocfs2]
  #9 ocfs2_dio_end_io_write at ffffffffc0c2bef9 [ocfs2]
#10 ocfs2_dio_end_io at ffffffffc0c2c0f5 [ocfs2]
#11 dio_complete at ffffffff8c2b9fa7
#12 do_blockdev_direct_IO at ffffffff8c2bc09f
#13 ocfs2_direct_IO at ffffffffc0c2b653 [ocfs2]
#14 generic_file_direct_write at ffffffff8c1dcf14
#15 __generic_file_write_iter at ffffffff8c1dd07b
#16 ocfs2_file_write_iter at ffffffffc0c49f1f [ocfs2]
#17 aio_write at ffffffff8c2cc72e
#18 kmem_cache_alloc at ffffffff8c248dde
#19 do_io_submit at ffffffff8c2ccada
#20 do_syscall_64 at ffffffff8c004984
#21 entry_SYSCALL_64_after_hwframe at ffffffff8c8000ba

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: c15471f ("ocfs2: fix sparse file & data ordering issue in direct io")
Signed-off-by: Jan Kara <[email protected]>
Reviewed-by: Joseph Qi <[email protected]>
Reviewed-by: Heming Zhao <[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: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Portia Stephens <[email protected]>
Signed-off-by: Roxana Nicolescu <[email protected]>
delphix-devops-bot pushed a commit that referenced this pull request Feb 7, 2025
BugLink: https://bugs.launchpad.net/bugs/2078289

[ Upstream commit f0c1802 ]

When running BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, the following kernel panic occurs:

  [...]
  Oops[#1]:
  CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ #18
  Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
     ... ...
     ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
    ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
   CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
   PRMD: 0000000c (PPLV0 +PIE +PWE)
   EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
   ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
  ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
   BADV: 0000000000000040
   PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
  Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
  Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
  Stack : ...
  Call Trace:
  [<9000000004162774>] copy_page_to_iter+0x74/0x1c0
  [<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
  [<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
  [<90000000049aae34>] inet_recvmsg+0x54/0x100
  [<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
  [<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
  [<900000000481e27c>] sys_recvfrom+0x1c/0x40
  [<9000000004c076ec>] do_syscall+0x8c/0xc0
  [<9000000003731da4>] handle_syscall+0xc4/0x160
  Code: ...
  ---[ end trace 0000000000000000 ]---
  Kernel panic - not syncing: Fatal exception
  Kernel relocated by 0x3510000
   .text @ 0x9000000003710000
   .data @ 0x9000000004d70000
   .bss  @ 0x9000000006469400
  ---[ end Kernel panic - not syncing: Fatal exception ]---
  [...]

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in the
sk_msg_recvmsg(). Due to the different implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on x86 platform. So this bug was hidden on x86 platform
for a while, but now it is exposed on Loongarch platform. The root cause
is that a zero length skb (skb->len == 0) was put on the queue.

This zero length skb is a TCP FIN packet, which was sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend <[email protected]>
Signed-off-by: Geliang Tang <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Reviewed-by: John Fastabend <[email protected]>
Link: https://lore.kernel.org/bpf/e3a16eacdc6740658ee02a33489b1b9d4912f378.1719992715.git.tanggeliang@kylinos.cn
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Portia Stephens <[email protected]>
Signed-off-by: Stefan Bader <[email protected]>
delphix-devops-bot pushed a commit that referenced this pull request Mar 26, 2025
…the Crashkernel Scenario

BugLink: https://bugs.launchpad.net/bugs/2097301

[ Upstream commit 4058c39 ]

The issue is that before entering the crash kernel, the DWC USB controller
did not perform operations such as resetting the interrupt mask bits.
After entering the crash kernel,before the USB interrupt handler
registration was completed while loading the DWC USB driver,an GINTSTS_SOF
interrupt was received.This triggered the misroute_irq process within the
GIC handling framework,ultimately leading to the misrouting of the
interrupt,causing it to be handled by the wrong interrupt handler
and resulting in the issue.

Summary:In a scenario where the kernel triggers a panic and enters
the crash kernel,it is necessary to ensure that the interrupt mask
bit is not enabled before the interrupt registration is complete.
If an interrupt reaches the CPU at this moment,it will certainly
not be handled correctly,especially in cases where this interrupt
is reported frequently.

Please refer to the Crashkernel dmesg information as follows
(the message on line 3 was added before devm_request_irq is
called by the dwc2_driver_probe function):
[    5.866837][    T1] dwc2 JMIC0010:01: supply vusb_d not found, using dummy regulator
[    5.874588][    T1] dwc2 JMIC0010:01: supply vusb_a not found, using dummy regulator
[    5.882335][    T1] dwc2 JMIC0010:01: before devm_request_irq  irq: [71], gintmsk[0xf300080e], gintsts[0x04200009]
[    5.892686][    C0] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.10.0-jmnd1.2_RC #18
[    5.900327][    C0] Hardware name: CMSS HyperCard4-25G/HyperCard4-25G, BIOS 1.6.4 Jul  8 2024
[    5.908836][    C0] Call trace:
[    5.911965][    C0]  dump_backtrace+0x0/0x1f0
[    5.916308][    C0]  show_stack+0x20/0x30
[    5.920304][    C0]  dump_stack+0xd8/0x140
[    5.924387][    C0]  pcie_xxx_handler+0x3c/0x1d8
[    5.930121][    C0]  __handle_irq_event_percpu+0x64/0x1e0
[    5.935506][    C0]  handle_irq_event+0x80/0x1d0
[    5.940109][    C0]  try_one_irq+0x138/0x174
[    5.944365][    C0]  misrouted_irq+0x134/0x140
[    5.948795][    C0]  note_interrupt+0x1d0/0x30c
[    5.953311][    C0]  handle_irq_event+0x13c/0x1d0
[    5.958001][    C0]  handle_fasteoi_irq+0xd4/0x260
[    5.962779][    C0]  __handle_domain_irq+0x88/0xf0
[    5.967555][    C0]  gic_handle_irq+0x9c/0x2f0
[    5.971985][    C0]  el1_irq+0xb8/0x140
[    5.975807][    C0]  __setup_irq+0x3dc/0x7cc
[    5.980064][    C0]  request_threaded_irq+0xf4/0x1b4
[    5.985015][    C0]  devm_request_threaded_irq+0x80/0x100
[    5.990400][    C0]  dwc2_driver_probe+0x1b8/0x6b0
[    5.995178][    C0]  platform_drv_probe+0x5c/0xb0
[    5.999868][    C0]  really_probe+0xf8/0x51c
[    6.004125][    C0]  driver_probe_device+0xfc/0x170
[    6.008989][    C0]  device_driver_attach+0xc8/0xd0
[    6.013853][    C0]  __driver_attach+0xe8/0x1b0
[    6.018369][    C0]  bus_for_each_dev+0x7c/0xdc
[    6.022886][    C0]  driver_attach+0x2c/0x3c
[    6.027143][    C0]  bus_add_driver+0xdc/0x240
[    6.031573][    C0]  driver_register+0x80/0x13c
[    6.036090][    C0]  __platform_driver_register+0x50/0x5c
[    6.041476][    C0]  dwc2_platform_driver_init+0x24/0x30
[    6.046774][    C0]  do_one_initcall+0x50/0x25c
[    6.051291][    C0]  do_initcall_level+0xe4/0xfc
[    6.055894][    C0]  do_initcalls+0x80/0xa4
[    6.060064][    C0]  kernel_init_freeable+0x198/0x240
[    6.065102][    C0]  kernel_init+0x1c/0x12c

Signed-off-by: Shawn Shao <[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]>
Signed-off-by: Manuel Diewald <[email protected]>
Signed-off-by: Koichiro Den <[email protected]>
delphix-devops-bot pushed a commit that referenced this pull request Apr 27, 2025
BugLink: https://bugs.launchpad.net/bugs/2098441

commit 6e64d6b upstream.

In commit e4b5ccd ("drm/v3d: Ensure job pointer is set to NULL
after job completion"), we introduced a change to assign the job pointer
to NULL after completing a job, indicating job completion.

However, this approach created a race condition between the DRM
scheduler workqueue and the IRQ execution thread. As soon as the fence is
signaled in the IRQ execution thread, a new job starts to be executed.
This results in a race condition where the IRQ execution thread sets the
job pointer to NULL simultaneously as the `run_job()` function assigns
a new job to the pointer.

This race condition can lead to a NULL pointer dereference if the IRQ
execution thread sets the job pointer to NULL after `run_job()` assigns
it to the new job. When the new job completes and the GPU emits an
interrupt, `v3d_irq()` is triggered, potentially causing a crash.

[  466.310099] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000c0
[  466.318928] Mem abort info:
[  466.321723]   ESR = 0x0000000096000005
[  466.325479]   EC = 0x25: DABT (current EL), IL = 32 bits
[  466.330807]   SET = 0, FnV = 0
[  466.333864]   EA = 0, S1PTW = 0
[  466.337010]   FSC = 0x05: level 1 translation fault
[  466.341900] Data abort info:
[  466.344783]   ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
[  466.350285]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[  466.355350]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[  466.360677] user pgtable: 4k pages, 39-bit VAs, pgdp=0000000089772000
[  466.367140] [00000000000000c0] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000
[  466.375875] Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP
[  466.382163] Modules linked in: rfcomm snd_seq_dummy snd_hrtimer snd_seq snd_seq_device algif_hash algif_skcipher af_alg bnep binfmt_misc vc4 snd_soc_hdmi_codec drm_display_helper cec brcmfmac_wcc spidev rpivid_hevc(C) drm_client_lib brcmfmac hci_uart drm_dma_helper pisp_be btbcm brcmutil snd_soc_core aes_ce_blk v4l2_mem2mem bluetooth aes_ce_cipher snd_compress videobuf2_dma_contig ghash_ce cfg80211 gf128mul snd_pcm_dmaengine videobuf2_memops ecdh_generic sha2_ce ecc videobuf2_v4l2 snd_pcm v3d sha256_arm64 rfkill videodev snd_timer sha1_ce libaes gpu_sched snd videobuf2_common sha1_generic drm_shmem_helper mc rp1_pio drm_kms_helper raspberrypi_hwmon spi_bcm2835 gpio_keys i2c_brcmstb rp1 raspberrypi_gpiomem rp1_mailbox rp1_adc nvmem_rmem uio_pdrv_genirq uio i2c_dev drm ledtrig_pattern drm_panel_orientation_quirks backlight fuse dm_mod ip_tables x_tables ipv6
[  466.458429] CPU: 0 UID: 1000 PID: 2008 Comm: chromium Tainted: G         C         6.13.0-v8+ #18
[  466.467336] Tainted: [C]=CRAP
[  466.470306] Hardware name: Raspberry Pi 5 Model B Rev 1.0 (DT)
[  466.476157] pstate: 404000c9 (nZcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[  466.483143] pc : v3d_irq+0x118/0x2e0 [v3d]
[  466.487258] lr : __handle_irq_event_percpu+0x60/0x228
[  466.492327] sp : ffffffc080003ea0
[  466.495646] x29: ffffffc080003ea0 x28: ffffff80c0c94200 x27: 0000000000000000
[  466.502807] x26: ffffffd08dd81d7b x25: ffffff80c0c94200 x24: ffffff8003bdc200
[  466.509969] x23: 0000000000000001 x22: 00000000000000a7 x21: 0000000000000000
[  466.517130] x20: ffffff8041bb0000 x19: 0000000000000001 x18: 0000000000000000
[  466.524291] x17: ffffffafadfb0000 x16: ffffffc080000000 x15: 0000000000000000
[  466.531452] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
[  466.538613] x11: 0000000000000000 x10: 0000000000000000 x9 : ffffffd08c527eb0
[  466.545777] x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000
[  466.552941] x5 : ffffffd08c4100d0 x4 : ffffffafadfb0000 x3 : ffffffc080003f70
[  466.560102] x2 : ffffffc0829e8058 x1 : 0000000000000001 x0 : 0000000000000000
[  466.567263] Call trace:
[  466.569711]  v3d_irq+0x118/0x2e0 [v3d] (P)
[  466.573826]  __handle_irq_event_percpu+0x60/0x228
[  466.578546]  handle_irq_event+0x54/0xb8
[  466.582391]  handle_fasteoi_irq+0xac/0x240
[  466.586498]  generic_handle_domain_irq+0x34/0x58
[  466.591128]  gic_handle_irq+0x48/0xd8
[  466.594798]  call_on_irq_stack+0x24/0x58
[  466.598730]  do_interrupt_handler+0x88/0x98
[  466.602923]  el0_interrupt+0x44/0xc0
[  466.606508]  __el0_irq_handler_common+0x18/0x28
[  466.611050]  el0t_64_irq_handler+0x10/0x20
[  466.615156]  el0t_64_irq+0x198/0x1a0
[  466.618740] Code: 52800035 3607faf3 f9442e80 52800021 (f9406018)
[  466.624853] ---[ end trace 0000000000000000 ]---
[  466.629483] Kernel panic - not syncing: Oops: Fatal exception in interrupt
[  466.636384] SMP: stopping secondary CPUs
[  466.640320] Kernel Offset: 0x100c400000 from 0xffffffc080000000
[  466.646259] PHYS_OFFSET: 0x0
[  466.649141] CPU features: 0x100,00000170,00901250,0200720b
[  466.654644] Memory Limit: none
[  466.657706] ---[ end Kernel panic - not syncing: Oops: Fatal exception in interrupt ]---

Fix the crash by assigning the job pointer to NULL before signaling the
fence. This ensures that the job pointer is cleared before any new job
starts execution, preventing the race condition and the NULL pointer
dereference crash.

Cc: [email protected]
Fixes: e4b5ccd ("drm/v3d: Ensure job pointer is set to NULL after job completion")
Signed-off-by: Maíra Canal <[email protected]>
Reviewed-by: Jose Maria Casanova Crespo <[email protected]>
Reviewed-by: Iago Toral Quiroga <[email protected]>
Tested-by: Phil Elwell <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Noah Wager <[email protected]>
Signed-off-by: Koichiro Den <[email protected]>
delphix-devops-bot pushed a commit that referenced this pull request Sep 25, 2025
BugLink: https://bugs.launchpad.net/bugs/2115678

[ Upstream commit 88f7f56d16f568f19e1a695af34a7f4a6ce537a6 ]

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]>
CVE-2025-38063
Signed-off-by: Manuel Diewald <[email protected]>
Signed-off-by: Mehmet Basaran <[email protected]>
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