next: rcu_preempt self-detected stall on CPU - queued_spin_lock_slowpath

[Naresh Kamboju]

The following kernel rcu info generated while running the test case
selftests: memfd: run_fuse_test.sh on qemu-arm64 running Linux
next-20240902. The qemu-arm64 did not recover.

This build was created with kselftest merge configs.

Anders bisected this to,
  # first bad commit:
    [5fb9c98e9d8ddf2abc645e2dcd9eb6703f77fdab]
    fuse: add support for no forget requests

Crash log:
----------
[    0.000000] Booting Linux on physical CPU 0x0000000000 [0x000f0510]
[    0.000000] Linux version 6.11.0-rc6-next-20240902
(tuxmake@tuxmake) (aarch64-linux-gnu-gcc (Debian 13.3.0-5) 13.3.0, GNU
ld (GNU Binutils for Debian) 2.43) #1 SMP PREEMPT @1725295942
[    0.000000] KASLR enabled
[    0.000000] random: crng init done
[    0.000000] Machine model: linux,dummy-virt
..
# selftests: memfd: run_fuse_test.sh
<3>[  107.408167] rcu: INFO: rcu_preempt self-detected stall on CPU
<3>[  107.409195] rcu: 1-....: (5249 ticks this GP)
idle=4d34/1/0x4000000000000000 softirq=10271/10271 fqs=2623
<3>[  107.410438] rcu: (t=5250 jiffies g=20109 q=58 ncpus=2)
<4>[  107.411776] CPU: 1 UID: 0 PID: 386 Comm: fuse_mnt Not tainted
6.11.0-rc6-next-20240902 #1
<4>[  107.412663] Hardware name: linux,dummy-virt (DT)
<4>[  107.413680] pstate: 03400009 (nzcv daif +PAN -UAO +TCO +DIT
-SSBS BTYPE=--)
<4>[  107.414341] pc : queued_spin_lock_slowpath+0x5c/0x440
<4>[  107.415481] lr : _raw_spin_lock+0x74/0x90
<4>[  107.415974] sp : ffff800080993ad0
<4>[  107.419229] x29: ffff800080993ad0 x28: 0000000000000008 x27:
fff000000635b800
<4>[  107.421148] x26: 0000000000000000 x25: 0000000000000000 x24:
ffff800080993ba0
<4>[  107.422099] x23: ffffa8c953aa02c8 x22: ffffa8c953aa02a0 x21:
0000000000000000
<4>[  107.423060] x20: fff0000005088330 x19: fff0000005088330 x18:
0000000000000000
<4>[  107.424145] x17: fff057375aeca000 x16: ffffa8c9a382f930 x15:
0000000000000000
<4>[  107.425097] x14: 0000000000000000 x13: 00000000000000d0 x12:
0000000000000000
<4>[  107.425990] x11: 0000000000000000 x10: fff00000ff7fb7b0 x9 :
ffffa8c9a382f9a4
<4>[  107.426955] x8 : ffff800080993a38 x7 : 0000000000000000 x6 :
0000000000000001
<4>[  107.427836] x5 : ffffa8c9a490a000 x4 : ffffa8c9a490a5c0 x3 :
0000000000000000
<4>[  107.428777] x2 : 0000000000000002 x1 : 0000000000000000 x0 :
0000000000000001
<4>[  107.430091] Call trace:
<4>[  107.430421]  queued_spin_lock_slowpath+0x5c/0x440
<4>[  107.431226]  _raw_spin_lock+0x74/0x90
<4>[  107.431841]  fuse_iget+0x1a0/0x2b8 [fuse]
<4>[  107.433439]  fuse_fill_super_common+0x344/0x468 [fuse]
<4>[  107.434320]  fuse_fill_super+0x6c/0xc8 [fuse]
<4>[  107.435044]  get_tree_nodev+0x78/0xc8
<4>[  107.435656]  fuse_get_tree+0xc8/0x1a0 [fuse]
<4>[  107.436133]  vfs_get_tree+0x30/0x100
<4>[  107.436927]  path_mount+0x3f4/0xa70
<4>[  107.437515]  __arm64_sys_mount+0x1e0/0x2a8
<4>[  107.438148]  invoke_syscall+0x50/0x120
<4>[  107.438760]  el0_svc_common.constprop.0+0x48/0xf0
<4>[  107.439484]  do_el0_svc+0x24/0x38
<4>[  107.440251]  el0_svc+0x3c/0x108
<4>[  107.440574]  el0t_64_sync_handler+0x120/0x130
<4>[  107.440978]  el0t_64_sync+0x190/0x198
<3>[  170.451886] rcu: INFO: rcu_preempt self-detected stall on CPU
<3>[  170.452546] rcu: 1-....: (21001 ticks this GP)
idle=4d34/1/0x4000000000000000 softirq=10271/10271 fqs=10494
<3>[  170.453323] rcu: (t=21011 jiffies g=20109 q=83 ncpus=2)
<4>[  170.454283] CPU: 1 UID: 0 PID: 386 Comm: fuse_mnt Not tainted
6.11.0-rc6-next-20240902 #1
<4>[  170.454966] Hardware name: linux,dummy-virt (DT)
<4>[  170.455736] pstate: 03400009 (nzcv daif +PAN -UAO +TCO +DIT
-SSBS BTYPE=--)
<4>[  170.456697] pc : queued_spin_lock_slowpath+0x5c/0x440
<4>[  170.457179] lr : _raw_spin_lock+0x74/0x90

boot Log links,
--------
 - https://storage.tuxsuite.com/public/linaro/lkft/tests/2lWV52ERJsLvYqFnGkWoPm2Wm9O/logs.txt
 - https://storage.tuxsuite.com/public/linaro/lkft/tests/2lWV52ERJsLvYqFnGkWoPm2Wm9O/logs.html

metadata:
----
  git describe: next-20240902
  git repo: https://gitlab.com/Linaro/lkft/mirrors/next/linux-next
  git sha: ecc768a84f0b8e631986f9ade3118fa37852fef0
  kernel config:
https://storage.tuxsuite.com/public/linaro/lkft/builds/2lWV3S20oiROqoJeQxul8mzi4Lo/config
  build url: https://storage.tuxsuite.com/public/linaro/lkft/builds/2lWV3S20oiROqoJeQxul8mzi4Lo/
  toolchain: gcc-13

Steps to reproduce:
---------
 - https://storage.tuxsuite.com/public/linaro/lkft/tests/2lWV52ERJsLvYqFnGkWoPm2Wm9O/
 - https://storage.tuxsuite.com/public/linaro/lkft/tests/2lWV52ERJsLvYqFnGkWoPm2Wm9O/tuxrun_reproducer.sh

--
Linaro LKFT
https://lkft.linaro.org