Kernel stacktrace on sun4v during boot

Kernel stacktrace on sun4v during boot

[John Paul Adrian Glaubitz]

Hi,

I noticed a kernel stacktrace on sun4v starting with Linux v6.12 with the Debian
kernel (see below). I tested multiple kernels and was not able to reproduce the
issue with older kernels and interestingly also not with v6.16-rc6, so this issue
may have been fixed with v6.16.

In order to make sure the issue is not hidden by configuration differences between
the Debian and upstream kernel, I built the exact same configuration like Debian
just with kernel and module signing disabled.

So, either the issue will be fixed with v6.16 or Debian is carrying a local patch
which introduces this issue (unlikely as Debian does not have sparc-specific patches
in its kernel package.

Adrian

===================================================================================

[    1.917534] ------------[ cut here ]------------
[    1.917573] WARNING: CPU: 0 PID: 267 at lib/kobject.c:734 kobject_put+0x64/0x240
[    1.917609] kobject: '(null)' ((____ptrval____)): is not initialized, yet kobject_put() is being called.
[    1.917627] Modules linked in:
[    1.917647] CPU: 0 UID: 0 PID: 267 Comm: kworker/u256:8 Not tainted 6.12.38+deb13-sparc64-smp #1  Debian 6.12.38-1
[    1.917658] Workqueue: async async_run_entry_fn
[    1.917672] Call Trace:
[    1.917676] [<0000000000f11864>] dump_stack+0x8/0x18
[    1.917688] [<000000000046e15c>] __warn+0xdc/0x140
[    1.917697] [<000000000046e2d8>] warn_slowpath_fmt+0x118/0x140
[    1.917704] [<0000000000ec8024>] kobject_put+0x64/0x240
[    1.917712] [<000000000072d98c>] sysfs_slab_release+0xc/0x20
[    1.917726] [<00000000006dc91c>] kmem_cache_destroy+0xdc/0x1a0
[    1.917741] [<00000000009593c4>] bioset_exit+0x144/0x1e0
[    1.917753] [<000000000097a8d4>] disk_release+0x54/0x120
[    1.917766] [<0000000000b94a0c>] device_release+0x2c/0xa0
[    1.917776] [<0000000000ec8088>] kobject_put+0xc8/0x240
[    1.917784] [<0000000000b94c74>] put_device+0x14/0x40
[    1.917791] [<000000000097ac58>] put_disk+0x18/0x40
[    1.917799] [<000000000140c2c8>] floppy_async_init+0xbec/0xd10
[    1.917811] [<00000000004a0cc8>] async_run_entry_fn+0x28/0x160
[    1.917818] [<000000000049091c>] process_one_work+0x15c/0x3c0
[    1.917828] [<0000000000490f24>] worker_thread+0x164/0x3e0
[    1.917837] ---[ end trace 0000000000000000 ]---
[    1.917996] ------------[ cut here ]------------
[    1.918007] WARNING: CPU: 0 PID: 267 at lib/refcount.c:28 refcount_warn_saturate+0x18c/0x1a0
[    1.918032] refcount_t: underflow; use-after-free.
[    1.918043] Modules linked in:
[    1.918059] CPU: 0 UID: 0 PID: 267 Comm: kworker/u256:8 Tainted: G        W          6.12.38+deb13-sparc64-smp #1  Debian 6.12.38-1
[    1.918069] Tainted: [W]=WARN
[    1.918073] Workqueue: async async_run_entry_fn
[    1.918080] Call Trace:
[    1.918082] [<0000000000f11864>] dump_stack+0x8/0x18
[    1.918090] [<000000000046e15c>] __warn+0xdc/0x140
[    1.918097] [<000000000046e2d8>] warn_slowpath_fmt+0x118/0x140
[    1.918103] [<00000000009d4d2c>] refcount_warn_saturate+0x18c/0x1a0
[    1.918111] [<0000000000ec8134>] kobject_put+0x174/0x240
[    1.918119] [<000000000072d98c>] sysfs_slab_release+0xc/0x20
[    1.918128] [<00000000006dc91c>] kmem_cache_destroy+0xdc/0x1a0
[    1.918135] [<00000000009593c4>] bioset_exit+0x144/0x1e0
[    1.918143] [<000000000097a8d4>] disk_release+0x54/0x120
[    1.918151] [<0000000000b94a0c>] device_release+0x2c/0xa0
[    1.918158] [<0000000000ec8088>] kobject_put+0xc8/0x240
[    1.918166] [<0000000000b94c74>] put_device+0x14/0x40
[    1.918173] [<000000000097ac58>] put_disk+0x18/0x40
[    1.918181] [<000000000140c2c8>] floppy_async_init+0xbec/0xd10
[    1.918189] [<00000000004a0cc8>] async_run_entry_fn+0x28/0x160
[    1.918196] [<000000000049091c>] process_one_work+0x15c/0x3c0
[    1.918204] ---[ end trace 0000000000000000 ]---

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer
`. `'   Physicist
  `-    GPG: 62FF 8A75 84E0 2956 9546  0006 7426 3B37 F5B5 F913