FYI, we noticed the following commit (built with gcc-7):
commit: 0f845cab957c0aef79a51bfc1d5bd9bef2c6a864 ("fscache: Maintain a catalogue of allocated cookies")
https://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git afs-next
in testcase: boot
on test machine: qemu-system-x86_64 -enable-kvm -m 420M
caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):
+---------------------------------------------+------------+------------+
| | b5ddac45de | 0f845cab95 |
+---------------------------------------------+------------+------------+
| boot_successes | 0 | 0 |
| boot_failures | 15 | 16 |
| WARNING:possible_recursive_locking_detected | 15 | 16 |
| BUG:unable_to_handle_kernel | 0 | 16 |
| Oops:#[##] | 0 | 16 |
| RIP:fscache_cookie_put | 0 | 16 |
| Kernel_panic-not_syncing:Fatal_exception | 0 | 16 |
+---------------------------------------------+------------+------------+
[ 8.262524] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
[ 8.263370] IP: fscache_cookie_put+0x70/0xc5
[ 8.263837] PGD 0 P4D 0
[ 8.264161] Oops: 0000 [#1] SMP PTI
[ 8.264554] Modules linked in:
[ 8.270560] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.16.0-rc6-02087-g0f845ca #244
[ 8.271391] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
[ 8.272257] RIP: 0010:fscache_cookie_put+0x70/0xc5
[ 8.272769] RSP: 0000:ffffb76240197e60 EFLAGS: 00010246
[ 8.273328] RAX: 0000000000006664 RBX: ffff949cebbd3b48 RCX: 0000000000000000
[ 8.274048] RDX: 0000000000000000 RSI: 0000000000000007 RDI: ffffffff937049a0
[ 8.274776] RBP: ffffffff9173ff80 R08: ffffffff91606b40 R09: 0000000000000000
[ 8.275524] R10: ffffb76240197da0 R11: 0000000000000228 R12: dead000000000100
[ 8.276240] R13: ffffffff937049a0 R14: ffffffff9268774c R15: 0000000000000000
[ 8.276946] FS: 0000000000000000(0000) GS:ffff949cf9c00000(0000) knlGS:0000000000000000
[ 8.277803] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 8.278398] CR2: 0000000000000000 CR3: 0000000032684000 CR4: 00000000000006f0
[ 8.279144] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 8.279874] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 8.280607] Call Trace:
[ 8.280912] __fscache_unregister_netfs+0x5b/0x78
[ 8.281458] afs_init+0x3c2/0x412
[ 8.281848] ? trace_event_define_fields_afs_call_state+0xe2/0xe2
[ 8.282475] do_one_initcall+0x9e/0x149
[ 8.282902] kernel_init_freeable+0x1d4/0x25c
[ 8.283422] ? rest_init+0xc4/0xc4
[ 8.283808] kernel_init+0xa/0xf5
[ 8.284210] ret_from_fork+0x3a/0x50
[ 8.284644] Code: 00 25 ff 7f 00 00 4c 8d 2c c5 80 16 6d 93 4c 89 ef e8 87 ee ff ff f6 c3 01 48 8b 93 b8 00 00 00 48 8b 8b c0 00 00 00 74 02 0f 0b <48> 8b 01 83 e0 01 48 09 d0 48 85 d2 48 89 01 74 04 48 89 4a 08
[ 8.286534] RIP: fscache_cookie_put+0x70/0xc5 RSP: ffffb76240197e60
[ 8.287211] CR2: 0000000000000000
[ 8.287592] ---[ end trace ce5706455109e764 ]---
To reproduce:
git clone https://github.com/intel/lkp-tests.git
cd lkp-tests
bin/lkp qemu -k <bzImage> job-script # job-script is attached in this email
Thanks,
Xiaolong