Re: [patch] io-wq: fully initialize wqe before calling cpuhp_state_add_instance_nocalls()

[Jens Axboe <axboe@kernel.dk>]

On Thu, 05 Oct 2023 13:55:31 -0400, Jeff Moyer wrote:
> I received a bug report with the following signature:
> 
> [ 1759.937637] BUG: unable to handle page fault for address: ffffffffffffffe8
> [ 1759.944564] #PF: supervisor read access in kernel mode
> [ 1759.949732] #PF: error_code(0x0000) - not-present page
> [ 1759.954901] PGD 7ab615067 P4D 7ab615067 PUD 7ab617067 PMD 0
> [ 1759.960596] Oops: 0000 1 PREEMPT SMP PTI
> [ 1759.964804] CPU: 15 PID: 109 Comm: cpuhp/15 Kdump: loaded Tainted: G X ------- — 5.14.0-362.3.1.el9_3.x86_64 #1
> [ 1759.976609] Hardware name: HPE ProLiant DL380 Gen10/ProLiant DL380 Gen10, BIOS U30 06/20/2018
> [ 1759.985181] RIP: 0010:io_wq_for_each_worker.isra.0+0x24/0xa0
> [ 1759.990877] Code: 90 90 90 90 90 90 0f 1f 44 00 00 41 56 41 55 41 54 55 48 8d 6f 78 53 48 8b 47 78 48 39 c5 74 4f 49 89 f5 49 89 d4 48 8d 58 e8 <8b> 13 85 d2 74 32 8d 4a 01 89 d0 f0 0f b1 0b 75 5c 09 ca 78 3d 48
> [ 1760.009758] RSP: 0000:ffffb6f403603e20 EFLAGS: 00010286
> [ 1760.015013] RAX: 0000000000000000 RBX: ffffffffffffffe8 RCX: 0000000000000000
> [ 1760.022188] RDX: ffffb6f403603e50 RSI: ffffffffb11e95b0 RDI: ffff9f73b09e9400
> [ 1760.029362] RBP: ffff9f73b09e9478 R08: 000000000000000f R09: 0000000000000000
> [ 1760.036536] R10: ffffffffffffff00 R11: ffffb6f403603d80 R12: ffffb6f403603e50
> [ 1760.043712] R13: ffffffffb11e95b0 R14: ffffffffb28531e8 R15: ffff9f7a6fbdf548
> [ 1760.050887] FS: 0000000000000000(0000) GS:ffff9f7a6fbc0000(0000) knlGS:0000000000000000
> [ 1760.059025] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 1760.064801] CR2: ffffffffffffffe8 CR3: 00000007ab610002 CR4: 00000000007706e0
> [ 1760.071976] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [ 1760.079150] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> [ 1760.086325] PKRU: 55555554
> [ 1760.089044] Call Trace:
> [ 1760.091501] <TASK>
> [ 1760.093612] ? show_trace_log_lvl+0x1c4/0x2df
> [ 1760.097995] ? show_trace_log_lvl+0x1c4/0x2df
> [ 1760.102377] ? __io_wq_cpu_online+0x54/0xb0
> [ 1760.106584] ? __die_body.cold+0x8/0xd
> [ 1760.110356] ? page_fault_oops+0x134/0x170
> [ 1760.114479] ? kernelmode_fixup_or_oops+0x84/0x110
> [ 1760.119298] ? exc_page_fault+0xa8/0x150
> [ 1760.123247] ? asm_exc_page_fault+0x22/0x30
> [ 1760.127458] ? __pfx_io_wq_worker_affinity+0x10/0x10
> [ 1760.132453] ? __pfx_io_wq_worker_affinity+0x10/0x10
> [ 1760.137446] ? io_wq_for_each_worker.isra.0+0x24/0xa0
> [ 1760.142527] __io_wq_cpu_online+0x54/0xb0
> [ 1760.146558] cpuhp_invoke_callback+0x109/0x460
> [ 1760.151029] ? __pfx_io_wq_cpu_offline+0x10/0x10
> [ 1760.155673] ? __pfx_smpboot_thread_fn+0x10/0x10
> [ 1760.160320] cpuhp_thread_fun+0x8d/0x140
> [ 1760.164266] smpboot_thread_fn+0xd3/0x1a0
> [ 1760.168297] kthread+0xdd/0x100
> [ 1760.171457] ? __pfx_kthread+0x10/0x10
> [ 1760.175225] ret_from_fork+0x29/0x50
> [ 1760.178826] </TASK>
> [ 1760.181022] Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs rfkill sunrpc vfat fat dm_multipath intel_rapl_msr intel_rapl_common isst_if_common ipmi_ssif nfit libnvdimm mgag200 i2c_algo_bit ioatdma drm_shmem_helper drm_kms_helper acpi_ipmi syscopyarea x86_pkg_temp_thermal sysfillrect ipmi_si intel_powerclamp sysimgblt ipmi_devintf coretemp acpi_power_meter ipmi_msghandler rapl pcspkr dca intel_pch_thermal intel_cstate ses lpc_ich intel_uncore enclosure hpilo mei_me mei acpi_tad fuse drm xfs sd_mod sg bnx2x nvme nvme_core crct10dif_pclmul crc32_pclmul nvme_common ghash_clmulni_intel smartpqi tg3 t10_pi mdio uas libcrc32c crc32c_intel scsi_transport_sas usb_storage hpwdt wmi dm_mirror dm_region_hash dm_log dm_mod
> [ 1760.248623] CR2: ffffffffffffffe8
> 
> [...]

Applied, thanks!

[1/1] io-wq: fully initialize wqe before calling cpuhp_state_add_instance_nocalls()
      commit: 0f8baa3c9802fbfe313c901e1598397b61b91ada

Best regards,
-- 
Jens Axboe