On 10/06/2024 10:51, Venkat Rao Bagalkote wrote:
Greetings!!!
Observing Kernel OOPS, while creating namespace on a NVMe device.
[ 140.209777] BUG: Unable to handle kernel data access at
0x18d7003065646fee
[ 140.209792] Faulting instruction address: 0xc00000000023b45c
[ 140.209798] Oops: Kernel access of bad area, sig: 11 [#1]
[ 140.209802] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=8192 NUMA pSeries
[ 140.209809] Modules linked in: rpadlpar_io rpaphp xsk_diag
nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet
nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat
bonding nf_conntrack tls nf_defrag_ipv6 nf_defrag_ipv4 rfkill ip_set
nf_tables nfnetlink vmx_crypto pseries_rng binfmt_misc fuse xfs
libcrc32c sd_mod sg ibmvscsi scsi_transport_srp ibmveth nvme nvme_core
t10_pi crc64_rocksoft_generic crc64_rocksoft crc64
[ 140.209864] CPU: 2 PID: 129 Comm: kworker/u65:3 Kdump: loaded Not
tainted 6.10.0-rc3 #2
[ 140.209870] Hardware name: IBM,9009-42A POWER9 (raw) 0x4e0202
0xf000005 of:IBM,FW950.A0 (VL950_141) hv:phyp pSeries
[ 140.209876] Workqueue: nvme-wq nvme_scan_work [nvme_core]
[ 140.209889] NIP: c00000000023b45c LR: c008000006a96b20 CTR:
c00000000023b42c
[ 140.209894] REGS: c0000000506078a0 TRAP: 0380 Not tainted
(6.10.0-rc3)
[ 140.209899] MSR: 800000000280b033
<SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 24000244 XER: 00000000
[ 140.209915] CFAR: c008000006aa80ac IRQMASK: 0
[ 140.209915] GPR00: c008000006a96b20 c000000050607b40
c000000001573700 c000000004291ee0
[ 140.209915] GPR04: 0000000000000000 c000000006150080
00000000c0080005 fffffffffffe0000
[ 140.209915] GPR08: 0000000000000000 18d7003065646f6e
0000000000000000 c008000006aa8098
[ 140.209915] GPR12: c00000000023b42c c00000000f7cdf00
c0000000001a151c c000000004f2be80
[ 140.209915] GPR16: 0000000000000000 0000000000000000
0000000000000000 0000000000000000
[ 140.209915] GPR20: c000000004dbcc00 0000000000000006
0000000000000002 c000000004911270
[ 140.209915] GPR24: 0000000000000000 0000000000000000
c0000000ee254ffc c0000000049111f0
[ 140.209915] GPR28: 0000000000000000 c000000004911260
c000000004291ee0 c000000004911260
[ 140.209975] NIP [c00000000023b45c] synchronize_srcu+0x30/0x1c0
[ 140.209984] LR [c008000006a96b20] nvme_ns_remove+0x80/0x2d8
[nvme_core]
[ 140.209994] Call Trace:
[ 140.209997] [c000000050607b90] [c008000006a96b20]
nvme_ns_remove+0x80/0x2d8 [nvme_core]
[ 140.210008] [c000000050607bd0] [c008000006a972b4]
nvme_remove_invalid_namespaces+0x144/0x1ac [nvme_core]
[ 140.210020] [c000000050607c60] [c008000006a9dbd4]
nvme_scan_ns_list+0x19c/0x370 [nvme_core]
[ 140.210032] [c000000050607d70] [c008000006a9dfc8]
nvme_scan_work+0xc8/0x278 [nvme_core]
[ 140.210043] [c000000050607e40] [c00000000019414c]
process_one_work+0x20c/0x4f4
[ 140.210051] [c000000050607ef0] [c0000000001950cc]
worker_thread+0x378/0x544
[ 140.210058] [c000000050607f90] [c0000000001a164c] kthread+0x138/0x140
[ 140.210065] [c000000050607fe0] [c00000000000df98]
start_kernel_thread+0x14/0x18
[ 140.210072] Code: 3c4c0134 384282d4 7c0802a6 60000000 7c0802a6
fbc1fff0 fba1ffe8 fbe1fff8 7c7e1b78 f8010010 f821ffb1 e9230010
<e9290080> 7c2004ac 71290003 41820008
[ 140.210093] ---[ end trace 0000000000000000 ]---
Issue is introduced by the patch:
be647e2c76b27f409cdd520f66c95be888b553a3.
Exactly this was the concern when introducing a behavior change in a
sensitive area of the code
to silence lockdep...
I'm assuming that the bad dereference is:
synchronize_srcu(&ns->ctrl->srcu);
btw, looking at the code again, I'm assuming that synchronizing srcu in
every ns remove
slows down batch removal of many namespaces greatly...
Reverting it, issue is not seen.
Regards,
Venkat.
