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Filename Latest commit message Latest commit date
Dave Airlie 1bc4825d4c nouveau: fix instmem race condition around ptr stores
commit fff1386cc889d8fb4089d285f883f8cba62d82ce upstream.

Running a lot of VK CTS in parallel against nouveau, once every
few hours you might see something like this crash.

BUG: kernel NULL pointer dereference, address: 0000000000000008
PGD 8000000114e6e067 P4D 8000000114e6e067 PUD 109046067 PMD 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 7 PID: 53891 Comm: deqp-vk Not tainted 6.8.0-rc6+ #27
Hardware name: Gigabyte Technology Co., Ltd. Z390 I AORUS PRO WIFI/Z390 I AORUS PRO WIFI-CF, BIOS F8 11/05/2021
RIP: 0010:gp100_vmm_pgt_mem+0xe3/0x180 [nouveau]
Code: c7 48 01 c8 49 89 45 58 85 d2 0f 84 95 00 00 00 41 0f b7 46 12 49 8b 7e 08 89 da 42 8d 2c f8 48 8b 47 08 41 83 c7 01 48 89 ee <48> 8b 40 08 ff d0 0f 1f 00 49 8b 7e 08 48 89 d9 48 8d 75 04 48 c1
RSP: 0000:ffffac20c5857838 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 00000000004d8001 RCX: 0000000000000001
RDX: 00000000004d8001 RSI: 00000000000006d8 RDI: ffffa07afe332180
RBP: 00000000000006d8 R08: ffffac20c5857ad0 R09: 0000000000ffff10
R10: 0000000000000001 R11: ffffa07af27e2de0 R12: 000000000000001c
R13: ffffac20c5857ad0 R14: ffffa07a96fe9040 R15: 000000000000001c
FS:  00007fe395eed7c0(0000) GS:ffffa07e2c980000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 000000011febe001 CR4: 00000000003706f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:

...

 ? gp100_vmm_pgt_mem+0xe3/0x180 [nouveau]
 ? gp100_vmm_pgt_mem+0x37/0x180 [nouveau]
 nvkm_vmm_iter+0x351/0xa20 [nouveau]
 ? __pfx_nvkm_vmm_ref_ptes+0x10/0x10 [nouveau]
 ? __pfx_gp100_vmm_pgt_mem+0x10/0x10 [nouveau]
 ? __pfx_gp100_vmm_pgt_mem+0x10/0x10 [nouveau]
 ? __lock_acquire+0x3ed/0x2170
 ? __pfx_gp100_vmm_pgt_mem+0x10/0x10 [nouveau]
 nvkm_vmm_ptes_get_map+0xc2/0x100 [nouveau]
 ? __pfx_nvkm_vmm_ref_ptes+0x10/0x10 [nouveau]
 ? __pfx_gp100_vmm_pgt_mem+0x10/0x10 [nouveau]
 nvkm_vmm_map_locked+0x224/0x3a0 [nouveau]

Adding any sort of useful debug usually makes it go away, so I hand
wrote the function in a line, and debugged the asm.

Every so often pt->memory->ptrs is NULL. This ptrs ptr is set in
the nv50_instobj_acquire called from nvkm_kmap.

If Thread A and Thread B both get to nv50_instobj_acquire around
the same time, and Thread A hits the refcount_set line, and in
lockstep thread B succeeds at refcount_inc_not_zero, there is a
chance the ptrs value won't have been stored since refcount_set
is unordered. Force a memory barrier here, I picked smp_mb, since
we want it on all CPUs and it's write followed by a read.

v2: use paired smp_rmb/smp_wmb.

Cc: <stable@vger.kernel.org>
Fixes: be55287aa5 ("drm/nouveau/imem/nv50: embed nvkm_instobj directly into nv04_instobj")
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240411011510.2546857-1-airlied@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-02 16:18:32 +02:00
arch x86/cpufeatures: Fix dependencies for GFNI, VAES, and VPCLMULQDQ 2024-05-02 16:18:31 +02:00
block block: prevent division by zero in blk_rq_stat_sum() 2024-04-13 12:51:38 +02:00
certs
crypto crypto: api - Disallow identical driver names 2024-02-23 08:24:48 +01:00
Documentation x86/cpu: Enable STIBP on AMD if Automatic IBRS is enabled 2024-04-13 12:51:32 +02:00
drivers nouveau: fix instmem race condition around ptr stores 2024-05-02 16:18:32 +02:00
fs fs: sysfs: Fix reference leak in sysfs_break_active_protection() 2024-05-02 16:18:32 +02:00
include af_unix: Do not use atomic ops for unix_sk(sk)->inflight. 2024-05-02 16:18:29 +02:00
init init: open /initrd.image with O_LARGEFILE 2024-04-13 12:51:36 +02:00
ipc
kernel Revert "tracing/trigger: Fix to return error if failed to alloc snapshot" 2024-05-02 16:18:30 +02:00
lib net: blackhole_dev: fix build warning for ethh set but not used 2024-03-26 18:22:15 -04:00
LICENSES
mm x86/mm/pat: fix VM_PAT handling in COW mappings 2024-04-13 12:51:40 +02:00
net netfilter: nf_tables: Fix potential data-race in __nft_expr_type_get() 2024-05-02 16:18:30 +02:00
samples media: rename VFL_TYPE_GRABBER to _VIDEO 2024-03-26 18:22:22 -04:00
scripts kbuild: Move -Wenum-{compare-conditional,enum-conversion} into W=1 2024-04-13 12:51:26 +02:00
security smack: Handle SMACK64TRANSMUTE in smack_inode_setsecurity() 2024-04-13 12:51:22 +02:00
sound ALSA: hda/realtek: Update Panasonic CF-SZ6 quirk to support headset with microphone 2024-04-13 12:51:36 +02:00
tools selftests/ftrace: Limit length in subsystem-enable tests 2024-05-02 16:18:29 +02:00
usr
virt KVM: Always flush async #PF workqueue when vCPU is being destroyed 2024-04-13 12:51:22 +02:00
.clang-format
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Makefile Linux 5.4.274 2024-04-13 12:51:41 +02:00
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