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* [PATCH] perf/x86/amd: check event before enable to avoid GPF
@ 2024-05-29 13:50 George Kennedy
  2024-05-30  3:37 ` Ravi Bangoria
  0 siblings, 1 reply; 20+ messages in thread
From: George Kennedy @ 2024-05-29 13:50 UTC (permalink / raw)
  To: peterz, mingo, acme, namhyung, mark.rutland, alexander.shishkin,
	jolsa, irogers, adrian.hunter, kan.liang, tglx, bp, dave.hansen,
	x86, hpa, linux-perf-users, linux-kernel
  Cc: george.kennedy, harshit.m.mogalapalli

Events can be deleted and the entry can be NULL.
Check event for NULL in amd_pmu_enable_all() before enable to avoid a GPF.
This appears to be an AMD only issue.

Syzkaller reported a GPF in amd_pmu_enable_all.

INFO: NMI handler (perf_event_nmi_handler) took too long to run: 13.170
    msecs
perf: interrupt took too long (191950 > 156435), lowering
    kernel.perf_event_max_sample_rate to 1000
Oops: general protection fault, probably for non-canonical address
    0xdffffc0000000034: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x00000000000001a0-0x00000000000001a7]

Call Trace:
 <IRQ>
amd_pmu_enable_all (arch/x86/events/amd/core.c:1341)
x86_pmu_enable (arch/x86/events/core.c:1276 arch/x86/events/core.c:1335)
__pmu_ctx_sched_out (kernel/events/core.c:8314 (discriminator 1))
ctx_sched_out (kernel/events/core.c:8328)
__perf_install_in_context (kernel/events/core.c:6235)
remote_function (./arch/x86/include/asm/atomic64_64.h:20)
__flush_smp_call_function_queue (kernel/smp.c:189 (discriminator 20)
    kernel/smp.c:197 (discriminator 20) kernel/smp.c:540 (discriminator 20))
__sysvec_call_function_single (arch/x86/kernel/smp.c:193 (discriminator 1))
sysvec_call_function_single (lib/maple_tree.c:3155 (discriminator 2))
asm_sysvec_call_function_single (./arch/x86/include/asm/idtentry.h:709)

Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: George Kennedy <george.kennedy@oracle.com>
---
 arch/x86/events/amd/core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c
index 1fc4ce44e743..0ead72d3e206 100644
--- a/arch/x86/events/amd/core.c
+++ b/arch/x86/events/amd/core.c
@@ -760,7 +760,8 @@ static void amd_pmu_enable_all(int added)
 		if (!test_bit(idx, cpuc->active_mask))
 			continue;
 
-		amd_pmu_enable_event(cpuc->events[idx]);
+		if (cpuc->events[idx])
+			amd_pmu_enable_event(cpuc->events[idx]);
 	}
 }
 
-- 
2.39.3


^ permalink raw reply related	[flat|nested] 20+ messages in thread

end of thread, other threads:[~2024-09-26  4:05 UTC | newest]

Thread overview: 20+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-05-29 13:50 [PATCH] perf/x86/amd: check event before enable to avoid GPF George Kennedy
2024-05-30  3:37 ` Ravi Bangoria
2024-05-30 18:30   ` George Kennedy
2024-05-30 20:26     ` George Kennedy
2024-06-04 13:16       ` Ravi Bangoria
2024-06-04 13:23         ` George Kennedy
2024-06-04 13:40           ` Ravi Bangoria
2024-06-04 14:26             ` George Kennedy
2024-06-07 19:13             ` George Kennedy
2024-06-10 10:51               ` Ravi Bangoria
2024-06-24 16:18                 ` George Kennedy
2024-07-01 14:15                   ` George Kennedy
2024-07-02  4:03                   ` Ravi Bangoria
2024-07-02 11:38                     ` George Kennedy
2024-09-24 17:13                     ` George Kennedy
2024-09-26  4:05                       ` Ravi Bangoria
2024-06-03  4:39     ` Ravi Bangoria
2024-06-03 13:30       ` George Kennedy
2024-06-04 13:02         ` Ravi Bangoria
2024-06-04 13:00     ` Ravi Bangoria

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