mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-26 12:15:15 +07:00
c64a3be39f
commit 6c605f8371159432ec61cbb1488dcf7ad24ad19a upstream.
KCSAN reports a data race between increment and decrement of pin_count:
write to 0xffff888237c2d4e0 of 4 bytes by task 15740 on cpu 1:
find_get_context kernel/events/core.c:4617
__do_sys_perf_event_open kernel/events/core.c:12097 [inline]
__se_sys_perf_event_open kernel/events/core.c:11933
...
read to 0xffff888237c2d4e0 of 4 bytes by task 15743 on cpu 0:
perf_unpin_context kernel/events/core.c:1525 [inline]
__do_sys_perf_event_open kernel/events/core.c:12328 [inline]
__se_sys_perf_event_open kernel/events/core.c:11933
...
Because neither read-modify-write here is atomic, this can lead to one
of the operations being lost, resulting in an inconsistent pin_count.
Fix it by adding the missing locking in the CPU-event case.
Fixes:
|
||
---|---|---|
.. | ||
callchain.c | ||
core.c | ||
hw_breakpoint.c | ||
internal.h | ||
Makefile | ||
ring_buffer.c | ||
uprobes.c |