diff options
| author | Li Huafei <[email protected]> | 2024-07-30 06:09:28 +0800 |
|---|---|---|
| committer | Peter Zijlstra <[email protected]> | 2024-07-31 12:57:39 +0200 |
| commit | f73cefa3b72eaa90abfc43bf6d68137ba059d4b1 (patch) | |
| tree | 34e9f009b8f2c610512323363777d1c3f86c7776 /tools/perf/util/scripting-engines/trace-event-python.c | |
| parent | b1d0e15c8725d21a73c22c099418a63940261041 (diff) | |
perf/x86: Fix smp_processor_id()-in-preemptible warnings
The following bug was triggered on a system built with
CONFIG_DEBUG_PREEMPT=y:
# echo p > /proc/sysrq-trigger
BUG: using smp_processor_id() in preemptible [00000000] code: sh/117
caller is perf_event_print_debug+0x1a/0x4c0
CPU: 3 UID: 0 PID: 117 Comm: sh Not tainted 6.11.0-rc1 #109
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x4f/0x60
check_preemption_disabled+0xc8/0xd0
perf_event_print_debug+0x1a/0x4c0
__handle_sysrq+0x140/0x180
write_sysrq_trigger+0x61/0x70
proc_reg_write+0x4e/0x70
vfs_write+0xd0/0x430
? handle_mm_fault+0xc8/0x240
ksys_write+0x9c/0xd0
do_syscall_64+0x96/0x190
entry_SYSCALL_64_after_hwframe+0x4b/0x53
This is because the commit d4b294bf84db ("perf/x86: Hybrid PMU support
for counters") took smp_processor_id() outside the irq critical section.
If a preemption occurs in perf_event_print_debug() and the task is
migrated to another cpu, we may get incorrect pmu debug information.
Move smp_processor_id() back inside the irq critical section to fix this
issue.
Fixes: d4b294bf84db ("perf/x86: Hybrid PMU support for counters")
Signed-off-by: Li Huafei <[email protected]>
Reviewed-and-tested-by: K Prateek Nayak <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Kan Liang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Diffstat (limited to 'tools/perf/util/scripting-engines/trace-event-python.c')
0 files changed, 0 insertions, 0 deletions