mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-07-16 09:32:36 -04:00
Code Issues Packages Projects Releases Wiki Activity

perf/core: Fix perf-stat / read()

Browse Source 
In the zeal to adjust all event->state checks to include the new
REVOKED state, one adjustment was made in error. Notably it resulted
in read() on the perf filedesc to stop working for any state lower
than ERROR, specifically EXIT.

This leads to problems with (among others) perf-stat, which wants to
read the counts after a program has finished execution.

Fixes: da916e96e2 ("perf: Make perf_pmu_unregister() useable")
Reported-by: "Mi, Dapeng" <dapeng1.mi@linux.intel.com>
Reported-by: James Clark <james.clark@linaro.org>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/77036114-8723-4af9-a068-1d535f4e2e81@linaro.org
Link: https://lore.kernel.org/r/20250417080725.GH38216@noisy.programming.kicks-ass.net
This commit is contained in:
Peter Zijlstra
2025-04-16 20:50:27 +02:00
committed by Ingo Molnar
parent 1d34a05433
commit f6938a562a
1 changed files with 1 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
kernel/events/core.c
View File

@@ -6021,7 +6021,7 @@ __perf_read(struct perf_event *event, char __user *buf, size_t count)
* error state (i.e. because it was pinned but it couldn't be
* scheduled on to the CPU at some point).
*/
if (event->state <= PERF_EVENT_STATE_ERROR)
if (event->state == PERF_EVENT_STATE_ERROR)
return 0;
if (count < event->read_size)