korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2025-01-22 22:04:47 +08:00
Code Issues Packages Projects Releases Wiki Activity

events: Reuse value read using READ_ONCE instead of re-reading it

Browse Source 
In perf_event_addr_filters_apply, the task associated with
the event (event->ctx->task) is read using READ_ONCE at the beginning
of the function, checked, and then re-read from event->ctx->task,
voiding all guarantees of the checks. Reuse the value that was read by
READ_ONCE to ensure the consistency of the task struct throughout the
function.

Fixes: 375637bc52 ("perf/core: Introduce address range filtering")
Signed-off-by: Baptiste Lepers <baptiste.lepers@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210906015310.12802-1-baptiste.lepers@gmail.com
This commit is contained in:
Baptiste Lepers 2021-09-06 11:53:10 +10:00 committed by Peter Zijlstra
parent 6880fa6c56
commit b89a05b21f
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
kernel/events/core.c
View File

@ -10193,7 +10193,7 @@ static void perf_event_addr_filters_apply(struct perf_event *event)
return;
if (ifh->nr_file_filters) {
mm = get_task_mm(event->ctx->task);
mm = get_task_mm(task);
if (!mm)
goto restart;