diff options
| author | Breno Leitao <leitao@debian.org> | 2025-01-17 06:41:07 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-03-07 18:27:05 +0100 |
| commit | dd536566dda9a551fc2a2acfab5313a5bb13ed02 (patch) | |
| tree | 45e20de1ee3b81afaf717220ddb2c07239487435 /kernel | |
| parent | 9ea170941f80cee86ecc642594e0fa105abd834b (diff) | |
| download | linux-dd536566dda9a551fc2a2acfab5313a5bb13ed02.tar.gz linux-dd536566dda9a551fc2a2acfab5313a5bb13ed02.tar.bz2 linux-dd536566dda9a551fc2a2acfab5313a5bb13ed02.zip | |
perf/core: Add RCU read lock protection to perf_iterate_ctx()
commit 0fe8813baf4b2e865d3b2c735ce1a15b86002c74 upstream.
The perf_iterate_ctx() function performs RCU list traversal but
currently lacks RCU read lock protection. This causes lockdep warnings
when running perf probe with unshare(1) under CONFIG_PROVE_RCU_LIST=y:
WARNING: suspicious RCU usage
kernel/events/core.c:8168 RCU-list traversed in non-reader section!!
Call Trace:
lockdep_rcu_suspicious
? perf_event_addr_filters_apply
perf_iterate_ctx
perf_event_exec
begin_new_exec
? load_elf_phdrs
load_elf_binary
? lock_acquire
? find_held_lock
? bprm_execve
bprm_execve
do_execveat_common.isra.0
__x64_sys_execve
do_syscall_64
entry_SYSCALL_64_after_hwframe
This protection was previously present but was removed in commit
bd2756811766 ("perf: Rewrite core context handling"). Add back the
necessary rcu_read_lock()/rcu_read_unlock() pair around
perf_iterate_ctx() call in perf_event_exec().
[ mingo: Use scoped_guard() as suggested by Peter ]
Fixes: bd2756811766 ("perf: Rewrite core context handling")
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250117-fix_perf_rcu-v1-1-13cb9210fc6a@debian.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/events/core.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 91c58014fe5d..e4cc6e0c54be 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -8284,7 +8284,8 @@ void perf_event_exec(void) perf_event_enable_on_exec(ctx); perf_event_remove_on_exec(ctx); - perf_iterate_ctx(ctx, perf_event_addr_filters_exec, NULL, true); + scoped_guard(rcu) + perf_iterate_ctx(ctx, perf_event_addr_filters_exec, NULL, true); perf_unpin_context(ctx); put_ctx(ctx); |