diff mbox series

[bpf,2/5] bpf: remove unnecessary rcu_read_{lock,unlock}() in multi-uprobe attach logic

Message ID 20240520234720.1748918-3-andrii@kernel.org (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series Fix BPF multi-uprobe PID filtering logic | expand

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netdev/cc_maintainers warning 13 maintainers not CCed: mhiramat@kernel.org song@kernel.org john.fastabend@gmail.com martin.lau@linux.dev kpsingh@kernel.org yonghong.song@linux.dev sdf@google.com haoluo@google.com linux-trace-kernel@vger.kernel.org rostedt@goodmis.org jolsa@kernel.org eddyz87@gmail.com mathieu.desnoyers@efficios.com
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Commit Message

Andrii Nakryiko May 20, 2024, 11:47 p.m. UTC 
get_pid_task() internally already calls rcu_read_lock() and
rcu_read_unlock(), so there is no point to do this one extra time.

This is a drive-by improvements and has no correctness implications.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
 kernel/trace/bpf_trace.c | 2 --
 1 file changed, 2 deletions(-)

Comments

Jiri Olsa May 21, 2024, 10:04 a.m. UTC | #1 
On Mon, May 20, 2024 at 04:47:17PM -0700, Andrii Nakryiko wrote:
> get_pid_task() internally already calls rcu_read_lock() and
> rcu_read_unlock(), so there is no point to do this one extra time.
> 
> This is a drive-by improvements and has no correctness implications.
> 
> Signed-off-by: Andrii Nakryiko <andrii@kernel.org>

Acked-by: Jiri Olsa <jolsa@kernel.org>

jirka

> ---
>  kernel/trace/bpf_trace.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> index 1baaeb9ca205..6249dac61701 100644
> --- a/kernel/trace/bpf_trace.c
> +++ b/kernel/trace/bpf_trace.c
> @@ -3423,9 +3423,7 @@ int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr
>  	}
>  
>  	if (pid) {
> -		rcu_read_lock();
>  		task = get_pid_task(find_vpid(pid), PIDTYPE_TGID);
> -		rcu_read_unlock();
>  		if (!task) {
>  			err = -ESRCH;
>  			goto error_path_put;
> -- 
> 2.43.0
> 
>
diff mbox series

Patch

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 1baaeb9ca205..6249dac61701 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -3423,9 +3423,7 @@  int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr
 	}
 
 	if (pid) {
-		rcu_read_lock();
 		task = get_pid_task(find_vpid(pid), PIDTYPE_TGID);
-		rcu_read_unlock();
 		if (!task) {
 			err = -ESRCH;
 			goto error_path_put;