On Wed, 21 May 2025 16:27:04 +0100
Lee Jones <lee@kernel.org> wrote:
> From: Kuniyuki Iwashima <kuniyu@amazon.com>
>
> [ Upstream commit d0f6dc26346863e1f4a23117f5468614e54df064 ]
>
> This is a prep patch for the last patch in this series so that
> checkpatch will not warn about BUG_ON().
Does any of this actually make any sense?
Either the BUG_ON() should be just deleted because it can't happen
(or doesn't matter) or there should be an error path.
Blindly replacing with WARN_ON_ONCE() can't be right.
The last change (repeated here)
> if (u) {
> - BUG_ON(!u->inflight);
> - BUG_ON(list_empty(&u->link));
> + WARN_ON_ONCE(!u->inflight);
> + WARN_ON_ONCE(list_empty(&u->link));
>
> u->inflight--;
> if (!u->inflight)
is clearly just plain wrong.
If 'inflight' is zero then 'decrementing' it to ~0 is just going
to 'crash and burn' very badly not much later on.
David
>
> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
> Acked-by: Jens Axboe <axboe@kernel.dk>
> Link: https://lore.kernel.org/r/20240129190435.57228-2-kuniyu@amazon.com
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> (cherry picked from commit d0f6dc26346863e1f4a23117f5468614e54df064)
> Signed-off-by: Lee Jones <lee@kernel.org>
> ---
> net/unix/garbage.c | 8 ++++----
> net/unix/scm.c | 8 ++++----
> 2 files changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/net/unix/garbage.c b/net/unix/garbage.c
> index 2934d7b68036..7eeaac165e85 100644
> --- a/net/unix/garbage.c
> +++ b/net/unix/garbage.c
> @@ -145,7 +145,7 @@ static void scan_children(struct sock *x, void (*func)(struct unix_sock *),
> /* An embryo cannot be in-flight, so it's safe
> * to use the list link.
> */
> - BUG_ON(!list_empty(&u->link));
> + WARN_ON_ONCE(!list_empty(&u->link));
> list_add_tail(&u->link, &embryos);
> }
> spin_unlock(&x->sk_receive_queue.lock);
> @@ -224,8 +224,8 @@ static void __unix_gc(struct work_struct *work)
>
> total_refs = file_count(sk->sk_socket->file);
>
> - BUG_ON(!u->inflight);
> - BUG_ON(total_refs < u->inflight);
> + WARN_ON_ONCE(!u->inflight);
> + WARN_ON_ONCE(total_refs < u->inflight);
> if (total_refs == u->inflight) {
> list_move_tail(&u->link, &gc_candidates);
> __set_bit(UNIX_GC_CANDIDATE, &u->gc_flags);
> @@ -318,7 +318,7 @@ static void __unix_gc(struct work_struct *work)
> list_move_tail(&u->link, &gc_inflight_list);
>
> /* All candidates should have been detached by now. */
> - BUG_ON(!list_empty(&gc_candidates));
> + WARN_ON_ONCE(!list_empty(&gc_candidates));
>
> /* Paired with READ_ONCE() in wait_for_unix_gc(). */
> WRITE_ONCE(gc_in_progress, false);
> diff --git a/net/unix/scm.c b/net/unix/scm.c
> index 693817a31ad8..6f446dd2deed 100644
> --- a/net/unix/scm.c
> +++ b/net/unix/scm.c
> @@ -50,10 +50,10 @@ void unix_inflight(struct user_struct *user, struct file *fp)
>
> if (u) {
> if (!u->inflight) {
> - BUG_ON(!list_empty(&u->link));
> + WARN_ON_ONCE(!list_empty(&u->link));
> list_add_tail(&u->link, &gc_inflight_list);
> } else {
> - BUG_ON(list_empty(&u->link));
> + WARN_ON_ONCE(list_empty(&u->link));
> }
> u->inflight++;
> /* Paired with READ_ONCE() in wait_for_unix_gc() */
> @@ -70,8 +70,8 @@ void unix_notinflight(struct user_struct *user, struct file *fp)
> spin_lock(&unix_gc_lock);
>