diff options
| author | Dag-Erling Smørgrav <des@FreeBSD.org> | 2026-03-16 20:36:56 +0000 |
|---|---|---|
| committer | Dag-Erling Smørgrav <des@FreeBSD.org> | 2026-03-16 20:36:56 +0000 |
| commit | aa15df4597053c0e95a15b2a7036296999cd562a (patch) | |
| tree | 3b3f65d87c8bcfb39429890de942986e09fdf616 | |
| parent | 889d10d5b12050b4b3923917b5edeac85e8ca706 (diff) | |
queue.h: Reorder STAILQ_INSERT_TAIL
The current implementation briefly violates the tail invariant. This
is not usually an issue, but if an insert is in flight when a panic
occurs, we may then trip the invariant while dumping core.
MFC after: 1 week
Sponsored by: Klara, Inc.
Sponsored by: NetApp, Inc.
Reviewed by: obiwac, olce, jhb
Differential Revision: https://reviews.freebsd.org/D55819
| -rw-r--r-- | sys/sys/queue.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/sys/sys/queue.h b/sys/sys/queue.h index aa6453889e6b..e2603bc664c3 100644 --- a/sys/sys/queue.h +++ b/sys/sys/queue.h @@ -499,9 +499,10 @@ struct { \ #define STAILQ_INSERT_TAIL(head, elm, field) do { \ QMD_STAILQ_CHECK_TAIL(head); \ + __typeof__((head)->stqh_last) prevlast = (head)->stqh_last; \ STAILQ_NEXT((elm), field) = NULL; \ - *(head)->stqh_last = (elm); \ (head)->stqh_last = &STAILQ_NEXT((elm), field); \ + *prevlast = (elm); \ } while (0) #define STAILQ_LAST(head, type, field) \ |