diff options
| author | MengEn Sun <mengensun@tencent.com> | 2024-12-06 12:13:47 +0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-01-12 20:21:00 -0800 |
| commit | f49b42d415a32faee6bc08923821f432f64a4e90 (patch) | |
| tree | 6a9e611872371390fc7c06d6af8b2a45f7a462c5 | |
| parent | c7bb5cf9fc4e95dff4a3a34b1d14363a6eebdc84 (diff) | |
ucounts: move kfree() out of critical zone protected by ucounts_lock
Although kfree is a non-sleep function, it is possible to enter a long
chain of calls probabilistically, so it looks better to move kfree from
alloc_ucounts() out of the critical zone of ucounts_lock.
Link: https://lkml.kernel.org/r/1733458427-11794-1-git-send-email-mengensun@tencent.com
Signed-off-by: MengEn Sun <mengensun@tencent.com>
Reviewed-by: YueHong Wu <yuehongwu@tencent.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrei Vagin <avagin@google.com>
Cc: Joel Granados <joel.granados@kernel.org>
Cc: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | kernel/ucount.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/kernel/ucount.c b/kernel/ucount.c index f950b5e59d63..86c5f1c0bad9 100644 --- a/kernel/ucount.c +++ b/kernel/ucount.c @@ -164,8 +164,8 @@ struct ucounts *get_ucounts(struct ucounts *ucounts) struct ucounts *alloc_ucounts(struct user_namespace *ns, kuid_t uid) { struct hlist_head *hashent = ucounts_hashentry(ns, uid); - struct ucounts *ucounts, *new; bool wrapped; + struct ucounts *ucounts, *new = NULL; spin_lock_irq(&ucounts_lock); ucounts = find_ucounts(ns, uid, hashent); @@ -182,17 +182,17 @@ struct ucounts *alloc_ucounts(struct user_namespace *ns, kuid_t uid) spin_lock_irq(&ucounts_lock); ucounts = find_ucounts(ns, uid, hashent); - if (ucounts) { - kfree(new); - } else { + if (!ucounts) { hlist_add_head(&new->node, hashent); get_user_ns(new->ns); spin_unlock_irq(&ucounts_lock); return new; } } + wrapped = !get_ucounts_or_wrap(ucounts); spin_unlock_irq(&ucounts_lock); + kfree(new); if (wrapped) { put_ucounts(ucounts); return NULL; |