From: Manfred Spraul <manfred@colorfullife.com>
Date: Wed, 22 Aug 2018 05:01:37 +0000 (-0700)
Subject: ipc/util.c: correct comment in ipc_obtain_object_check
X-Git-Tag: v4.19-rc1~59^2~7
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=2e5ceb452c9b7f0a30c87bd61c01260e3d8464ad;p=thirdparty%2Fkernel%2Flinux.git

ipc/util.c: correct comment in ipc_obtain_object_check

The comment that explains ipc_obtain_object_check is wrong: The function
checks the sequence number, not the reference counter.

Note that checking the reference counter would be meaningless: The
reference counter is decreased without holding any locks, thus an object
with kern_ipc_perm.deleted=true may disappear at the end of the next rcu
grace period.

Link: http://lkml.kernel.org/r/20180712185241.4017-6-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Kees Cook <keescook@chromium.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/ipc/util.c b/ipc/util.c
index 1d88dffd75e7b..dcb437095cbde 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -629,8 +629,8 @@ err:
  * @ids: ipc identifier set
  * @id: ipc id to look for
  *
- * Similar to ipc_obtain_object_idr() but also checks
- * the ipc object reference counter.
+ * Similar to ipc_obtain_object_idr() but also checks the ipc object
+ * sequence number.
  *
  * Call inside the RCU critical section.
  * The ipc object is *not* locked on exit.