From 2cd648c110b5570c3280bd645797658cabbe5f5c Mon Sep 17 00:00:00 2001
From: Manfred Spraul <manfred@colorfullife.com>
Date: Wed, 12 Jul 2017 14:34:44 -0700
Subject: [PATCH 03/20] include/linux/sem.h: correctly document sem_ctime
Git-commit: 2cd648c110b5570c3280bd645797658cabbe5f5c
Patch-mainline: v4.13-rc1
References: bsc#1050323
sem_ctime is initialized to the semget() time and then updated at every
semctl() that changes the array.
Thus it does not represent the time of the last change.
Especially, semop() calls are only stored in sem_otime, not in
sem_ctime.
This is already described in ipc/sem.c, I just overlooked that there is
a comment in include/linux/sem.h and man semctl(2) as well.
So: Correct wrong comments.
Link: http://lkml.kernel.org/r/20170515171912.6298-4-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: <1vier1@web.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
---
include/linux/sem.h | 2 +-
include/uapi/linux/sem.h | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/linux/sem.h b/include/linux/sem.h
index 9db14093b73c..be5cf2ea14ad 100644
--- a/include/linux/sem.h
+++ b/include/linux/sem.h
@@ -30,7 +30,7 @@ struct sem {
/* One sem_array data structure for each set of semaphores in the system. */
struct sem_array {
struct kern_ipc_perm sem_perm; /* permissions .. see ipc.h */
- time_t sem_ctime; /* last change time */
+ time_t sem_ctime; /* create/last semctl() time */
struct list_head pending_alter; /* pending operations */
/* that alter the array */
struct list_head pending_const; /* pending complex operations */
diff --git a/include/uapi/linux/sem.h b/include/uapi/linux/sem.h
index dd73b908b2f3..67eb90361692 100644
--- a/include/uapi/linux/sem.h
+++ b/include/uapi/linux/sem.h
@@ -23,7 +23,7 @@
struct semid_ds {
struct ipc_perm sem_perm; /* permissions .. see ipc.h */
__kernel_time_t sem_otime; /* last semop time */
- __kernel_time_t sem_ctime; /* last change time */
+ __kernel_time_t sem_ctime; /* create/last semctl() time */
struct sem *sem_base; /* ptr to first semaphore in array */
struct sem_queue *sem_pending; /* pending operations to be processed */
struct sem_queue **sem_pending_last; /* last pending operation */
--
2.12.0