Manfred Spraul 17d056e0bd ipc/sem.c: use READ_ONCE()/WRITE_ONCE() for use_global_lock ... The patch solves three weaknesses in ipc/sem.c: 1) The initial read of use_global_lock in sem_lock() is an intentional race. KCSAN detects these accesses and prints a warning. 2) The code assumes that plain C read/writes are not mangled by the CPU or the compiler. 3) The comment it sysvipc_sem_proc_show() was hard to understand: The rest of the comments in ipc/sem.c speaks about sem_perm.lock, and suddenly this function speaks about ipc_lock_object(). To solve 1) and 2), use READ_ONCE()/WRITE_ONCE(). Plain C reads are used in code that owns sma->sem_perm.lock. The comment is updated to solve 3) [manfred@colorfullife.com: use READ_ONCE()/WRITE_ONCE() for use_global_lock] Link: https://lkml.kernel.org/r/20210627161919.3196-3-manfred@colorfullife.com Link: https://lkml.kernel.org/r/20210514175319.12195-1-manfred@colorfullife.com Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Davidlohr Bueso <dbueso@suse.de> Cc: <1vier1@web.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2021-07-01 11:06:07 -07:00
..
compat.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
ipc_sysctl.c	ipc: adjust proc_ipc_sem_dointvec definition to match prototype	2020-09-05 12:14:29 -07:00
Makefile	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
mq_sysctl.c	sysctl: pass kernel pointers to ->proc_handler	2020-04-27 02:07:40 -04:00
mqueue.c	ipc/mqueue, msg, sem: avoid relying on a stack reference past its expiry	2021-05-22 15:09:07 -10:00
msg.c	ipc: use kmalloc for msg_queue and shmid_kernel	2021-07-01 11:06:07 -07:00
msgutil.c	ipc: Use generic ns_common::count	2020-08-19 14:13:52 +02:00
namespace.c	ipc: Use generic ns_common::count	2020-08-19 14:13:52 +02:00
sem.c	ipc/sem.c: use READ_ONCE()/WRITE_ONCE() for use_global_lock	2021-07-01 11:06:07 -07:00
shm.c	ipc: use kmalloc for msg_queue and shmid_kernel	2021-07-01 11:06:07 -07:00
syscall.c	y2038: remove CONFIG_64BIT_TIME	2019-11-15 14:38:27 +01:00
util.c	ipc/util.c: sysvipc_find_ipc() incorrectly updates position index	2020-05-14 10:00:35 -07:00
util.h	ipc: fix sparc64 ipc() wrapper	2019-09-07 21:42:25 +02:00