mirror of
https://github.com/torvalds/linux
synced 2024-09-06 09:51:23 +00:00
ipc/sem.c: synchronize the proc interface
The proc interface is not aware of sem_lock(), it instead calls ipc_lock_object() directly. This means that simple semop() operations can run in parallel with the proc interface. Right now, this is uncritical, because the implementation doesn't do anything that requires a proper synchronization. But it is dangerous and therefore should be fixed. Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
6d07b68ce1
commit
d8c633766a
|
@ -2103,6 +2103,14 @@ static int sysvipc_sem_proc_show(struct seq_file *s, void *it)
|
|||
struct sem_array *sma = it;
|
||||
time_t sem_otime;
|
||||
|
||||
/*
|
||||
* The proc interface isn't aware of sem_lock(), it calls
|
||||
* ipc_lock_object() directly (in sysvipc_find_ipc).
|
||||
* In order to stay compatible with sem_lock(), we must wait until
|
||||
* all simple semop() calls have left their critical regions.
|
||||
*/
|
||||
sem_wait_array(sma);
|
||||
|
||||
sem_otime = get_semotime(sma);
|
||||
|
||||
return seq_printf(s,
|
||||
|
|
Loading…
Reference in a new issue