kernel core: use helpers for rlimits

Make sure compiler won't do weird things with limits.  E.g.  fetching them
twice may return 2 different values after writable limits are implemented.

I.e.  either use rlimit helpers added in commit 3e10e716abf3 ("resource:
add helpers for fetching rlimits") or ACCESS_ONCE if not applicable.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 2 deletions

diff --git a/kernel/sys.c b/kernel/sys.c
index 877fe4f8e05e..9814e43fb23b 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -571,8 +571,7 @@ static int set_user(struct cred *new)
         if (!new_user)
                 return -EAGAIN;
 
-        if (atomic_read(&new_user->processes) >=
-                                current->signal->rlim[RLIMIT_NPROC].rlim_cur &&
+        if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) &&
                         new_user != INIT_USER) {
                 free_uid(new_user);
                 return -EAGAIN;