seccomp: Replace smp_read_barrier_depends() with lockless_dereference()

Recently lockless_dereference() was added which can be used in place of hard-coding smp_read_barrier_depends(). The following PATCH makes the change. Signed-off-by: Pranith Kumar <[email protected]> Signed-off-by: Kees Cook <[email protected]>
chewitt · Jul 15, 2015 · 8225d38 · 8225d38
1 parent b3bddff
commit 8225d38
Showing 1 changed file with 3 additions and 4 deletions.
diff --git a/kernel/seccomp.c b/kernel/seccomp.c
@@ -175,17 +175,16 @@ static int seccomp_check_filter(struct sock_filter *filter, unsigned int flen)
  */
 static u32 seccomp_run_filters(struct seccomp_data *sd)
 {
-	struct seccomp_filter *f = ACCESS_ONCE(current->seccomp.filter);
 	struct seccomp_data sd_local;
 	u32 ret = SECCOMP_RET_ALLOW;
+	/* Make sure cross-thread synced filter points somewhere sane. */
+	struct seccomp_filter *f =
+			lockless_dereference(current->seccomp.filter);
 
 	/* Ensure unexpected behavior doesn't result in failing open. */
 	if (unlikely(WARN_ON(f == NULL)))
 		return SECCOMP_RET_KILL;
 
-	/* Make sure cross-thread synced filter points somewhere sane. */
-	smp_read_barrier_depends();
-
 	if (!sd) {
 		populate_seccomp_data(&sd_local);
 		sd = &sd_local;