linux-kernel - [PATCH v2 5/9] percpu: Replace smp_read_barrier_depends() with lockless

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1416582363-20661-6-git-send-email-bobby.prani@gmail.com>
Date:	Fri, 21 Nov 2014 10:05:59 -0500
From:	Pranith Kumar <bobby.prani@...il.com>
To:	Tejun Heo <tj@...nel.org>,
	Christoph Lameter <cl@...ux-foundation.org>,
	linux-kernel@...r.kernel.org (open list)
Subject: [PATCH v2 5/9] percpu: 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 <bobby.prani@...il.com>
---
 include/linux/percpu-refcount.h | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/include/linux/percpu-refcount.h b/include/linux/percpu-refcount.h
index 494ab05..3cf6759 100644
--- a/include/linux/percpu-refcount.h
+++ b/include/linux/percpu-refcount.h
@@ -128,10 +128,8 @@ static inline void percpu_ref_kill(struct percpu_ref *ref)
 static inline bool __ref_is_percpu(struct percpu_ref *ref,
 					  unsigned long __percpu **percpu_countp)
 {
-	unsigned long percpu_ptr = ACCESS_ONCE(ref->percpu_count_ptr);
-
 	/* paired with smp_store_release() in percpu_ref_reinit() */
-	smp_read_barrier_depends();
+	unsigned long percpu_ptr = lockless_dereference(ref->percpu_count_ptr);
 
 	if (unlikely(percpu_ptr & __PERCPU_REF_ATOMIC))
 		return false;
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/