From cf9eb56580e4ebabff35cfa5484ece3c86f1120c Mon Sep 17 00:00:00 2001
From: Richard Earnshaw <rearnsha@arm.com>
Date: Thu, 3 Dec 2009 14:26:46 +0000
Subject: [PATCH] linux-atomic.c (SYNC_LOCK_RELEASE): Place memory barrier
before the lock release.
* arm/linux-atomic.c (SYNC_LOCK_RELEASE): Place memory barrier
before the lock release.
From-SVN: r154949
---
gcc/ChangeLog | 5 +++++
gcc/config/arm/linux-atomic.c | 4 +++-
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 0c99c6e24078..258890d1746f 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2009-12-03 Richard Earnshaw <rearnsha@arm.com>
+
+ * arm/linux-atomic.c (SYNC_LOCK_RELEASE): Place memory barrier
+ before the lock release.
+
2009-12-03 Michael Matz <matz@suse.de>
PR middle-end/38474
diff --git a/gcc/config/arm/linux-atomic.c b/gcc/config/arm/linux-atomic.c
index 14d4a5380f75..20ad2960f496 100644
--- a/gcc/config/arm/linux-atomic.c
+++ b/gcc/config/arm/linux-atomic.c
@@ -266,8 +266,10 @@ SUBWORD_TEST_AND_SET (char, 1)
void HIDDEN \
__sync_lock_release_##WIDTH (TYPE *ptr) \
{ \
- *ptr = 0; \
+ /* All writes before this point must be seen before we release \
+ the lock itself. */ \
__kernel_dmb (); \
+ *ptr = 0; \
}
SYNC_LOCK_RELEASE (int, 4)
--
GitLab