From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andres Lagar-Cavilla Subject: [PATCH] x86/mm: Fix operator associativity bug in mm-locks.h Date: Thu, 12 Jan 2012 11:20:06 -0500 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel@lists.xensource.com Cc: tim@xen.org List-Id: xen-devel@lists.xenproject.org xen/arch/x86/mm/mm-locks.h | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) In an order-enforcing wrapper for an "external" recursive lock, we aim to increment/decrement a recurse count and only update the lock ordering on zero counts. Unfortunately we incrementing/decrementing the pointer to the recurse count, rather than the count itself. Signed-off-by: Andres Lagar-Cavilla diff -r 91f9a26a8d94 -r e7028b298fe3 xen/arch/x86/mm/mm-locks.h --- a/xen/arch/x86/mm/mm-locks.h +++ b/xen/arch/x86/mm/mm-locks.h @@ -81,7 +81,7 @@ static inline void _mm_enforce_order_loc { if ( recurse_count ) { - if ( *recurse_count++ == 0 ) + if ( (*recurse_count)++ == 0 ) { *unlock_level = __get_lock_level(); } @@ -125,7 +125,7 @@ static inline void mm_enforce_order_unlo if ( recurse_count ) { BUG_ON(*recurse_count == 0); - if ( *recurse_count-- == 1 ) + if ( (*recurse_count)-- == 1 ) { __set_lock_level(unlock_level); }