Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Will Deacon , Russell King , Wang Weidong Subject: [PATCH 3.10 28/85] ARM: 7811/1: locks: use early clobber in arch_spin_trylock Date: Thu, 20 Mar 2014 17:09:31 -0700 Message-Id: <20140321000602.636108124@linuxfoundation.org> In-Reply-To: <20140321000558.606667505@linuxfoundation.org> References: <20140321000558.606667505@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Will Deacon commit afa31d8eb86fc2f25083e675d57ac8173a98f999 upstream. The res variable is written before we've finished with the input operands (namely the lock address), so ensure that we mark it as `early clobber' to avoid unintended register sharing. Signed-off-by: Will Deacon Signed-off-by: Russell King Cc: Wang Weidong Signed-off-by: Greg Kroah-Hartman --- arch/arm/include/asm/spinlock.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/arm/include/asm/spinlock.h +++ b/arch/arm/include/asm/spinlock.h @@ -107,7 +107,7 @@ static inline int arch_spin_trylock(arch " subs %1, %0, %0, ror #16\n" " addeq %0, %0, %4\n" " strexeq %2, %0, [%3]" - : "=&r" (slock), "=&r" (contended), "=r" (res) + : "=&r" (slock), "=&r" (contended), "=&r" (res) : "r" (&lock->slock), "I" (1 << TICKET_SHIFT) : "cc"); } while (res);