diff options
| author | Will Deacon <will.deacon@arm.com> | 2013-08-12 18:03:26 +0100 |
|---|---|---|
| committer | Nitin Garg <nitin.garg@freescale.com> | 2014-04-01 21:28:37 -0500 |
| commit | e43a78d6638fca6a5be7a95258491c3aca502a70 (patch) | |
| tree | 7b2758a9974fdfd6c6213f0487dd8c0b0706c124 | |
| parent | 48d6784d723ca82c4c3a28cfbfe5350cf5fec411 (diff) | |
ARM: 7811/1: locks: use early clobber in arch_spin_trylock
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 <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Wang Weidong <wangweidong1@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/arm/include/asm/spinlock.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm/include/asm/spinlock.h b/arch/arm/include/asm/spinlock.h index dd64cc6f9cba..b07c09e5a0ac 100644 --- 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_spinlock_t *lock) " 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); |