[tip:locking/core] locking/atomic/x86: Use 's64 *' for 'old' argument of atomic64_try_cmpxchg()

tip-bot for Dmitry Vyukov
2017-07-25T13:59:50Z

Commit-ID: 007d185b44620f6ffa58f52476bed6e6d7d69d3b
Gitweb: http://git.kernel.org/tip/007d185b44620f6ffa58f52476bed6e6d7d69d3b
Author: Dmitry Vyukov <dvyukov@google.com>
AuthorDate: Sat, 17 Jun 2017 11:15:28 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Wed, 28 Jun 2017 18:55:55 +0200

locking/atomic/x86: Use 's64 *' for 'old' argument of atomic64_try_cmpxchg()

atomic64_try_cmpxchg() declares old argument as 'long *',
this makes it impossible to use it in portable code.
If caller passes 'long *', it becomes 32-bits on 32-bit arches.
If caller passes 's64 *', it does not compile on x86_64.

Change type of old argument to 's64 *' instead.

Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: kasan-dev@googlegroups.com
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/fa6f77f2375150d26ea796a77e8b59195fd2ab13.1497690003.git.dvyukov@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/include/asm/atomic64_64.h | 12 ++++++------
arch/x86/include/asm/cmpxchg.h | 2 +-
2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/x86/include/asm/atomic64_64.h b/arch/x86/include/asm/atomic64_64.h
index 8db8879a..5d9de36 100644
--- a/arch/x86/include/asm/atomic64_64.h
+++ b/arch/x86/include/asm/atomic64_64.h
@@ -177,7 +177,7 @@ static inline long atomic64_cmpxchg(atomic64_t *v, long old, long new)
}

#define atomic64_try_cmpxchg atomic64_try_cmpxchg
-static __always_inline bool atomic64_try_cmpxchg(atomic64_t *v, long *old, long new)
+static __always_inline bool atomic64_try_cmpxchg(atomic64_t *v, s64 *old, long new)
{
return try_cmpxchg(&v->counter, old, new);
}
@@ -198,7 +198,7 @@ static inline long atomic64_xchg(atomic64_t *v, long new)
*/
static inline bool atomic64_add_unless(atomic64_t *v, long a, long u)
{
- long c = atomic64_read(v);
+ s64 c = atomic64_read(v);
do {
if (unlikely(c == u))
return false;
@@ -217,7 +217,7 @@ static inline bool atomic64_add_unless(atomic64_t *v, long a, long u)
*/
static inline long atomic64_dec_if_positive(atomic64_t *v)
{
- long dec, c = atomic64_read(v);
+ s64 dec, c = atomic64_read(v);
do {
dec = c - 1;
if (unlikely(dec < 0))
@@ -236,7 +236,7 @@ static inline void atomic64_and(long i, atomic64_t *v)

static inline long atomic64_fetch_and(long i, atomic64_t *v)
{
- long val = atomic64_read(v);
+ s64 val = atomic64_read(v);

do {
} while (!atomic64_try_cmpxchg(v, &val, val & i));
@@ -253,7 +253,7 @@ static inline void atomic64_or(long i, atomic64_t *v)

static inline long atomic64_fetch_or(long i, atomic64_t *v)
{
- long val = atomic64_read(v);
+ s64 val = atomic64_read(v);

do {
} while (!atomic64_try_cmpxchg(v, &val, val | i));
@@ -270,7 +270,7 @@ static inline void atomic64_xor(long i, atomic64_t *v)

static inline long atomic64_fetch_xor(long i, atomic64_t *v)
{
- long val = atomic64_read(v);
+ s64 val = atomic64_read(v);

do {
} while (!atomic64_try_cmpxchg(v, &val, val ^ i));
diff --git a/arch/x86/include/asm/cmpxchg.h b/arch/x86/include/asm/cmpxchg.h
index d90296d..b5069e8 100644
--- a/arch/x86/include/asm/cmpxchg.h
+++ b/arch/x86/include/asm/cmpxchg.h
@@ -157,7 +157,7 @@ extern void __add_wrong_size(void)
#define __raw_try_cmpxchg(_ptr, _pold, _new, size, lock) \
({ \
bool success; \
- __typeof__(_ptr) _old = (_pold); \
+ __typeof__(_ptr) _old = (__typeof__(_ptr))(_pold); \
__typeof__(*(_ptr)) __old = *_old; \
__typeof__(*(_ptr)) __new = (_new); \
switch (size) { \