diff options
author | Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> | 2013-10-17 10:45:29 (GMT) |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2013-10-18 19:58:54 (GMT) |
commit | b0267507dfd0187fb7840a0ec461a510a7f041c5 (patch) | |
tree | 8d17053d2ac87eb4f53120dc8d83cc084819096a | |
parent | 04919afb85c8f007b7326c4da5eb61c52e91b9c7 (diff) | |
download | linux-b0267507dfd0187fb7840a0ec461a510a7f041c5.tar.xz |
mutex: Avoid gcc version dependent __builtin_constant_p() usage
Commit 040a0a37 ("mutex: Add support for wound/wait style locks")
used "!__builtin_constant_p(p == NULL)" but gcc 3.x cannot
handle such expression correctly, leading to boot failure when
built with CONFIG_DEBUG_MUTEXES=y.
Fix it by explicitly passing a bool which tells whether p != NULL
or not.
[ PeterZ: This is a sad patch, but provided it actually generates
similar code I suppose its the best we can do bar whole
sale deprecating gcc-3. ]
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Cc: peterz@infradead.org
Cc: imirkin@alum.mit.edu
Cc: daniel.vetter@ffwll.ch
Cc: robdclark@gmail.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/201310171945.AGB17114.FSQVtHOJFOOFML@I-love.SAKURA.ne.jp
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r-- | kernel/mutex.c | 32 |
1 files changed, 16 insertions, 16 deletions
diff --git a/kernel/mutex.c b/kernel/mutex.c index 6d647ae..d24105b 100644 --- a/kernel/mutex.c +++ b/kernel/mutex.c @@ -410,7 +410,7 @@ ww_mutex_set_context_fastpath(struct ww_mutex *lock, static __always_inline int __sched __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass, struct lockdep_map *nest_lock, unsigned long ip, - struct ww_acquire_ctx *ww_ctx) + struct ww_acquire_ctx *ww_ctx, const bool use_ww_ctx) { struct task_struct *task = current; struct mutex_waiter waiter; @@ -450,7 +450,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass, struct task_struct *owner; struct mspin_node node; - if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) { + if (use_ww_ctx && ww_ctx->acquired > 0) { struct ww_mutex *ww; ww = container_of(lock, struct ww_mutex, base); @@ -480,7 +480,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass, if ((atomic_read(&lock->count) == 1) && (atomic_cmpxchg(&lock->count, 1, 0) == 1)) { lock_acquired(&lock->dep_map, ip); - if (!__builtin_constant_p(ww_ctx == NULL)) { + if (use_ww_ctx) { struct ww_mutex *ww; ww = container_of(lock, struct ww_mutex, base); @@ -551,7 +551,7 @@ slowpath: goto err; } - if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) { + if (use_ww_ctx && ww_ctx->acquired > 0) { ret = __mutex_lock_check_stamp(lock, ww_ctx); if (ret) goto err; @@ -575,7 +575,7 @@ skip_wait: lock_acquired(&lock->dep_map, ip); mutex_set_owner(lock); - if (!__builtin_constant_p(ww_ctx == NULL)) { + if (use_ww_ctx) { struct ww_mutex *ww = container_of(lock, struct ww_mutex, base); struct mutex_waiter *cur; @@ -615,7 +615,7 @@ mutex_lock_nested(struct mutex *lock, unsigned int subclass) { might_sleep(); __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, - subclass, NULL, _RET_IP_, NULL); + subclass, NULL, _RET_IP_, NULL, 0); } EXPORT_SYMBOL_GPL(mutex_lock_nested); @@ -625,7 +625,7 @@ _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest) { might_sleep(); __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, - 0, nest, _RET_IP_, NULL); + 0, nest, _RET_IP_, NULL, 0); } EXPORT_SYMBOL_GPL(_mutex_lock_nest_lock); @@ -635,7 +635,7 @@ mutex_lock_killable_nested(struct mutex *lock, unsigned int subclass) { might_sleep(); return __mutex_lock_common(lock, TASK_KILLABLE, - subclass, NULL, _RET_IP_, NULL); + subclass, NULL, _RET_IP_, NULL, 0); } EXPORT_SYMBOL_GPL(mutex_lock_killable_nested); @@ -644,7 +644,7 @@ mutex_lock_interruptible_nested(struct mutex *lock, unsigned int subclass) { might_sleep(); return __mutex_lock_common(lock, TASK_INTERRUPTIBLE, - subclass, NULL, _RET_IP_, NULL); + subclass, NULL, _RET_IP_, NULL, 0); } EXPORT_SYMBOL_GPL(mutex_lock_interruptible_nested); @@ -682,7 +682,7 @@ __ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) might_sleep(); ret = __mutex_lock_common(&lock->base, TASK_UNINTERRUPTIBLE, - 0, &ctx->dep_map, _RET_IP_, ctx); + 0, &ctx->dep_map, _RET_IP_, ctx, 1); if (!ret && ctx->acquired > 1) return ww_mutex_deadlock_injection(lock, ctx); @@ -697,7 +697,7 @@ __ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) might_sleep(); ret = __mutex_lock_common(&lock->base, TASK_INTERRUPTIBLE, - 0, &ctx->dep_map, _RET_IP_, ctx); + 0, &ctx->dep_map, _RET_IP_, ctx, 1); if (!ret && ctx->acquired > 1) return ww_mutex_deadlock_injection(lock, ctx); @@ -809,28 +809,28 @@ __mutex_lock_slowpath(atomic_t *lock_count) struct mutex *lock = container_of(lock_count, struct mutex, count); __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0, - NULL, _RET_IP_, NULL); + NULL, _RET_IP_, NULL, 0); } static noinline int __sched __mutex_lock_killable_slowpath(struct mutex *lock) { return __mutex_lock_common(lock, TASK_KILLABLE, 0, - NULL, _RET_IP_, NULL); + NULL, _RET_IP_, NULL, 0); } static noinline int __sched __mutex_lock_interruptible_slowpath(struct mutex *lock) { return __mutex_lock_common(lock, TASK_INTERRUPTIBLE, 0, - NULL, _RET_IP_, NULL); + NULL, _RET_IP_, NULL, 0); } static noinline int __sched __ww_mutex_lock_slowpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) { return __mutex_lock_common(&lock->base, TASK_UNINTERRUPTIBLE, 0, - NULL, _RET_IP_, ctx); + NULL, _RET_IP_, ctx, 1); } static noinline int __sched @@ -838,7 +838,7 @@ __ww_mutex_lock_interruptible_slowpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) { return __mutex_lock_common(&lock->base, TASK_INTERRUPTIBLE, 0, - NULL, _RET_IP_, ctx); + NULL, _RET_IP_, ctx, 1); } #endif |