* [PATCH for 3.12] mutex: Avoid gcc version dependent __builtin_constant_p() usage.
@ 2013-10-17 10:45 Tetsuo Handa
2013-10-17 10:52 ` Peter Zijlstra
2013-10-20 19:31 ` [tip:core/urgent] " tip-bot for Tetsuo Handa
0 siblings, 2 replies; 9+ messages in thread
From: Tetsuo Handa @ 2013-10-17 10:45 UTC (permalink / raw)
To: mingo
Cc: peterz, maarten.lankhorst, imirkin, linux-kernel, daniel.vetter,
robdclark
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.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
---
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
--
1.7.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [PATCH for 3.12] mutex: Avoid gcc version dependent __builtin_constant_p() usage.
2013-10-17 10:45 [PATCH for 3.12] mutex: Avoid gcc version dependent __builtin_constant_p() usage Tetsuo Handa
@ 2013-10-17 10:52 ` Peter Zijlstra
2013-10-17 10:54 ` Maarten Lankhorst
2013-10-20 19:31 ` [tip:core/urgent] " tip-bot for Tetsuo Handa
1 sibling, 1 reply; 9+ messages in thread
From: Peter Zijlstra @ 2013-10-17 10:52 UTC (permalink / raw)
To: Tetsuo Handa
Cc: mingo, maarten.lankhorst, imirkin, linux-kernel, daniel.vetter,
robdclark
On Thu, Oct 17, 2013 at 07:45:29PM +0900, Tetsuo Handa wrote:
> 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.
So I completely forgot all about this, but wouldn't something like:
!(__builtin_constant_p(p) && p == NULL)
Not also work and generate the same code?
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH for 3.12] mutex: Avoid gcc version dependent __builtin_constant_p() usage.
2013-10-17 10:52 ` Peter Zijlstra
@ 2013-10-17 10:54 ` Maarten Lankhorst
2013-10-17 11:02 ` Peter Zijlstra
0 siblings, 1 reply; 9+ messages in thread
From: Maarten Lankhorst @ 2013-10-17 10:54 UTC (permalink / raw)
To: Peter Zijlstra, Tetsuo Handa
Cc: mingo, imirkin, linux-kernel, daniel.vetter, robdclark
op 17-10-13 12:52, Peter Zijlstra schreef:
> On Thu, Oct 17, 2013 at 07:45:29PM +0900, Tetsuo Handa wrote:
>> 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.
> So I completely forgot all about this, but wouldn't something like:
>
> !(__builtin_constant_p(p) && p == NULL)
>
> Not also work and generate the same code?
>
See earlier discussion. It was already answered why that was undesirable. ;)
~Maarten
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH for 3.12] mutex: Avoid gcc version dependent __builtin_constant_p() usage.
2013-10-17 10:54 ` Maarten Lankhorst
@ 2013-10-17 11:02 ` Peter Zijlstra
2013-10-18 12:51 ` [PATCH for 3.12] mutex: Avoid gcc version dependent__builtin_constant_p() usage Tetsuo Handa
0 siblings, 1 reply; 9+ messages in thread
From: Peter Zijlstra @ 2013-10-17 11:02 UTC (permalink / raw)
To: Maarten Lankhorst
Cc: Tetsuo Handa, mingo, imirkin, linux-kernel, daniel.vetter,
robdclark
On Thu, Oct 17, 2013 at 12:54:21PM +0200, Maarten Lankhorst wrote:
> op 17-10-13 12:52, Peter Zijlstra schreef:
> > On Thu, Oct 17, 2013 at 07:45:29PM +0900, Tetsuo Handa wrote:
> >> 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.
> > So I completely forgot all about this, but wouldn't something like:
> >
> > !(__builtin_constant_p(p) && p == NULL)
> >
> > Not also work and generate the same code?
> >
> See earlier discussion. It was already answered why that was undesirable. ;)
OK; I forgot if we covered that particular option.. I so hate this
patch; but I'm afraid we'll have to take it :-/
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH for 3.12] mutex: Avoid gcc version dependent__builtin_constant_p() usage.
2013-10-17 11:02 ` Peter Zijlstra
@ 2013-10-18 12:51 ` Tetsuo Handa
2013-10-18 13:13 ` Ingo Molnar
0 siblings, 1 reply; 9+ messages in thread
From: Tetsuo Handa @ 2013-10-18 12:51 UTC (permalink / raw)
To: mingo
Cc: peterz, maarten.lankhorst, imirkin, linux-kernel, daniel.vetter,
robdclark
Peter Zijlstra wrote:
> On Thu, Oct 17, 2013 at 12:54:21PM +0200, Maarten Lankhorst wrote:
> > op 17-10-13 12:52, Peter Zijlstra schreef:
> > > On Thu, Oct 17, 2013 at 07:45:29PM +0900, Tetsuo Handa wrote:
> > >> 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.
> > > So I completely forgot all about this, but wouldn't something like:
> > >
> > > !(__builtin_constant_p(p) && p == NULL)
> > >
> > > Not also work and generate the same code?
> > >
> > See earlier discussion. It was already answered why that was undesirable. ;)
>
> OK; I forgot if we covered that particular option.. I so hate this
> patch; but I'm afraid we'll have to take it :-/
>
I see. Ingo, would you send this patch via your tree?
Then, I'll post a patch for 3.11-stable which differs white spaces.
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH for 3.12] mutex: Avoid gcc version dependent__builtin_constant_p() usage.
2013-10-18 12:51 ` [PATCH for 3.12] mutex: Avoid gcc version dependent__builtin_constant_p() usage Tetsuo Handa
@ 2013-10-18 13:13 ` Ingo Molnar
2013-10-18 15:51 ` Maarten Lankhorst
0 siblings, 1 reply; 9+ messages in thread
From: Ingo Molnar @ 2013-10-18 13:13 UTC (permalink / raw)
To: Tetsuo Handa
Cc: peterz, maarten.lankhorst, imirkin, linux-kernel, daniel.vetter,
robdclark
* Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> wrote:
> Peter Zijlstra wrote:
> > On Thu, Oct 17, 2013 at 12:54:21PM +0200, Maarten Lankhorst wrote:
> > > op 17-10-13 12:52, Peter Zijlstra schreef:
> > > > On Thu, Oct 17, 2013 at 07:45:29PM +0900, Tetsuo Handa wrote:
> > > >> 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.
> > > > So I completely forgot all about this, but wouldn't something like:
> > > >
> > > > !(__builtin_constant_p(p) && p == NULL)
> > > >
> > > > Not also work and generate the same code?
> > > >
> > > See earlier discussion. It was already answered why that was undesirable. ;)
> >
> > OK; I forgot if we covered that particular option.. I so hate this
> > patch; but I'm afraid we'll have to take it :-/
> >
>
> I see. Ingo, would you send this patch via your tree?
> Then, I'll post a patch for 3.11-stable which differs white spaces.
If it has Maarten's and PeterZ's Acked-by then sure.
Thanks,
Ingo
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH for 3.12] mutex: Avoid gcc version dependent__builtin_constant_p() usage.
2013-10-18 13:13 ` Ingo Molnar
@ 2013-10-18 15:51 ` Maarten Lankhorst
2013-10-30 13:14 ` [PATCH 3.11-stable] mutex: Avoid gcc version dependent __builtin_constant_p() usage Tetsuo Handa
0 siblings, 1 reply; 9+ messages in thread
From: Maarten Lankhorst @ 2013-10-18 15:51 UTC (permalink / raw)
To: Ingo Molnar, Tetsuo Handa
Cc: peterz, imirkin, linux-kernel, daniel.vetter, robdclark
op 18-10-13 15:13, Ingo Molnar schreef:
> * Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> wrote:
>
>> Peter Zijlstra wrote:
>>> On Thu, Oct 17, 2013 at 12:54:21PM +0200, Maarten Lankhorst wrote:
>>>> op 17-10-13 12:52, Peter Zijlstra schreef:
>>>>> On Thu, Oct 17, 2013 at 07:45:29PM +0900, Tetsuo Handa wrote:
>>>>>> 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.
>>>>> So I completely forgot all about this, but wouldn't something like:
>>>>>
>>>>> !(__builtin_constant_p(p) && p == NULL)
>>>>>
>>>>> Not also work and generate the same code?
>>>>>
>>>> See earlier discussion. It was already answered why that was undesirable. ;)
>>> OK; I forgot if we covered that particular option.. I so hate this
>>> patch; but I'm afraid we'll have to take it :-/
>>>
>> I see. Ingo, would you send this patch via your tree?
>> Then, I'll post a patch for 3.11-stable which differs white spaces.
> If it has Maarten's and PeterZ's Acked-by then sure.
>
> Thanks,
>
> Ingo
>
Acked. ;-)
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH 3.11-stable] mutex: Avoid gcc version dependent __builtin_constant_p() usage
2013-10-18 15:51 ` Maarten Lankhorst
@ 2013-10-30 13:14 ` Tetsuo Handa
0 siblings, 0 replies; 9+ messages in thread
From: Tetsuo Handa @ 2013-10-30 13:14 UTC (permalink / raw)
To: stable; +Cc: linux-kernel
Commit b0267507dfd0187fb7840a0ec461a510a7f041c5 upstream.
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>
---
kernel/mutex.c | 32 ++++++++++++++++----------------
1 files changed, 16 insertions(+), 16 deletions(-)
--- linux-3.11.6.orig/kernel/mutex.c
+++ linux-3.11.6/kernel/mutex.c
@@ -408,7 +408,7 @@ ww_mutex_set_context_fastpath(struct ww_
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;
@@ -448,7 +448,7 @@ __mutex_lock_common(struct mutex *lock,
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);
@@ -478,7 +478,7 @@ __mutex_lock_common(struct mutex *lock,
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);
@@ -548,7 +548,7 @@ 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;
@@ -568,7 +568,7 @@ done:
mutex_remove_waiter(lock, &waiter, current_thread_info());
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);
@@ -618,7 +618,7 @@ mutex_lock_nested(struct mutex *lock, un
{
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);
@@ -628,7 +628,7 @@ _mutex_lock_nest_lock(struct mutex *lock
{
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);
@@ -638,7 +638,7 @@ mutex_lock_killable_nested(struct mutex
{
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);
@@ -647,7 +647,7 @@ mutex_lock_interruptible_nested(struct m
{
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);
@@ -685,7 +685,7 @@ __ww_mutex_lock(struct ww_mutex *lock, s
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);
@@ -700,7 +700,7 @@ __ww_mutex_lock_interruptible(struct ww_
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);
@@ -812,28 +812,28 @@ __mutex_lock_slowpath(atomic_t *lock_cou
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
@@ -841,7 +841,7 @@ __ww_mutex_lock_interruptible_slowpath(s
struct ww_acquire_ctx *ctx)
{
return __mutex_lock_common(&lock->base, TASK_INTERRUPTIBLE, 0,
- NULL, _RET_IP_, ctx);
+ NULL, _RET_IP_, ctx, 1);
}
#endif
^ permalink raw reply [flat|nested] 9+ messages in thread
* [tip:core/urgent] mutex: Avoid gcc version dependent __builtin_constant_p() usage
2013-10-17 10:45 [PATCH for 3.12] mutex: Avoid gcc version dependent __builtin_constant_p() usage Tetsuo Handa
2013-10-17 10:52 ` Peter Zijlstra
@ 2013-10-20 19:31 ` tip-bot for Tetsuo Handa
1 sibling, 0 replies; 9+ messages in thread
From: tip-bot for Tetsuo Handa @ 2013-10-20 19:31 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, hpa, mingo, torvalds, a.p.zijlstra, penguin-kernel,
akpm, tglx, maarten.lankhorst
Commit-ID: b0267507dfd0187fb7840a0ec461a510a7f041c5
Gitweb: http://git.kernel.org/tip/b0267507dfd0187fb7840a0ec461a510a7f041c5
Author: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
AuthorDate: Thu, 17 Oct 2013 19:45:29 +0900
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Fri, 18 Oct 2013 21:58:54 +0200
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>
---
kernel/mutex.c | 32 ++++++++++++++++----------------
1 file 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
^ permalink raw reply related [flat|nested] 9+ messages in thread
end of thread, other threads:[~2013-10-30 13:14 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-10-17 10:45 [PATCH for 3.12] mutex: Avoid gcc version dependent __builtin_constant_p() usage Tetsuo Handa
2013-10-17 10:52 ` Peter Zijlstra
2013-10-17 10:54 ` Maarten Lankhorst
2013-10-17 11:02 ` Peter Zijlstra
2013-10-18 12:51 ` [PATCH for 3.12] mutex: Avoid gcc version dependent__builtin_constant_p() usage Tetsuo Handa
2013-10-18 13:13 ` Ingo Molnar
2013-10-18 15:51 ` Maarten Lankhorst
2013-10-30 13:14 ` [PATCH 3.11-stable] mutex: Avoid gcc version dependent __builtin_constant_p() usage Tetsuo Handa
2013-10-20 19:31 ` [tip:core/urgent] " tip-bot for Tetsuo Handa
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