[tip:sched/core] sched/wait: Add might_sleep() checks

tip-bot for Peter Zijlstra
2014-10-28T11:10:58Z

Commit-ID: e22b886a8a43b147e1994a9f970f678fc0df2033
Gitweb: http://git.kernel.org/tip/e22b886a8a43b147e1994a9f970f678fc0df2033
Author: Peter Zijlstra <peterz@infradead.org>
AuthorDate: Wed, 24 Sep 2014 10:18:48 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 28 Oct 2014 10:55:23 +0100

sched/wait: Add might_sleep() checks

Add more might_sleep() checks, suppose someone put a wait_event() like
thing in a wait loop..

Can't put might_sleep() in ___wait_event() because there's the locked
primitives which call ___wait_event() with locks held.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: tglx@linutronix.de
Cc: ilya.dryomov@inktank.com
Cc: umgwanakikbuti@gmail.com
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140924082242.119255706@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
include/linux/wait.h | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/include/linux/wait.h b/include/linux/wait.h
index fc0e993..0421775 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -261,6 +261,7 @@ __out: __ret; \
*/
#define wait_event(wq, condition) \
do { \
+ might_sleep(); \
if (condition) \
break; \
__wait_event(wq, condition); \
@@ -293,6 +294,7 @@ do { \
#define wait_event_timeout(wq, condition, timeout) \
({ \
long __ret = timeout; \
+ might_sleep(); \
if (!___wait_cond_timeout(condition)) \
__ret = __wait_event_timeout(wq, condition, timeout); \
__ret; \
@@ -318,6 +320,7 @@ do { \
*/
#define wait_event_cmd(wq, condition, cmd1, cmd2) \
do { \
+ might_sleep(); \
if (condition) \
break; \
__wait_event_cmd(wq, condition, cmd1, cmd2); \
@@ -345,6 +348,7 @@ do { \
#define wait_event_interruptible(wq, condition) \
({ \
int __ret = 0; \
+ might_sleep(); \
if (!(condition)) \
__ret = __wait_event_interruptible(wq, condition); \
__ret; \
@@ -378,6 +382,7 @@ do { \
#define wait_event_interruptible_timeout(wq, condition, timeout) \
({ \
long __ret = timeout; \
+ might_sleep(); \
if (!___wait_cond_timeout(condition)) \
__ret = __wait_event_interruptible_timeout(wq, \
condition, timeout); \
@@ -428,6 +433,7 @@ do { \
#define wait_event_hrtimeout(wq, condition, timeout) \
({ \
int __ret = 0; \
+ might_sleep(); \
if (!(condition)) \
__ret = __wait_event_hrtimeout(wq, condition, timeout, \
TASK_UNINTERRUPTIBLE); \
@@ -453,6 +459,7 @@ do { \
#define wait_event_interruptible_hrtimeout(wq, condition, timeout) \
({ \
long __ret = 0; \
+ might_sleep(); \
if (!(condition)) \
__ret = __wait_event_hrtimeout(wq, condition, timeout, \
TASK_INTERRUPTIBLE); \
@@ -466,6 +473,7 @@ do { \
#define wait_event_interruptible_exclusive(wq, condition) \
({ \
int __ret = 0; \
+ might_sleep(); \
if (!(condition)) \
__ret = __wait_event_interruptible_exclusive(wq, condition);\
__ret; \
@@ -640,6 +648,7 @@ do { \
#define wait_event_killable(wq, condition) \
({ \
int __ret = 0; \
+ might_sleep(); \
if (!(condition)) \
__ret = __wait_event_killable(wq, condition); \
__ret; \
@@ -891,6 +900,7 @@ extern int bit_wait_io_timeout(struct wait_bit_key *);
static inline int
wait_on_bit(void *word, int bit, unsigned mode)
{
+ might_sleep();
if (!test_bit(bit, word))
return 0;
return out_of_line_wait_on_bit(word, bit,
@@ -915,6 +925,7 @@ wait_on_bit(void *word, int bit, unsigned mode)
static inline int
wait_on_bit_io(void *word, int bit, unsigned mode)
{
+ might_sleep();
if (!test_bit(bit, word))
return 0;
return out_of_line_wait_on_bit(word, bit,
@@ -941,6 +952,7 @@ wait_on_bit_io(void *word, int bit, unsigned mode)
static inline int
wait_on_bit_action(void *word, int bit, wait_bit_action_f *action, unsigned mode)
{
+ might_sleep();
if (!test_bit(bit, word))
return 0;
return out_of_line_wait_on_bit(word, bit, action, mode);
@@ -968,6 +980,7 @@ wait_on_bit_action(void *word, int bit, wait_bit_action_f *action, unsigned mode
static inline int
wait_on_bit_lock(void *word, int bit, unsigned mode)
{
+ might_sleep();
if (!test_and_set_bit(bit, word))
return 0;
return out_of_line_wait_on_bit_lock(word, bit, bit_wait, mode);
@@ -991,6 +1004,7 @@ wait_on_bit_lock(void *word, int bit, unsigned mode)
static inline int
wait_on_bit_lock_io(void *word, int bit, unsigned mode)
{
+ might_sleep();
if (!test_and_set_bit(bit, word))
return 0;
return out_of_line_wait_on_bit_lock(word, bit, bit_wait_io, mode);
@@ -1016,6 +1030,7 @@ wait_on_bit_lock_io(void *word, int bit, unsigned mode)
static inline int
wait_on_bit_lock_action(void *word, int bit, wait_bit_action_f *action, unsigned mode)
{
+ might_sleep();
if (!test_and_set_bit(bit, word))
return 0;
return out_of_line_wait_on_bit_lock(word, bit, action, mode);
@@ -1034,6 +1049,7 @@ wait_on_bit_lock_action(void *word, int bit, wait_bit_action_f *action, unsigned
static inline
int wait_on_atomic_t(atomic_t *val, int (*action)(atomic_t *), unsigned mode)
{
+ might_sleep();
if (atomic_read(val) == 0)
return 0;
return out_of_line_wait_on_atomic_t(val, action, mode);