From 86fd39f354778eb10e77a7c1660b59ca16ffcc16 Mon Sep 17 00:00:00 2001 From: Brian Behlendorf Date: Fri, 24 Jun 2011 11:57:14 -0700 Subject: Linux 2.6.39 compat, mutex owner Prior to Linux 2.6.39 when CONFIG_DEBUG_MUTEXES was defined the kernel stored a thread_info pointer as the mutex owner. From this you could get the pointer of the current task_struct to compare with get_current(). As of Linux 2.6.39 this behavior has changed and now the mutex stores a pointer to the task_struct. This commit detects the type of pointer stored in the mutex and adjusts the mutex_owner() and mutex_owned() functions to perform the correct comparision. --- include/sys/mutex.h | 21 +++++++++------------ 1 file changed, 9 insertions(+), 12 deletions(-) (limited to 'include/sys') diff --git a/include/sys/mutex.h b/include/sys/mutex.h index ebf9151f1..659214f50 100644 --- a/include/sys/mutex.h +++ b/include/sys/mutex.h @@ -48,21 +48,18 @@ typedef struct { static inline kthread_t * mutex_owner(kmutex_t *mp) { - struct thread_info *owner; - - owner = ACCESS_ONCE(mp->m.owner); - if (owner) - return owner->task; - - return NULL; -} +#if defined(HAVE_MUTEX_OWNER_TASK_STRUCT) + return ACCESS_ONCE(mp->m.owner); +#else + struct thread_info *owner = ACCESS_ONCE(mp->m.owner); + if (owner) + return owner->task; -static inline int -mutex_owned(kmutex_t *mp) -{ - return (ACCESS_ONCE(mp->m.owner) == current_thread_info()); + return NULL; +#endif } +#define mutex_owned(mp) (mutex_owner(mp) == current) #define MUTEX_HELD(mp) mutex_owned(mp) #define MUTEX_NOT_HELD(mp) (!MUTEX_HELD(mp)) #undef mutex_init -- cgit v1.2.3