From: Liam Howlett <liam.howlett@xxxxxxxxxx> Subject: mmap_lock: change trace and locking order Print to the trace log before releasing the lock to avoid racing with other trace log printers of the same lock type. Link: https://lkml.kernel.org/r/20210903022041.1843024-1-Liam.Howlett@xxxxxxxxxx Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx> Suggested-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> Reviewed-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Cc: Michel Lespinasse <walken.cr@xxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/mmap_lock.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/include/linux/mmap_lock.h~mmap_lock-change-trace-and-locking-order +++ a/include/linux/mmap_lock.h @@ -101,14 +101,14 @@ static inline bool mmap_write_trylock(st static inline void mmap_write_unlock(struct mm_struct *mm) { - up_write(&mm->mmap_lock); __mmap_lock_trace_released(mm, true); + up_write(&mm->mmap_lock); } static inline void mmap_write_downgrade(struct mm_struct *mm) { - downgrade_write(&mm->mmap_lock); __mmap_lock_trace_acquire_returned(mm, false, true); + downgrade_write(&mm->mmap_lock); } static inline void mmap_read_lock(struct mm_struct *mm) @@ -140,8 +140,8 @@ static inline bool mmap_read_trylock(str static inline void mmap_read_unlock(struct mm_struct *mm) { - up_read(&mm->mmap_lock); __mmap_lock_trace_released(mm, false); + up_read(&mm->mmap_lock); } static inline bool mmap_read_trylock_non_owner(struct mm_struct *mm) @@ -155,8 +155,8 @@ static inline bool mmap_read_trylock_non static inline void mmap_read_unlock_non_owner(struct mm_struct *mm) { - up_read_non_owner(&mm->mmap_lock); __mmap_lock_trace_released(mm, false); + up_read_non_owner(&mm->mmap_lock); } static inline void mmap_assert_locked(struct mm_struct *mm) _
