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Yong Zhang authored
Since commit f59de899 ("lockdep: Clear whole lockdep_map on initialization"), lockdep_init_map() will clear all the struct. But it will break lock_set_class()/lock_set_subclass(). A typical race condition is like below: CPU A CPU B lock_set_subclass(lockA); lock_set_class(lockA); lockdep_init_map(lockA); /* lockA->name is cleared */ memset(lockA); __lock_acquire(lockA); /* lockA->class_cache[] is cleared */ register_lock_class(lockA); look_up_lock_class(lockA); WARN_ON_ONCE(class->name != lock->name); lock->name = name; So restore to what we have done before commit f59de899 but annotate ->lock with kmemcheck_mark_initialized() to suppress the kmemcheck warning reported in commit f59de899. Reported-by:
Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reported-by:
Borislav Petkov <bp@alien8.de> Suggested-by:
Vegard Nossum <vegard.nossum@gmail.com> Signed-off-by:
Yong Zhang <yong.zhang0@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: <stable@kernel.org> Signed-off-by:
Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20111109080451.GB8124@zhySigned-off-by:
Ingo Molnar <mingo@elte.hu>
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