[PATCH 0/2] tighten lglock lockdep annotations

[Michel Lespinasse <walken@google.com>]

Oleg Nesterov recently noticed that the lockdep annotations in lglock.c
are not sufficient to detect some obvious deadlocks, such as
lg_local_lock(LOCK) + lg_local_lock(LOCK) or
spin_lock(X) + lg_local_lock(Y) vs lg_local_lock(Y) + spin_lock(X).

Both issues can be fixed by indicating to lockdep that lglock's local
locks are not recursive.

Patch 1 introduces helper macros for lockdep annotations.

Patch 2 makes sure to use the appropriate helper macros to indicate that
the lglock local lock is a shared, non-recursive lock.

Michel Lespinasse (2):
  lockdep: introduce lock_acquire_exclusive/shared helper macros
  lglock: update lockdep annotations to report recursive local locks

 include/linux/lockdep.h | 92 +++++++++++++------------------------------------
 kernel/lglock.c         | 12 +++----
 2 files changed, 29 insertions(+), 75 deletions(-)

-- 
1.8.1.3