From 1ca7d67cf5d5a2aef26a8d9afd789006fa098347 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Mon, 7 Oct 2013 15:51:59 -0700 Subject: seqcount: Add lockdep functionality to seqcount/seqlock structures Currently seqlocks and seqcounts don't support lockdep. After running across a seqcount related deadlock in the timekeeping code, I used a less-refined and more focused variant of this patch to narrow down the cause of the issue. This is a first-pass attempt to properly enable lockdep functionality on seqlocks and seqcounts. Since seqcounts are used in the vdso gettimeofday code, I've provided non-lockdep accessors for those needs. I've also handled one case where there were nested seqlock writers and there may be more edge cases. Comments and feedback would be appreciated! Signed-off-by: John Stultz Signed-off-by: Peter Zijlstra Cc: Eric Dumazet Cc: Li Zefan Cc: Mathieu Desnoyers Cc: Steven Rostedt Cc: "David S. Miller" Cc: netdev@vger.kernel.org Link: http://lkml.kernel.org/r/1381186321-4906-3-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar --- include/linux/lockdep.h | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'include/linux/lockdep.h') diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index cfc2f119779a..92b1bfc5da60 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -497,6 +497,10 @@ static inline void print_irqtrace_events(struct task_struct *curr) #define rwlock_acquire_read(l, s, t, i) lock_acquire_shared_recursive(l, s, t, NULL, i) #define rwlock_release(l, n, i) lock_release(l, n, i) +#define seqcount_acquire(l, s, t, i) lock_acquire_exclusive(l, s, t, NULL, i) +#define seqcount_acquire_read(l, s, t, i) lock_acquire_shared_recursive(l, s, t, NULL, i) +#define seqcount_release(l, n, i) lock_release(l, n, i) + #define mutex_acquire(l, s, t, i) lock_acquire_exclusive(l, s, t, NULL, i) #define mutex_acquire_nest(l, s, t, n, i) lock_acquire_exclusive(l, s, t, n, i) #define mutex_release(l, n, i) lock_release(l, n, i) @@ -504,11 +508,11 @@ static inline void print_irqtrace_events(struct task_struct *curr) #define rwsem_acquire(l, s, t, i) lock_acquire_exclusive(l, s, t, NULL, i) #define rwsem_acquire_nest(l, s, t, n, i) lock_acquire_exclusive(l, s, t, n, i) #define rwsem_acquire_read(l, s, t, i) lock_acquire_shared(l, s, t, NULL, i) -# define rwsem_release(l, n, i) lock_release(l, n, i) +#define rwsem_release(l, n, i) lock_release(l, n, i) #define lock_map_acquire(l) lock_acquire_exclusive(l, 0, 0, NULL, _THIS_IP_) #define lock_map_acquire_read(l) lock_acquire_shared_recursive(l, 0, 0, NULL, _THIS_IP_) -# define lock_map_release(l) lock_release(l, 1, _THIS_IP_) +#define lock_map_release(l) lock_release(l, 1, _THIS_IP_) #ifdef CONFIG_PROVE_LOCKING # define might_lock(lock) \ -- cgit v1.2.3-59-g8ed1b