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authorByungchul Park <byungchul.park@lge.com>2017-08-07 16:12:52 +0900
committerIngo Molnar <mingo@kernel.org>2017-08-10 12:29:07 +0200
commitb09be676e0ff25bd6d2e7637e26d349f9109ad75 (patch)
tree8dc82ceaa001d29bb07a51f5c4814759b303e8e4 /include/linux/sched.h
parentce07a9415f266e181a0a33033a5f7138760240a4 (diff)
locking/lockdep: Implement the 'crossrelease' feature
Lockdep is a runtime locking correctness validator that detects and reports a deadlock or its possibility by checking dependencies between locks. It's useful since it does not report just an actual deadlock but also the possibility of a deadlock that has not actually happened yet. That enables problems to be fixed before they affect real systems. However, this facility is only applicable to typical locks, such as spinlocks and mutexes, which are normally released within the context in which they were acquired. However, synchronization primitives like page locks or completions, which are allowed to be released in any context, also create dependencies and can cause a deadlock. So lockdep should track these locks to do a better job. The 'crossrelease' implementation makes these primitives also be tracked. Signed-off-by: Byungchul Park <byungchul.park@lge.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akpm@linux-foundation.org Cc: boqun.feng@gmail.com Cc: kernel-team@lge.com Cc: kirill@shutemov.name Cc: npiggin@gmail.com Cc: walken@google.com Cc: willy@infradead.org Link: http://lkml.kernel.org/r/1502089981-21272-6-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/sched.h')
-rw-r--r--include/linux/sched.h8
1 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 57db70ec70d0..5235fba537fc 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -848,6 +848,14 @@ struct task_struct {
struct held_lock held_locks[MAX_LOCK_DEPTH];
#endif
+#ifdef CONFIG_LOCKDEP_CROSSRELEASE
+#define MAX_XHLOCKS_NR 64UL
+ struct hist_lock *xhlocks; /* Crossrelease history locks */
+ unsigned int xhlock_idx;
+ /* For restoring at history boundaries */
+ unsigned int xhlock_idx_hist[XHLOCK_CTX_NR];
+#endif
+
#ifdef CONFIG_UBSAN
unsigned int in_ubsan;
#endif