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author | Steven Rostedt <rostedt@goodmis.org> | 2008-05-12 19:21:00 (GMT) |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2008-05-23 19:50:21 (GMT) |
commit | bb065afb8ebd07a03155502dba29ebf0f6fe67e8 (patch) | |
tree | aa32a9461cd38f336797cfba4d07c58789a6f1be /kernel/lockdep.c | |
parent | a98a3c3fde3ae7614f19758a043691b6f59dac53 (diff) | |
download | linux-fsl-qoriq-bb065afb8ebd07a03155502dba29ebf0f6fe67e8.tar.xz |
lockdep: update lockdep_recursion on graph_lock
With the introduction of ftrace, it is possible to recurse into
the lockdep functions via the mcount call. To prevent possible
lockups, updating the lockdep_recursion counter on grabbing the internal
lockdep_lock should prevent deadlocks.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/lockdep.c')
-rw-r--r-- | kernel/lockdep.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 90a440c..65548ef 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -82,6 +82,8 @@ static int graph_lock(void) __raw_spin_unlock(&lockdep_lock); return 0; } + /* prevent any recursions within lockdep from causing deadlocks */ + current->lockdep_recursion++; return 1; } @@ -90,6 +92,7 @@ static inline int graph_unlock(void) if (debug_locks && !__raw_spin_is_locked(&lockdep_lock)) return DEBUG_LOCKS_WARN_ON(1); + current->lockdep_recursion--; __raw_spin_unlock(&lockdep_lock); return 0; } |