Messages in this thread Patch in this message | | | Date | Mon, 30 Mar 2009 21:24:51 GMT | From | Peter Zijlstra <> | Subject | [tip:core/locking-v2] lockdep: fix deadlock in lockdep_trace_alloc |
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Commit-ID: 2f8501815256af8498904e68bd0984b1afffd6f8 Gitweb: http://git.kernel.org/tip/2f8501815256af8498904e68bd0984b1afffd6f8 Author: Peter Zijlstra <peterz@infradead.org> AuthorDate: Fri, 20 Mar 2009 11:13:20 +0100 Committer: Ingo Molnar <mingo@elte.hu> CommitDate: Mon, 30 Mar 2009 23:19:24 +0200
lockdep: fix deadlock in lockdep_trace_alloc
Heiko reported that we grab the graph lock with irqs enabled.
Fix this by providng the same wrapper as all other lockdep entry functions have.
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Nick Piggin <npiggin@suse.de> LKML-Reference: <1237544000.24626.52.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
--- kernel/lockdep.c | 21 +++++++++++++++++++-- 1 files changed, 19 insertions(+), 2 deletions(-)
diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 022d2ed..3673a3f 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -2260,7 +2260,7 @@ void trace_softirqs_off(unsigned long ip) debug_atomic_inc(&redundant_softirqs_off); } -void lockdep_trace_alloc(gfp_t gfp_mask) +static void __lockdep_trace_alloc(gfp_t gfp_mask, unsigned long flags) { struct task_struct *curr = current; @@ -2279,12 +2279,29 @@ void lockdep_trace_alloc(gfp_t gfp_mask) if (!(gfp_mask & __GFP_FS)) return; - if (DEBUG_LOCKS_WARN_ON(irqs_disabled())) + if (DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags))) return; mark_held_locks(curr, RECLAIM_FS); } +static void check_flags(unsigned long flags); + +void lockdep_trace_alloc(gfp_t gfp_mask) +{ + unsigned long flags; + + if (unlikely(current->lockdep_recursion)) + return; + + raw_local_irq_save(flags); + check_flags(flags); + current->lockdep_recursion = 1; + __lockdep_trace_alloc(gfp_mask, flags); + current->lockdep_recursion = 0; + raw_local_irq_restore(flags); +} + static int mark_irqflags(struct task_struct *curr, struct held_lock *hlock) { /*
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