From 2f8501815256af8498904e68bd0984b1afffd6f8 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 20 Mar 2009 11:13:20 +0100 Subject: [PATCH 1/1] 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 Signed-off-by: Peter Zijlstra Cc: Nick Piggin LKML-Reference: <1237544000.24626.52.camel@twins> Signed-off-by: Ingo Molnar --- kernel/lockdep.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 022d2ed7fd8..3673a3f44d9 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) { /* -- 2.41.1