From 7d36b26be0f3c6b86e3ab7e1539e42f3a3bc79ca Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 26 Jul 2011 13:13:44 +0200 Subject: lockdep: Fix trace_hardirqs_on_caller() Commit dd4e5d3ac4a ("lockdep: Fix trace_[soft,hard]irqs_[on,off]() recursion") made a bit of a mess of the various checks and error conditions. In particular it moved the check for !irqs_disabled() before the spurious enable test, resulting in some warnings. Reported-by: Arnaud Lacombe Reported-by: Dave Jones Reported-and-tested-by: Sergey Senozhatsky Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1311679697.24752.28.camel@twins Signed-off-by: Ingo Molnar --- kernel/lockdep.c | 30 ++++++++++++++++-------------- 1 file changed, 16 insertions(+), 14 deletions(-) (limited to 'kernel/lockdep.c') diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 3956f5149e2..74ca247a4d4 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -2485,23 +2485,9 @@ static void __trace_hardirqs_on_caller(unsigned long ip) { struct task_struct *curr = current; - if (DEBUG_LOCKS_WARN_ON(unlikely(early_boot_irqs_disabled))) - return; - - if (unlikely(curr->hardirqs_enabled)) { - /* - * Neither irq nor preemption are disabled here - * so this is racy by nature but losing one hit - * in a stat is not a big deal. - */ - __debug_atomic_inc(redundant_hardirqs_on); - return; - } /* we'll do an OFF -> ON transition: */ curr->hardirqs_enabled = 1; - if (DEBUG_LOCKS_WARN_ON(current->hardirq_context)) - return; /* * We are going to turn hardirqs on, so set the * usage bit for all held locks: @@ -2529,9 +2515,25 @@ void trace_hardirqs_on_caller(unsigned long ip) if (unlikely(!debug_locks || current->lockdep_recursion)) return; + if (unlikely(current->hardirqs_enabled)) { + /* + * Neither irq nor preemption are disabled here + * so this is racy by nature but losing one hit + * in a stat is not a big deal. + */ + __debug_atomic_inc(redundant_hardirqs_on); + return; + } + if (DEBUG_LOCKS_WARN_ON(!irqs_disabled())) return; + if (DEBUG_LOCKS_WARN_ON(unlikely(early_boot_irqs_disabled))) + return; + + if (DEBUG_LOCKS_WARN_ON(current->hardirq_context)) + return; + current->lockdep_recursion = 1; __trace_hardirqs_on_caller(ip); current->lockdep_recursion = 0; -- cgit v1.2.3-70-g09d2 From 70a0686a72c7a7e554b404ca11406ceec709d425 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 25 Jul 2011 12:09:59 +0200 Subject: lockdep: Fix up warning On Sun, 2011-07-24 at 21:06 -0400, Arnaud Lacombe wrote: > /src/linux/linux/kernel/lockdep.c: In function 'mark_held_locks': > /src/linux/linux/kernel/lockdep.c:2471:31: warning: comparison of > distinct pointer types lacks a cast The warning is harmless in this case, but the below makes it go away. Reported-by: Arnaud Lacombe Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1311588599.2617.56.camel@laptop Signed-off-by: Ingo Molnar --- kernel/lockdep.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/lockdep.c') diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 74ca247a4d4..5903586f32a 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -2468,7 +2468,7 @@ mark_held_locks(struct task_struct *curr, enum mark_type mark) BUG_ON(usage_bit >= LOCK_USAGE_STATES); - if (hlock_class(hlock)->key == &__lockdep_no_validate__) + if (hlock_class(hlock)->key == __lockdep_no_validate__.subkeys) continue; if (!mark_lock(curr, hlock, usage_bit)) -- cgit v1.2.3-70-g09d2 From f59de8992aa6dc85e81aadc26b0f69e17809721d Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 14 Jul 2011 15:19:09 +0200 Subject: lockdep: Clear whole lockdep_map on initialization lockdep_init_map() only initializes parts of lockdep_map and triggers kmemcheck warning when it is copied as a whole. There isn't anything to be gained by clearing selectively. memset() the whole structure and remove loop for ->class_cache[] clearing. Addresses https://bugzilla.kernel.org/show_bug.cgi?id=35532 Signed-off-by: Tejun Heo Reported-and-tested-by: Christian Casteyde Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=35532 Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/20110714131909.GJ3455@htj.dyndns.org Signed-off-by: Ingo Molnar --- kernel/lockdep.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'kernel/lockdep.c') diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 5903586f32a..8c24294e477 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -2874,10 +2874,7 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this, void lockdep_init_map(struct lockdep_map *lock, const char *name, struct lock_class_key *key, int subclass) { - int i; - - for (i = 0; i < NR_LOCKDEP_CACHING_CLASSES; i++) - lock->class_cache[i] = NULL; + memset(lock, 0, sizeof(*lock)); #ifdef CONFIG_LOCK_STAT lock->cpu = raw_smp_processor_id(); -- cgit v1.2.3-70-g09d2