From: Jarek Poplawski Date: Thu, 7 Dec 2006 09:45:25 +0000 (+0100) Subject: [PATCH] lockdep: internal locking fixes X-Git-Tag: v2.6.20-rc1~145^2^2~206 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=910b1b2e6d7d10e1c3bffdd12a90ec82f535f9a5;p=linux-2.6 [PATCH] lockdep: internal locking fixes Here are mainly some lockdep returns with 0 with unlocking fixes. Signed-off-by: Jarek Poplawski Signed-off-by: Andrew Morton Signed-off-by: Ingo Molnar Signed-off-by: Linus Torvalds --- diff --git a/kernel/lockdep.c b/kernel/lockdep.c index e33f6207f5..f76a24f2ac 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -237,8 +237,10 @@ e locks. */ trace->max_entries = trace->nr_entries; nr_stack_trace_entries += trace->nr_entries; - if (DEBUG_LOCKS_WARN_ON(nr_stack_trace_entries > MAX_STACK_TRACE_ENTRIES)) + if (DEBUG_LOCKS_WARN_ON(nr_stack_trace_entries > MAX_STACK_TRACE_ENTRIES)) { + __raw_spin_unlock(&hash_lock); return 0; + } if (nr_stack_trace_entries == MAX_STACK_TRACE_ENTRIES) { __raw_spin_unlock(&hash_lock); @@ -474,7 +476,8 @@ static int add_lock_to_list(struct lock_class *class, struct lock_class *this, return 0; entry->class = this; - save_trace(&entry->trace); + if (!save_trace(&entry->trace)) + return 0; /* * Since we never remove from the dependency list, the list can @@ -562,8 +565,12 @@ static noinline int print_circular_bug_tail(void) if (debug_locks_silent) return 0; + /* hash_lock unlocked by the header */ + __raw_spin_lock(&hash_lock); this.class = check_source->class; - save_trace(&this.trace); + if (!save_trace(&this.trace)) + return 0; + __raw_spin_unlock(&hash_lock); print_circular_bug_entry(&this, 0); printk("\nother info that might help us debug this:\n\n"); @@ -966,14 +973,11 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, &prev->class->locks_after, next->acquire_ip); if (!ret) return 0; - /* - * Return value of 2 signals 'dependency already added', - * in that case we dont have to add the backlink either. - */ - if (ret == 2) - return 2; + ret = add_lock_to_list(next->class, prev->class, &next->class->locks_before, next->acquire_ip); + if (!ret) + return 0; /* * Debugging printouts: @@ -1025,7 +1029,8 @@ check_prevs_add(struct task_struct *curr, struct held_lock *next) * added: */ if (hlock->read != 2) { - check_prev_add(curr, hlock, next); + if (!check_prev_add(curr, hlock, next)) + return 0; /* * Stop after the first non-trylock entry, * as non-trylock entries have added their