ftrace: fix locking
we can hold all cpu trace buffer locks at once - put each into a
separate lock class.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index a40687a..b3811ca 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1865,11 +1865,8 @@
}
- for_each_possible_cpu(cpu) {
+ for_each_cpu_mask(cpu, mask) {
data = iter->tr->data[cpu];
-
- if (!cpu_isset(cpu, mask))
- continue;
spin_unlock(&data->lock);
atomic_dec(&data->disabled);
}
@@ -2076,6 +2073,7 @@
for_each_possible_cpu(i) {
data = global_trace.data[i];
spin_lock_init(&data->lock);
+ lockdep_set_class(&data->lock, &data->lock_key);
page = list_entry(pages.next, struct page, lru);
list_del_init(&page->lru);
list_add_tail(&page->lru, &data->trace_pages);
@@ -2084,6 +2082,7 @@
#ifdef CONFIG_TRACER_MAX_TRACE
data = max_tr.data[i];
spin_lock_init(&data->lock);
+ lockdep_set_class(&data->lock, &data->lock_key);
page = list_entry(pages.next, struct page, lru);
list_del_init(&page->lru);
list_add_tail(&page->lru, &data->trace_pages);
@@ -2203,5 +2202,4 @@
}
return ret;
}
-
fs_initcall(tracer_alloc_buffers);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 29a7ea5..b040835 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -56,6 +56,7 @@
struct list_head trace_pages;
atomic_t disabled;
spinlock_t lock;
+ struct lock_class_key lock_key;
cycle_t time_offset;
/* these fields get copied into max-trace: */