diff options
| -rw-r--r-- | include/linux/ring_buffer.h | 14 | ||||
| -rw-r--r-- | kernel/trace/ring_buffer.c | 9 |
2 files changed, 20 insertions, 3 deletions
diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h index f1345828c7c..8670f1575fe 100644 --- a/include/linux/ring_buffer.h +++ b/include/linux/ring_buffer.h @@ -105,7 +105,19 @@ void ring_buffer_discard_commit(struct ring_buffer *buffer, * size is in bytes for each per CPU buffer. */ struct ring_buffer * -ring_buffer_alloc(unsigned long size, unsigned flags); +__ring_buffer_alloc(unsigned long size, unsigned flags, struct lock_class_key *key); + +/* + * Because the ring buffer is generic, if other users of the ring buffer get + * traced by ftrace, it can produce lockdep warnings. We need to keep each + * ring buffer's lock class separate. + */ +#define ring_buffer_alloc(size, flags) \ +({ \ + static struct lock_class_key __key; \ + __ring_buffer_alloc((size), (flags), &__key); \ +}) + void ring_buffer_free(struct ring_buffer *buffer); int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size); diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 7102d7a2fad..22878b0d370 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -426,6 +426,8 @@ struct ring_buffer { atomic_t record_disabled; cpumask_var_t cpumask; + struct lock_class_key *reader_lock_key; + struct mutex mutex; struct ring_buffer_per_cpu **buffers; @@ -565,6 +567,7 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu) cpu_buffer->cpu = cpu; cpu_buffer->buffer = buffer; spin_lock_init(&cpu_buffer->reader_lock); + lockdep_set_class(&cpu_buffer->reader_lock, buffer->reader_lock_key); cpu_buffer->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED; INIT_LIST_HEAD(&cpu_buffer->pages); @@ -635,7 +638,8 @@ static int rb_cpu_notify(struct notifier_block *self, * when the buffer wraps. If this flag is not set, the buffer will * drop data when the tail hits the head. */ -struct ring_buffer *ring_buffer_alloc(unsigned long size, unsigned flags) +struct ring_buffer *__ring_buffer_alloc(unsigned long size, unsigned flags, + struct lock_class_key *key) { struct ring_buffer *buffer; int bsize; @@ -658,6 +662,7 @@ struct ring_buffer *ring_buffer_alloc(unsigned long size, unsigned flags) buffer->pages = DIV_ROUND_UP(size, BUF_PAGE_SIZE); buffer->flags = flags; buffer->clock = trace_clock_local; + buffer->reader_lock_key = key; /* need at least two pages */ if (buffer->pages == 1) @@ -715,7 +720,7 @@ struct ring_buffer *ring_buffer_alloc(unsigned long size, unsigned flags) kfree(buffer); return NULL; } -EXPORT_SYMBOL_GPL(ring_buffer_alloc); +EXPORT_SYMBOL_GPL(__ring_buffer_alloc); /** * ring_buffer_free - free a ring buffer. |