diff --git a/drivers/oprofile/event_buffer.c b/drivers/oprofile/event_buffer.c index 2b7ae366ceb1..c38adb389064 100644 --- a/drivers/oprofile/event_buffer.c +++ b/drivers/oprofile/event_buffer.c @@ -41,6 +41,12 @@ static atomic_t buffer_ready = ATOMIC_INIT(0); */ void add_event_entry(unsigned long value) { + /* + * catch potential error + */ + if (!event_buffer) + return; + if (buffer_pos == buffer_size) { atomic_inc(&oprofile_stats.event_lost_overflow); return; @@ -92,9 +98,10 @@ out: void free_event_buffer(void) { + mutex_lock(&buffer_mutex); vfree(event_buffer); - event_buffer = NULL; + mutex_unlock(&buffer_mutex); } @@ -167,6 +174,11 @@ static ssize_t event_buffer_read(struct file *file, char __user *buf, mutex_lock(&buffer_mutex); + if (!event_buffer) { + retval = -EINTR; + goto out; + } + atomic_set(&buffer_ready, 0); retval = -EFAULT;