Commit c7cedb12 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

Merge branch 'urgent' of... 

Merge branch 'urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile into core/urgent
parents 3365e779 c0868934

drivers/oprofile/event_buffer.c

+26 −9
Original line number Diff line number Diff line
@@ -35,12 +35,23 @@ static size_t buffer_pos; 
/* atomic_t because wait_event checks it outside of buffer_mutex */

static atomic_t buffer_ready = ATOMIC_INIT(0);



/* Add an entry to the event buffer. When we

 * get near to the end we wake up the process

 * sleeping on the read() of the file.

/*

 * Add an entry to the event buffer. When we get near to the end we

 * wake up the process sleeping on the read() of the file. To protect

 * the event_buffer this function may only be called when buffer_mutex

 * is set.

 */

void add_event_entry(unsigned long value)

{

	/*

	 * This shouldn't happen since all workqueues or handlers are

	 * canceled or flushed before the event buffer is freed.

	 */

	if (!event_buffer) {

		WARN_ON_ONCE(1);

		return;

	}



	if (buffer_pos == buffer_size) {

		atomic_inc(&oprofile_stats.event_lost_overflow);

		return;
@@ -69,7 +80,6 @@ void wake_up_buffer_waiter(void) 


int alloc_event_buffer(void)

{

	int err = -ENOMEM;

	unsigned long flags;



	spin_lock_irqsave(&oprofilefs_lock, flags);
@@ -80,21 +90,22 @@ int alloc_event_buffer(void) 
	if (buffer_watershed >= buffer_size)

		return -EINVAL;



	buffer_pos = 0;

	event_buffer = vmalloc(sizeof(unsigned long) * buffer_size);

	if (!event_buffer)

		goto out;

		return -ENOMEM;



	err = 0;

out:

	return err;

	return 0;

}





void free_event_buffer(void)

{

	mutex_lock(&buffer_mutex);

	vfree(event_buffer);



	buffer_pos = 0;

	event_buffer = NULL;

	mutex_unlock(&buffer_mutex);

}
@@ -167,6 +178,12 @@ static ssize_t event_buffer_read(struct file *file, char __user *buf, 


	mutex_lock(&buffer_mutex);



	/* May happen if the buffer is freed during pending reads. */

	if (!event_buffer) {

		retval = -EINTR;

		goto out;

	}



	atomic_set(&buffer_ready, 0);



	retval = -EFAULT;