Merge branch 'urgent' of... (c7cedb12) · Commits · e / devices / android_kernel_oneplus_sm8150

drivers/oprofile/event_buffer.c

+26 −9

Original line number	Original line	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 */		/* atomic_t because wait_event checks it outside of buffer_mutex */
	static atomic_t buffer_ready = ATOMIC_INIT(0);		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		* Add an entry to the event buffer. When we get near to the end we
	* sleeping on the read() of the file.		* 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)		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) {		if (buffer_pos == buffer_size) {
	atomic_inc(&oprofile_stats.event_lost_overflow);		atomic_inc(&oprofile_stats.event_lost_overflow);
	return;		return;
	@@ -69,7 +80,6 @@ void wake_up_buffer_waiter(void)

	int alloc_event_buffer(void)		int alloc_event_buffer(void)
	{		{
	int err = -ENOMEM;
	unsigned long flags;		unsigned long flags;

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

			buffer_pos = 0;
	event_buffer = vmalloc(sizeof(unsigned long) * buffer_size);		event_buffer = vmalloc(sizeof(unsigned long) * buffer_size);
	if (!event_buffer)		if (!event_buffer)
	goto out;		return -ENOMEM;

	err = 0;		return 0;
	out:
	return err;
	}		}


	void free_event_buffer(void)		void free_event_buffer(void)
	{		{
			mutex_lock(&buffer_mutex);
	vfree(event_buffer);		vfree(event_buffer);
			buffer_pos = 0;
	event_buffer = NULL;		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);		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);		atomic_set(&buffer_ready, 0);

	retval = -EFAULT;		retval = -EFAULT;