tracing: Add snapshot_raw to extract the raw data from snapshot (6de58e62) · Commits · e / devices / android_kernel_xiaomi_nabu

kernel/trace/trace.c

+95 −18

Original line number	Original line	Diff line number	Diff line
	@@ -4206,6 +4206,12 @@ static int tracing_clock_open(struct inode inode, struct file file)
	return single_open(file, tracing_clock_show, inode->i_private);		return single_open(file, tracing_clock_show, inode->i_private);
	}		}

			struct ftrace_buffer_info {
			struct trace_iterator iter;
			void *spare;
			unsigned int read;
			};

	#ifdef CONFIG_TRACER_SNAPSHOT		#ifdef CONFIG_TRACER_SNAPSHOT
	static int tracing_snapshot_open(struct inode inode, struct file file)		static int tracing_snapshot_open(struct inode inode, struct file file)
	{		{
	@@ -4336,6 +4342,35 @@ static int tracing_snapshot_release(struct inode inode, struct file file)
	return 0;		return 0;
	}		}

			static int tracing_buffers_open(struct inode inode, struct file filp);
			static ssize_t tracing_buffers_read(struct file filp, char __user ubuf,
			size_t count, loff_t *ppos);
			static int tracing_buffers_release(struct inode inode, struct file file);
			static ssize_t tracing_buffers_splice_read(struct file file, loff_t ppos,
			struct pipe_inode_info *pipe, size_t len, unsigned int flags);

			static int snapshot_raw_open(struct inode inode, struct file filp)
			{
			struct ftrace_buffer_info *info;
			int ret;

			ret = tracing_buffers_open(inode, filp);
			if (ret < 0)
			return ret;

			info = filp->private_data;

			if (info->iter.trace->use_max_tr) {
			tracing_buffers_release(inode, filp);
			return -EBUSY;
			}

			info->iter.snapshot = true;
			info->iter.trace_buffer = &info->iter.tr->max_buffer;

			return ret;
			}

	#endif /* CONFIG_TRACER_SNAPSHOT */		#endif /* CONFIG_TRACER_SNAPSHOT */


	@@ -4402,14 +4437,17 @@ static const struct file_operations snapshot_fops = {
	.llseek = tracing_seek,		.llseek = tracing_seek,
	.release = tracing_snapshot_release,		.release = tracing_snapshot_release,
	};		};
	#endif /* CONFIG_TRACER_SNAPSHOT */

	struct ftrace_buffer_info {		static const struct file_operations snapshot_raw_fops = {
	struct trace_iterator iter;		.open = snapshot_raw_open,
	void *spare;		.read = tracing_buffers_read,
	unsigned int read;		.release = tracing_buffers_release,
			.splice_read = tracing_buffers_splice_read,
			.llseek = no_llseek,
	};		};

			#endif /* CONFIG_TRACER_SNAPSHOT */

	static int tracing_buffers_open(struct inode inode, struct file filp)		static int tracing_buffers_open(struct inode inode, struct file filp)
	{		{
	struct trace_cpu *tc = inode->i_private;		struct trace_cpu *tc = inode->i_private;
	@@ -4452,16 +4490,26 @@ tracing_buffers_read(struct file filp, char __user ubuf,
	struct ftrace_buffer_info *info = filp->private_data;		struct ftrace_buffer_info *info = filp->private_data;
	struct trace_iterator *iter = &info->iter;		struct trace_iterator *iter = &info->iter;
	ssize_t ret;		ssize_t ret;
	size_t size;		ssize_t size;

	if (!count)		if (!count)
	return 0;		return 0;

			mutex_lock(&trace_types_lock);

			#ifdef CONFIG_TRACER_MAX_TRACE
			if (iter->snapshot && iter->tr->current_trace->use_max_tr) {
			size = -EBUSY;
			goto out_unlock;
			}
			#endif

	if (!info->spare)		if (!info->spare)
	info->spare = ring_buffer_alloc_read_page(iter->trace_buffer->buffer,		info->spare = ring_buffer_alloc_read_page(iter->trace_buffer->buffer,
	iter->cpu_file);		iter->cpu_file);
			size = -ENOMEM;
	if (!info->spare)		if (!info->spare)
	return -ENOMEM;		goto out_unlock;

	/* Do we have previous read data to read? */		/* Do we have previous read data to read? */
	if (info->read < PAGE_SIZE)		if (info->read < PAGE_SIZE)
	@@ -4477,31 +4525,42 @@ tracing_buffers_read(struct file filp, char __user ubuf,

	if (ret < 0) {		if (ret < 0) {
	if (trace_empty(iter)) {		if (trace_empty(iter)) {
	if ((filp->f_flags & O_NONBLOCK))		if ((filp->f_flags & O_NONBLOCK)) {
	return -EAGAIN;		size = -EAGAIN;
			goto out_unlock;
			}
			mutex_unlock(&trace_types_lock);
	iter->trace->wait_pipe(iter);		iter->trace->wait_pipe(iter);
	if (signal_pending(current))		mutex_lock(&trace_types_lock);
	return -EINTR;		if (signal_pending(current)) {
			size = -EINTR;
			goto out_unlock;
			}
	goto again;		goto again;
	}		}
	return 0;		size = 0;
			goto out_unlock;
	}		}

	info->read = 0;		info->read = 0;

	read:		read:
	size = PAGE_SIZE - info->read;		size = PAGE_SIZE - info->read;
	if (size > count)		if (size > count)
	size = count;		size = count;

	ret = copy_to_user(ubuf, info->spare + info->read, size);		ret = copy_to_user(ubuf, info->spare + info->read, size);
	if (ret == size)		if (ret == size) {
	return -EFAULT;		size = -EFAULT;
			goto out_unlock;
			}
	size -= ret;		size -= ret;

	*ppos += size;		*ppos += size;
	info->read += size;		info->read += size;

			out_unlock:
			mutex_unlock(&trace_types_lock);

	return size;		return size;
	}		}

	@@ -4591,10 +4650,21 @@ tracing_buffers_splice_read(struct file file, loff_t ppos,
	};		};
	struct buffer_ref *ref;		struct buffer_ref *ref;
	int entries, size, i;		int entries, size, i;
	size_t ret;		ssize_t ret;

	if (splice_grow_spd(pipe, &spd))		mutex_lock(&trace_types_lock);
	return -ENOMEM;
			#ifdef CONFIG_TRACER_MAX_TRACE
			if (iter->snapshot && iter->tr->current_trace->use_max_tr) {
			ret = -EBUSY;
			goto out;
			}
			#endif

			if (splice_grow_spd(pipe, &spd)) {
			ret = -ENOMEM;
			goto out;
			}

	if (*ppos & (PAGE_SIZE - 1)) {		if (*ppos & (PAGE_SIZE - 1)) {
	ret = -EINVAL;		ret = -EINVAL;
	@@ -4666,7 +4736,9 @@ tracing_buffers_splice_read(struct file file, loff_t ppos,
	ret = -EAGAIN;		ret = -EAGAIN;
	goto out;		goto out;
	}		}
			mutex_unlock(&trace_types_lock);
	iter->trace->wait_pipe(iter);		iter->trace->wait_pipe(iter);
			mutex_lock(&trace_types_lock);
	if (signal_pending(current)) {		if (signal_pending(current)) {
	ret = -EINTR;		ret = -EINTR;
	goto out;		goto out;
	@@ -4677,6 +4749,8 @@ tracing_buffers_splice_read(struct file file, loff_t ppos,
	ret = splice_to_pipe(pipe, &spd);		ret = splice_to_pipe(pipe, &spd);
	splice_shrink_spd(&spd);		splice_shrink_spd(&spd);
	out:		out:
			mutex_unlock(&trace_types_lock);

	return ret;		return ret;
	}		}

	@@ -4880,6 +4954,9 @@ tracing_init_debugfs_percpu(struct trace_array *tr, long cpu)
	#ifdef CONFIG_TRACER_SNAPSHOT		#ifdef CONFIG_TRACER_SNAPSHOT
	trace_create_file("snapshot", 0644, d_cpu,		trace_create_file("snapshot", 0644, d_cpu,
	(void *)&data->trace_cpu, &snapshot_fops);		(void *)&data->trace_cpu, &snapshot_fops);

			trace_create_file("snapshot_raw", 0444, d_cpu,
			(void *)&data->trace_cpu, &snapshot_raw_fops);
	#endif		#endif
	}		}