Merge tag 'trace-v4.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace (4c04b4b5) · Commits · 戴 / test

kernel/trace/trace.c

+16 −13

Original line number	Diff line number	Diff line
		@@ -5124,19 +5124,20 @@ tracing_read_pipe(struct file filp, char __user ubuf,
		struct trace_iterator *iter = filp->private_data;
		ssize_t sret;

		/* return any leftover data */
		sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
		if (sret != -EBUSY)
		return sret;

		trace_seq_init(&iter->seq);

		/*
		* Avoid more than one consumer on a single file descriptor
		* This is just a matter of traces coherency, the ring buffer itself
		* is protected.
		*/
		mutex_lock(&iter->mutex);

		/* return any leftover data */
		sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
		if (sret != -EBUSY)
		goto out;

		trace_seq_init(&iter->seq);

		if (iter->trace->read) {
		sret = iter->trace->read(iter, filp, ubuf, cnt, ppos);
		if (sret)
		@@ -6163,9 +6164,6 @@ tracing_buffers_splice_read(struct file file, loff_t ppos,
		return -EBUSY;
		#endif

		if (splice_grow_spd(pipe, &spd))
		return -ENOMEM;

		if (*ppos & (PAGE_SIZE - 1))
		return -EINVAL;

		@@ -6175,6 +6173,9 @@ tracing_buffers_splice_read(struct file file, loff_t ppos,
		len &= PAGE_MASK;
		}

		if (splice_grow_spd(pipe, &spd))
		return -ENOMEM;

		again:
		trace_access_lock(iter->cpu_file);
		entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file);
		@@ -6232,19 +6233,21 @@ tracing_buffers_splice_read(struct file file, loff_t ppos,
		/* did we read anything? */
		if (!spd.nr_pages) {
		if (ret)
		return ret;
		goto out;

		ret = -EAGAIN;
		if ((file->f_flags & O_NONBLOCK) \|\| (flags & SPLICE_F_NONBLOCK))
		return -EAGAIN;
		goto out;

		ret = wait_on_pipe(iter, true);
		if (ret)
		return ret;
		goto out;

		goto again;
		}

		ret = splice_to_pipe(pipe, &spd);
		out:
		splice_shrink_spd(&spd);

		return ret;

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