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-rw-r--r--kernel/trace/trace.c29
1 files changed, 16 insertions, 13 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index dade4c9559cc..7bc56762ca35 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -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;