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;