Merge remote-tracking branch 'grant/devicetree/next' into for-next

1 files changed, 12 insertions, 0 deletions

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index ce69901176d8..c3e5a3b817ab 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -2768,6 +2768,18 @@ int perf_session__read_header(struct perf_session *session)
         if (perf_file_header__read(&f_header, header, fd) < 0)
                 return -EINVAL;
 
+        /*
+         * Sanity check that perf.data was written cleanly; data size is
+         * initialized to 0 and updated only if the on_exit function is run.
+         * If data size is still 0 then the file contains only partial
+         * information.  Just warn user and process it as much as it can.
+         */
+        if (f_header.data.size == 0) {
+                pr_warning("WARNING: The %s file's data size field is 0 which is unexpected.\n"
+                           "Was the 'perf record' command properly terminated?\n",
+                           session->filename);
+        }
+
         nr_attrs = f_header.attrs.size / f_header.attr_size;
         lseek(fd, f_header.attrs.offset, SEEK_SET);