perf machine: Return NULL instead of null-terminating /proc/version array

Return NULL instead of null-terminating version char array when fgets
fails due to end-of-file or error.

Signed-off-by: Donald Yandt <donald.yandt@gmail.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Fixes: 30ba5b0e66c8 ("perf machine: Null-terminate version char array upon fgets(/proc/version) error")
Link: http://lkml.kernel.org/r/20190528134128.30841-1-donald.yandt@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index f5569f0..17eec39 100644 (file)
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -1241,9 +1241,9 @@ static char *get_kernel_version(const char *root_dir)
                return NULL;
 
        tmp = fgets(version, sizeof(version), file);
-       if (!tmp)
-               *version = '\0';
        fclose(file);
+       if (!tmp)
+               return NULL;
 
        name = strstr(version, prefix);
        if (!name)