perf-counter: use 'int' instead of size_t

'size_t' does not allow for catching the case where 'read' returns
an error code, which is a negative number.

Reported-by: Ben Pfaff <blp@nicira.com>
Signed-off-by: Andy Zhou <azhou@nicira.com>

diff --git a/lib/perf-counter.c b/lib/perf-counter.c
index b700e49..4188f6b 100644 (file)
--- a/lib/perf-counter.c
+++ b/lib/perf-counter.c
@@ -39,7 +39,7 @@ static int fd__ = 0;
 uint64_t
 perf_counter_read(uint64_t *counter)
 {
-    size_t size = sizeof *counter;
+    int size = sizeof *counter;
 
     if (fd__ <= 0 || read(fd__, counter, size) < size) {
         *counter = 0;