1 files changed, 2 insertions, 0 deletions

diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c
index 05076e683938..97cf4fab564b 100644
--- a/tools/perf/util/mmap.c
+++ b/tools/perf/util/mmap.c
@@ -302,6 +302,8 @@ int perf_mmap__push(struct perf_mmap *md, bool overwrite,
                         return -1;
         }
 
+        size = end - start;
+
         if ((start & md->mask) + size != (end & md->mask)) {
                 buf = &data[start & md->mask];
                 size = md->mask + 1 - (start & md->mask);