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-rw-r--r--tools/perf/util/evlist.c2
-rw-r--r--tools/perf/util/util.h11
2 files changed, 13 insertions, 0 deletions
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 963d63dde457..fa1837088ca8 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -563,6 +563,8 @@ int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages,
/* 512 kiB: default amount of unprivileged mlocked memory */
if (pages == UINT_MAX)
pages = (512 * 1024) / page_size;
+ else if (!is_power_of_2(pages))
+ return -EINVAL;
mask = pages * page_size - 1;
diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
index 0128906bac88..37be34dff798 100644
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -245,4 +245,15 @@ int readn(int fd, void *buf, size_t size);
#define _STR(x) #x
#define STR(x) _STR(x)
+/*
+ * Determine whether some value is a power of two, where zero is
+ * *not* considered a power of two.
+ */
+
+static inline __attribute__((const))
+bool is_power_of_2(unsigned long n)
+{
+ return (n != 0 && ((n & (n - 1)) == 0));
+}
+
#endif