perf evlist: Fix mmap pages rounding to power of 2

'next_pow2()' only works for 'unsigned int' but the argument is
'unsigned long'.  Checking for values less than (1 << 31) ensures that
'next_pow2()' is not passed a value out of range but lets anything else
go through unvalidated.

As a result mmap_pages of zero is used e.g.

  perf record -v -m2147483649 uname
  mmap size 0B
  failed to mmap with 22 (Invalid argument)

Fixed:

  perf record -m2147483649 uname
  rounding mmap pages size to 17592186044416 bytes (4294967296 pages)
  Invalid argument for --mmap_pages/-m

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1386595120-22978-4-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 98ec96b..af25055 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -734,9 +734,11 @@ static long parse_pages_arg(const char *str, unsigned long min,
 
 	if (pages == 0 && min == 0) {
 		/* leave number of pages at 0 */
-	} else if (pages < (1UL << 31) && !is_power_of_2(pages)) {
+	} else if (!is_power_of_2(pages)) {
 		/* round pages up to next power of 2 */
-		pages = next_pow2(pages);
+		pages = next_pow2_l(pages);
+		if (!pages)
+			return -EINVAL;
 		pr_info("rounding mmap pages size to %lu bytes (%lu pages)\n",
 			pages * page_size, pages);
 	}