Commit 1dbfa938 authored Dec 09, 2013 by Adrian Hunter Committed by Arnaldo Carvalho de Melo Dec 09, 2013

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>

parent f5ae9c42

tools/perf/util/evlist.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -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);
		}

tools/perf/util/util.h

+12 −0

Original line number	Diff line number	Diff line
		@@ -73,6 +73,7 @@
		#include <sys/ttydefaults.h>
		#include <lk/debugfs.h>
		#include <termios.h>
		#include <linux/bitops.h>

		extern const char *graph_line;
		extern const char *graph_dotted_line;
		@@ -281,6 +282,17 @@ static inline unsigned next_pow2(unsigned x)
		return 1ULL << (32 - __builtin_clz(x - 1));
		}

		static inline unsigned long next_pow2_l(unsigned long x)
		{
		#if BITS_PER_LONG == 64
		if (x <= (1UL << 31))
		return next_pow2(x);
		return (unsigned long)next_pow2(x >> 32) << 32;
		#else
		return next_pow2(x);
		#endif
		}

		size_t hex_width(u64 v);
		int hex2u64(const char ptr, u64 val);