Revert "perf: Remove the extra validity check on nr_pages"
authorKan Liang <kan.liang@intel.com>
Mon, 2 Mar 2015 07:14:26 +0000 (02:14 -0500)
committerArnaldo Carvalho de Melo <acme@redhat.com>
Mon, 2 Mar 2015 21:25:38 +0000 (18:25 -0300)
commit2ed11312eb19506c027e7cac039994ad42a9cb2c
treea3a146330ebd8386c16d1228a9bd926a1c872cc3
parent543d976fa2ebf5543bd07b5d487bf3a6144c0886
Revert "perf: Remove the extra validity check on nr_pages"

This reverts commit 74390aa55678 ("perf: Remove the extra validity check
on nr_pages")

nr_pages equals to number of pages - 1 in perf_mmap. So nr_pages = 0 is
valid.

So the nr_pages != 0 && !is_power_of_2(nr_pages) are all
needed for checking. Otherwise, for example, perf test 6 failed.

 # perf test 6
  6: x86 rdpmc test                                         :Error:
 mmap() syscall returned with (Invalid argument)
 FAILED!

Signed-off-by: Kan Liang <kan.liang@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1425280466-7830-1-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
kernel/events/core.c