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| author | Kan Liang <kan.liang@intel.com> | 2015-03-02 02:14:26 -0500 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2015-03-02 18:25:38 -0300 |
| commit | 2ed11312eb19506c027e7cac039994ad42a9cb2c (patch) | |
| tree | a3a146330ebd8386c16d1228a9bd926a1c872cc3 /kernel/events | |
| parent | 543d976fa2ebf5543bd07b5d487bf3a6144c0886 (diff) | |
| download | linux-2ed11312eb19506c027e7cac039994ad42a9cb2c.tar.bz2 | |
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>
Diffstat (limited to 'kernel/events')
| -rw-r--r-- | kernel/events/core.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index af924bc38121..8bb20cc39a92 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -4446,7 +4446,7 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) * If we have rb pages ensure they're a power-of-two number, so we * can do bitmasks instead of modulo. */ - if (!is_power_of_2(nr_pages)) + if (nr_pages != 0 && !is_power_of_2(nr_pages)) return -EINVAL; if (vma_size != PAGE_SIZE * (1 + nr_pages)) |