Em Mon, Mar 02, 2015 at 02:14:26AM -0500, [email protected] escreveu: > From: Kan Liang <[email protected]> > > 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 > valide. 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!
Yeah, my bad, we need to revert this, its just on tip/perf/core, will put the revert in my next pull request, thanks for spotting this! - Arnaldo > Signed-off-by: Kan Liang <[email protected]> > --- > kernel/events/core.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/events/core.c b/kernel/events/core.c > index 89f0f16..a83581c 100644 > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -4423,7 +4423,7 @@ 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)) > -- > 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
