Commit 51896864 authored Oct 05, 2018 by YueHaibing Committed by Greg Kroah-Hartman Oct 05, 2018

mm/gup_benchmark: fix unsigned comparison to zero in __gup_benchmark_ioctl

get_user_pages_fast() will return negative value if no pages were pinned,
then be converted to a unsigned, which is compared to zero, giving the
wrong result.

Link: http://lkml.kernel.org/r/20180921095015.26088-1-yuehaibing@huawei.com


Fixes: 09e35a4a ("mm/gup_benchmark: handle gup failures")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent e125fe40

mm/gup_benchmark.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -19,7 +19,8 @@ static int __gup_benchmark_ioctl(unsigned int cmd,
		struct gup_benchmark *gup)
		{
		ktime_t start_time, end_time;
		unsigned long i, nr, nr_pages, addr, next;
		unsigned long i, nr_pages, addr, next;
		int nr;
		struct page **pages;

		nr_pages = gup->size / PAGE_SIZE;

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