Re: [PATCH] Test seeks from LLONG_MIN

["Darrick J. Wong" <djwong@kernel.org>]

On Tue, Jul 06, 2021 at 09:14:46PM +0100, Matthew Wilcox wrote:
> We don't currently test seeking from LLONG_MIN, which apparently can
> produce an UBSAN warning, although I've been unable to reproduce that.
> In any case, it's a good corner case to test and straightforward to add.
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Seems reasonable to me...
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> 
> diff --git a/src/seek_sanity_test.c b/src/seek_sanity_test.c
> index cb036f7b..76587b7f 100644
> --- a/src/seek_sanity_test.c
> +++ b/src/seek_sanity_test.c
> @@ -395,8 +395,12 @@ static int test18(int fd, int testnum)
>  	int ret = 0;
>  
>  	/* file size doesn't matter in this test, set to 0 */
> +	ftruncate(fd, 0);
> +
>  	ret += do_lseek(testnum, 1, fd, 0, SEEK_HOLE, -1, -1);
>  	ret += do_lseek(testnum, 2, fd, 0, SEEK_DATA, -1, -1);
> +	ret += do_lseek(testnum, 3, fd, 0, SEEK_HOLE, LLONG_MIN, -1);
> +	ret += do_lseek(testnum, 4, fd, 0, SEEK_DATA, LLONG_MIN, -1);
>  
>  	return ret;
>  }
>