Re: [PATCH 2/2] bitmap: Add test for bitmap_cut()

[Andy Shevchenko]

On Sun, Jun 14, 2020 at 07:40:54PM +0200, Stefano Brivio wrote:
> Inspired by an original patch from Yury Norov: introduce a test for
> bitmap_cut() that also makes sure functionality is as described for
> partially overlapping src and dst.

Taking into account recent fixes for BE 64-bit, do we have test cases for a such?

> Signed-off-by: Stefano Brivio <sbrivio@xxxxxxxxxx>
> ---
> v2:
>   - use expect_eq_bitmap() instead of open coding result check (Andy
>     Shevchenko)
>   - don't use uncommon Co-authored-by: tag (Andy Shevchenko), drop
>     it altogether as Yury asked me to go ahead with this and I haven't
>     heard back in a while. Patch is now rather different anyway
>   - avoid stack overflow, buffer needs to be five unsigned longs and
>     not four as 'in' is shifted by one, spotted by kernel test robot
>     with CONFIG_STACKPROTECTOR_STRONG
> 
>  lib/test_bitmap.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 58 insertions(+)
> 
> diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c
> index 6b13150667f5..df903c53952b 100644
> --- a/lib/test_bitmap.c
> +++ b/lib/test_bitmap.c
> @@ -610,6 +610,63 @@ static void __init test_for_each_set_clump8(void)
>  		expect_eq_clump8(start, CLUMP_EXP_NUMBITS, clump_exp, &clump);
>  }
>  
> +struct test_bitmap_cut {
> +	unsigned int first;
> +	unsigned int cut;
> +	unsigned int nbits;
> +	unsigned long in[4];
> +	unsigned long expected[4];
> +};
> +
> +static struct test_bitmap_cut test_cut[] = {
> +	{  0,  0,  8, { 0x0000000aUL, }, { 0x0000000aUL, }, },
> +	{  0,  0, 32, { 0xdadadeadUL, }, { 0xdadadeadUL, }, },
> +	{  0,  3,  8, { 0x000000aaUL, }, { 0x00000015UL, }, },
> +	{  3,  3,  8, { 0x000000aaUL, }, { 0x00000012UL, }, },
> +	{  0,  1, 32, { 0xa5a5a5a5UL, }, { 0x52d2d2d2UL, }, },
> +	{  0,  8, 32, { 0xdeadc0deUL, }, { 0x00deadc0UL, }, },
> +	{  1,  1, 32, { 0x5a5a5a5aUL, }, { 0x2d2d2d2cUL, }, },
> +	{  0, 15, 32, { 0xa5a5a5a5UL, }, { 0x00014b4bUL, }, },
> +	{  0, 16, 32, { 0xa5a5a5a5UL, }, { 0x0000a5a5UL, }, },
> +	{ 15, 15, 32, { 0xa5a5a5a5UL, }, { 0x000125a5UL, }, },
> +	{ 15, 16, 32, { 0xa5a5a5a5UL, }, { 0x0000a5a5UL, }, },
> +	{ 16, 15, 32, { 0xa5a5a5a5UL, }, { 0x0001a5a5UL, }, },
> +
> +	{ BITS_PER_LONG, BITS_PER_LONG, BITS_PER_LONG,
> +		{ 0xa5a5a5a5UL, 0xa5a5a5a5UL, },
> +		{ 0xa5a5a5a5UL, 0xa5a5a5a5UL, },
> +	},
> +	{ 1, BITS_PER_LONG - 1, BITS_PER_LONG,
> +		{ 0xa5a5a5a5UL, 0xa5a5a5a5UL, },
> +		{ 0x00000001UL, 0x00000001UL, },
> +	},
> +
> +	{ 0, BITS_PER_LONG * 2, BITS_PER_LONG * 2 + 1,
> +		{ 0xa5a5a5a5UL, 0x00000001UL, 0x00000001UL, 0x00000001UL },
> +		{ 0x00000001UL, },
> +	},
> +	{ 16, BITS_PER_LONG * 2 + 1, BITS_PER_LONG * 2 + 1 + 16,
> +		{ 0x0000ffffUL, 0x5a5a5a5aUL, 0x5a5a5a5aUL, 0x5a5a5a5aUL },
> +		{ 0x2d2dffffUL, },
> +	},
> +};
> +
> +static void __init test_bitmap_cut(void)
> +{
> +	unsigned long b[5], *in = &b[1], *out = &b[0];	/* Partial overlap */
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(test_cut); i++) {
> +		struct test_bitmap_cut *t = &test_cut[i];
> +
> +		memcpy(in, t->in, sizeof(t->in));
> +
> +		bitmap_cut(out, in, t->first, t->cut, t->nbits);
> +
> +		expect_eq_bitmap(t->expected, out, t->nbits);
> +	}
> +}
> +
>  static void __init selftest(void)
>  {
>  	test_zero_clear();
> @@ -623,6 +680,7 @@ static void __init selftest(void)
>  	test_bitmap_parselist_user();
>  	test_mem_optimisations();
>  	test_for_each_set_clump8();
> +	test_bitmap_cut();
>  }
>  
>  KSTM_MODULE_LOADERS(test_bitmap);
> -- 
> 2.27.0
> 

-- 
With Best Regards,
Andy Shevchenko