[PATCH 1/2] lib/test_bitmap: increment failure counter properly

[PATCH 1/2] lib/test_bitmap: increment failure counter properly

[Yury Norov]

The tests that don't use expect_eq() macro to determine that a test is
failured must increment failed_tests explicitly.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/lkml/20230225184702.GA3587246@roeck-us.net/
Signed-off-by: Yury Norov <yury.norov@gmail.com>
---
 lib/test_bitmap.c | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c
index 8954610ec683..c4b90d145398 100644
--- a/lib/test_bitmap.c
+++ b/lib/test_bitmap.c
@@ -471,6 +471,7 @@ static void __init test_bitmap_parselist(void)
 		if (err != ptest.errno) {
 			pr_err("parselist: %d: input is %s, errno is %d, expected %d\n",
 					i, ptest.in, err, ptest.errno);
+			failed_tests++;
 			continue;
 		}
 
@@ -479,6 +480,7 @@ static void __init test_bitmap_parselist(void)
 			pr_err("parselist: %d: input is %s, result is 0x%lx, expected 0x%lx\n",
 					i, ptest.in, bmap[0],
 					*ptest.expected);
+			failed_tests++;
 			continue;
 		}
 
@@ -512,11 +514,13 @@ static void __init test_bitmap_printlist(void)
 
 	if (ret != slen + 1) {
 		pr_err("bitmap_print_to_pagebuf: result is %d, expected %d\n", ret, slen);
+		failed_tests++;
 		goto out;
 	}
 
 	if (strncmp(buf, expected, slen)) {
 		pr_err("bitmap_print_to_pagebuf: result is %s, expected %s\n", buf, expected);
+		failed_tests++;
 		goto out;
 	}
 
@@ -584,6 +588,7 @@ static void __init test_bitmap_parse(void)
 		if (err != test.errno) {
 			pr_err("parse: %d: input is %s, errno is %d, expected %d\n",
 					i, test.in, err, test.errno);
+			failed_tests++;
 			continue;
 		}
 
@@ -592,6 +597,7 @@ static void __init test_bitmap_parse(void)
 			pr_err("parse: %d: input is %s, result is 0x%lx, expected 0x%lx\n",
 					i, test.in, bmap[0],
 					*test.expected);
+			failed_tests++;
 			continue;
 		}
 
@@ -616,10 +622,12 @@ static void __init test_bitmap_arr32(void)
 
 		next_bit = find_next_bit(bmap2,
 				round_up(nbits, BITS_PER_LONG), nbits);
-		if (next_bit < round_up(nbits, BITS_PER_LONG))
+		if (next_bit < round_up(nbits, BITS_PER_LONG)) {
 			pr_err("bitmap_copy_arr32(nbits == %d:"
 				" tail is not safely cleared: %d\n",
 				nbits, next_bit);
+			failed_tests++;
+		}
 
 		if (nbits < EXP1_IN_BITS - 32)
 			expect_eq_uint(arr[DIV_ROUND_UP(nbits, 32)],
@@ -642,15 +650,19 @@ static void __init test_bitmap_arr64(void)
 		expect_eq_bitmap(bmap2, exp1, nbits);
 
 		next_bit = find_next_bit(bmap2, round_up(nbits, BITS_PER_LONG), nbits);
-		if (next_bit < round_up(nbits, BITS_PER_LONG))
+		if (next_bit < round_up(nbits, BITS_PER_LONG)) {
 			pr_err("bitmap_copy_arr64(nbits == %d:"
 				" tail is not safely cleared: %d\n", nbits, next_bit);
+			failed_tests++;
+		}
 
 		if ((nbits % 64) &&
-		    (arr[(nbits - 1) / 64] & ~GENMASK_ULL((nbits - 1) % 64, 0)))
+		    (arr[(nbits - 1) / 64] & ~GENMASK_ULL((nbits - 1) % 64, 0))) {
 			pr_err("bitmap_to_arr64(nbits == %d): tail is not safely cleared: 0x%016llx (must be 0x%016llx)\n",
 			       nbits, arr[(nbits - 1) / 64],
 			       GENMASK_ULL((nbits - 1) % 64, 0));
+			failed_tests++;
+		}
 
 		if (nbits < EXP1_IN_BITS - 64)
 			expect_eq_uint(arr[DIV_ROUND_UP(nbits, 64)], 0xa5a5a5a5);
-- 
2.34.1

[PATCH 2/2] lib/bitmap: drop optimization of bitmap_{from,to}_arr64

[Yury Norov]

bitmap_{from,to}_arr64() optimization is overly optimistic on 32-bit LE
architectures when it's wired to bitmap_copy_clear_tail().

bitmap_copy_clear_tail() takes care of unused bits in the bitmap up to
the next word boundary. But on 32-bit machines when copying bits from
bitmap to array of 64-bit words, it's expected that the unused part of
a recipient array must be cleared up to 64-bit boundary, so the last 4
bytes may stay untouched when nbits % 64 <= 32.

While the copying part of the optimization works correct, that clear-tail
trick makes corresponding tests reasonably fail:

test_bitmap: bitmap_to_arr64(nbits == 1): tail is not safely cleared: 0xa5a5a5a500000001 (must be 0x0000000000000001)

Fix it by removing bitmap_{from,to}_arr64() optimization for 32-bit LE
arches.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/lkml/20230225184702.GA3587246@roeck-us.net/
Fixes: 0a97953fd221 ("lib: add bitmap_{from,to}_arr64")
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
---
 include/linux/bitmap.h | 8 +++-----
 lib/bitmap.c           | 2 +-
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index 40e53a2ecc0d..7d4c90eb3df4 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -302,12 +302,10 @@ void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap,
 #endif
 
 /*
- * On 64-bit systems bitmaps are represented as u64 arrays internally. On LE32
- * machines the order of hi and lo parts of numbers match the bitmap structure.
- * In both cases conversion is not needed when copying data from/to arrays of
- * u64.
+ * On 64-bit systems bitmaps are represented as u64 arrays internally. So,
+ * the conversion is not needed when copying data from/to arrays of u64.
  */
-#if (BITS_PER_LONG == 32) && defined(__BIG_ENDIAN)
+#if BITS_PER_LONG == 32
 void bitmap_from_arr64(unsigned long *bitmap, const u64 *buf, unsigned int nbits);
 void bitmap_to_arr64(u64 *buf, const unsigned long *bitmap, unsigned int nbits);
 #else
diff --git a/lib/bitmap.c b/lib/bitmap.c
index 1c81413c51f8..ddb31015e38a 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -1495,7 +1495,7 @@ void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, unsigned int nbits)
 EXPORT_SYMBOL(bitmap_to_arr32);
 #endif
 
-#if (BITS_PER_LONG == 32) && defined(__BIG_ENDIAN)
+#if BITS_PER_LONG == 32
 /**
  * bitmap_from_arr64 - copy the contents of u64 array of bits to bitmap
  *	@bitmap: array of unsigned longs, the destination bitmap
-- 
2.34.1

Re: [PATCH 1/2] lib/test_bitmap: increment failure counter properly

[Andy Shevchenko]

On Mon, Feb 27, 2023 at 01:45:23PM -0800, Yury Norov wrote:
> The tests that don't use expect_eq() macro to determine that a test is
> failured must increment failed_tests explicitly.

...

>  			pr_err("bitmap_copy_arr32(nbits == %d:"
>  				" tail is not safely cleared: %d\n",

Usually we don't split string literals (since checkpatch doesn't complain on a
looong lines with them at the end of the line),

...

>  			pr_err("bitmap_copy_arr64(nbits == %d:"
>  				" tail is not safely cleared: %d\n", nbits, next_bit);

Ditto.

P.S. Seems a material for another patch.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH 1/2] lib/test_bitmap: increment failure counter properly

[Yury Norov]

On Tue, Feb 28, 2023 at 12:55:05AM +0200, Andy Shevchenko wrote:
> On Mon, Feb 27, 2023 at 01:45:23PM -0800, Yury Norov wrote:
> > The tests that don't use expect_eq() macro to determine that a test is
> > failured must increment failed_tests explicitly.
> 
> ...
> 
> >  			pr_err("bitmap_copy_arr32(nbits == %d:"
> >  				" tail is not safely cleared: %d\n",
> 
> Usually we don't split string literals (since checkpatch doesn't complain on a
> looong lines with them at the end of the line),
> 
> ...
> 
> >  			pr_err("bitmap_copy_arr64(nbits == %d:"
> >  				" tail is not safely cleared: %d\n", nbits, next_bit);
> 
> Ditto.
> 
> P.S. Seems a material for another patch.

If you're OK with this patch, can you give your review tag please?

Thanks,
Yury

Re: [PATCH 2/2] lib/bitmap: drop optimization of bitmap_{from,to}_arr64

[Alexander Lobakin]

From: Yury Norov <yury.norov@gmail.com>
Date: Mon, 27 Feb 2023 13:45:24 -0800

> bitmap_{from,to}_arr64() optimization is overly optimistic on 32-bit LE
> architectures when it's wired to bitmap_copy_clear_tail().
> 
> bitmap_copy_clear_tail() takes care of unused bits in the bitmap up to
> the next word boundary. But on 32-bit machines when copying bits from
> bitmap to array of 64-bit words, it's expected that the unused part of
> a recipient array must be cleared up to 64-bit boundary, so the last 4
> bytes may stay untouched when nbits % 64 <= 32.
> 
> While the copying part of the optimization works correct, that clear-tail
> trick makes corresponding tests reasonably fail:
> 
> test_bitmap: bitmap_to_arr64(nbits == 1): tail is not safely cleared: 0xa5a5a5a500000001 (must be 0x0000000000000001)
> 
> Fix it by removing bitmap_{from,to}_arr64() optimization for 32-bit LE
> arches.
> 
> Reported-by: Guenter Roeck <linux@roeck-us.net>
> Link: https://lore.kernel.org/lkml/20230225184702.GA3587246@roeck-us.net/
> Fixes: 0a97953fd221 ("lib: add bitmap_{from,to}_arr64")
> Signed-off-by: Yury Norov <yury.norov@gmail.com>
> Tested-by: Guenter Roeck <linux@roeck-us.net>
> ---
>  include/linux/bitmap.h | 8 +++-----
>  lib/bitmap.c           | 2 +-
>  2 files changed, 4 insertions(+), 6 deletions(-)
> 
> diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
> index 40e53a2ecc0d..7d4c90eb3df4 100644
> --- a/include/linux/bitmap.h
> +++ b/include/linux/bitmap.h
> @@ -302,12 +302,10 @@ void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap,
>  #endif
>  
>  /*
> - * On 64-bit systems bitmaps are represented as u64 arrays internally. On LE32
> - * machines the order of hi and lo parts of numbers match the bitmap structure.
> - * In both cases conversion is not needed when copying data from/to arrays of
> - * u64.
> + * On 64-bit systems bitmaps are represented as u64 arrays internally. So,
> + * the conversion is not needed when copying data from/to arrays of u64.
>   */
> -#if (BITS_PER_LONG == 32) && defined(__BIG_ENDIAN)
> +#if BITS_PER_LONG == 32
>  void bitmap_from_arr64(unsigned long *bitmap, const u64 *buf, unsigned int nbits);
>  void bitmap_to_arr64(u64 *buf, const unsigned long *bitmap, unsigned int nbits);
>  #else
> diff --git a/lib/bitmap.c b/lib/bitmap.c
> index 1c81413c51f8..ddb31015e38a 100644
> --- a/lib/bitmap.c
> +++ b/lib/bitmap.c
> @@ -1495,7 +1495,7 @@ void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, unsigned int nbits)
>  EXPORT_SYMBOL(bitmap_to_arr32);
>  #endif
>  
> -#if (BITS_PER_LONG == 32) && defined(__BIG_ENDIAN)
> +#if BITS_PER_LONG == 32
>  /**
>   * bitmap_from_arr64 - copy the contents of u64 array of bits to bitmap
>   *	@bitmap: array of unsigned longs, the destination bitmap

For the series:

Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>

Thanks,
Olek

Re: [PATCH 1/2] lib/test_bitmap: increment failure counter properly

[Andy Shevchenko]

On Mon, Feb 27, 2023 at 06:49:29PM -0800, Yury Norov wrote:
> On Tue, Feb 28, 2023 at 12:55:05AM +0200, Andy Shevchenko wrote:
> > On Mon, Feb 27, 2023 at 01:45:23PM -0800, Yury Norov wrote:
> > > The tests that don't use expect_eq() macro to determine that a test is
> > > failured must increment failed_tests explicitly.
> > 
> > ...
> > 
> > >  			pr_err("bitmap_copy_arr32(nbits == %d:"
> > >  				" tail is not safely cleared: %d\n",
> > 
> > Usually we don't split string literals (since checkpatch doesn't complain on a
> > looong lines with them at the end of the line),
> > 
> > ...
> > 
> > >  			pr_err("bitmap_copy_arr64(nbits == %d:"
> > >  				" tail is not safely cleared: %d\n", nbits, next_bit);
> > 
> > Ditto.
> > 
> > P.S. Seems a material for another patch.
> 
> If you're OK with this patch, can you give your review tag please?

I'm fine with the series,
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

-- 
With Best Regards,
Andy Shevchenko