Re: [PATCH v3 3/3] overflow: Remove is_non_negative() and is_negative()

[kernel test robot <lkp@intel.com>]

Hi Vincent,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 3e7f562e20ee87a25e104ef4fce557d39d62fa85]

url:    https://github.com/intel-lab-lkp/linux/commits/Vincent-Mailhol/kbuild-remove-gcc-s-Wtype-limits/20251220-190509
base:   3e7f562e20ee87a25e104ef4fce557d39d62fa85
patch link:    https://lore.kernel.org/r/20251220-remove_wtype-limits-v3-3-24b170af700e%40kernel.org
patch subject: [PATCH v3 3/3] overflow: Remove is_non_negative() and is_negative()
config: i386-randconfig-141-20251222 (https://download.01.org/0day-ci/archive/20251223/202512230342.Lgha2HGH-lkp@intel.com/config)
compiler: gcc-14 (Debian 14.2.0-19) 14.2.0

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202512230342.Lgha2HGH-lkp@intel.com/

New smatch warnings:
block/blk-settings.c:702 blk_stack_atomic_writes_chunk_sectors() warn: unsigned '*_d' is never less than zero.
block/blk-settings.c:702 blk_stack_atomic_writes_chunk_sectors() warn: unsigned '_a' is never less than zero.
drivers/nvme/host/core.c:3353 nvme_mps_to_sectors() warn: unsigned '*_d' is never less than zero.
drivers/nvme/host/core.c:3353 nvme_mps_to_sectors() warn: unsigned '_a' is never less than zero.

Old smatch warnings:
drivers/nvme/host/core.c:5032 nvme_free_cels() warn: iterator 'i' not incremented

vim +702 block/blk-settings.c

d7f36dc446e894 John Garry 2024-11-18  689  
63d092d1c1b1f7 John Garry 2025-07-11  690  static void blk_stack_atomic_writes_chunk_sectors(struct queue_limits *t)
d7f36dc446e894 John Garry 2024-11-18  691  {
63d092d1c1b1f7 John Garry 2025-07-11  692  	unsigned int chunk_bytes;
d7f36dc446e894 John Garry 2024-11-18  693  
63d092d1c1b1f7 John Garry 2025-07-11  694  	if (!t->chunk_sectors)
63d092d1c1b1f7 John Garry 2025-07-11  695  		return;
63d092d1c1b1f7 John Garry 2025-07-11  696  
63d092d1c1b1f7 John Garry 2025-07-11  697  	/*
63d092d1c1b1f7 John Garry 2025-07-11  698  	 * If chunk sectors is so large that its value in bytes overflows
63d092d1c1b1f7 John Garry 2025-07-11  699  	 * UINT_MAX, then just shift it down so it definitely will fit.
63d092d1c1b1f7 John Garry 2025-07-11  700  	 * We don't support atomic writes of such a large size anyway.
63d092d1c1b1f7 John Garry 2025-07-11  701  	 */
63d092d1c1b1f7 John Garry 2025-07-11 @702  	if (check_shl_overflow(t->chunk_sectors, SECTOR_SHIFT, &chunk_bytes))
63d092d1c1b1f7 John Garry 2025-07-11  703  		chunk_bytes = t->chunk_sectors;
d7f36dc446e894 John Garry 2024-11-18  704  
d7f36dc446e894 John Garry 2024-11-18  705  	/*
d7f36dc446e894 John Garry 2024-11-18  706  	 * Find values for limits which work for chunk size.
d7f36dc446e894 John Garry 2024-11-18  707  	 * b->atomic_write_hw_unit_{min, max} may not be aligned with chunk
63d092d1c1b1f7 John Garry 2025-07-11  708  	 * size, as the chunk size is not restricted to a power-of-2.
d7f36dc446e894 John Garry 2024-11-18  709  	 * So we need to find highest power-of-2 which works for the chunk
d7f36dc446e894 John Garry 2024-11-18  710  	 * size.
63d092d1c1b1f7 John Garry 2025-07-11  711  	 * As an example scenario, we could have t->unit_max = 16K and
63d092d1c1b1f7 John Garry 2025-07-11  712  	 * t->chunk_sectors = 24KB. For this case, reduce t->unit_max to a
63d092d1c1b1f7 John Garry 2025-07-11  713  	 * value aligned with both limits, i.e. 8K in this example.
d7f36dc446e894 John Garry 2024-11-18  714  	 */
63d092d1c1b1f7 John Garry 2025-07-11  715  	t->atomic_write_hw_unit_max = min(t->atomic_write_hw_unit_max,
63d092d1c1b1f7 John Garry 2025-07-11  716  					max_pow_of_two_factor(chunk_bytes));
d7f36dc446e894 John Garry 2024-11-18  717  
63d092d1c1b1f7 John Garry 2025-07-11  718  	t->atomic_write_hw_unit_min = min(t->atomic_write_hw_unit_min,
d7f36dc446e894 John Garry 2024-11-18  719  					  t->atomic_write_hw_unit_max);
63d092d1c1b1f7 John Garry 2025-07-11  720  	t->atomic_write_hw_max = min(t->atomic_write_hw_max, chunk_bytes);
63d092d1c1b1f7 John Garry 2025-07-11  721  }
d7f36dc446e894 John Garry 2024-11-18  722  

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