Re: [PATCH v7 2/2] PCI: dwc: Validate max-link-speed property

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

Hi Hans,

kernel test robot noticed the following build warnings:

[auto build test WARNING on c23719abc3308df7ed3ad35650ad211fb2d2003d]

url:    https://github.com/intel-lab-lkp/linux/commits/Hans-Zhang/PCI-of-Remove-max-link-speed-generation-validation/20260308-223128
base:   c23719abc3308df7ed3ad35650ad211fb2d2003d
patch link:    https://lore.kernel.org/r/20260308142629.75392-3-18255117159%40163.com
patch subject: [PATCH v7 2/2] PCI: dwc: Validate max-link-speed property
config: i386-randconfig-004-20260308 (https://download.01.org/0day-ci/archive/20260309/202603091845.8xKRO6rW-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260309/202603091845.8xKRO6rW-lkp@intel.com/reproduce)

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/202603091845.8xKRO6rW-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/pci/controller/dwc/pcie-designware.c:128:19: error: invalid application of 'sizeof' to an incomplete type 'const unsigned char[]'
     128 |             max_speed >= ARRAY_SIZE(pcie_link_speed) ||
         |                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/array_size.h:11:32: note: expanded from macro 'ARRAY_SIZE'
      11 | #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
         |                                ^~~~~
>> drivers/pci/controller/dwc/pcie-designware.c:255:9: warning: indirection of non-volatile null pointer will be deleted, not trap [-Wnull-dereference]
     255 |         return PCI_FIND_NEXT_CAP(dw_pcie_read_cfg, PCI_CAPABILITY_LIST, cap,
         |                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     256 |                                  NULL, pci);
         |                                  ~~~~~~~~~~
   drivers/pci/controller/dwc/../../pci.h:159:5: note: expanded from macro 'PCI_FIND_NEXT_CAP'
     159 |                                 *(u8 *)prev_ptr = __prev_pos;           \
         |                                 ^~~~~~~~~~~~~~~
   drivers/pci/controller/dwc/pcie-designware.c:255:9: note: consider using __builtin_trap() or qualifying pointer with 'volatile'
   drivers/pci/controller/dwc/../../pci.h:159:5: note: expanded from macro 'PCI_FIND_NEXT_CAP'
     159 |                                 *(u8 *)prev_ptr = __prev_pos;           \
         |                                 ^
   drivers/pci/controller/dwc/pcie-designware.c:262:9: warning: indirection of non-volatile null pointer will be deleted, not trap [-Wnull-dereference]
     262 |         return PCI_FIND_NEXT_EXT_CAP(dw_pcie_read_cfg, 0, cap, NULL, pci);
         |                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/pci/controller/dwc/../../pci.h:207:5: note: expanded from macro 'PCI_FIND_NEXT_EXT_CAP'
     207 |                                 *(u16 *)prev_ptr = __prev_pos;          \
         |                                 ^~~~~~~~~~~~~~~~
   drivers/pci/controller/dwc/pcie-designware.c:262:9: note: consider using __builtin_trap() or qualifying pointer with 'volatile'
   drivers/pci/controller/dwc/../../pci.h:207:5: note: expanded from macro 'PCI_FIND_NEXT_EXT_CAP'
     207 |                                 *(u16 *)prev_ptr = __prev_pos;          \
         |                                 ^
   drivers/pci/controller/dwc/pcie-designware.c:329:17: warning: indirection of non-volatile null pointer will be deleted, not trap [-Wnull-dereference]
     329 |         while ((vsec = PCI_FIND_NEXT_EXT_CAP(dw_pcie_read_cfg, vsec,
         |                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     330 |                                              PCI_EXT_CAP_ID_VNDR, NULL, pci))) {
         |                                              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/pci/controller/dwc/../../pci.h:207:5: note: expanded from macro 'PCI_FIND_NEXT_EXT_CAP'
     207 |                                 *(u16 *)prev_ptr = __prev_pos;          \
         |                                 ^~~~~~~~~~~~~~~~
   drivers/pci/controller/dwc/pcie-designware.c:329:17: note: consider using __builtin_trap() or qualifying pointer with 'volatile'
   drivers/pci/controller/dwc/../../pci.h:207:5: note: expanded from macro 'PCI_FIND_NEXT_EXT_CAP'
     207 |                                 *(u16 *)prev_ptr = __prev_pos;          \
         |                                 ^
   3 warnings and 1 error generated.


vim +255 drivers/pci/controller/dwc/pcie-designware.c

13e9d3900c2024 Serge Semin 2022-06-24  252  
7a6854f6874ff4 Vidya Sagar 2019-08-13  253  u8 dw_pcie_find_capability(struct dw_pcie *pci, u8 cap)
7a6854f6874ff4 Vidya Sagar 2019-08-13  254  {
8ffc9f234fdf33 Hans Zhang  2025-08-13 @255  	return PCI_FIND_NEXT_CAP(dw_pcie_read_cfg, PCI_CAPABILITY_LIST, cap,
a2582e05e39adf Qiang Yu    2025-11-09  256  				 NULL, pci);
7a6854f6874ff4 Vidya Sagar 2019-08-13  257  }
7a6854f6874ff4 Vidya Sagar 2019-08-13  258  EXPORT_SYMBOL_GPL(dw_pcie_find_capability);
7a6854f6874ff4 Vidya Sagar 2019-08-13  259  

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