drivers/accel/qaic/qaic_control.c:348:17: warning: array subscript 'struct wrapper_msg[0]' is partly outside array bounds of 'unsigned char[44]'

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

Hi Jeffrey,

First bad commit (maybe != root cause):

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   06dc10eae55b5ceabfef287a7e5f16ceea204aa0
commit: 759662e4f1f8cd6ea0ec466e10cf29fe7c1fec36 accel/qaic: Add qaic driver to the build system
date:   7 months ago
config: i386-buildonly-randconfig-006-20230906 (https://download.01.org/0day-ci/archive/20231018/202310182253.bcb9JcyJ-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231018/202310182253.bcb9JcyJ-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/202310182253.bcb9JcyJ-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In function 'add_wrapper',
       inlined from 'abort_dma_cont' at drivers/accel/qaic/qaic_control.c:1107:12,
       inlined from 'qaic_manage_msg_xfer' at drivers/accel/qaic/qaic_control.c:1165:9:
>> drivers/accel/qaic/qaic_control.c:348:17: warning: array subscript 'struct wrapper_msg[0]' is partly outside array bounds of 'unsigned char[44]' [-Warray-bounds]
     348 |         w->head = wrappers;
         |         ~~~~~~~~^~~~~~~~~~
   In file included from include/linux/fs.h:45,
                    from include/linux/huge_mm.h:8,
                    from include/linux/mm.h:855,
                    from include/linux/scatterlist.h:8,
                    from include/linux/dma-mapping.h:10,
                    from drivers/accel/qaic/qaic_control.c:10:
   In function 'kmalloc',
       inlined from 'kzalloc' at include/linux/slab.h:720:9,
       inlined from 'add_wrapper' at drivers/accel/qaic/qaic_control.c:342:26,
       inlined from 'abort_dma_cont' at drivers/accel/qaic/qaic_control.c:1107:12,
       inlined from 'qaic_manage_msg_xfer' at drivers/accel/qaic/qaic_control.c:1165:9:
   include/linux/slab.h:580:24: note: object of size 44 allocated by 'kmalloc_trace'
     580 |                 return kmalloc_trace(
         |                        ^~~~~~~~~~~~~~
     581 |                                 kmalloc_caches[kmalloc_type(flags)][index],
         |                                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     582 |                                 flags, size);
         |                                 ~~~~~~~~~~~~
   In function 'abort_dma_cont',
       inlined from 'qaic_manage_msg_xfer' at drivers/accel/qaic/qaic_control.c:1165:9:
   drivers/accel/qaic/qaic_control.c:1121:22: warning: array subscript 'struct wrapper_msg[0]' is partly outside array bounds of 'unsigned char[44]' [-Warray-bounds]
    1121 |         wrapper->len = size;
         |         ~~~~~~~~~~~~~^~~~~~
   In function 'kmalloc',
       inlined from 'kzalloc' at include/linux/slab.h:720:9,
       inlined from 'add_wrapper' at drivers/accel/qaic/qaic_control.c:342:26,
       inlined from 'abort_dma_cont' at drivers/accel/qaic/qaic_control.c:1107:12,
       inlined from 'qaic_manage_msg_xfer' at drivers/accel/qaic/qaic_control.c:1165:9:
   include/linux/slab.h:580:24: note: object of size 44 allocated by 'kmalloc_trace'
     580 |                 return kmalloc_trace(
         |                        ^~~~~~~~~~~~~~
     581 |                                 kmalloc_caches[kmalloc_type(flags)][index],
         |                                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     582 |                                 flags, size);
         |                                 ~~~~~~~~~~~~


vim +348 drivers/accel/qaic/qaic_control.c

129776ac2e38231 Jeffrey Hugo 2023-03-27  339  
129776ac2e38231 Jeffrey Hugo 2023-03-27  340  static struct wrapper_msg *add_wrapper(struct wrapper_list *wrappers, u32 size)
129776ac2e38231 Jeffrey Hugo 2023-03-27  341  {
129776ac2e38231 Jeffrey Hugo 2023-03-27  342  	struct wrapper_msg *w = kzalloc(size, GFP_KERNEL);
129776ac2e38231 Jeffrey Hugo 2023-03-27  343  
129776ac2e38231 Jeffrey Hugo 2023-03-27  344  	if (!w)
129776ac2e38231 Jeffrey Hugo 2023-03-27  345  		return NULL;
129776ac2e38231 Jeffrey Hugo 2023-03-27  346  	list_add_tail(&w->list, &wrappers->list);
129776ac2e38231 Jeffrey Hugo 2023-03-27  347  	kref_init(&w->ref_count);
129776ac2e38231 Jeffrey Hugo 2023-03-27 @348  	w->head = wrappers;
129776ac2e38231 Jeffrey Hugo 2023-03-27  349  	return w;
129776ac2e38231 Jeffrey Hugo 2023-03-27  350  }
129776ac2e38231 Jeffrey Hugo 2023-03-27  351  

:::::: The code at line 348 was first introduced by commit
:::::: 129776ac2e38231fa9c02ce20e116c99de291666 accel/qaic: Add control path

:::::: TO: Jeffrey Hugo <quic_jhugo@quicinc.com>
:::::: CC: Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>

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