drivers/infiniband/sw/rxe/rxe_mr.c:106:9: warning: array subscript 0 is outside array bounds of 'struct sg_table[0]'

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

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   dd72f9c7e512da377074d47d990564959b772643
commit: 592627ccbdff0ec6fff00fc761142a76db750dd4 RDMA/rxe: Replace rxe_map and rxe_phys_buf by xarray
date:   9 months ago
config: sparc-randconfig-c023-20211015 (https://download.01.org/0day-ci/archive/20231019/202310192300.lurP44yG-lkp@intel.com/config)
compiler: sparc64-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231019/202310192300.lurP44yG-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/202310192300.lurP44yG-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/infiniband/sw/rxe/rxe_mr.c: In function 'rxe_mr_fill_pages_from_sgt.constprop':
>> drivers/infiniband/sw/rxe/rxe_mr.c:106:9: warning: array subscript 0 is outside array bounds of 'struct sg_table[0]' [-Warray-bounds=]
     106 |         __sg_page_iter_start(&sg_iter, sgt->sgl, sgt->orig_nents, 0);
         |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   cc1: note: source object is likely at address zero
>> drivers/infiniband/sw/rxe/rxe_mr.c:106:9: warning: array subscript 0 is outside array bounds of 'struct sg_table[0]' [-Warray-bounds=]
   cc1: note: source object is likely at address zero


vim +106 drivers/infiniband/sw/rxe/rxe_mr.c

    98	
    99	static int rxe_mr_fill_pages_from_sgt(struct rxe_mr *mr, struct sg_table *sgt)
   100	{
   101		XA_STATE(xas, &mr->page_list, 0);
   102		struct sg_page_iter sg_iter;
   103		struct page *page;
   104		bool persistent = !!(mr->access & IB_ACCESS_FLUSH_PERSISTENT);
   105	
 > 106		__sg_page_iter_start(&sg_iter, sgt->sgl, sgt->orig_nents, 0);
   107		if (!__sg_page_iter_next(&sg_iter))
   108			return 0;
   109	
   110		do {
   111			xas_lock(&xas);
   112			while (true) {
   113				page = sg_page_iter_page(&sg_iter);
   114	
   115				if (persistent && !is_pmem_page(page)) {
   116					rxe_dbg_mr(mr, "Page can't be persistent\n");
   117					xas_set_err(&xas, -EINVAL);
   118					break;
   119				}
   120	
   121				xas_store(&xas, page);
   122				if (xas_error(&xas))
   123					break;
   124				xas_next(&xas);
   125				if (!__sg_page_iter_next(&sg_iter))
   126					break;
   127			}
   128			xas_unlock(&xas);
   129		} while (xas_nomem(&xas, GFP_KERNEL));
   130	
   131		return xas_error(&xas);
   132	}
   133	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki