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

From: kernel test robot
Date: Thu Oct 19 2023 - 11:33:22 EST


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@xxxxxxxxx/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@xxxxxxxxx/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@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202310192300.lurP44yG-lkp@xxxxxxxxx/

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

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