> Subject: [PATCH] RDMA/irdma: avoid fortify-string warning in irdma_clr_wqes
>
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> Commit df8fc4e934c1 ("kbuild: Enable -fstrict-flex-arrays=3") triggers a warning for
> fortified memset():
>
> In function 'fortify_memset_chk',
> inlined from 'irdma_clr_wqes' at drivers/infiniband/hw/irdma/uk.c:103:4:
> include/linux/fortify-string.h:493:25: error: call to '__write_overflow_field' declared
> with attribute warning: detected write beyond size of field (1st parameter); maybe
> use struct_group()? [-Werror=attribute-warning]
> 493 | __write_overflow_field(p_size_field, size);
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> The problem here isthat the inner array only has four 8-byte elements, so clearing
> 4096 bytes overflows that. As this structure is part of an outer array, change the
> code to pass a pointer to the irdma_qp_quanta instead, and change the size
> argument for readability, matching the comment above it.
>
> Fixes: 551c46edc769 ("RDMA/irdma: Add user/kernel shared libraries")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
> drivers/infiniband/hw/irdma/uk.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/infiniband/hw/irdma/uk.c b/drivers/infiniband/hw/irdma/uk.c
> index 16183e894da7..dd428d915c17 100644
> --- a/drivers/infiniband/hw/irdma/uk.c
> +++ b/drivers/infiniband/hw/irdma/uk.c
> @@ -93,16 +93,18 @@ static int irdma_nop_1(struct irdma_qp_uk *qp)
> */
> void irdma_clr_wqes(struct irdma_qp_uk *qp, u32 qp_wqe_idx) {
> - __le64 *wqe;
> + struct irdma_qp_quanta *sq;
> u32 wqe_idx;
>
> if (!(qp_wqe_idx & 0x7F)) {
> wqe_idx = (qp_wqe_idx + 128) % qp->sq_ring.size;
> - wqe = qp->sq_base[wqe_idx].elem;
> + sq = qp->sq_base + wqe_idx;
> if (wqe_idx)
> - memset(wqe, qp->swqe_polarity ? 0 : 0xFF, 0x1000);
> + memset(sq, qp->swqe_polarity ? 0 : 0xFF,
> + 128 * sizeof(*sq));
> else
> - memset(wqe, qp->swqe_polarity ? 0xFF : 0, 0x1000);
> + memset(sq, qp->swqe_polarity ? 0xFF : 0,
> + 128 * sizeof(*sq));
> }
> }
>
> --
Acked-by: Shiraz Saleem <shiraz.saleem@xxxxxxxxx>
