IB/hfi1: Replace 1-element array with singleton

Zero-length arrays are deprecated[1] and are being replaced with flexible
array members in support of the ongoing efforts to tighten the
FORTIFY_SOURCE routines on memcpy(), correctly instrument array indexing
with UBSAN_BOUNDS, and to globally enable -fstrict-flex-arrays=3.

Replace zero-length array with flexible-array member "lvs" in struct
opa_port_data_counters_msg and struct opa_port_error_counters64_msg.

Additionally, the "port" member of several structs is defined as a
single-element, but is only ever accessed at index 0. Replace it with a
singleton so that flexible array usage is sane.

This results in no differences in binary output.

[1] https://github.com/KSPP/linux/issues/78

Link: https://lore.kernel.org/r/20221118215847.never.416-kees@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

diff --git a/drivers/infiniband/hw/hfi1/mad.c b/drivers/infiniband/hw/hfi1/mad.c
index 4146a2113a9540ea0e7435364c6ee5b7ef158beb..e5e783c45810b2a0135e7eeb977f609f939bcb26 100644 (file)
--- a/drivers/infiniband/hw/hfi1/mad.c
+++ b/drivers/infiniband/hw/hfi1/mad.c
@@ -2437,9 +2437,9 @@ struct opa_port_data_counters_msg {
                        __be64 port_vl_xmit_wait_data;
                        __be64 port_vl_rcv_bubble;
                        __be64 port_vl_mark_fecn;
-               } vls[0];
+               } vls[];
                /* array size defined by #bits set in vl_select_mask*/
-       } port[1]; /* array size defined by  #ports in attribute modifier */
+       } port;
 };
 
 struct opa_port_error_counters64_msg {
@@ -2470,9 +2470,9 @@ struct opa_port_error_counters64_msg {
                u8 reserved3[7];
                struct _vls_ectrs {
                        __be64 port_vl_xmit_discards;
-               } vls[0];
+               } vls[];
                /* array size defined by #bits set in vl_select_mask */
-       } port[1]; /* array size defined by #ports in attribute modifier */
+       } port;
 };
 
 struct opa_port_error_info_msg {
@@ -2543,7 +2543,7 @@ struct opa_port_error_info_msg {
                        u8 error_info;
                } __packed fm_config_ei;
                __u32 reserved9;
-       } port[1]; /* actual array size defined by #ports in attr modifier */
+       } port;
 };
 
 /* opa_port_error_info_msg error_info_select_mask bit definitions */
@@ -2966,7 +2966,7 @@ static int pma_get_opa_datacounters(struct opa_pma_mad *pmp,
        }
 
        /* Sanity check */
-       response_data_size = struct_size(req, port[0].vls, num_vls);
+       response_data_size = struct_size(req, port.vls, num_vls);
 
        if (response_data_size > sizeof(pmp->data)) {
                pmp->mad_hdr.status |= IB_SMP_INVALID_FIELD;
@@ -2986,7 +2986,7 @@ static int pma_get_opa_datacounters(struct opa_pma_mad *pmp,
                return reply((struct ib_mad_hdr *)pmp);
        }
 
-       rsp = &req->port[0];
+       rsp = &req->port;
        memset(rsp, 0, sizeof(*rsp));
 
        rsp->port_number = port;
@@ -3182,7 +3182,7 @@ static int pma_get_opa_porterrors(struct opa_pma_mad *pmp,
                return reply((struct ib_mad_hdr *)pmp);
        }
 
-       response_data_size = struct_size(req, port[0].vls, num_vls);
+       response_data_size = struct_size(req, port.vls, num_vls);
 
        if (response_data_size > sizeof(pmp->data)) {
                pmp->mad_hdr.status |= IB_SMP_INVALID_FIELD;
@@ -3201,7 +3201,7 @@ static int pma_get_opa_porterrors(struct opa_pma_mad *pmp,
                return reply((struct ib_mad_hdr *)pmp);
        }
 
-       rsp = &req->port[0];
+       rsp = &req->port;
 
        ibp = to_iport(ibdev, port_num);
        ppd = ppd_from_ibp(ibp);
@@ -3340,7 +3340,7 @@ static int pma_get_opa_errorinfo(struct opa_pma_mad *pmp,
        u64 reg;
 
        req = (struct opa_port_error_info_msg *)pmp->data;
-       rsp = &req->port[0];
+       rsp = &req->port;
 
        num_ports = OPA_AM_NPORT(be32_to_cpu(pmp->mad_hdr.attr_mod));
        num_pslm = hweight64(be64_to_cpu(req->port_select_mask[3]));
@@ -3590,7 +3590,7 @@ static int pma_set_opa_errorinfo(struct opa_pma_mad *pmp,
        u32 error_info_select;
 
        req = (struct opa_port_error_info_msg *)pmp->data;
-       rsp = &req->port[0];
+       rsp = &req->port;
 
        num_ports = OPA_AM_NPORT(be32_to_cpu(pmp->mad_hdr.attr_mod));
        num_pslm = hweight64(be64_to_cpu(req->port_select_mask[3]));