RDMA/uverbs: Simplify ib_uverbs_ex_query_device

We truncate the response structure if there is not enough room in the
user buffer so there is no reason to have all the mess with finely managing
response_length. Just fully fill the attrs and truncate on copy.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index c605412708b88d3b83c0469832e09ac3a4a1528c..3cc746639c7b28f4de3015ba0e8ad8e30b344175 100644 (file)
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -3660,7 +3660,7 @@ static int ib_uverbs_destroy_srq(struct uverbs_attr_bundle *attrs,
 static int ib_uverbs_ex_query_device(struct uverbs_attr_bundle *attrs,
                                     struct ib_udata *ucore)
 {
-       struct ib_uverbs_ex_query_device_resp resp = { {0} };
+       struct ib_uverbs_ex_query_device_resp resp = {};
        struct ib_uverbs_ex_query_device  cmd;
        struct ib_device_attr attr = {0};
        struct ib_ucontext *ucontext;
@@ -3672,10 +3672,7 @@ static int ib_uverbs_ex_query_device(struct uverbs_attr_bundle *attrs,
                return PTR_ERR(ucontext);
        ib_dev = ucontext->device;
 
-       if (ucore->inlen < sizeof(cmd))
-               return -EINVAL;
-
-       err = ib_copy_from_udata(&cmd, ucore, sizeof(cmd));
+       err = uverbs_request(attrs, &cmd, sizeof(cmd));
        if (err)
                return err;
 
@@ -3685,20 +3682,12 @@ static int ib_uverbs_ex_query_device(struct uverbs_attr_bundle *attrs,
        if (cmd.reserved)
                return -EINVAL;
 
-       resp.response_length = offsetof(typeof(resp), odp_caps);
-
-       if (ucore->outlen < resp.response_length)
-               return -ENOSPC;
-
        err = ib_dev->query_device(ib_dev, &attr, &attrs->driver_udata);
        if (err)
                return err;
 
        copy_query_dev_fields(ucontext, &resp.base, &attr);
 
-       if (ucore->outlen < resp.response_length + sizeof(resp.odp_caps))
-               goto end;
-
 #ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
        resp.odp_caps.general_caps = attr.odp_caps.general_caps;
        resp.odp_caps.per_transport_caps.rc_odp_caps =
@@ -3708,74 +3697,29 @@ static int ib_uverbs_ex_query_device(struct uverbs_attr_bundle *attrs,
        resp.odp_caps.per_transport_caps.ud_odp_caps =
                attr.odp_caps.per_transport_caps.ud_odp_caps;
 #endif
-       resp.response_length += sizeof(resp.odp_caps);
-
-       if (ucore->outlen < resp.response_length + sizeof(resp.timestamp_mask))
-               goto end;
 
        resp.timestamp_mask = attr.timestamp_mask;
-       resp.response_length += sizeof(resp.timestamp_mask);
-
-       if (ucore->outlen < resp.response_length + sizeof(resp.hca_core_clock))
-               goto end;
-
        resp.hca_core_clock = attr.hca_core_clock;
-       resp.response_length += sizeof(resp.hca_core_clock);
-
-       if (ucore->outlen < resp.response_length + sizeof(resp.device_cap_flags_ex))
-               goto end;
-
        resp.device_cap_flags_ex = attr.device_cap_flags;
-       resp.response_length += sizeof(resp.device_cap_flags_ex);
-
-       if (ucore->outlen < resp.response_length + sizeof(resp.rss_caps))
-               goto end;
-
        resp.rss_caps.supported_qpts = attr.rss_caps.supported_qpts;
        resp.rss_caps.max_rwq_indirection_tables =
                attr.rss_caps.max_rwq_indirection_tables;
        resp.rss_caps.max_rwq_indirection_table_size =
                attr.rss_caps.max_rwq_indirection_table_size;
-
-       resp.response_length += sizeof(resp.rss_caps);
-
-       if (ucore->outlen < resp.response_length + sizeof(resp.max_wq_type_rq))
-               goto end;
-
        resp.max_wq_type_rq = attr.max_wq_type_rq;
-       resp.response_length += sizeof(resp.max_wq_type_rq);
-
-       if (ucore->outlen < resp.response_length + sizeof(resp.raw_packet_caps))
-               goto end;
-
        resp.raw_packet_caps = attr.raw_packet_caps;
-       resp.response_length += sizeof(resp.raw_packet_caps);
-
-       if (ucore->outlen < resp.response_length + sizeof(resp.tm_caps))
-               goto end;
-
        resp.tm_caps.max_rndv_hdr_size  = attr.tm_caps.max_rndv_hdr_size;
        resp.tm_caps.max_num_tags       = attr.tm_caps.max_num_tags;
        resp.tm_caps.max_ops            = attr.tm_caps.max_ops;
        resp.tm_caps.max_sge            = attr.tm_caps.max_sge;
        resp.tm_caps.flags              = attr.tm_caps.flags;
-       resp.response_length += sizeof(resp.tm_caps);
-
-       if (ucore->outlen < resp.response_length + sizeof(resp.cq_moderation_caps))
-               goto end;
-
        resp.cq_moderation_caps.max_cq_moderation_count  =
                attr.cq_caps.max_cq_moderation_count;
        resp.cq_moderation_caps.max_cq_moderation_period =
                attr.cq_caps.max_cq_moderation_period;
-       resp.response_length += sizeof(resp.cq_moderation_caps);
-
-       if (ucore->outlen < resp.response_length + sizeof(resp.max_dm_size))
-               goto end;
-
        resp.max_dm_size = attr.max_dm_size;
-       resp.response_length += sizeof(resp.max_dm_size);
-end:
+       resp.response_length = uverbs_response_length(attrs, sizeof(resp));
+
        return uverbs_response(attrs, &resp, sizeof(resp));
 }