From 335708c751c1462b674892212e965fdde4c9b0d9 Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Sun, 25 Nov 2018 20:58:42 +0200 Subject: [PATCH] RDMA/uverbs: Add a simple iterator interface for reading the command Several methods have a command with a trailing flex array, and they all open code some extraction scheme. Centralize this into a simple iterator API. Signed-off-by: Jason Gunthorpe Signed-off-by: Leon Romanovsky Signed-off-by: Doug Ledford --- drivers/infiniband/core/uverbs_cmd.c | 113 ++++++++++++++++++++--------------- 1 file changed, 65 insertions(+), 48 deletions(-) diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c index 3cc7466..a89b844 100644 --- a/drivers/infiniband/core/uverbs_cmd.c +++ b/drivers/infiniband/core/uverbs_cmd.c @@ -112,6 +112,51 @@ static u32 uverbs_response_length(struct uverbs_attr_bundle *attrs, return min_t(size_t, attrs->ucore.outlen, resp_len); } +/* + * The iterator version of the request interface is for handlers that need to + * step over a flex array at the end of a command header. + */ +struct uverbs_req_iter { + const void __user *cur; + const void __user *end; +}; + +static int uverbs_request_start(struct uverbs_attr_bundle *attrs, + struct uverbs_req_iter *iter, + void *req, + size_t req_len) +{ + if (attrs->ucore.inlen < req_len) + return -ENOSPC; + + if (copy_from_user(req, attrs->ucore.inbuf, req_len)) + return -EFAULT; + + iter->cur = attrs->ucore.inbuf + req_len; + iter->end = attrs->ucore.inbuf + attrs->ucore.inlen; + return 0; +} + +static int uverbs_request_next(struct uverbs_req_iter *iter, void *val, + size_t len) +{ + if (iter->cur + len > iter->end) + return -ENOSPC; + + if (copy_from_user(val, iter->cur, len)) + return -EFAULT; + + iter->cur += len; + return 0; +} + +static int uverbs_request_finish(struct uverbs_req_iter *iter) +{ + if (!ib_is_buffer_cleared(iter->cur, iter->end - iter->cur)) + return -EOPNOTSUPP; + return 0; +} + static struct ib_uverbs_completion_event_file * _ib_uverbs_lookup_comp_file(s32 fd, const struct uverbs_attr_bundle *attrs) { @@ -3060,10 +3105,10 @@ static int ib_uverbs_ex_modify_wq(struct uverbs_attr_bundle *attrs, static int ib_uverbs_ex_create_rwq_ind_table(struct uverbs_attr_bundle *attrs, struct ib_udata *ucore) { - struct ib_uverbs_ex_create_rwq_ind_table cmd = {}; + struct ib_uverbs_ex_create_rwq_ind_table cmd; struct ib_uverbs_ex_create_rwq_ind_table_resp resp = {}; struct ib_uobject *uobj; - int err = 0; + int err; struct ib_rwq_ind_table_init_attr init_attr = {}; struct ib_rwq_ind_table *rwq_ind_tbl; struct ib_wq **wqs = NULL; @@ -3071,27 +3116,13 @@ static int ib_uverbs_ex_create_rwq_ind_table(struct uverbs_attr_bundle *attrs, struct ib_wq *wq = NULL; int i, j, num_read_wqs; u32 num_wq_handles; - u32 expected_in_size; - size_t required_cmd_sz_header; - size_t required_resp_len; + struct uverbs_req_iter iter; struct ib_device *ib_dev; - required_cmd_sz_header = offsetof(typeof(cmd), log_ind_tbl_size) + sizeof(cmd.log_ind_tbl_size); - required_resp_len = offsetof(typeof(resp), ind_tbl_num) + sizeof(resp.ind_tbl_num); - - if (ucore->inlen < required_cmd_sz_header) - return -EINVAL; - - if (ucore->outlen < required_resp_len) - return -ENOSPC; - - err = ib_copy_from_udata(&cmd, ucore, required_cmd_sz_header); + err = uverbs_request_start(attrs, &iter, &cmd, sizeof(cmd)); if (err) return err; - ucore->inbuf += required_cmd_sz_header; - ucore->inlen -= required_cmd_sz_header; - if (cmd.comp_mask) return -EOPNOTSUPP; @@ -3099,26 +3130,17 @@ static int ib_uverbs_ex_create_rwq_ind_table(struct uverbs_attr_bundle *attrs, return -EINVAL; num_wq_handles = 1 << cmd.log_ind_tbl_size; - expected_in_size = num_wq_handles * sizeof(__u32); - if (num_wq_handles == 1) - /* input size for wq handles is u64 aligned */ - expected_in_size += sizeof(__u32); - - if (ucore->inlen < expected_in_size) - return -EINVAL; - - if (ucore->inlen > expected_in_size && - !ib_is_udata_cleared(ucore, expected_in_size, - ucore->inlen - expected_in_size)) - return -EOPNOTSUPP; - wqs_handles = kcalloc(num_wq_handles, sizeof(*wqs_handles), GFP_KERNEL); if (!wqs_handles) return -ENOMEM; - err = ib_copy_from_udata(wqs_handles, ucore, - num_wq_handles * sizeof(__u32)); + err = uverbs_request_next(&iter, wqs_handles, + num_wq_handles * sizeof(__u32)); + if (err) + goto err_free; + + err = uverbs_request_finish(&iter); if (err) goto err_free; @@ -3224,24 +3246,16 @@ static int ib_uverbs_ex_create_flow(struct uverbs_attr_bundle *attrs, struct ib_qp *qp; struct ib_uflow_resources *uflow_res; struct ib_uverbs_flow_spec_hdr *kern_spec; - int err = 0; + struct uverbs_req_iter iter; + int err; void *ib_spec; int i; struct ib_device *ib_dev; - if (ucore->inlen < sizeof(cmd)) - return -EINVAL; - - if (ucore->outlen < sizeof(resp)) - return -ENOSPC; - - err = ib_copy_from_udata(&cmd, ucore, sizeof(cmd)); + err = uverbs_request_start(attrs, &iter, &cmd, sizeof(cmd)); if (err) return err; - ucore->inbuf += sizeof(cmd); - ucore->inlen -= sizeof(cmd); - if (cmd.comp_mask) return -EINVAL; @@ -3259,8 +3273,7 @@ static int ib_uverbs_ex_create_flow(struct uverbs_attr_bundle *attrs, if (cmd.flow_attr.num_of_specs > IB_FLOW_SPEC_SUPPORT_LAYERS) return -EINVAL; - if (cmd.flow_attr.size > ucore->inlen || - cmd.flow_attr.size > + if (cmd.flow_attr.size > (cmd.flow_attr.num_of_specs * sizeof(struct ib_uverbs_flow_spec))) return -EINVAL; @@ -3275,14 +3288,18 @@ static int ib_uverbs_ex_create_flow(struct uverbs_attr_bundle *attrs, return -ENOMEM; *kern_flow_attr = cmd.flow_attr; - err = ib_copy_from_udata(&kern_flow_attr->flow_specs, ucore, - cmd.flow_attr.size); + err = uverbs_request_next(&iter, &kern_flow_attr->flow_specs, + cmd.flow_attr.size); if (err) goto err_free_attr; } else { kern_flow_attr = &cmd.flow_attr; } + err = uverbs_request_finish(&iter); + if (err) + goto err_free_attr; + uobj = uobj_alloc(UVERBS_OBJECT_FLOW, attrs, &ib_dev); if (IS_ERR(uobj)) { err = PTR_ERR(uobj); -- 2.7.4