Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
  IB/uverbs: Handle large number of entries in poll CQ

1 files changed, 56 insertions, 43 deletions

diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index b342248aec05..c42699285f8e 100644
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -893,68 +893,81 @@ out:
         return ret ? ret : in_len;
 }
 
+static int copy_wc_to_user(void __user *dest, struct ib_wc *wc)
+{
+        struct ib_uverbs_wc tmp;
+
+        tmp.wr_id               = wc->wr_id;
+        tmp.status              = wc->status;
+        tmp.opcode              = wc->opcode;
+        tmp.vendor_err          = wc->vendor_err;
+        tmp.byte_len            = wc->byte_len;
+        tmp.ex.imm_data         = (__u32 __force) wc->ex.imm_data;
+        tmp.qp_num              = wc->qp->qp_num;
+        tmp.src_qp              = wc->src_qp;
+        tmp.wc_flags            = wc->wc_flags;
+        tmp.pkey_index          = wc->pkey_index;
+        tmp.slid                = wc->slid;
+        tmp.sl                  = wc->sl;
+        tmp.dlid_path_bits      = wc->dlid_path_bits;
+        tmp.port_num            = wc->port_num;
+        tmp.reserved            = 0;
+
+        if (copy_to_user(dest, &tmp, sizeof tmp))
+                return -EFAULT;
+
+        return 0;
+}
+
 ssize_t ib_uverbs_poll_cq(struct ib_uverbs_file *file,
                           const char __user *buf, int in_len,
                           int out_len)
 {
         struct ib_uverbs_poll_cq       cmd;
-        struct ib_uverbs_poll_cq_resp *resp;
+        struct ib_uverbs_poll_cq_resp  resp;
+        u8 __user                     *header_ptr;
+        u8 __user                     *data_ptr;
         struct ib_cq                  *cq;
-        struct ib_wc                  *wc;
-        int                            ret = 0;
-        int                            i;
-        int                            rsize;
+        struct ib_wc                   wc;
+        int                            ret;
 
         if (copy_from_user(&cmd, buf, sizeof cmd))
                 return -EFAULT;
 
-        wc = kmalloc(cmd.ne * sizeof *wc, GFP_KERNEL);
-        if (!wc)
-                return -ENOMEM;
-
-        rsize = sizeof *resp + cmd.ne * sizeof(struct ib_uverbs_wc);
-        resp = kmalloc(rsize, GFP_KERNEL);
-        if (!resp) {
-                ret = -ENOMEM;
-                goto out_wc;
-        }
-
         cq = idr_read_cq(cmd.cq_handle, file->ucontext, 0);
-        if (!cq) {
-                ret = -EINVAL;
-                goto out;
-        }
+        if (!cq)
+                return -EINVAL;
 
-        resp->count = ib_poll_cq(cq, cmd.ne, wc);
+        /* we copy a struct ib_uverbs_poll_cq_resp to user space */
+        header_ptr = (void __user *)(unsigned long) cmd.response;
+        data_ptr = header_ptr + sizeof resp;
 
-        put_cq_read(cq);
+        memset(&resp, 0, sizeof resp);
+        while (resp.count < cmd.ne) {
+                ret = ib_poll_cq(cq, 1, &wc);
+                if (ret < 0)
+                        goto out_put;
+                if (!ret)
+                        break;
+
+                ret = copy_wc_to_user(data_ptr, &wc);
+                if (ret)
+                        goto out_put;
 
-        for (i = 0; i < resp->count; i++) {
-                resp->wc[i].wr_id          = wc[i].wr_id;
-                resp->wc[i].status         = wc[i].status;
-                resp->wc[i].opcode         = wc[i].opcode;
-                resp->wc[i].vendor_err     = wc[i].vendor_err;
-                resp->wc[i].byte_len       = wc[i].byte_len;
-                resp->wc[i].ex.imm_data    = (__u32 __force) wc[i].ex.imm_data;
-                resp->wc[i].qp_num         = wc[i].qp->qp_num;
-                resp->wc[i].src_qp         = wc[i].src_qp;
-                resp->wc[i].wc_flags       = wc[i].wc_flags;
-                resp->wc[i].pkey_index     = wc[i].pkey_index;
-                resp->wc[i].slid           = wc[i].slid;
-                resp->wc[i].sl             = wc[i].sl;
-                resp->wc[i].dlid_path_bits = wc[i].dlid_path_bits;
-                resp->wc[i].port_num       = wc[i].port_num;
+                data_ptr += sizeof(struct ib_uverbs_wc);
+                ++resp.count;
         }
 
-        if (copy_to_user((void __user *) (unsigned long) cmd.response, resp, rsize))
+        if (copy_to_user(header_ptr, &resp, sizeof resp)) {
                 ret = -EFAULT;
+                goto out_put;
+        }
 
-out:
-        kfree(resp);
+        ret = in_len;
 
-out_wc:
-        kfree(wc);
-        return ret ? ret : in_len;
+out_put:
+        put_cq_read(cq);
+        return ret;
 }
 
 ssize_t ib_uverbs_req_notify_cq(struct ib_uverbs_file *file,