[PATCH] hv: utils: handle and propagate errors in kvp_register

[Thorsten Blum]

Make kvp_register() return an error code instead of silently ignoring
failures, and propagate the error from kvp_handle_handshake() instead of
returning success.

This propagates both kzalloc_obj() and hvutil_transport_send() failures
to kvp_handle_handshake() and thus to kvp_on_msg().

Fixes: 245ba56a52a3 ("Staging: hv: Implement key/value pair (KVP)")
Cc: sta...@vger.kernel.org
Signed-off-by: Thorsten Blum <thorsten.b...@linux.dev>
---
 drivers/hv/hv_kvp.c | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/drivers/hv/hv_kvp.c b/drivers/hv/hv_kvp.c
index 0d73daf745a7..6180ebe040ff 100644
--- a/drivers/hv/hv_kvp.c
+++ b/drivers/hv/hv_kvp.c
@@ -93,7 +93,7 @@ static void kvp_send_key(struct work_struct *dummy);
 static void kvp_respond_to_host(struct hv_kvp_msg *msg, int error);
 static void kvp_timeout_func(struct work_struct *dummy);
 static void kvp_host_handshake_func(struct work_struct *dummy);
-static void kvp_register(int);
+static int kvp_register(int);
 
 static DECLARE_DELAYED_WORK(kvp_timeout_work, kvp_timeout_func);
 static DECLARE_DELAYED_WORK(kvp_host_handshake_work, kvp_host_handshake_func);
@@ -127,24 +127,26 @@ static void kvp_register_done(void)
        hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
 }
 
-static void
+static int
 kvp_register(int reg_value)
 {
 
        struct hv_kvp_msg *kvp_msg;
        char *version;
+       int ret;
 
        kvp_msg = kzalloc_obj(*kvp_msg);
+       if (!kvp_msg)
+               return -ENOMEM;
 
-       if (kvp_msg) {
-               version = kvp_msg->body.kvp_register.version;
-               kvp_msg->kvp_hdr.operation = reg_value;
-               strcpy(version, HV_DRV_VERSION);
+       version = kvp_msg->body.kvp_register.version;
+       kvp_msg->kvp_hdr.operation = reg_value;
+       strcpy(version, HV_DRV_VERSION);
 
-               hvutil_transport_send(hvt, kvp_msg, sizeof(*kvp_msg),
-                                     kvp_register_done);
-               kfree(kvp_msg);
-       }
+       ret = hvutil_transport_send(hvt, kvp_msg, sizeof(*kvp_msg),
+                                   kvp_register_done);
+       kfree(kvp_msg);
+       return ret;
 }
 
 static void kvp_timeout_func(struct work_struct *dummy)
@@ -186,9 +188,8 @@ static int kvp_handle_handshake(struct hv_kvp_msg *msg)
         */
        pr_debug("KVP: userspace daemon ver. %d connected\n",
                 msg->kvp_hdr.operation);
-       kvp_register(dm_reg_value);
 
-       return 0;
+       return kvp_register(dm_reg_value);
 }