Merge remote-tracking branch 'remotes/gkurz/tags/for-upstream' into s…

…taging

This pull request fixes a potential QEMU hang in 9pfs and two issues
reported by Coverity.

# gpg: Signature made Tue 21 Mar 2017 09:57:58 GMT
# gpg:                using DSA key 0x02FC3AEB0101DBC2
# gpg: Good signature from "Greg Kurz <[email protected]>"
# gpg:                 aka "Greg Kurz <[email protected]>"
# gpg:                 aka "Greg Kurz <[email protected]>"
# gpg:                 aka "Gregory Kurz (Groug) <[email protected]>"
# gpg:                 aka "[jpeg image of size 3330]"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 2BD4 3B44 535E C0A7 9894  DBA2 02FC 3AEB 0101 DBC2

* remotes/gkurz/tags/for-upstream:
  9pfs: proxy: assert if unmarshal fails
  9pfs: don't try to flush self and avoid QEMU hang on reset

Signed-off-by: Peter Maydell <[email protected]>

hw/9pfs/9p-proxy.c

@@ -165,7 +165,8 @@ static int v9fs_receive_response(V9fsProxy *proxy, int type,
         return retval;
     }
     reply->iov_len = PROXY_HDR_SZ;
-    proxy_unmarshal(reply, 0, "dd", &header.type, &header.size);
+    retval = proxy_unmarshal(reply, 0, "dd", &header.type, &header.size);
+    assert(retval == 4 * 2);
     /*
      * if response size > PROXY_MAX_IO_SZ, read the response but ignore it and
      * return -ENOBUFS
@@ -194,9 +195,7 @@ static int v9fs_receive_response(V9fsProxy *proxy, int type,
     if (header.type == T_ERROR) {
         int ret;
         ret = proxy_unmarshal(reply, PROXY_HDR_SZ, "d", status);
-        if (ret < 0) {
-            *status = ret;
-        }
+        assert(ret == 4);
         return 0;
     }
 
@@ -213,6 +212,7 @@ static int v9fs_receive_response(V9fsProxy *proxy, int type,
                                  &prstat.st_atim_sec, &prstat.st_atim_nsec,
                                  &prstat.st_mtim_sec, &prstat.st_mtim_nsec,
                                  &prstat.st_ctim_sec, &prstat.st_ctim_nsec);
+        assert(retval == 8 * 3 + 4 * 3 + 8 * 10);
         prstat_to_stat(response, &prstat);
         break;
     }
@@ -225,6 +225,7 @@ static int v9fs_receive_response(V9fsProxy *proxy, int type,
                                  &prstfs.f_files, &prstfs.f_ffree,
                                  &prstfs.f_fsid[0], &prstfs.f_fsid[1],
                                  &prstfs.f_namelen, &prstfs.f_frsize);
+        assert(retval == 8 * 11);
         prstatfs_to_statfs(response, &prstfs);
         break;
     }
@@ -246,7 +247,8 @@ static int v9fs_receive_response(V9fsProxy *proxy, int type,
         break;
     }
     case T_GETVERSION:
-        proxy_unmarshal(reply, PROXY_HDR_SZ, "q", response);
+        retval = proxy_unmarshal(reply, PROXY_HDR_SZ, "q", response);
+        assert(retval == 8);
         break;
     default:
         return -1;
@@ -274,18 +276,16 @@ static int v9fs_receive_status(V9fsProxy *proxy,
         return retval;
     }
     reply->iov_len = PROXY_HDR_SZ;
-    proxy_unmarshal(reply, 0, "dd", &header.type, &header.size);
-    if (header.size != sizeof(int)) {
-        *status = -ENOBUFS;
-        return 0;
-    }
+    retval = proxy_unmarshal(reply, 0, "dd", &header.type, &header.size);
+    assert(retval == 4 * 2);
     retval = socket_read(proxy->sockfd,
                          reply->iov_base + PROXY_HDR_SZ, header.size);
     if (retval < 0) {
         return retval;
     }
     reply->iov_len += header.size;
-    proxy_unmarshal(reply, PROXY_HDR_SZ, "d", status);
+    retval = proxy_unmarshal(reply, PROXY_HDR_SZ, "d", status);
+    assert(retval == 4);
     return 0;
 }
 

hw/9pfs/9p.c

@@ -2353,7 +2353,7 @@ static void coroutine_fn v9fs_flush(void *opaque)
     ssize_t err;
     int16_t tag;
     size_t offset = 7;
-    V9fsPDU *cancel_pdu;
+    V9fsPDU *cancel_pdu = NULL;
     V9fsPDU *pdu = opaque;
     V9fsState *s = pdu->s;
 
@@ -2364,9 +2364,13 @@ static void coroutine_fn v9fs_flush(void *opaque)
     }
     trace_v9fs_flush(pdu->tag, pdu->id, tag);
 
-    QLIST_FOREACH(cancel_pdu, &s->active_list, next) {
-        if (cancel_pdu->tag == tag) {
-            break;
+    if (pdu->tag == tag) {
+        error_report("Warning: the guest sent a self-referencing 9P flush request");
+    } else {
+        QLIST_FOREACH(cancel_pdu, &s->active_list, next) {
+            if (cancel_pdu->tag == tag) {
+                break;
+            }
         }
     }
     if (cancel_pdu) {