[PATCH 3/4] vhost: use alloca instead of vla sizeof

[Tyler Retzlaff]

RFC sample illustrating conversion of VLA to alloca() where
sizeof(array) was in use.

Signed-off-by: Tyler Retzlaff <roret...@linux.microsoft.com>
---
 lib/vhost/socket.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lib/vhost/socket.c b/lib/vhost/socket.c
index 96b3ab5..cedcfb2 100644
--- a/lib/vhost/socket.c
+++ b/lib/vhost/socket.c
@@ -110,7 +110,8 @@ struct vhost_user {
 {
        struct iovec iov;
        struct msghdr msgh;
-       char control[CMSG_SPACE(max_fds * sizeof(int))];
+       const size_t control_sz = sizeof(char) * CMSG_SPACE(max_fds * 
sizeof(int));
+       char *control = alloca(control_sz);
        struct cmsghdr *cmsg;
        int got_fds = 0;
        int ret;
@@ -124,7 +125,7 @@ struct vhost_user {
        msgh.msg_iov = &iov;
        msgh.msg_iovlen = 1;
        msgh.msg_control = control;
-       msgh.msg_controllen = sizeof(control);
+       msgh.msg_controllen = control_sz;
 
        ret = recvmsg(sockfd, &msgh, 0);
        if (ret <= 0) {
-- 
1.8.3.1