uml: fix recvmsg return value checking

Stupid bug - we need to compare the return value of recvmsg to the value of
iov_len, not its size.  This caused port_helper processes not to be killed on
shutdown on x86_64 because the pids weren't being passed out properly.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 2 deletions

diff --git a/arch/um/os-Linux/file.c b/arch/um/os-Linux/file.c
index b542a3a021bf..f83462758627 100644
--- a/arch/um/os-Linux/file.c
+++ b/arch/um/os-Linux/file.c
@@ -496,8 +496,7 @@ int os_rcv_fd(int fd, int *helper_pid_out)
         n = recvmsg(fd, &msg, 0);
         if(n < 0)
                 return -errno;
-
-        else if(n != sizeof(iov.iov_len))
+        else if(n != iov.iov_len)
                 *helper_pid_out = -1;
 
         cmsg = CMSG_FIRSTHDR(&msg);