On Mon, Dec 17, 2018 at 10:40 PM Arnd Bergmann <arnd@xxxxxxxx> wrote:
>
> On Mon, Dec 17, 2018 at 2:06 PM Heiko Carstens
> <heiko.carstens@xxxxxxxxxx> wrote:
> >
> > Hi Arnd,
> >
> > in linux-next as of today 16 strace self tests fail on s390. I could
> > bisect this to b136972b063b ("y2038: socket: Add compat_sys_recvmmsg_time64").
> >
> > The following tests fail:
>
> Hi Heiko,
>
> Thanks for the report and sorry I broke things. I'll have a closer look
> tomorrow if I don't find it right away. I suppose the regression was in
> native system calls, not the compat syscalls with 31-bit user space,
> right?
I found a bug in my patch by inspection. Can you try if the patch
below makes it all work (apologies for the garbled whitespace),
I'm considering a rewrite of that function now (to split it into two
again), but want to make sure there isn't another problem in my
original patch.
Arnd
----
diff --git a/net/socket.c b/net/socket.c
index 3bb2ee083f97..7f9f225d0b6c 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2486,12 +2486,12 @@ int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg,
return -EFAULT;
if (!timeout && !timeout32)
- do_recvmmsg(fd, mmsg, vlen, flags, NULL);
+ return do_recvmmsg(fd, mmsg, vlen, flags, NULL);
datagrams = do_recvmmsg(fd, mmsg, vlen, flags, &timeout_sys);
- if (!datagrams)
- return 0;
+ if (datagrams <= 0)
+ return datagrams;
if (timeout && put_timespec64(&timeout_sys, timeout))
datagrams = -EFAULT;
