On Tue, Jan 8, 2019 at 6:24 AM Deepa Dinamani deepa.kernel@gmail.com wrote:
SO_RCVTIMEO and SO_SNDTIMEO socket options use struct timeval as the time format. struct timeval is not y2038 safe. The subsequent patches in the series add support for new socket timeout options with _NEW suffix that are y2038 safe. Rename the existing options with _OLD suffix forms so that the right option is enabled for userspace applications according to the architecture and time_t definition of libc.
Signed-off-by: Deepa Dinamani deepa.kernel@gmail.com
Looks good overall. A few minor concerns:
The description above makes it sound like there is a bug with y2038-safety in this particular interface, which I think is just not what you meant, as the change is only needed for compatiblity with new C libraries that work around the y2038 problem in general by changing their timeval definition.
diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c index 76976d6e50f9..c98ad9777ad9 100644 --- a/fs/dlm/lowcomms.c +++ b/fs/dlm/lowcomms.c @@ -1089,12 +1089,12 @@ static void sctp_connect_to_sock(struct connection *con) * since O_NONBLOCK argument in connect() function does not work here, * then, we should restore the default value of this attribute. */
kernel_setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO, (char *)&tv,
kernel_setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO_OLD, (char *)&tv, sizeof(tv)); result = sock->ops->connect(sock, (struct sockaddr *)&daddr, addr_len, 0); memset(&tv, 0, sizeof(tv));
kernel_setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO, (char *)&tv,
kernel_setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO_OLD, (char *)&tv, sizeof(tv)); if (result == -EINPROGRESS)
It took me a bit to realize there that this is safe as well even if we don't use SO_SNDTIMEO_NEW, for the same reason.
--- a/net/compat.c +++ b/net/compat.c @@ -378,7 +378,7 @@ static int compat_sock_setsockopt(struct socket *sock, int level, int optname, return do_set_attach_filter(sock, level, optname, optval, optlen); if (!COMPAT_USE_64BIT_TIME &&
(optname == SO_RCVTIMEO || optname == SO_SNDTIMEO))
(optname == SO_RCVTIMEO_OLD || optname == SO_SNDTIMEO_OLD)) return do_set_sock_timeout(sock, level, optname, optval, optlen); return sock_setsockopt(sock, level, optname, optval, optlen);@@ -450,7 +450,7 @@ static int compat_sock_getsockopt(struct socket *sock, int level, int optname, char __user *optval, int __user *optlen) { if (!COMPAT_USE_64BIT_TIME &&
(optname == SO_RCVTIMEO || optname == SO_SNDTIMEO))
(optname == SO_RCVTIMEO_OLD || optname == SO_SNDTIMEO_OLD)) return do_get_sock_timeout(sock, level, optname, optval, optlen); return sock_getsockopt(sock, level, optname, optval, optlen);}
I looked at the original code and noticed that it's horrible, which of course is not your fault, but I wonder if we should just fix it now to avoid that get_fs()/set_fs() hack, since that code mostly implements what you also have in your patch 3 (which is done more nicely).
I'll follow up with a patch to demonstrate what I mean here. Your third patch will then just have to add another code path so we can handle all of old_timespec32 (for existing 32-bit user space), __kernel_old_timespec (for sparc64) and __kernel_sock_timeval (for everything else).
Arnd