Merge tag 'y2038-for-4.21' of ssh://gitolite.kernel.org:/pub/scm/linux/kernel/git/arnd/playground

Pull y2038 updates from Arnd Bergmann:
 "More syscalls and cleanups

  This concludes the main part of the system call rework for 64-bit
  time_t, which has spread over most of year 2018, the last six system
  calls being

    - ppoll
    - pselect6
    - io_pgetevents
    - recvmmsg
    - futex
    - rt_sigtimedwait

  As before, nothing changes for 64-bit architectures, while 32-bit
  architectures gain another entry point that differs only in the layout
  of the timespec structure. Hopefully in the next release we can wire
  up all 22 of those system calls on all 32-bit architectures, which
  gives us a baseline version for glibc to start using them.

  This does not include the clock_adjtime, getrusage/waitid, and
  getitimer/setitimer system calls. I still plan to have new versions of
  those as well, but they are not required for correct operation of the
  C library since they can be emulated using the old 32-bit time_t based
  system calls.

  Aside from the system calls, there are also a few cleanups here,
  removing old kernel internal interfaces that have become unused after
  all references got removed. The arch/sh cleanups are part of this,
  there were posted several times over the past year without a reaction
  from the maintainers, while the corresponding changes made it into all
  other architectures"

* tag 'y2038-for-4.21' of ssh://gitolite.kernel.org:/pub/scm/linux/kernel/git/arnd/playground:
  timekeeping: remove obsolete time accessors
  vfs: replace current_kernel_time64 with ktime equivalent
  timekeeping: remove timespec_add/timespec_del
  timekeeping: remove unused {read,update}_persistent_clock
  sh: remove board_time_init() callback
  sh: remove unused rtc_sh_get/set_time infrastructure
  sh: sh03: rtc: push down rtc class ops into driver
  sh: dreamcast: rtc: push down rtc class ops into driver
  y2038: signal: Add compat_sys_rt_sigtimedwait_time64
  y2038: signal: Add sys_rt_sigtimedwait_time32
  y2038: socket: Add compat_sys_recvmmsg_time64
  y2038: futex: Add support for __kernel_timespec
  y2038: futex: Move compat implementation into futex.c
  io_pgetevents: use __kernel_timespec
  pselect6: use __kernel_timespec
  ppoll: use __kernel_timespec
  signal: Add restore_user_sigmask()
  signal: Add set_user_sigmask()

2 files changed, 58 insertions, 38 deletions

diff --git a/net/compat.c b/net/compat.c
index 47a614b370cd..f7084780a8f8 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -810,34 +810,23 @@ COMPAT_SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, buf, compat_size_t, len
 	return __compat_sys_recvfrom(fd, buf, len, flags, addr, addrlen);
 }
 
-static int __compat_sys_recvmmsg(int fd, struct compat_mmsghdr __user *mmsg,
-				 unsigned int vlen, unsigned int flags,
-				 struct old_timespec32 __user *timeout)
+COMPAT_SYSCALL_DEFINE5(recvmmsg_time64, int, fd, struct compat_mmsghdr __user *, mmsg,
+		       unsigned int, vlen, unsigned int, flags,
+		       struct __kernel_timespec __user *, timeout)
 {
-	int datagrams;
-	struct timespec64 ktspec;
-
-	if (timeout == NULL)
-		return __sys_recvmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
-				      flags | MSG_CMSG_COMPAT, NULL);
-
-	if (compat_get_timespec64(&ktspec, timeout))
-		return -EFAULT;
-
-	datagrams = __sys_recvmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
-				   flags | MSG_CMSG_COMPAT, &ktspec);
-	if (datagrams > 0 && compat_put_timespec64(&ktspec, timeout))
-		datagrams = -EFAULT;
-
-	return datagrams;
+	return __sys_recvmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
+			      flags | MSG_CMSG_COMPAT, timeout, NULL);
 }
 
+#ifdef CONFIG_COMPAT_32BIT_TIME
 COMPAT_SYSCALL_DEFINE5(recvmmsg, int, fd, struct compat_mmsghdr __user *, mmsg,
 		       unsigned int, vlen, unsigned int, flags,
 		       struct old_timespec32 __user *, timeout)
 {
-	return __compat_sys_recvmmsg(fd, mmsg, vlen, flags, timeout);
+	return __sys_recvmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
+			      flags | MSG_CMSG_COMPAT, NULL, timeout);
 }
+#endif
 
 COMPAT_SYSCALL_DEFINE2(socketcall, int, call, u32 __user *, args)
 {
@@ -925,8 +914,9 @@ COMPAT_SYSCALL_DEFINE2(socketcall, int, call, u32 __user *, args)
 		ret = __compat_sys_recvmsg(a0, compat_ptr(a1), a[2]);
 		break;
 	case SYS_RECVMMSG:
-		ret = __compat_sys_recvmmsg(a0, compat_ptr(a1), a[2], a[3],
-					    compat_ptr(a[4]));
+		ret = __sys_recvmmsg(a0, compat_ptr(a1), a[2],
+				     a[3] | MSG_CMSG_COMPAT, NULL,
+				     compat_ptr(a[4]));
 		break;
 	case SYS_ACCEPT4:
 		ret = __sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), a[3]);
diff --git a/net/socket.c b/net/socket.c
index 334fcc617ef2..e89884e2197b 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2341,8 +2341,9 @@ SYSCALL_DEFINE3(recvmsg, int, fd, struct user_msghdr __user *, msg,
  *     Linux recvmmsg interface
  */
 
-int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen,
-		   unsigned int flags, struct timespec64 *timeout)
+static int do_recvmmsg(int fd, struct mmsghdr __user *mmsg,
+			  unsigned int vlen, unsigned int flags,
+			  struct timespec64 *timeout)
 {
 	int fput_needed, err, datagrams;
 	struct socket *sock;
@@ -2451,25 +2452,32 @@ out_put:
 	return datagrams;
 }
 
-static int do_sys_recvmmsg(int fd, struct mmsghdr __user *mmsg,
-			   unsigned int vlen, unsigned int flags,
-			   struct __kernel_timespec __user *timeout)
+int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg,
+		   unsigned int vlen, unsigned int flags,
+		   struct __kernel_timespec __user *timeout,
+		   struct old_timespec32 __user *timeout32)
 {
 	int datagrams;
 	struct timespec64 timeout_sys;
 
-	if (flags & MSG_CMSG_COMPAT)
-		return -EINVAL;
-
-	if (!timeout)
-		return __sys_recvmmsg(fd, mmsg, vlen, flags, NULL);
+	if (timeout && get_timespec64(&timeout_sys, timeout))
+		return -EFAULT;
 
-	if (get_timespec64(&timeout_sys, timeout))
+	if (timeout32 && get_old_timespec32(&timeout_sys, timeout32))
 		return -EFAULT;
 
-	datagrams = __sys_recvmmsg(fd, mmsg, vlen, flags, &timeout_sys);
+	if (!timeout && !timeout32)
+		return do_recvmmsg(fd, mmsg, vlen, flags, NULL);
+
+	datagrams = do_recvmmsg(fd, mmsg, vlen, flags, &timeout_sys);
 
-	if (datagrams > 0 && put_timespec64(&timeout_sys, timeout))
+	if (datagrams <= 0)
+		return datagrams;
+
+	if (timeout && put_timespec64(&timeout_sys, timeout))
+		datagrams = -EFAULT;
+
+	if (timeout32 && put_old_timespec32(&timeout_sys, timeout32))
 		datagrams = -EFAULT;
 
 	return datagrams;
@@ -2479,8 +2487,23 @@ SYSCALL_DEFINE5(recvmmsg, int, fd, struct mmsghdr __user *, mmsg,
 		unsigned int, vlen, unsigned int, flags,
 		struct __kernel_timespec __user *, timeout)
 {
-	return do_sys_recvmmsg(fd, mmsg, vlen, flags, timeout);
+	if (flags & MSG_CMSG_COMPAT)
+		return -EINVAL;
+
+	return __sys_recvmmsg(fd, mmsg, vlen, flags, timeout, NULL);
+}
+
+#ifdef CONFIG_COMPAT_32BIT_TIME
+SYSCALL_DEFINE5(recvmmsg_time32, int, fd, struct mmsghdr __user *, mmsg,
+		unsigned int, vlen, unsigned int, flags,
+		struct old_timespec32 __user *, timeout)
+{
+	if (flags & MSG_CMSG_COMPAT)
+		return -EINVAL;
+
+	return __sys_recvmmsg(fd, mmsg, vlen, flags, NULL, timeout);
 }
+#endif
 
 #ifdef __ARCH_WANT_SYS_SOCKETCALL
 /* Argument list sizes for sys_socketcall */
@@ -2600,8 +2623,15 @@ SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args)
 				    a[2], true);
 		break;
 	case SYS_RECVMMSG:
-		err = do_sys_recvmmsg(a0, (struct mmsghdr __user *)a1, a[2],
-				      a[3], (struct __kernel_timespec __user *)a[4]);
+		if (IS_ENABLED(CONFIG_64BIT) || !IS_ENABLED(CONFIG_64BIT_TIME))
+			err = __sys_recvmmsg(a0, (struct mmsghdr __user *)a1,
+					     a[2], a[3],
+					     (struct __kernel_timespec __user *)a[4],
+					     NULL);
+		else
+			err = __sys_recvmmsg(a0, (struct mmsghdr __user *)a1,
+					     a[2], a[3], NULL,
+					     (struct old_timespec32 __user *)a[4]);
 		break;
 	case SYS_ACCEPT4:
 		err = __sys_accept4(a0, (struct sockaddr __user *)a1,