Merge tag 'y2038-ipc' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground into timers/2038

Pull 'y2038: IPC system call conversion' from Arnd Bergmann:

"This is a follow-up to Deepa's work on the timekeeping system calls,
 providing a y2038-safe syscall API for SYSVIPC. It uses a combination
 of two strategies:

 For sys_msgctl, sys_semctl and sys_shmctl, I do not introduce a completely
 new set of replacement system calls, but instead extend the existing
 ones to return data in the reserved fields of the normal data structure.

 This should be completely transparent to any existing user space, and
 only after the 32-bit time_t wraps, it will make a difference in the
 returned data.

 libc implementations will consequently have to provide their own data
 structures when they move to 64-bit time_t, and convert the structures
 in user space from the ones returned by the kernel.

 In contrast, mq_timedsend, mq_timedreceive and and semtimedop all do
 need to change because having a libc redefine the timespec type
 breaks the ABI, so with this series there will be two separate entry
 points for 32-bit architectures.

 There are three cases here:

 - little-endian architectures (except powerpc and mips) can use
   the normal layout and just cast the data structure to the user space
   type that contains 64-bit numbers.

 - parisc and sparc can do the same thing with big-endian user space

 - little-endian powerpc and most big-endian architectures have
   to flip the upper and lower 32-bit halves of the time_t value in memory,
   but can otherwise keep using the normal layout

 - mips and big-endian xtensa need to be more careful because
   they are not consistent in their definitions, and they have to provide
   custom libc implementations for the system calls to use 64-bit time_t."

37 files changed, 320 insertions, 587 deletions

diff --git a/arch/alpha/include/uapi/asm/Kbuild b/arch/alpha/include/uapi/asm/Kbuild
index 9afaba5e5503..1a5b75310cf4 100644
--- a/arch/alpha/include/uapi/asm/Kbuild
+++ b/arch/alpha/include/uapi/asm/Kbuild
@@ -2,4 +2,8 @@
 include include/uapi/asm-generic/Kbuild.asm
 
 generic-y += bpf_perf_event.h
+generic-y += ipcbuf.h
+generic-y += msgbuf.h
 generic-y += poll.h
+generic-y += sembuf.h
+generic-y += shmbuf.h
diff --git a/arch/alpha/include/uapi/asm/ipcbuf.h b/arch/alpha/include/uapi/asm/ipcbuf.h
deleted file mode 100644
index 90d6445a14df..000000000000
--- a/arch/alpha/include/uapi/asm/ipcbuf.h
+++ /dev/null
@@ -1,2 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#include <asm-generic/ipcbuf.h>
diff --git a/arch/alpha/include/uapi/asm/msgbuf.h b/arch/alpha/include/uapi/asm/msgbuf.h
deleted file mode 100644
index 8c5d4d8c1b16..000000000000
--- a/arch/alpha/include/uapi/asm/msgbuf.h
+++ /dev/null
@@ -1,28 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef _ALPHA_MSGBUF_H
-#define _ALPHA_MSGBUF_H
-
-/* 
- * The msqid64_ds structure for alpha architecture.
- * Note extra padding because this structure is passed back and forth
- * between kernel and user space.
- *
- * Pad space is left for:
- * - 2 miscellaneous 64-bit values
- */
-
-struct msqid64_ds {
-	struct ipc64_perm msg_perm;
-	__kernel_time_t msg_stime;	/* last msgsnd time */
-	__kernel_time_t msg_rtime;	/* last msgrcv time */
-	__kernel_time_t msg_ctime;	/* last change time */
-	unsigned long  msg_cbytes;	/* current number of bytes on queue */
-	unsigned long  msg_qnum;	/* number of messages in queue */
-	unsigned long  msg_qbytes;	/* max number of bytes on queue */
-	__kernel_pid_t msg_lspid;	/* pid of last msgsnd */
-	__kernel_pid_t msg_lrpid;	/* last receive pid */
-	unsigned long  __unused1;
-	unsigned long  __unused2;
-};
-
-#endif /* _ALPHA_MSGBUF_H */
diff --git a/arch/alpha/include/uapi/asm/sembuf.h b/arch/alpha/include/uapi/asm/sembuf.h
deleted file mode 100644
index f28ffa668b2f..000000000000
--- a/arch/alpha/include/uapi/asm/sembuf.h
+++ /dev/null
@@ -1,23 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef _ALPHA_SEMBUF_H
-#define _ALPHA_SEMBUF_H
-
-/* 
- * The semid64_ds structure for alpha architecture.
- * Note extra padding because this structure is passed back and forth
- * between kernel and user space.
- *
- * Pad space is left for:
- * - 2 miscellaneous 64-bit values
- */
-
-struct semid64_ds {
-	struct ipc64_perm sem_perm;		/* permissions .. see ipc.h */
-	__kernel_time_t	sem_otime;		/* last semop time */
-	__kernel_time_t	sem_ctime;		/* last change time */
-	unsigned long	sem_nsems;		/* no. of semaphores in array */
-	unsigned long	__unused1;
-	unsigned long	__unused2;
-};
-
-#endif /* _ALPHA_SEMBUF_H */
diff --git a/arch/alpha/include/uapi/asm/shmbuf.h b/arch/alpha/include/uapi/asm/shmbuf.h
deleted file mode 100644
index 7e041ca2eb40..000000000000
--- a/arch/alpha/include/uapi/asm/shmbuf.h
+++ /dev/null
@@ -1,39 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef _ALPHA_SHMBUF_H
-#define _ALPHA_SHMBUF_H
-
-/* 
- * The shmid64_ds structure for alpha architecture.
- * Note extra padding because this structure is passed back and forth
- * between kernel and user space.
- *
- * Pad space is left for:
- * - 2 miscellaneous 64-bit values
- */
-
-struct shmid64_ds {
-	struct ipc64_perm	shm_perm;	/* operation perms */
-	size_t			shm_segsz;	/* size of segment (bytes) */
-	__kernel_time_t		shm_atime;	/* last attach time */
-	__kernel_time_t		shm_dtime;	/* last detach time */
-	__kernel_time_t		shm_ctime;	/* last change time */
-	__kernel_pid_t		shm_cpid;	/* pid of creator */
-	__kernel_pid_t		shm_lpid;	/* pid of last operator */
-	unsigned long		shm_nattch;	/* no. of current attaches */
-	unsigned long		__unused1;
-	unsigned long		__unused2;
-};
-
-struct shminfo64 {
-	unsigned long	shmmax;
-	unsigned long	shmmin;
-	unsigned long	shmmni;
-	unsigned long	shmseg;
-	unsigned long	shmall;
-	unsigned long	__unused1;
-	unsigned long	__unused2;
-	unsigned long	__unused3;
-	unsigned long	__unused4;
-};
-
-#endif /* _ALPHA_SHMBUF_H */
diff --git a/arch/arm64/include/asm/compat.h b/arch/arm64/include/asm/compat.h
index 0030f79808b3..1a037b94eba1 100644
--- a/arch/arm64/include/asm/compat.h
+++ b/arch/arm64/include/asm/compat.h
@@ -181,10 +181,10 @@ struct compat_ipc64_perm {
 
 struct compat_semid64_ds {
 	struct compat_ipc64_perm sem_perm;
-	compat_time_t  sem_otime;
-	compat_ulong_t __unused1;
-	compat_time_t  sem_ctime;
-	compat_ulong_t __unused2;
+	compat_ulong_t sem_otime;
+	compat_ulong_t sem_otime_high;
+	compat_ulong_t sem_ctime;
+	compat_ulong_t sem_ctime_high;
 	compat_ulong_t sem_nsems;
 	compat_ulong_t __unused3;
 	compat_ulong_t __unused4;
@@ -192,12 +192,12 @@ struct compat_semid64_ds {
 
 struct compat_msqid64_ds {
 	struct compat_ipc64_perm msg_perm;
-	compat_time_t  msg_stime;
-	compat_ulong_t __unused1;
-	compat_time_t  msg_rtime;
-	compat_ulong_t __unused2;
-	compat_time_t  msg_ctime;
-	compat_ulong_t __unused3;
+	compat_ulong_t msg_stime;
+	compat_ulong_t msg_stime_high;
+	compat_ulong_t msg_rtime;
+	compat_ulong_t msg_rtime_high;
+	compat_ulong_t msg_ctime;
+	compat_ulong_t msg_ctime_high;
 	compat_ulong_t msg_cbytes;
 	compat_ulong_t msg_qnum;
 	compat_ulong_t msg_qbytes;
@@ -210,12 +210,12 @@ struct compat_msqid64_ds {
 struct compat_shmid64_ds {
 	struct compat_ipc64_perm shm_perm;
 	compat_size_t  shm_segsz;
-	compat_time_t  shm_atime;
-	compat_ulong_t __unused1;
-	compat_time_t  shm_dtime;
-	compat_ulong_t __unused2;
-	compat_time_t  shm_ctime;
-	compat_ulong_t __unused3;
+	compat_ulong_t shm_atime;
+	compat_ulong_t shm_atime_high;
+	compat_ulong_t shm_dtime;
+	compat_ulong_t shm_dtime_high;
+	compat_ulong_t shm_ctime;
+	compat_ulong_t shm_ctime_high;
 	compat_pid_t   shm_cpid;
 	compat_pid_t   shm_lpid;
 	compat_ulong_t shm_nattch;
diff --git a/arch/ia64/include/uapi/asm/Kbuild b/arch/ia64/include/uapi/asm/Kbuild
index c0527cfc48f0..3982e673e967 100644
--- a/arch/ia64/include/uapi/asm/Kbuild
+++ b/arch/ia64/include/uapi/asm/Kbuild
@@ -2,5 +2,9 @@
 include include/uapi/asm-generic/Kbuild.asm
 
 generic-y += bpf_perf_event.h
+generic-y += ipcbuf.h
 generic-y += kvm_para.h
+generic-y += msgbuf.h
 generic-y += poll.h
+generic-y += sembuf.h
+generic-y += shmbuf.h
diff --git a/arch/ia64/include/uapi/asm/ipcbuf.h b/arch/ia64/include/uapi/asm/ipcbuf.h
deleted file mode 100644
index 90d6445a14df..000000000000
--- a/arch/ia64/include/uapi/asm/ipcbuf.h
+++ /dev/null
@@ -1,2 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#include <asm-generic/ipcbuf.h>
diff --git a/arch/ia64/include/uapi/asm/msgbuf.h b/arch/ia64/include/uapi/asm/msgbuf.h
deleted file mode 100644
index aa25df92d9dc..000000000000
--- a/arch/ia64/include/uapi/asm/msgbuf.h
+++ /dev/null
@@ -1,28 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef _ASM_IA64_MSGBUF_H
-#define _ASM_IA64_MSGBUF_H
-
-/*
- * The msqid64_ds structure for IA-64 architecture.
- * Note extra padding because this structure is passed back and forth
- * between kernel and user space.
- *
- * Pad space is left for:
- * - 2 miscellaneous 64-bit values
- */
-
-struct msqid64_ds {
-	struct ipc64_perm msg_perm;
-	__kernel_time_t msg_stime;	/* last msgsnd time */
-	__kernel_time_t msg_rtime;	/* last msgrcv time */
-	__kernel_time_t msg_ctime;	/* last change time */
-	unsigned long  msg_cbytes;	/* current number of bytes on queue */
-	unsigned long  msg_qnum;	/* number of messages in queue */
-	unsigned long  msg_qbytes;	/* max number of bytes on queue */
-	__kernel_pid_t msg_lspid;	/* pid of last msgsnd */
-	__kernel_pid_t msg_lrpid;	/* last receive pid */
-	unsigned long  __unused1;
-	unsigned long  __unused2;
-};
-
-#endif /* _ASM_IA64_MSGBUF_H */
diff --git a/arch/ia64/include/uapi/asm/sembuf.h b/arch/ia64/include/uapi/asm/sembuf.h
deleted file mode 100644
index 6ed058760afc..000000000000
--- a/arch/ia64/include/uapi/asm/sembuf.h
+++ /dev/null
@@ -1,23 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef _ASM_IA64_SEMBUF_H
-#define _ASM_IA64_SEMBUF_H
-
-/*
- * The semid64_ds structure for IA-64 architecture.
- * Note extra padding because this structure is passed back and forth
- * between kernel and user space.
- *
- * Pad space is left for:
- * - 2 miscellaneous 64-bit values
- */
-
-struct semid64_ds {
-	struct ipc64_perm sem_perm;		/* permissions .. see ipc.h */
-	__kernel_time_t	sem_otime;		/* last semop time */
-	__kernel_time_t	sem_ctime;		/* last change time */
-	unsigned long	sem_nsems;		/* no. of semaphores in array */
-	unsigned long	__unused1;
-	unsigned long	__unused2;
-};
-
-#endif /* _ASM_IA64_SEMBUF_H */
diff --git a/arch/ia64/include/uapi/asm/shmbuf.h b/arch/ia64/include/uapi/asm/shmbuf.h
deleted file mode 100644
index 6ef57cb70dee..000000000000
--- a/arch/ia64/include/uapi/asm/shmbuf.h
+++ /dev/null
@@ -1,39 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef _ASM_IA64_SHMBUF_H
-#define _ASM_IA64_SHMBUF_H
-
-/*
- * The shmid64_ds structure for IA-64 architecture.
- * Note extra padding because this structure is passed back and forth
- * between kernel and user space.
- *
- * Pad space is left for:
- * - 2 miscellaneous 64-bit values
- */
-
-struct shmid64_ds {
-	struct ipc64_perm	shm_perm;	/* operation perms */
-	size_t			shm_segsz;	/* size of segment (bytes) */
-	__kernel_time_t		shm_atime;	/* last attach time */
-	__kernel_time_t		shm_dtime;	/* last detach time */
-	__kernel_time_t		shm_ctime;	/* last change time */
-	__kernel_pid_t		shm_cpid;	/* pid of creator */
-	__kernel_pid_t		shm_lpid;	/* pid of last operator */
-	unsigned long		shm_nattch;	/* no. of current attaches */
-	unsigned long		__unused1;
-	unsigned long		__unused2;
-};
-
-struct shminfo64 {
-	unsigned long	shmmax;
-	unsigned long	shmmin;
-	unsigned long	shmmni;
-	unsigned long	shmseg;
-	unsigned long	shmall;
-	unsigned long	__unused1;
-	unsigned long	__unused2;
-	unsigned long	__unused3;
-	unsigned long	__unused4;
-};
-
-#endif /* _ASM_IA64_SHMBUF_H */
diff --git a/arch/mips/include/asm/compat.h b/arch/mips/include/asm/compat.h
index 3e548ee99a2f..78675f19440f 100644
--- a/arch/mips/include/asm/compat.h
+++ b/arch/mips/include/asm/compat.h
@@ -37,9 +37,11 @@ typedef struct {
 typedef s32		compat_timer_t;
 typedef s32		compat_key_t;
 
+typedef s16		compat_short_t;
 typedef s32		compat_int_t;
 typedef s32		compat_long_t;
 typedef s64		compat_s64;
+typedef u16		compat_ushort_t;
 typedef u32		compat_uint_t;
 typedef u32		compat_ulong_t;
 typedef u64		compat_u64;
@@ -157,35 +159,35 @@ struct compat_ipc64_perm {
 
 struct compat_semid64_ds {
 	struct compat_ipc64_perm sem_perm;
-	compat_time_t	sem_otime;
-	compat_time_t	sem_ctime;
+	compat_ulong_t	sem_otime;
+	compat_ulong_t	sem_ctime;
 	compat_ulong_t	sem_nsems;
-	compat_ulong_t	__unused1;
-	compat_ulong_t	__unused2;
+	compat_ulong_t	sem_otime_high;
+	compat_ulong_t	sem_ctime_high;
 };
 
 struct compat_msqid64_ds {
 	struct compat_ipc64_perm msg_perm;
 #ifndef CONFIG_CPU_LITTLE_ENDIAN
-	compat_ulong_t	__unused1;
+	compat_ulong_t	msg_stime_high;
 #endif
-	compat_time_t	msg_stime;
+	compat_ulong_t	msg_stime;
 #ifdef CONFIG_CPU_LITTLE_ENDIAN
-	compat_ulong_t	__unused1;
+	compat_ulong_t	msg_stime_high;
 #endif
 #ifndef CONFIG_CPU_LITTLE_ENDIAN
-	compat_ulong_t	__unused2;
+	compat_ulong_t	msg_rtime_high;
 #endif
-	compat_time_t	msg_rtime;
+	compat_ulong_t	msg_rtime;
 #ifdef CONFIG_CPU_LITTLE_ENDIAN
-	compat_ulong_t	__unused2;
+	compat_ulong_t	msg_rtime_high;
 #endif
 #ifndef CONFIG_CPU_LITTLE_ENDIAN
-	compat_ulong_t	__unused3;
+	compat_ulong_t	msg_ctime_high;
 #endif
-	compat_time_t	msg_ctime;
+	compat_ulong_t	msg_ctime;
 #ifdef CONFIG_CPU_LITTLE_ENDIAN
-	compat_ulong_t	__unused3;
+	compat_ulong_t	msg_ctime_high;
 #endif
 	compat_ulong_t	msg_cbytes;
 	compat_ulong_t	msg_qnum;
@@ -199,14 +201,16 @@ struct compat_msqid64_ds {
 struct compat_shmid64_ds {
 	struct compat_ipc64_perm shm_perm;
 	compat_size_t	shm_segsz;
-	compat_time_t	shm_atime;
-	compat_time_t	shm_dtime;
-	compat_time_t	shm_ctime;
+	compat_ulong_t	shm_atime;
+	compat_ulong_t	shm_dtime;
+	compat_ulong_t	shm_ctime;
 	compat_pid_t	shm_cpid;
 	compat_pid_t	shm_lpid;
 	compat_ulong_t	shm_nattch;
-	compat_ulong_t	__unused1;
-	compat_ulong_t	__unused2;
+	compat_ushort_t	shm_atime_high;
+	compat_ushort_t	shm_dtime_high;
+	compat_ushort_t	shm_ctime_high;
+	compat_ushort_t	__unused2;
 };
 
 /* MIPS has unusual order of fields in stack_t */
diff --git a/arch/mips/include/uapi/asm/msgbuf.h b/arch/mips/include/uapi/asm/msgbuf.h
index eb4d0f9d7364..46aa15b13e4e 100644
--- a/arch/mips/include/uapi/asm/msgbuf.h
+++ b/arch/mips/include/uapi/asm/msgbuf.h
@@ -9,33 +9,15 @@
  * between kernel and user space.
  *
  * Pad space is left for:
- * - extension of time_t to 64-bit on 32-bitsystem to solve the y2038 problem
  * - 2 miscellaneous unsigned long values
  */
 
+#if defined(__mips64)
 struct msqid64_ds {
 	struct ipc64_perm msg_perm;
-#if !defined(__mips64) && defined(__MIPSEB__)
-	unsigned long	__unused1;
-#endif
 	__kernel_time_t msg_stime;	/* last msgsnd time */
-#if !defined(__mips64) && defined(__MIPSEL__)
-	unsigned long	__unused1;
-#endif
-#if !defined(__mips64) && defined(__MIPSEB__)
-	unsigned long	__unused2;
-#endif
 	__kernel_time_t msg_rtime;	/* last msgrcv time */
-#if !defined(__mips64) && defined(__MIPSEL__)
-	unsigned long	__unused2;
-#endif
-#if !defined(__mips64) && defined(__MIPSEB__)
-	unsigned long	__unused3;
-#endif
 	__kernel_time_t msg_ctime;	/* last change time */
-#if !defined(__mips64) && defined(__MIPSEL__)
-	unsigned long	__unused3;
-#endif
 	unsigned long  msg_cbytes;	/* current number of bytes on queue */
 	unsigned long  msg_qnum;	/* number of messages in queue */
 	unsigned long  msg_qbytes;	/* max number of bytes on queue */
@@ -44,5 +26,42 @@ struct msqid64_ds {
 	unsigned long  __unused4;
 	unsigned long  __unused5;
 };
+#elif defined (__MIPSEB__)
+struct msqid64_ds {
+	struct ipc64_perm msg_perm;
+	unsigned long  msg_stime_high;
+	unsigned long  msg_stime;	/* last msgsnd time */
+	unsigned long  msg_rtime_high;
+	unsigned long  msg_rtime;	/* last msgrcv time */
+	unsigned long  msg_ctime_high;
+	unsigned long  msg_ctime;	/* last change time */
+	unsigned long  msg_cbytes;	/* current number of bytes on queue */
+	unsigned long  msg_qnum;	/* number of messages in queue */
+	unsigned long  msg_qbytes;	/* max number of bytes on queue */
+	__kernel_pid_t msg_lspid;	/* pid of last msgsnd */
+	__kernel_pid_t msg_lrpid;	/* last receive pid */
+	unsigned long  __unused4;
+	unsigned long  __unused5;
+};
+#elif defined (__MIPSEL__)
+struct msqid64_ds {
+	struct ipc64_perm msg_perm;
+	unsigned long  msg_stime;	/* last msgsnd time */
+	unsigned long  msg_stime_high;
+	unsigned long  msg_rtime;	/* last msgrcv time */
+	unsigned long  msg_rtime_high;
+	unsigned long  msg_ctime;	/* last change time */
+	unsigned long  msg_ctime_high;
+	unsigned long  msg_cbytes;	/* current number of bytes on queue */
+	unsigned long  msg_qnum;	/* number of messages in queue */
+	unsigned long  msg_qbytes;	/* max number of bytes on queue */
+	__kernel_pid_t msg_lspid;	/* pid of last msgsnd */
+	__kernel_pid_t msg_lrpid;	/* last receive pid */
+	unsigned long  __unused4;
+	unsigned long  __unused5;
+};
+#else
+#warning no endianess set
+#endif
 
 #endif /* _ASM_MSGBUF_H */
diff --git a/arch/mips/include/uapi/asm/sembuf.h b/arch/mips/include/uapi/asm/sembuf.h
index 2c0f507ab7d1..60c89e6cb25b 100644
--- a/arch/mips/include/uapi/asm/sembuf.h
+++ b/arch/mips/include/uapi/asm/sembuf.h
@@ -7,10 +7,11 @@
  * Note extra padding because this structure is passed back and forth
  * between kernel and user space.
  *
- * Pad space is left for:
- * - 2 miscellaneous 64-bit values
+ * Pad space is left for 2 miscellaneous 64-bit values on mips64,
+ * but used for the upper 32 bit of the time values on mips32.
  */
 
+#ifdef __mips64
 struct semid64_ds {
 	struct ipc64_perm sem_perm;		/* permissions .. see ipc.h */
 	__kernel_time_t sem_otime;		/* last semop time */
@@ -19,5 +20,15 @@ struct semid64_ds {
 	unsigned long	__unused1;
 	unsigned long	__unused2;
 };
+#else
+struct semid64_ds {
+	struct ipc64_perm sem_perm;		/* permissions .. see ipc.h */
+	unsigned long   sem_otime;		/* last semop time */
+	unsigned long   sem_ctime;		/* last change time */
+	unsigned long	sem_nsems;		/* no. of semaphores in array */
+	unsigned long	sem_otime_high;
+	unsigned long	sem_ctime_high;
+};
+#endif
 
 #endif /* _ASM_SEMBUF_H */
diff --git a/arch/mips/include/uapi/asm/shmbuf.h b/arch/mips/include/uapi/asm/shmbuf.h
index 379e6bca518b..9b9bba3401f2 100644
--- a/arch/mips/include/uapi/asm/shmbuf.h
+++ b/arch/mips/include/uapi/asm/shmbuf.h
@@ -7,10 +7,13 @@
  * Note extra padding because this structure is passed back and forth
  * between kernel and user space.
  *
- * Pad space is left for:
- * - 2 miscellaneous 32-bit rsp. 64-bit values
+ * As MIPS was lacking proper padding after shm_?time, we use 48 bits
+ * of the padding at the end to store a few additional bits of the time.
+ * libc implementations need to take care to convert this into a proper
+ * data structure when moving to 64-bit time_t.
  */
 
+#ifdef __mips64
 struct shmid64_ds {
 	struct ipc64_perm	shm_perm;	/* operation perms */
 	size_t			shm_segsz;	/* size of segment (bytes) */
@@ -23,6 +26,22 @@ struct shmid64_ds {
 	unsigned long		__unused1;
 	unsigned long		__unused2;
 };
+#else
+struct shmid64_ds {
+	struct ipc64_perm	shm_perm;	/* operation perms */
+	size_t			shm_segsz;	/* size of segment (bytes) */
+	unsigned long		shm_atime;	/* last attach time */
+	unsigned long		shm_dtime;	/* last detach time */
+	unsigned long		shm_ctime;	/* last change time */
+	__kernel_pid_t		shm_cpid;	/* pid of creator */
+	__kernel_pid_t		shm_lpid;	/* pid of last operator */
+	unsigned long		shm_nattch;	/* no. of current attaches */
+	unsigned short		shm_atime_high;
+	unsigned short		shm_dtime_high;
+	unsigned short		shm_ctime_high;
+	unsigned short		__unused1;
+};
+#endif
 
 struct shminfo64 {
 	unsigned long	shmmax;
diff --git a/arch/parisc/include/asm/compat.h b/arch/parisc/include/asm/compat.h
index 0cdfec8857bd..ab8a54771507 100644
--- a/arch/parisc/include/asm/compat.h
+++ b/arch/parisc/include/asm/compat.h
@@ -138,10 +138,10 @@ struct compat_ipc64_perm {
 
 struct compat_semid64_ds {
 	struct compat_ipc64_perm sem_perm;
-	unsigned int __unused1;
-	compat_time_t sem_otime;
-	unsigned int __unused2;
-	compat_time_t sem_ctime;
+	unsigned int sem_otime_high;
+	unsigned int sem_otime;
+	unsigned int sem_ctime_high;
+	unsigned int sem_ctime;
 	compat_ulong_t sem_nsems;
 	compat_ulong_t __unused3;
 	compat_ulong_t __unused4;
@@ -149,12 +149,12 @@ struct compat_semid64_ds {
 
 struct compat_msqid64_ds {
 	struct compat_ipc64_perm msg_perm;
-	unsigned int __unused1;
-	compat_time_t msg_stime;
-	unsigned int __unused2;
-	compat_time_t msg_rtime;
-	unsigned int __unused3;
-	compat_time_t msg_ctime;
+	unsigned int msg_stime_high;
+	unsigned int msg_stime;
+	unsigned int msg_rtime_high;
+	unsigned int msg_rtime;
+	unsigned int msg_ctime_high;
+	unsigned int msg_ctime;
 	compat_ulong_t msg_cbytes;
 	compat_ulong_t msg_qnum;
 	compat_ulong_t msg_qbytes;
@@ -166,12 +166,12 @@ struct compat_msqid64_ds {
 
 struct compat_shmid64_ds {
 	struct compat_ipc64_perm shm_perm;
-	unsigned int __unused1;
-	compat_time_t shm_atime;
-	unsigned int __unused2;
-	compat_time_t shm_dtime;
-	unsigned int __unused3;
-	compat_time_t shm_ctime;
+	unsigned int shm_atime_high;
+	unsigned int shm_atime;
+	unsigned int shm_dtime_high;
+	unsigned int shm_dtime;
+	unsigned int shm_ctime_high;
+	unsigned int shm_ctime;
 	unsigned int __unused4;
 	compat_size_t shm_segsz;
 	compat_pid_t shm_cpid;
diff --git a/arch/parisc/include/uapi/asm/msgbuf.h b/arch/parisc/include/uapi/asm/msgbuf.h
index b48b810e626b..6a2e9ab2ef8d 100644
--- a/arch/parisc/include/uapi/asm/msgbuf.h
+++ b/arch/parisc/include/uapi/asm/msgbuf.h
@@ -10,31 +10,30 @@
  * between kernel and user space.
  *
  * Pad space is left for:
- * - 64-bit time_t to solve y2038 problem
  * - 2 miscellaneous 32-bit values
  */
 
 struct msqid64_ds {
 	struct ipc64_perm msg_perm;
-#if __BITS_PER_LONG != 64
-	unsigned int   __pad1;
-#endif
+#if __BITS_PER_LONG == 64
 	__kernel_time_t msg_stime;	/* last msgsnd time */
-#if __BITS_PER_LONG != 64
-	unsigned int   __pad2;
-#endif
 	__kernel_time_t msg_rtime;	/* last msgrcv time */
-#if __BITS_PER_LONG != 64
-	unsigned int   __pad3;
-#endif
 	__kernel_time_t msg_ctime;	/* last change time */
-	unsigned long msg_cbytes;	/* current number of bytes on queue */
-	unsigned long msg_qnum;		/* number of messages in queue */
-	unsigned long msg_qbytes;	/* max number of bytes on queue */
-	__kernel_pid_t msg_lspid;	/* pid of last msgsnd */
-	__kernel_pid_t msg_lrpid;	/* last receive pid */
-	unsigned long __unused1;
-	unsigned long __unused2;
+#else
+	unsigned long	msg_stime_high;
+	unsigned long	msg_stime;	/* last msgsnd time */
+	unsigned long	msg_rtime_high;
+	unsigned long	msg_rtime;	/* last msgrcv time */
+	unsigned long	msg_ctime_high;
+	unsigned long	msg_ctime;	/* last change time */
+#endif
+	unsigned long	msg_cbytes;	/* current number of bytes on queue */
+	unsigned long	msg_qnum;	/* number of messages in queue */
+	unsigned long	msg_qbytes;	/* max number of bytes on queue */
+	__kernel_pid_t	msg_lspid;	/* pid of last msgsnd */
+	__kernel_pid_t	msg_lrpid;	/* last receive pid */
+	unsigned long	__unused1;
+	unsigned long	__unused2;
 };
 
 #endif /* _PARISC_MSGBUF_H */
diff --git a/arch/parisc/include/uapi/asm/sembuf.h b/arch/parisc/include/uapi/asm/sembuf.h
index 746c5d86a9b1..3c31163b1241 100644
--- a/arch/parisc/include/uapi/asm/sembuf.h
+++ b/arch/parisc/include/uapi/asm/sembuf.h
@@ -10,21 +10,21 @@
  * between kernel and user space.
  *
  * Pad space is left for:
- * - 64-bit time_t to solve y2038 problem
  * - 2 miscellaneous 32-bit values
  */
 
 struct semid64_ds {
 	struct ipc64_perm sem_perm;		/* permissions .. see ipc.h */
-#if __BITS_PER_LONG != 64
-	unsigned int	__pad1;
-#endif
+#if __BITS_PER_LONG == 64
 	__kernel_time_t	sem_otime;		/* last semop time */
-#if __BITS_PER_LONG != 64
-	unsigned int	__pad2;
-#endif
 	__kernel_time_t	sem_ctime;		/* last change time */
-	unsigned long 	sem_nsems;		/* no. of semaphores in array */
+#else
+	unsigned long	sem_otime_high;
+	unsigned long	sem_otime;		/* last semop time */
+	unsigned long	sem_ctime_high;
+	unsigned long	sem_ctime;		/* last change time */
+#endif
+	unsigned long	sem_nsems;		/* no. of semaphores in array */
 	unsigned long	__unused1;
 	unsigned long	__unused2;
 };
diff --git a/arch/parisc/include/uapi/asm/shmbuf.h b/arch/parisc/include/uapi/asm/shmbuf.h
index cd4dbce55d0b..c89b3dd8db21 100644
--- a/arch/parisc/include/uapi/asm/shmbuf.h
+++ b/arch/parisc/include/uapi/asm/shmbuf.h
@@ -10,25 +10,22 @@
  * between kernel and user space.
  *
  * Pad space is left for:
- * - 64-bit time_t to solve y2038 problem
  * - 2 miscellaneous 32-bit values
  */
 
 struct shmid64_ds {
 	struct ipc64_perm	shm_perm;	/* operation perms */
-#if __BITS_PER_LONG != 64
-	unsigned int		__pad1;
-#endif
+#if __BITS_PER_LONG == 64
 	__kernel_time_t		shm_atime;	/* last attach time */
-#if __BITS_PER_LONG != 64
-	unsigned int		__pad2;
-#endif
 	__kernel_time_t		shm_dtime;	/* last detach time */
-#if __BITS_PER_LONG != 64
-	unsigned int		__pad3;
-#endif
 	__kernel_time_t		shm_ctime;	/* last change time */
-#if __BITS_PER_LONG != 64
+#else
+	unsigned long		shm_atime_high;
+	unsigned long		shm_atime;	/* last attach time */
+	unsigned long		shm_dtime_high;
+	unsigned long		shm_dtime;	/* last detach time */
+	unsigned long		shm_ctime_high;
+	unsigned long		shm_ctime;	/* last change time */
 	unsigned int		__pad4;
 #endif
 	__kernel_size_t		shm_segsz;	/* size of segment (bytes) */
diff --git a/arch/powerpc/include/asm/compat.h b/arch/powerpc/include/asm/compat.h
index b4773c81f7d5..85c8af2bb272 100644
--- a/arch/powerpc/include/asm/compat.h
+++ b/arch/powerpc/include/asm/compat.h
@@ -162,10 +162,10 @@ struct compat_ipc64_perm {
 
 struct compat_semid64_ds {
 	struct compat_ipc64_perm sem_perm;
-	unsigned int __unused1;
-	compat_time_t sem_otime;
-	unsigned int __unused2;
-	compat_time_t sem_ctime;
+	unsigned int sem_otime_high;
+	unsigned int sem_otime;
+	unsigned int sem_ctime_high;
+	unsigned int sem_ctime;
 	compat_ulong_t sem_nsems;
 	compat_ulong_t __unused3;
 	compat_ulong_t __unused4;
@@ -173,12 +173,12 @@ struct compat_semid64_ds {
 
 struct compat_msqid64_ds {
 	struct compat_ipc64_perm msg_perm;
-	unsigned int __unused1;
-	compat_time_t msg_stime;
-	unsigned int __unused2;
-	compat_time_t msg_rtime;
-	unsigned int __unused3;
-	compat_time_t msg_ctime;
+	unsigned int msg_stime_high;
+	unsigned int msg_stime;
+	unsigned int msg_rtime_high;
+	unsigned int msg_rtime;
+	unsigned int msg_ctime_high;
+	unsigned int msg_ctime;
 	compat_ulong_t msg_cbytes;
 	compat_ulong_t msg_qnum;
 	compat_ulong_t msg_qbytes;
@@ -190,12 +190,12 @@ struct compat_msqid64_ds {
 
 struct compat_shmid64_ds {
 	struct compat_ipc64_perm shm_perm;
-	unsigned int __unused1;
-	compat_time_t shm_atime;
-	unsigned int __unused2;
-	compat_time_t shm_dtime;
-	unsigned int __unused3;
-	compat_time_t shm_ctime;
+	unsigned int shm_atime_high;
+	unsigned int shm_atime;
+	unsigned int shm_dtime_high;
+	unsigned int shm_dtime;
+	unsigned int shm_ctime_high;
+	unsigned int shm_ctime;
 	unsigned int __unused4;
 	compat_size_t shm_segsz;
 	compat_pid_t shm_cpid;
diff --git a/arch/powerpc/include/uapi/asm/msgbuf.h b/arch/powerpc/include/uapi/asm/msgbuf.h
index 65beb0942500..2b1b37797a47 100644
--- a/arch/powerpc/include/uapi/asm/msgbuf.h
+++ b/arch/powerpc/include/uapi/asm/msgbuf.h
@@ -10,18 +10,18 @@
 
 struct msqid64_ds {
 	struct ipc64_perm msg_perm;
-#ifndef __powerpc64__
-	unsigned int	__unused1;
-#endif
+#ifdef __powerpc64__
 	__kernel_time_t msg_stime;	/* last msgsnd time */
-#ifndef __powerpc64__
-	unsigned int	__unused2;
-#endif
 	__kernel_time_t msg_rtime;	/* last msgrcv time */
-#ifndef __powerpc64__
-	unsigned int	__unused3;
-#endif
 	__kernel_time_t msg_ctime;	/* last change time */
+#else
+	unsigned long  msg_stime_high;
+	unsigned long  msg_stime;	/* last msgsnd time */
+	unsigned long  msg_rtime_high;
+	unsigned long  msg_rtime;	/* last msgrcv time */
+	unsigned long  msg_ctime_high;
+	unsigned long  msg_ctime;	/* last change time */
+#endif
 	unsigned long  msg_cbytes;	/* current number of bytes on queue */
 	unsigned long  msg_qnum;	/* number of messages in queue */
 	unsigned long  msg_qbytes;	/* max number of bytes on queue */
diff --git a/arch/powerpc/include/uapi/asm/sembuf.h b/arch/powerpc/include/uapi/asm/sembuf.h
index 8f393d60f02d..3f60946f77e3 100644
--- a/arch/powerpc/include/uapi/asm/sembuf.h
+++ b/arch/powerpc/include/uapi/asm/sembuf.h
@@ -15,20 +15,20 @@
  * between kernel and user space.
  *
  * Pad space is left for:
- * - 64-bit time_t to solve y2038 problem
- * - 2 miscellaneous 32-bit values
+ * - 2 miscellaneous 32/64-bit values
  */
 
 struct semid64_ds {
 	struct ipc64_perm sem_perm;	/* permissions .. see ipc.h */
 #ifndef __powerpc64__
-	unsigned long	__unused1;
-#endif
+	unsigned long	sem_otime_high;
+	unsigned long	sem_otime;	/* last semop time */
+	unsigned long	sem_ctime_high;
+	unsigned long	sem_ctime;	/* last change time */
+#else
 	__kernel_time_t	sem_otime;	/* last semop time */
-#ifndef __powerpc64__
-	unsigned long	__unused2;
-#endif
 	__kernel_time_t	sem_ctime;	/* last change time */
+#endif
 	unsigned long	sem_nsems;	/* no. of semaphores in array */
 	unsigned long	__unused3;
 	unsigned long	__unused4;
diff --git a/arch/powerpc/include/uapi/asm/shmbuf.h b/arch/powerpc/include/uapi/asm/shmbuf.h
index deb1c3e503d3..b591c4d7e4c5 100644
--- a/arch/powerpc/include/uapi/asm/shmbuf.h
+++ b/arch/powerpc/include/uapi/asm/shmbuf.h
@@ -16,25 +16,22 @@
  * between kernel and user space.
  *
  * Pad space is left for:
- * - 64-bit time_t to solve y2038 problem
  * - 2 miscellaneous 32-bit values
  */
 
 struct shmid64_ds {
 	struct ipc64_perm	shm_perm;	/* operation perms */
-#ifndef __powerpc64__
-	unsigned long		__unused1;
-#endif
+#ifdef __powerpc64__
 	__kernel_time_t		shm_atime;	/* last attach time */
-#ifndef __powerpc64__
-	unsigned long		__unused2;
-#endif
 	__kernel_time_t		shm_dtime;	/* last detach time */
-#ifndef __powerpc64__
-	unsigned long		__unused3;
-#endif
 	__kernel_time_t		shm_ctime;	/* last change time */
-#ifndef __powerpc64__
+#else
+	unsigned long		shm_atime_high;
+	unsigned long		shm_atime;	/* last attach time */
+	unsigned long		shm_dtime_high;
+	unsigned long		shm_dtime;	/* last detach time */
+	unsigned long		shm_ctime_high;
+	unsigned long		shm_ctime;	/* last change time */
 	unsigned long		__unused4;
 #endif
 	size_t			shm_segsz;	/* size of segment (bytes) */
diff --git a/arch/s390/include/asm/compat.h b/arch/s390/include/asm/compat.h
index 501aaff85304..97db2fba546a 100644
--- a/arch/s390/include/asm/compat.h
+++ b/arch/s390/include/asm/compat.h
@@ -232,10 +232,10 @@ struct compat_ipc64_perm {
 
 struct compat_semid64_ds {
 	struct compat_ipc64_perm sem_perm;
-	compat_time_t  sem_otime;
-	compat_ulong_t __pad1;
-	compat_time_t  sem_ctime;
-	compat_ulong_t __pad2;
+	compat_ulong_t sem_otime;
+	compat_ulong_t sem_otime_high;
+	compat_ulong_t sem_ctime;
+	compat_ulong_t sem_ctime_high;
 	compat_ulong_t sem_nsems;
 	compat_ulong_t __unused1;
 	compat_ulong_t __unused2;
@@ -243,12 +243,12 @@ struct compat_semid64_ds {
 
 struct compat_msqid64_ds {
 	struct compat_ipc64_perm msg_perm;
-	compat_time_t   msg_stime;
-	compat_ulong_t __pad1;
-	compat_time_t   msg_rtime;
-	compat_ulong_t __pad2;
-	compat_time_t   msg_ctime;
-	compat_ulong_t __pad3;
+	compat_ulong_t msg_stime;
+	compat_ulong_t msg_stime_high;
+	compat_ulong_t msg_rtime;
+	compat_ulong_t msg_rtime_high;
+	compat_ulong_t msg_ctime;
+	compat_ulong_t msg_ctime_high;
 	compat_ulong_t msg_cbytes;
 	compat_ulong_t msg_qnum;
 	compat_ulong_t msg_qbytes;
@@ -261,12 +261,12 @@ struct compat_msqid64_ds {
 struct compat_shmid64_ds {
 	struct compat_ipc64_perm shm_perm;
 	compat_size_t  shm_segsz;
-	compat_time_t  shm_atime;
-	compat_ulong_t __pad1;
-	compat_time_t  shm_dtime;
-	compat_ulong_t __pad2;
-	compat_time_t  shm_ctime;
-	compat_ulong_t __pad3;
+	compat_ulong_t shm_atime;
+	compat_ulong_t shm_atime_high;
+	compat_ulong_t shm_dtime;
+	compat_ulong_t shm_dtime_high;
+	compat_ulong_t shm_ctime;
+	compat_ulong_t shm_ctime_high;
 	compat_pid_t   shm_cpid;
 	compat_pid_t   shm_lpid;
 	compat_ulong_t shm_nattch;
diff --git a/arch/s390/include/uapi/asm/Kbuild b/arch/s390/include/uapi/asm/Kbuild
index faef3f7e8353..e364873e0d10 100644
--- a/arch/s390/include/uapi/asm/Kbuild
+++ b/arch/s390/include/uapi/asm/Kbuild
@@ -9,9 +9,12 @@ generic-y += errno.h
 generic-y += fcntl.h
 generic-y += ioctl.h
 generic-y += mman.h
+generic-y += msgbuf.h
 generic-y += param.h
 generic-y += poll.h
 generic-y += resource.h
+generic-y += sembuf.h
+generic-y += shmbuf.h
 generic-y += sockios.h
 generic-y += swab.h
 generic-y += termbits.h
diff --git a/arch/s390/include/uapi/asm/msgbuf.h b/arch/s390/include/uapi/asm/msgbuf.h
deleted file mode 100644
index 604f847cd68c..000000000000
--- a/arch/s390/include/uapi/asm/msgbuf.h
+++ /dev/null
@@ -1,38 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef _S390_MSGBUF_H
-#define _S390_MSGBUF_H
-
-/* 
- * The msqid64_ds structure for S/390 architecture.
- * Note extra padding because this structure is passed back and forth
- * between kernel and user space.
- *
- * Pad space is left for:
- * - 64-bit time_t to solve y2038 problem
- * - 2 miscellaneous 32-bit values
- */
-
-struct msqid64_ds {
-	struct ipc64_perm msg_perm;
-	__kernel_time_t msg_stime;	/* last msgsnd time */
-#ifndef __s390x__
-	unsigned long	__unused1;
-#endif /* ! __s390x__ */
-	__kernel_time_t msg_rtime;	/* last msgrcv time */
-#ifndef __s390x__
-	unsigned long	__unused2;
-#endif /* ! __s390x__ */
-	__kernel_time_t msg_ctime;	/* last change time */
-#ifndef __s390x__
-	unsigned long	__unused3;
-#endif /* ! __s390x__ */
-	unsigned long  msg_cbytes;	/* current number of bytes on queue */
-	unsigned long  msg_qnum;	/* number of messages in queue */
-	unsigned long  msg_qbytes;	/* max number of bytes on queue */
-	__kernel_pid_t msg_lspid;	/* pid of last msgsnd */
-	__kernel_pid_t msg_lrpid;	/* last receive pid */
-	unsigned long  __unused4;
-	unsigned long  __unused5;
-};
-
-#endif /* _S390_MSGBUF_H */
diff --git a/arch/s390/include/uapi/asm/sembuf.h b/arch/s390/include/uapi/asm/sembuf.h
deleted file mode 100644
index 3e917697b668..000000000000
--- a/arch/s390/include/uapi/asm/sembuf.h
+++ /dev/null
@@ -1,30 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef _S390_SEMBUF_H
-#define _S390_SEMBUF_H
-
-/* 
- * The semid64_ds structure for S/390 architecture.
- * Note extra padding because this structure is passed back and forth
- * between kernel and user space.
- *
- * Pad space is left for:
- * - 64-bit time_t to solve y2038 problem (for !__s390x__)
- * - 2 miscellaneous 32-bit values
- */
-
-struct semid64_ds {
-	struct ipc64_perm sem_perm;		/* permissions .. see ipc.h */
-	__kernel_time_t	sem_otime;		/* last semop time */
-#ifndef __s390x__
-	unsigned long	__unused1;
-#endif /* ! __s390x__ */
-	__kernel_time_t	sem_ctime;		/* last change time */
-#ifndef __s390x__
-	unsigned long	__unused2;
-#endif /* ! __s390x__ */
-	unsigned long	sem_nsems;		/* no. of semaphores in array */
-	unsigned long	__unused3;
-	unsigned long	__unused4;
-};
-
-#endif /* _S390_SEMBUF_H */
diff --git a/arch/s390/include/uapi/asm/shmbuf.h b/arch/s390/include/uapi/asm/shmbuf.h
deleted file mode 100644
index 9cdce8d7ce60..000000000000
--- a/arch/s390/include/uapi/asm/shmbuf.h
+++ /dev/null
@@ -1,49 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef _S390_SHMBUF_H
-#define _S390_SHMBUF_H
-
-/* 
- * The shmid64_ds structure for S/390 architecture.
- * Note extra padding because this structure is passed back and forth
- * between kernel and user space.
- *
- * Pad space is left for:
- * - 64-bit time_t to solve y2038 problem (for !__s390x__)
- * - 2 miscellaneous 32-bit values
- */
-
-struct shmid64_ds {
-	struct ipc64_perm	shm_perm;	/* operation perms */
-	size_t			shm_segsz;	/* size of segment (bytes) */
-	__kernel_time_t		shm_atime;	/* last attach time */
-#ifndef __s390x__
-	unsigned long		__unused1;
-#endif /* ! __s390x__ */
-	__kernel_time_t		shm_dtime;	/* last detach time */
-#ifndef __s390x__
-	unsigned long		__unused2;
-#endif /* ! __s390x__ */
-	__kernel_time_t		shm_ctime;	/* last change time */
-#ifndef __s390x__
-	unsigned long		__unused3;
-#endif /* ! __s390x__ */
-	__kernel_pid_t		shm_cpid;	/* pid of creator */
-	__kernel_pid_t		shm_lpid;	/* pid of last operator */
-	unsigned long		shm_nattch;	/* no. of current attaches */
-	unsigned long		__unused4;
-	unsigned long		__unused5;
-};
-
-struct shminfo64 {
-	unsigned long	shmmax;
-	unsigned long	shmmin;
-	unsigned long	shmmni;
-	unsigned long	shmseg;
-	unsigned long	shmall;
-	unsigned long	__unused1;
-	unsigned long	__unused2;
-	unsigned long	__unused3;
-	unsigned long	__unused4;
-};
-
-#endif /* _S390_SHMBUF_H */
diff --git a/arch/sparc/include/asm/compat.h b/arch/sparc/include/asm/compat.h
index 1910c44521e3..4eb51d2dae98 100644
--- a/arch/sparc/include/asm/compat.h
+++ b/arch/sparc/include/asm/compat.h
@@ -192,10 +192,10 @@ struct compat_ipc64_perm {
 
 struct compat_semid64_ds {
 	struct compat_ipc64_perm sem_perm;
-	unsigned int	__pad1;
-	compat_time_t	sem_otime;
-	unsigned int	__pad2;
-	compat_time_t	sem_ctime;
+	unsigned int	sem_otime_high;
+	unsigned int	sem_otime;
+	unsigned int	sem_ctime_high;
+	unsigned int	sem_ctime;
 	u32		sem_nsems;
 	u32		__unused1;
 	u32		__unused2;
@@ -203,12 +203,12 @@ struct compat_semid64_ds {
 
 struct compat_msqid64_ds {
 	struct compat_ipc64_perm msg_perm;
-	unsigned int	__pad1;
-	compat_time_t	msg_stime;
-	unsigned int	__pad2;
-	compat_time_t	msg_rtime;
-	unsigned int	__pad3;
-	compat_time_t	msg_ctime;
+	unsigned int	msg_stime_high;
+	unsigned int	msg_stime;
+	unsigned int	msg_rtime_high;
+	unsigned int	msg_rtime;
+	unsigned int	msg_ctime_high;
+	unsigned int	msg_ctime;
 	unsigned int	msg_cbytes;
 	unsigned int	msg_qnum;
 	unsigned int	msg_qbytes;
@@ -220,12 +220,12 @@ struct compat_msqid64_ds {
 
 struct compat_shmid64_ds {
 	struct compat_ipc64_perm shm_perm;
-	unsigned int	__pad1;
-	compat_time_t	shm_atime;
-	unsigned int	__pad2;
-	compat_time_t	shm_dtime;
-	unsigned int	__pad3;
-	compat_time_t	shm_ctime;
+	unsigned int	shm_atime_high;
+	unsigned int	shm_atime;
+	unsigned int	shm_dtime_high;
+	unsigned int	shm_dtime;
+	unsigned int	shm_ctime_high;
+	unsigned int	shm_ctime;
 	compat_size_t	shm_segsz;
 	compat_pid_t	shm_cpid;
 	compat_pid_t	shm_lpid;
diff --git a/arch/sparc/include/uapi/asm/msgbuf.h b/arch/sparc/include/uapi/asm/msgbuf.h
index b601c4f4d956..ffc46c211d6d 100644
--- a/arch/sparc/include/uapi/asm/msgbuf.h
+++ b/arch/sparc/include/uapi/asm/msgbuf.h
@@ -8,25 +8,22 @@
  * between kernel and user space.
  *
  * Pad space is left for:
- * - 64-bit time_t to solve y2038 problem
  * - 2 miscellaneous 32-bit values
  */
-
-#if defined(__sparc__) && defined(__arch64__)
-# define PADDING(x)
-#else
-# define PADDING(x) unsigned int x;
-#endif
-
-
 struct msqid64_ds {
 	struct ipc64_perm msg_perm;
-	PADDING(__pad1)
+#if defined(__sparc__) && defined(__arch64__)
 	__kernel_time_t msg_stime;	/* last msgsnd time */
-	PADDING(__pad2)
 	__kernel_time_t msg_rtime;	/* last msgrcv time */
-	PADDING(__pad3)
 	__kernel_time_t msg_ctime;	/* last change time */
+#else
+	unsigned long msg_stime_high;
+	unsigned long msg_stime;	/* last msgsnd time */
+	unsigned long msg_rtime_high;
+	unsigned long msg_rtime;	/* last msgrcv time */
+	unsigned long msg_ctime_high;
+	unsigned long msg_ctime;	/* last change time */
+#endif
 	unsigned long  msg_cbytes;	/* current number of bytes on queue */
 	unsigned long  msg_qnum;	/* number of messages in queue */
 	unsigned long  msg_qbytes;	/* max number of bytes on queue */
@@ -35,5 +32,4 @@ struct msqid64_ds {
 	unsigned long  __unused1;
 	unsigned long  __unused2;
 };
-#undef PADDING
 #endif /* _SPARC_MSGBUF_H */
diff --git a/arch/sparc/include/uapi/asm/sembuf.h b/arch/sparc/include/uapi/asm/sembuf.h
index f49b0ffa0ab8..f3d309c2e1cd 100644
--- a/arch/sparc/include/uapi/asm/sembuf.h
+++ b/arch/sparc/include/uapi/asm/sembuf.h
@@ -8,25 +8,23 @@
  * between kernel and user space.
  *
  * Pad space is left for:
- * - 64-bit time_t to solve y2038 problem
  * - 2 miscellaneous 32-bit values
  */
-#if defined(__sparc__) && defined(__arch64__)
-# define PADDING(x)
-#else
-# define PADDING(x) unsigned int x;
-#endif
 
 struct semid64_ds {
 	struct ipc64_perm sem_perm;		/* permissions .. see ipc.h */
-	PADDING(__pad1)
+#if defined(__sparc__) && defined(__arch64__)
 	__kernel_time_t	sem_otime;		/* last semop time */
-	PADDING(__pad2)
 	__kernel_time_t	sem_ctime;		/* last change time */
+#else
+	unsigned long	sem_otime_high;
+	unsigned long	sem_otime;		/* last semop time */
+	unsigned long	sem_ctime_high;
+	unsigned long	sem_ctime;		/* last change time */
+#endif
 	unsigned long	sem_nsems;		/* no. of semaphores in array */
 	unsigned long	__unused1;
 	unsigned long	__unused2;
 };
-#undef PADDING
 
 #endif /* _SPARC64_SEMBUF_H */
diff --git a/arch/sparc/include/uapi/asm/shmbuf.h b/arch/sparc/include/uapi/asm/shmbuf.h
index 286631db705c..06618b84822d 100644
--- a/arch/sparc/include/uapi/asm/shmbuf.h
+++ b/arch/sparc/include/uapi/asm/shmbuf.h
@@ -8,24 +8,23 @@
  * between kernel and user space.
  *
  * Pad space is left for:
- * - 64-bit time_t to solve y2038 problem
  * - 2 miscellaneous 32-bit values
  */
 
-#if defined(__sparc__) && defined(__arch64__)
-# define PADDING(x)
-#else
-# define PADDING(x) unsigned int x;
-#endif
-
 struct shmid64_ds {
 	struct ipc64_perm	shm_perm;	/* operation perms */
-	PADDING(__pad1)
+#if defined(__sparc__) && defined(__arch64__)
 	__kernel_time_t		shm_atime;	/* last attach time */
-	PADDING(__pad2)
 	__kernel_time_t		shm_dtime;	/* last detach time */
-	PADDING(__pad3)
 	__kernel_time_t		shm_ctime;	/* last change time */
+#else
+	unsigned long		shm_atime_high;
+	unsigned long		shm_atime;	/* last attach time */
+	unsigned long		shm_dtime_high;
+	unsigned long		shm_dtime;	/* last detach time */
+	unsigned long		shm_ctime_high;
+	unsigned long		shm_ctime;	/* last change time */
+#endif
 	size_t			shm_segsz;	/* size of segment (bytes) */
 	__kernel_pid_t		shm_cpid;	/* pid of creator */
 	__kernel_pid_t		shm_lpid;	/* pid of last operator */
@@ -46,6 +45,4 @@ struct shminfo64 {
 	unsigned long	__unused4;
 };
 
-#undef PADDING
-
 #endif /* _SPARC_SHMBUF_H */
diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h
index 7cd314b71c51..fb97cf7c4137 100644
--- a/arch/x86/include/asm/compat.h
+++ b/arch/x86/include/asm/compat.h
@@ -134,10 +134,10 @@ struct compat_ipc64_perm {
 
 struct compat_semid64_ds {
 	struct compat_ipc64_perm sem_perm;
-	compat_time_t  sem_otime;
-	compat_ulong_t __unused1;
-	compat_time_t  sem_ctime;
-	compat_ulong_t __unused2;
+	compat_ulong_t sem_otime;
+	compat_ulong_t sem_otime_high;
+	compat_ulong_t sem_ctime;
+	compat_ulong_t sem_ctime_high;
 	compat_ulong_t sem_nsems;
 	compat_ulong_t __unused3;
 	compat_ulong_t __unused4;
@@ -145,12 +145,12 @@ struct compat_semid64_ds {
 
 struct compat_msqid64_ds {
 	struct compat_ipc64_perm msg_perm;
-	compat_time_t  msg_stime;
-	compat_ulong_t __unused1;
-	compat_time_t  msg_rtime;
-	compat_ulong_t __unused2;
-	compat_time_t  msg_ctime;
-	compat_ulong_t __unused3;
+	compat_ulong_t msg_stime;
+	compat_ulong_t msg_stime_high;
+	compat_ulong_t msg_rtime;
+	compat_ulong_t msg_rtime_high;
+	compat_ulong_t msg_ctime;
+	compat_ulong_t msg_ctime_high;
 	compat_ulong_t msg_cbytes;
 	compat_ulong_t msg_qnum;
 	compat_ulong_t msg_qbytes;
@@ -163,12 +163,12 @@ struct compat_msqid64_ds {
 struct compat_shmid64_ds {
 	struct compat_ipc64_perm shm_perm;
 	compat_size_t  shm_segsz;
-	compat_time_t  shm_atime;
-	compat_ulong_t __unused1;
-	compat_time_t  shm_dtime;
-	compat_ulong_t __unused2;
-	compat_time_t  shm_ctime;
-	compat_ulong_t __unused3;
+	compat_ulong_t shm_atime;
+	compat_ulong_t shm_atime_high;
+	compat_ulong_t shm_dtime;
+	compat_ulong_t shm_dtime_high;
+	compat_ulong_t shm_ctime;
+	compat_ulong_t shm_ctime_high;
 	compat_pid_t   shm_cpid;
 	compat_pid_t   shm_lpid;
 	compat_ulong_t shm_nattch;
diff --git a/arch/x86/include/uapi/asm/sembuf.h b/arch/x86/include/uapi/asm/sembuf.h
index cabd7476bd6c..89de6cd9f0a7 100644
--- a/arch/x86/include/uapi/asm/sembuf.h
+++ b/arch/x86/include/uapi/asm/sembuf.h
@@ -8,15 +8,24 @@
  * between kernel and user space.
  *
  * Pad space is left for:
- * - 64-bit time_t to solve y2038 problem
  * - 2 miscellaneous 32-bit values
+ *
+ * x86_64 and x32 incorrectly added padding here, so the structures
+ * are still incompatible with the padding on x86.
  */
 struct semid64_ds {
 	struct ipc64_perm sem_perm;	/* permissions .. see ipc.h */
+#ifdef __i386__
+	unsigned long	sem_otime;	/* last semop time */
+	unsigned long	sem_otime_high;
+	unsigned long	sem_ctime;	/* last change time */
+	unsigned long	sem_ctime_high;
+#else
 	__kernel_time_t	sem_otime;	/* last semop time */
 	__kernel_ulong_t __unused1;
 	__kernel_time_t	sem_ctime;	/* last change time */
 	__kernel_ulong_t __unused2;
+#endif
 	__kernel_ulong_t sem_nsems;	/* no. of semaphores in array */
 	__kernel_ulong_t __unused3;
 	__kernel_ulong_t __unused4;
diff --git a/arch/xtensa/include/uapi/asm/msgbuf.h b/arch/xtensa/include/uapi/asm/msgbuf.h
index 36e2e103ca38..d6915e9f071c 100644
--- a/arch/xtensa/include/uapi/asm/msgbuf.h
+++ b/arch/xtensa/include/uapi/asm/msgbuf.h
@@ -7,7 +7,6 @@
  * between kernel and user space.
  *
  * Pad space is left for:
- * - 64-bit time_t to solve y2038 problem
  * - 2 miscellaneous 32-bit values
  *
  * This file is subject to the terms and conditions of the GNU General
@@ -21,19 +20,19 @@
 struct msqid64_ds {
 	struct ipc64_perm msg_perm;
 #ifdef __XTENSA_EB__
-	unsigned int	__unused1;
-	__kernel_time_t msg_stime;	/* last msgsnd time */
-	unsigned int	__unused2;
-	__kernel_time_t msg_rtime;	/* last msgrcv time */
-	unsigned int	__unused3;
-	__kernel_time_t msg_ctime;	/* last change time */
+	unsigned long  msg_stime_high;
+	unsigned long  msg_stime;	/* last msgsnd time */
+	unsigned long  msg_rtime_high;
+	unsigned long  msg_rtime;	/* last msgrcv time */
+	unsigned long  msg_ctime_high;
+	unsigned long  msg_ctime;	/* last change time */
 #elif defined(__XTENSA_EL__)
-	__kernel_time_t msg_stime;	/* last msgsnd time */
-	unsigned int	__unused1;
-	__kernel_time_t msg_rtime;	/* last msgrcv time */
-	unsigned int	__unused2;
-	__kernel_time_t msg_ctime;	/* last change time */
-	unsigned int	__unused3;
+	unsigned long  msg_stime;	/* last msgsnd time */
+	unsigned long  msg_stime_high;
+	unsigned long  msg_rtime;	/* last msgrcv time */
+	unsigned long  msg_rtime_high;
+	unsigned long  msg_ctime;	/* last change time */
+	unsigned long  msg_ctime_high;
 #else
 # error processor byte order undefined!
 #endif
diff --git a/arch/xtensa/include/uapi/asm/sembuf.h b/arch/xtensa/include/uapi/asm/sembuf.h
index f61b6331a10c..09f348d643f1 100644
--- a/arch/xtensa/include/uapi/asm/sembuf.h
+++ b/arch/xtensa/include/uapi/asm/sembuf.h
@@ -14,7 +14,6 @@
  * between kernel and user space.
  *
  * Pad space is left for:
- * - 64-bit time_t to solve y2038 problem
  * - 2 miscellaneous 32-bit values
  *
  */
@@ -27,15 +26,15 @@
 struct semid64_ds {
 	struct ipc64_perm sem_perm;		/* permissions .. see ipc.h */
 #ifdef __XTENSA_EL__
-	__kernel_time_t	sem_otime;		/* last semop time */
-	unsigned long	__unused1;
-	__kernel_time_t	sem_ctime;		/* last change time */
-	unsigned long	__unused2;
+	unsigned long	sem_otime;		/* last semop time */
+	unsigned long	sem_otime_high;
+	unsigned long	sem_ctime;		/* last change time */
+	unsigned long	sem_ctime_high;
 #else
-	unsigned long	__unused1;
-	__kernel_time_t	sem_otime;		/* last semop time */
-	unsigned long	__unused2;
-	__kernel_time_t	sem_ctime;		/* last change time */
+	unsigned long	sem_otime_high;
+	unsigned long	sem_otime;		/* last semop time */
+	unsigned long	sem_ctime_high;
+	unsigned long	sem_ctime;		/* last change time */
 #endif
 	unsigned long	sem_nsems;		/* no. of semaphores in array */
 	unsigned long	__unused3;
diff --git a/arch/xtensa/include/uapi/asm/shmbuf.h b/arch/xtensa/include/uapi/asm/shmbuf.h
index 26550bdc8430..554a57a6a90f 100644
--- a/arch/xtensa/include/uapi/asm/shmbuf.h
+++ b/arch/xtensa/include/uapi/asm/shmbuf.h
@@ -4,10 +4,10 @@
  *
  * The shmid64_ds structure for Xtensa architecture.
  * Note extra padding because this structure is passed back and forth
- * between kernel and user space.
+ * between kernel and user space, but the padding is on the wrong
+ * side for big-endian xtensa, for historic reasons.
  *
  * Pad space is left for:
- * - 64-bit time_t to solve y2038 problem
  * - 2 miscellaneous 32-bit values
  *
  * This file is subject to the terms and conditions of the GNU General Public
@@ -20,42 +20,21 @@
 #ifndef _XTENSA_SHMBUF_H
 #define _XTENSA_SHMBUF_H
 
-#if defined (__XTENSA_EL__)
 struct shmid64_ds {
 	struct ipc64_perm	shm_perm;	/* operation perms */
 	size_t			shm_segsz;	/* size of segment (bytes) */
-	__kernel_time_t		shm_atime;	/* last attach time */
-	unsigned long		__unused1;
-	__kernel_time_t		shm_dtime;	/* last detach time */
-	unsigned long		__unused2;
-	__kernel_time_t		shm_ctime;	/* last change time */
-	unsigned long		__unused3;
+	unsigned long		shm_atime;	/* last attach time */
+	unsigned long		shm_atime_high;
+	unsigned long		shm_dtime;	/* last detach time */
+	unsigned long		shm_dtime_high;
+	unsigned long		shm_ctime;	/* last change time */
+	unsigned long		shm_ctime_high;
 	__kernel_pid_t		shm_cpid;	/* pid of creator */
 	__kernel_pid_t		shm_lpid;	/* pid of last operator */
 	unsigned long		shm_nattch;	/* no. of current attaches */
 	unsigned long		__unused4;
 	unsigned long		__unused5;
 };
-#elif defined (__XTENSA_EB__)
-struct shmid64_ds {
-	struct ipc64_perm	shm_perm;	/* operation perms */
-	size_t			shm_segsz;	/* size of segment (bytes) */
-	__kernel_time_t		shm_atime;	/* last attach time */
-	unsigned long		__unused1;
-	__kernel_time_t		shm_dtime;	/* last detach time */
-	unsigned long		__unused2;
-	__kernel_time_t		shm_ctime;	/* last change time */
-	unsigned long		__unused3;
-	__kernel_pid_t		shm_cpid;	/* pid of creator */
-	__kernel_pid_t		shm_lpid;	/* pid of last operator */
-	unsigned long		shm_nattch;	/* no. of current attaches */
-	unsigned long		__unused4;
-	unsigned long		__unused5;
-};
-#else
-# error endian order not defined
-#endif
-
 
 struct shminfo64 {
 	unsigned long	shmmax;