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."

4 files changed, 48 insertions, 52 deletions

diff --git a/arch/parisc/include/asm/compat.h b/arch/parisc/include/asm/compat.h
index 0cdfec8..ab8a547 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 b48b810..6a2e9ab 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 746c5d8..3c31163 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 cd4dbce..c89b3dd 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) */