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[3/9] y2038: mips: extend sysvipc data structures

Message ID 1432134445-804487-4-git-send-email-arnd@arndb.de
State Not Applicable
Headers show

Commit Message

Arnd Bergmann May 20, 2015, 3:07 p.m. UTC
MIPS is the weirdest case for sysvipc, because each of the
three data structures is done differently:

* msqid64_ds has padding in the right place so we could in theory
  extend this one to just have 64-bit values instead of time_t.
  As this does not work for most of the other combinations,
  we just handle it in the common manner though.

* semid64_ds has no padding for 64-bit time_t, but has two reserved
  'long' fields, which are sufficient to extend the sem_otime
  and sem_ctime fields to 64 bit. In order to do this, the libc
  implementation will have to copy the data into another structure
  that has the fields in a different order. MIPS is the only
  architecture with this problem, so this is best done in MIPS
  specific libc code.

* shmid64_ds is slightly worse than that, because it has three
  time_t fields but only two unused 32-bit words. As a workaround,
  we extend each field only by 16 bits, ending up with 48-bit
  timestamps that user space again has to work around by itself.

The compat versions of the data structures are changed in the
same way.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/mips/include/asm/compat.h      | 38 +++++++++++++------------
 arch/mips/include/uapi/asm/msgbuf.h | 56 +++++++++++++++++++++++++------------
 arch/mips/include/uapi/asm/sembuf.h | 15 ++++++++--
 arch/mips/include/uapi/asm/shmbuf.h | 23 +++++++++++++--
 4 files changed, 92 insertions(+), 40 deletions(-)
diff mbox

Patch

diff --git a/arch/mips/include/asm/compat.h b/arch/mips/include/asm/compat.h
index 6495b37a6fbc..97e014aa2bf3 100644
--- a/arch/mips/include/asm/compat.h
+++ b/arch/mips/include/asm/compat.h
@@ -225,35 +225,35 @@  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;
@@ -267,14 +267,16 @@  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 df849e87d9ae..460c3117912c 100644
--- a/arch/mips/include/uapi/asm/msgbuf.h
+++ b/arch/mips/include/uapi/asm/msgbuf.h
@@ -12,29 +12,12 @@ 
  * - 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 */
@@ -43,5 +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 e1085ac880f2..055fddb4fdb0 100644
--- a/arch/mips/include/uapi/asm/sembuf.h
+++ b/arch/mips/include/uapi/asm/sembuf.h
@@ -6,10 +6,11 @@ 
  * 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 */
@@ -18,5 +19,15 @@  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_otime_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 f994438277bf..3a1399f7dfdc 100644
--- a/arch/mips/include/uapi/asm/shmbuf.h
+++ b/arch/mips/include/uapi/asm/shmbuf.h
@@ -6,10 +6,13 @@ 
  * 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) */
@@ -22,6 +25,22 @@  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;