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[PATCH v4 07/16] y2038: mips: Extend sysvipc data structures
- From: Arnd Bergmann <arnd at arndb dot de>
- To: y2038 at lists dot linaro dot org, linux-kernel at vger dot kernel dot org
- Cc: linux-api at vger dot kernel dot org, linux-arch at vger dot kernel dot org, libc-alpha at sourceware dot org, tglx at linutronix dot de, deepa dot kernel at gmail dot com, viro at zeniv dot linux dot org dot uk, ebiederm at xmission dot com, albert dot aribaud at 3adev dot fr, linux-s390 at vger dot kernel dot org, schwidefsky at de dot ibm dot com, x86 at kernel dot org, catalin dot marinas at arm dot com, will dot deacon at arm dot com, linux-mips at linux-mips dot org, jhogan at kernel dot org, ralf at linux-mips dot org, linuxppc-dev at lists dot ozlabs dot org, sparclinux at vger dot kernel dot org, zackw at panix dot com, noloader at gmail dot com, Arnd Bergmann <arnd at arndb dot de>
- Date: Wed, 25 Apr 2018 17:05:57 +0200
- Subject: [PATCH v4 07/16] y2038: mips: Extend sysvipc data structures
- References: <20180425132242.1500539-1-arnd@arndb.de>
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 | 40 ++++++++++++++------------
arch/mips/include/uapi/asm/msgbuf.h | 57 ++++++++++++++++++++++++-------------
arch/mips/include/uapi/asm/sembuf.h | 15 ++++++++--
arch/mips/include/uapi/asm/shmbuf.h | 23 +++++++++++++--
4 files changed, 94 insertions(+), 41 deletions(-)
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;
--
2.9.0