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y2038: mips: Extend sysvipc data structures

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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>
This commit is contained in:
Arnd Bergmann
2015-05-05 22:53:12 +02:00
parent 83335eb4f6
commit 3f3a4b3fbf
4 changed files with 94 additions and 41 deletions
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40
arch/mips/include/asm/compat.h
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@@ -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 */