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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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57
arch/mips/include/uapi/asm/msgbuf.h
View File

@@ -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 */