mirror of
https://github.com/torvalds/linux.git
synced 2024-12-22 02:52:56 +00:00
3f3a4b3fbf
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>
59 lines
1.9 KiB
C
59 lines
1.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
|
|
#ifndef _ASM_SHMBUF_H
|
|
#define _ASM_SHMBUF_H
|
|
|
|
/*
|
|
* The shmid64_ds structure for the MIPS architecture.
|
|
* Note extra padding because this structure is passed back and forth
|
|
* between kernel and user space.
|
|
*
|
|
* 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) */
|
|
__kernel_time_t shm_atime; /* last attach time */
|
|
__kernel_time_t shm_dtime; /* last detach time */
|
|
__kernel_time_t 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 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;
|
|
unsigned long shmmin;
|
|
unsigned long shmmni;
|
|
unsigned long shmseg;
|
|
unsigned long shmall;
|
|
unsigned long __unused1;
|
|
unsigned long __unused2;
|
|
unsigned long __unused3;
|
|
unsigned long __unused4;
|
|
};
|
|
|
|
#endif /* _ASM_SHMBUF_H */
|