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Linux/Alpha specific semctl implementation.

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This commit is contained in:
Ulrich Drepper 2000-02-11 21:00:16 +00:00
parent 9e683793e4
commit 3b6c96e67b
1 changed files with 132 additions and 0 deletions
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sysdeps/unix/sysv/linux/alpha/semctl.c Normal file
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/* Copyright (C) 1995, 1997, 1998, 2000 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, August 1995.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <errno.h>
#include <stdarg.h>
#include <sys/sem.h>
#include <ipc_priv.h>
#include <sysdep.h>
#include <string.h>
#include <sys/syscall.h>
#include "kernel-features.h"
struct __old_semid_ds
{
struct __old_ipc_perm sem_perm; /* operation permission struct */
__time_t sem_otime; /* last semop() time */
__time_t sem_ctime; /* last time changed by semctl() */
struct sem *__sembase; /* ptr to first semaphore in array */
struct sem_queue *__sem_pending; /* pending operations */
struct sem_queue *__sem_pending_last; /* last pending operation */
struct sem_undo *__undo; /* ondo requests on this array */
unsigned short int sem_nsems; /* number of semaphores in set */
};
/* Define a `union semun' suitable for Linux here. */
union semun
{
int val; /* value for SETVAL */
struct semid_ds *buf; /* buffer for IPC_STAT & IPC_SET */
unsigned short int *array; /* array for GETALL & SETALL */
struct seminfo *__buf; /* buffer for IPC_INFO */
};
/* Return identifier for array of NSEMS semaphores associated with
KEY. */
int __new_semctl (int semid, int semnum, int cmd, ...);
int
__new_semctl (int semid, int semnum, int cmd, ...)
{
union semun arg;
va_list ap;
va_start (ap, cmd);
/* Get the argument. */
arg = va_arg (ap, union semun);
va_end (ap);
#if __ASSUME_32BITUIDS > 0
return INLINE_SYSCALL (semctl, 4, semid, semnum, cmd | __IPC_64, &arg);
#else
switch (cmd) {
case SEM_STAT:
case IPC_STAT:
case IPC_SET:
break;
default:
return INLINE_SYSCALL (semctl, 4, semid, semnum, cmd, &arg);
}
{
int save_errno = errno, result;
struct __old_semid_ds old;
struct semid_ds *buf;
/* Unfortunately there is no way how to find out for sure whether
we should use old or new semctl. */
result = INLINE_SYSCALL (semctl, 4, semid, semnum, cmd | __IPC_64, &arg);
if (result != -1 || errno != EINVAL)
return result;
__set_errno(save_errno);
buf = arg.buf;
arg.buf = (struct semid_ds *)&old;
if (cmd == IPC_SET)
{
old.sem_perm.uid = buf->sem_perm.uid;
old.sem_perm.gid = buf->sem_perm.gid;
old.sem_perm.mode = buf->sem_perm.mode;
if (old.sem_perm.uid != buf->sem_perm.uid ||
old.sem_perm.gid != buf->sem_perm.gid)
{
__set_errno (EINVAL);
return -1;
}
}
result = INLINE_SYSCALL (semctl, 4, semid, semnum, cmd, &arg);
if (result != -1 && cmd != IPC_SET)
{
memset(buf, 0, sizeof(*buf));
buf->sem_perm.__key = old.sem_perm.__key;
buf->sem_perm.uid = old.sem_perm.uid;
buf->sem_perm.gid = old.sem_perm.gid;
buf->sem_perm.cuid = old.sem_perm.cuid;
buf->sem_perm.cgid = old.sem_perm.cgid;
buf->sem_perm.mode = old.sem_perm.mode;
buf->sem_perm.__seq = old.sem_perm.__seq;
buf->sem_otime = old.sem_otime;
buf->sem_ctime = old.sem_ctime;
buf->sem_nsems = old.sem_nsems;
}
return result;
}
#endif
}
#if defined PIC && DO_VERSIONING
default_symbol_version (__new_semctl, semctl, GLIBC_2.2);
#else
weak_alias (__new_semctl, semctl);
#endif