glibc/sysdeps/unix/sysv/linux/shmctl.c

126 lines
3.8 KiB
C

/* Copyright (C) 1995-2020 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 Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <sys/shm.h>
#include <stdarg.h>
#include <ipc_priv.h>
#include <sysdep.h>
#include <shlib-compat.h>
#include <errno.h>
#ifndef DEFAULT_VERSION
# ifndef __ASSUME_SYSVIPC_BROKEN_MODE_T
# define DEFAULT_VERSION GLIBC_2_2
# else
# define DEFAULT_VERSION GLIBC_2_31
# endif
#endif
static int
shmctl_syscall (int shmid, int cmd, struct shmid_ds *buf)
{
#ifdef __ASSUME_DIRECT_SYSVIPC_SYSCALLS
return INLINE_SYSCALL_CALL (shmctl, shmid, cmd | __IPC_64, buf);
#else
return INLINE_SYSCALL_CALL (ipc, IPCOP_shmctl, shmid, cmd | __IPC_64, 0,
buf);
#endif
}
/* Provide operations to control over shared memory segments. */
int
__new_shmctl (int shmid, int cmd, struct shmid_ds *buf)
{
/* POSIX states ipc_perm mode should have type of mode_t. */
_Static_assert (sizeof ((struct shmid_ds){0}.shm_perm.mode)
== sizeof (mode_t),
"sizeof (msqid_ds.msg_perm.mode) != sizeof (mode_t)");
#ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T
struct shmid_ds tmpds;
if (cmd == IPC_SET)
{
tmpds = *buf;
tmpds.shm_perm.mode *= 0x10000U;
buf = &tmpds;
}
#endif
int ret = shmctl_syscall (shmid, cmd, buf);
#ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T
if (ret >= 0)
{
switch (cmd)
{
case IPC_STAT:
case SHM_STAT:
case SHM_STAT_ANY:
buf->shm_perm.mode >>= 16;
}
}
#endif
return ret;
}
versioned_symbol (libc, __new_shmctl, shmctl, DEFAULT_VERSION);
#if defined __ASSUME_SYSVIPC_BROKEN_MODE_T \
&& SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_31)
int
attribute_compat_text_section
__shmctl_mode16 (int shmid, int cmd, struct shmid_ds *buf)
{
return shmctl_syscall (shmid, cmd, buf);
}
compat_symbol (libc, __shmctl_mode16, shmctl, GLIBC_2_2);
#endif
#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
struct __old_shmid_ds
{
struct __old_ipc_perm shm_perm; /* operation permission struct */
int shm_segsz; /* size of segment in bytes */
__time_t shm_atime; /* time of last shmat() */
__time_t shm_dtime; /* time of last shmdt() */
__time_t shm_ctime; /* time of last change by shmctl() */
__ipc_pid_t shm_cpid; /* pid of creator */
__ipc_pid_t shm_lpid; /* pid of last shmop */
unsigned short int shm_nattch; /* number of current attaches */
unsigned short int __shm_npages; /* size of segment (pages) */
unsigned long int *__shm_pages; /* array of ptrs to frames -> SHMMAX */
struct vm_area_struct *__attaches; /* descriptors for attaches */
};
int
attribute_compat_text_section
__old_shmctl (int shmid, int cmd, struct __old_shmid_ds *buf)
{
#if defined __ASSUME_DIRECT_SYSVIPC_SYSCALLS \
&& !defined __ASSUME_SYSVIPC_DEFAULT_IPC_64
/* For architecture that have wire-up shmctl but also have __IPC_64 to a
value different than default (0x0), it means the compat symbol used the
__NR_ipc syscall. */
return INLINE_SYSCALL_CALL (shmctl, shmid, cmd, buf);
#else
return INLINE_SYSCALL_CALL (ipc, IPCOP_shmctl, shmid, cmd, 0, buf);
#endif
}
compat_symbol (libc, __old_shmctl, shmctl, GLIBC_2_0);
#endif