linux/ipc/syscall.c
Arnd Bergmann 5dc0b1529d y2038: ipc: Redirect ipc(SEMTIMEDOP, ...) to compat_ksys_semtimedop
32-bit architectures implementing 64BIT_TIME and COMPAT_32BIT_TIME
need to have the traditional semtimedop() behavior with 32-bit timestamps
for sys_ipc() by calling compat_ksys_semtimedop(), while those that
are not yet converted need to keep using ksys_semtimedop() like
64-bit architectures do.

Note that I chose to not implement a new SEMTIMEDOP64 function that
corresponds to the new sys_semtimedop() with 64-bit timeouts. The reason
here is that sys_ipc() should no longer be used for new system calls,
and libc should just call the semtimedop syscall directly.

One open question remain to whether we want to completely avoid the
sys_ipc() system call for architectures that do not yet have all the
individual calls as they get converted to 64-bit time_t. Doing that
would require adding several extra system calls on m68k, mips, powerpc,
s390, sh, sparc, and x86-32.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-04-20 16:20:30 +02:00

200 lines
4.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* sys_ipc() is the old de-multiplexer for the SysV IPC calls.
*
* This is really horribly ugly, and new architectures should just wire up
* the individual syscalls instead.
*/
#include <linux/unistd.h>
#include <linux/syscalls.h>
#include <linux/security.h>
#include <linux/ipc_namespace.h>
#include "util.h"
#ifdef __ARCH_WANT_SYS_IPC
#include <linux/errno.h>
#include <linux/ipc.h>
#include <linux/shm.h>
#include <linux/uaccess.h>
SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second,
unsigned long, third, void __user *, ptr, long, fifth)
{
int version, ret;
version = call >> 16; /* hack for backward compatibility */
call &= 0xffff;
switch (call) {
case SEMOP:
return ksys_semtimedop(first, (struct sembuf __user *)ptr,
second, NULL);
case SEMTIMEDOP:
if (IS_ENABLED(CONFIG_64BIT) || !IS_ENABLED(CONFIG_64BIT_TIME))
return ksys_semtimedop(first, ptr, second,
(const struct __kernel_timespec __user *)fifth);
else if (IS_ENABLED(CONFIG_COMPAT_32BIT_TIME))
return compat_ksys_semtimedop(first, ptr, second,
(const struct compat_timespec __user *)fifth);
else
return -ENOSYS;
case SEMGET:
return ksys_semget(first, second, third);
case SEMCTL: {
unsigned long arg;
if (!ptr)
return -EINVAL;
if (get_user(arg, (unsigned long __user *) ptr))
return -EFAULT;
return ksys_semctl(first, second, third, arg);
}
case MSGSND:
return ksys_msgsnd(first, (struct msgbuf __user *) ptr,
second, third);
case MSGRCV:
switch (version) {
case 0: {
struct ipc_kludge tmp;
if (!ptr)
return -EINVAL;
if (copy_from_user(&tmp,
(struct ipc_kludge __user *) ptr,
sizeof(tmp)))
return -EFAULT;
return ksys_msgrcv(first, tmp.msgp, second,
tmp.msgtyp, third);
}
default:
return ksys_msgrcv(first,
(struct msgbuf __user *) ptr,
second, fifth, third);
}
case MSGGET:
return ksys_msgget((key_t) first, second);
case MSGCTL:
return ksys_msgctl(first, second,
(struct msqid_ds __user *)ptr);
case SHMAT:
switch (version) {
default: {
unsigned long raddr;
ret = do_shmat(first, (char __user *)ptr,
second, &raddr, SHMLBA);
if (ret)
return ret;
return put_user(raddr, (unsigned long __user *) third);
}
case 1:
/*
* This was the entry point for kernel-originating calls
* from iBCS2 in 2.2 days.
*/
return -EINVAL;
}
case SHMDT:
return ksys_shmdt((char __user *)ptr);
case SHMGET:
return ksys_shmget(first, second, third);
case SHMCTL:
return ksys_shmctl(first, second,
(struct shmid_ds __user *) ptr);
default:
return -ENOSYS;
}
}
#endif
#ifdef CONFIG_COMPAT
#include <linux/compat.h>
#ifndef COMPAT_SHMLBA
#define COMPAT_SHMLBA SHMLBA
#endif
struct compat_ipc_kludge {
compat_uptr_t msgp;
compat_long_t msgtyp;
};
#ifdef CONFIG_ARCH_WANT_OLD_COMPAT_IPC
COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
u32, third, compat_uptr_t, ptr, u32, fifth)
{
int version;
u32 pad;
version = call >> 16; /* hack for backward compatibility */
call &= 0xffff;
switch (call) {
case SEMOP:
/* struct sembuf is the same on 32 and 64bit :)) */
return ksys_semtimedop(first, compat_ptr(ptr), second, NULL);
case SEMTIMEDOP:
if (!IS_ENABLED(CONFIG_COMPAT_32BIT_TIME))
return -ENOSYS;
return compat_ksys_semtimedop(first, compat_ptr(ptr), second,
compat_ptr(fifth));
case SEMGET:
return ksys_semget(first, second, third);
case SEMCTL:
if (!ptr)
return -EINVAL;
if (get_user(pad, (u32 __user *) compat_ptr(ptr)))
return -EFAULT;
return compat_ksys_semctl(first, second, third, pad);
case MSGSND:
return compat_ksys_msgsnd(first, ptr, second, third);
case MSGRCV: {
void __user *uptr = compat_ptr(ptr);
if (first < 0 || second < 0)
return -EINVAL;
if (!version) {
struct compat_ipc_kludge ipck;
if (!uptr)
return -EINVAL;
if (copy_from_user(&ipck, uptr, sizeof(ipck)))
return -EFAULT;
return compat_ksys_msgrcv(first, ipck.msgp, second,
ipck.msgtyp, third);
}
return compat_ksys_msgrcv(first, ptr, second, fifth, third);
}
case MSGGET:
return ksys_msgget(first, second);
case MSGCTL:
return compat_ksys_msgctl(first, second, compat_ptr(ptr));
case SHMAT: {
int err;
unsigned long raddr;
if (version == 1)
return -EINVAL;
err = do_shmat(first, compat_ptr(ptr), second, &raddr,
COMPAT_SHMLBA);
if (err < 0)
return err;
return put_user(raddr, (compat_ulong_t __user *)compat_ptr(third));
}
case SHMDT:
return ksys_shmdt(compat_ptr(ptr));
case SHMGET:
return ksys_shmget(first, (unsigned int)second, third);
case SHMCTL:
return compat_ksys_shmctl(first, second, compat_ptr(ptr));
}
return -ENOSYS;
}
#endif
#endif