alistair23-linux/ipc/syscall.c
Will Deacon 079a96ae38 ipc: add COMPAT_SHMLBA support
If the SHMLBA definition for a native task differs from the definition for
a compat task, the do_shmat() function would need to handle both.

This patch introduces COMPAT_SHMLBA, which is used by the compat shmat
syscall when calling the ipc code and allows architectures such as AArch64
(where the native SHMLBA is 64k but the compat (AArch32) definition is
16k) to provide the correct semantics for compat IPC system calls.

Cc: David S. Miller <davem@davemloft.net>
Cc: Chris Zankel <chris@zankel.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30 17:25:20 -07:00

100 lines
2.3 KiB
C

/*
* 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>
#ifdef __ARCH_WANT_SYS_IPC
#include <linux/errno.h>
#include <linux/ipc.h>
#include <linux/shm.h>
#include <linux/syscalls.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 sys_semtimedop(first, (struct sembuf __user *)ptr,
second, NULL);
case SEMTIMEDOP:
return sys_semtimedop(first, (struct sembuf __user *)ptr,
second,
(const struct timespec __user *)fifth);
case SEMGET:
return sys_semget(first, second, third);
case SEMCTL: {
union semun fourth;
if (!ptr)
return -EINVAL;
if (get_user(fourth.__pad, (void __user * __user *) ptr))
return -EFAULT;
return sys_semctl(first, second, third, fourth);
}
case MSGSND:
return sys_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 sys_msgrcv(first, tmp.msgp, second,
tmp.msgtyp, third);
}
default:
return sys_msgrcv(first,
(struct msgbuf __user *) ptr,
second, fifth, third);
}
case MSGGET:
return sys_msgget((key_t) first, second);
case MSGCTL:
return sys_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 sys_shmdt((char __user *)ptr);
case SHMGET:
return sys_shmget(first, second, third);
case SHMCTL:
return sys_shmctl(first, second,
(struct shmid_ds __user *) ptr);
default:
return -ENOSYS;
}
}
#endif