compat.c

/*
 * 32 bit compatibility code for System V IPC
 *
 * Copyright (C) 1997,1998	Jakub Jelinek (jj@sunsite.mff.cuni.cz)
 * Copyright (C) 1997		David S. Miller (davem@caip.rutgers.edu)
 * Copyright (C) 1999		Arun Sharma <arun.sharma@intel.com>
 * Copyright (C) 2000		VA Linux Co
 * Copyright (C) 2000		Don Dugger <n0ano@valinux.com>
 * Copyright (C) 2000           Hewlett-Packard Co.
 * Copyright (C) 2000           David Mosberger-Tang <davidm@hpl.hp.com>
 * Copyright (C) 2000           Gerhard Tonn (ton@de.ibm.com)
 * Copyright (C) 2000-2002      Andi Kleen, SuSE Labs (x86-64 port)
 * Copyright (C) 2000		Silicon Graphics, Inc.
 * Copyright (C) 2001		IBM
 * Copyright (C) 2004		IBM Deutschland Entwicklung GmbH, IBM Corporation
 * Copyright (C) 2004		Arnd Bergmann (arnd@arndb.de)
 *
 * This code is collected from the versions for sparc64, mips64, s390x, ia64,
 * ppc64 and x86_64, all of which are based on the original sparc64 version
 * by Jakub Jelinek.
 *
 */
#include <linux/compat.h>
#include <linux/errno.h>
#include <linux/highuid.h>
#include <linux/init.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/syscalls.h>
#include <linux/ptrace.h>

#include <linux/mutex.h>
#include <linux/uaccess.h>

#include "util.h"

struct compat_msgbuf {
	compat_long_t mtype;
	char mtext[1];
};

struct compat_ipc_kludge {
	compat_uptr_t msgp;
	compat_long_t msgtyp;
};

int get_compat_ipc64_perm(struct ipc64_perm *to,
			  struct compat_ipc64_perm __user *from)
{
	struct compat_ipc64_perm v;
	if (copy_from_user(&v, from, sizeof(v)))
		return -EFAULT;
	to->uid = v.uid;
	to->gid = v.gid;
	to->mode = v.mode;
	return 0;
}

int get_compat_ipc_perm(struct ipc64_perm *to,
			struct compat_ipc_perm __user *from)
{
	struct compat_ipc_perm v;
	if (copy_from_user(&v, from, sizeof(v)))
		return -EFAULT;
	to->uid = v.uid;
	to->gid = v.gid;
	to->mode = v.mode;
	return 0;
}

void to_compat_ipc64_perm(struct compat_ipc64_perm *to, struct ipc64_perm *from)
{
	to->key = from->key;
	to->uid = from->uid;
	to->gid = from->gid;
	to->cuid = from->cuid;
	to->cgid = from->cgid;
	to->mode = from->mode;
	to->seq = from->seq;
}

void to_compat_ipc_perm(struct compat_ipc_perm *to, struct ipc64_perm *from)
{
	to->key = from->key;
	SET_UID(to->uid, from->uid);
	SET_GID(to->gid, from->gid);
	SET_UID(to->cuid, from->cuid);
	SET_GID(to->cgid, from->cgid);
	to->mode = from->mode;
	to->seq = from->seq;
}

static long compat_do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)
{
	struct compat_msgbuf __user *msgp = dest;
	size_t msgsz;

	if (put_user(msg->m_type, &msgp->mtype))
		return -EFAULT;

	msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz;
	if (store_msg(msgp->mtext, msg, msgsz))
		return -EFAULT;
	return msgsz;
}

#ifndef COMPAT_SHMLBA
#define COMPAT_SHMLBA	SHMLBA
#endif

#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 sys_semtimedop(first, compat_ptr(ptr), second, NULL);
	case SEMTIMEDOP:
		return compat_sys_semtimedop(first, compat_ptr(ptr), second,
						compat_ptr(fifth));
	case SEMGET:
		return sys_semget(first, second, third);
	case SEMCTL:
		if (!ptr)
			return -EINVAL;
		if (get_user(pad, (u32 __user *) compat_ptr(ptr)))
			return -EFAULT;
		return compat_sys_semctl(first, second, third, pad);

	case MSGSND: {
		struct compat_msgbuf __user *up = compat_ptr(ptr);
		compat_long_t type;

		if (first < 0 || second < 0)
			return -EINVAL;

		if (get_user(type, &up->mtype))
			return -EFAULT;

		return do_msgsnd(first, type, up->mtext, 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;
			uptr = compat_ptr(ipck.msgp);
			fifth = ipck.msgtyp;
		}
		return do_msgrcv(first, uptr, second, (s32)fifth, third,
				 compat_do_msg_fill);
	}
	case MSGGET:
		return sys_msgget(first, second);
	case MSGCTL:
		return compat_sys_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 *)compat_ptr(third));
	}
	case SHMDT:
		return sys_shmdt(compat_ptr(ptr));
	case SHMGET:
		return sys_shmget(first, (unsigned)second, third);
	case SHMCTL:
		return compat_sys_shmctl(first, second, compat_ptr(ptr));
	}

	return -ENOSYS;
}
#endif

COMPAT_SYSCALL_DEFINE4(msgsnd, int, msqid, compat_uptr_t, msgp,
		       compat_ssize_t, msgsz, int, msgflg)
{
	struct compat_msgbuf __user *up = compat_ptr(msgp);
	compat_long_t mtype;

	if (get_user(mtype, &up->mtype))
		return -EFAULT;
	return do_msgsnd(msqid, mtype, up->mtext, (ssize_t)msgsz, msgflg);
}

COMPAT_SYSCALL_DEFINE5(msgrcv, int, msqid, compat_uptr_t, msgp,
		       compat_ssize_t, msgsz, compat_long_t, msgtyp, int, msgflg)
{
	return do_msgrcv(msqid, compat_ptr(msgp), (ssize_t)msgsz, (long)msgtyp,
			 msgflg, compat_do_msg_fill);
}

COMPAT_SYSCALL_DEFINE3(shmat, int, shmid, compat_uptr_t, shmaddr, int, shmflg)
{
	unsigned long ret;
	long err;

	err = do_shmat(shmid, compat_ptr(shmaddr), shmflg, &ret, COMPAT_SHMLBA);
	if (err)
		return err;
	force_successful_syscall_return();
	return (long)ret;
}

COMPAT_SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsems,
		       unsigned, nsops,
		       const struct compat_timespec __user *, timeout)
{
	struct timespec __user *ts64;
	if (compat_convert_timespec(&ts64, timeout))
		return -EFAULT;
	return sys_semtimedop(semid, tsems, nsops, ts64);
}