linux/ipc/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 <asm/uaccess.h>

#include "util.h"

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

struct compat_ipc_perm {
	key_t key;
	__compat_uid_t uid;
	__compat_gid_t gid;
	__compat_uid_t cuid;
	__compat_gid_t cgid;
	compat_mode_t mode;
	unsigned short seq;
};

struct compat_semid_ds {
	struct compat_ipc_perm sem_perm;
	compat_time_t sem_otime;
	compat_time_t sem_ctime;
	compat_uptr_t sem_base;
	compat_uptr_t sem_pending;
	compat_uptr_t sem_pending_last;
	compat_uptr_t undo;
	unsigned short sem_nsems;
};

struct compat_msqid_ds {
	struct compat_ipc_perm msg_perm;
	compat_uptr_t msg_first;
	compat_uptr_t msg_last;
	compat_time_t msg_stime;
	compat_time_t msg_rtime;
	compat_time_t msg_ctime;
	compat_ulong_t msg_lcbytes;
	compat_ulong_t msg_lqbytes;
	unsigned short msg_cbytes;
	unsigned short msg_qnum;
	unsigned short msg_qbytes;
	compat_ipc_pid_t msg_lspid;
	compat_ipc_pid_t msg_lrpid;
};

struct compat_shmid_ds {
	struct compat_ipc_perm shm_perm;
	int shm_segsz;
	compat_time_t shm_atime;
	compat_time_t shm_dtime;
	compat_time_t shm_ctime;
	compat_ipc_pid_t shm_cpid;
	compat_ipc_pid_t shm_lpid;
	unsigned short shm_nattch;
	unsigned short shm_unused;
	compat_uptr_t shm_unused2;
	compat_uptr_t shm_unused3;
};

struct compat_ipc_kludge {
	compat_uptr_t msgp;
	compat_long_t msgtyp;
};

struct compat_shminfo64 {
	compat_ulong_t shmmax;
	compat_ulong_t shmmin;
	compat_ulong_t shmmni;
	compat_ulong_t shmseg;
	compat_ulong_t shmall;
	compat_ulong_t __unused1;
	compat_ulong_t __unused2;
	compat_ulong_t __unused3;
	compat_ulong_t __unused4;
};

struct compat_shm_info {
	compat_int_t used_ids;
	compat_ulong_t shm_tot, shm_rss, shm_swp;
	compat_ulong_t swap_attempts, swap_successes;
};

extern int sem_ctls[];
#define sc_semopm	(sem_ctls[2])

static inline int compat_ipc_parse_version(int *cmd)
{
#ifdef CONFIG_ARCH_WANT_OLD_COMPAT_IPC
	int version = *cmd & IPC_64;

	/* this is tricky: architectures that have support for the old
	 * ipc structures in 64 bit binaries need to have IPC_64 set
	 * in cmd, the others need to have it cleared */
#ifndef ipc_parse_version
	*cmd |= IPC_64;
#else
	*cmd &= ~IPC_64;
#endif
	return version;
#else
	/* With the asm-generic APIs, we always use the 64-bit versions. */
	return IPC_64;
#endif
}

static inline int __get_compat_ipc64_perm(struct ipc64_perm *p64,
					  struct compat_ipc64_perm __user *up64)
{
	int err;

	err  = __get_user(p64->uid, &up64->uid);
	err |= __get_user(p64->gid, &up64->gid);
	err |= __get_user(p64->mode, &up64->mode);
	return err;
}

static inline int __get_compat_ipc_perm(struct ipc64_perm *p,
					struct compat_ipc_perm __user *up)
{
	int err;

	err  = __get_user(p->uid, &up->uid);
	err |= __get_user(p->gid, &up->gid);
	err |= __get_user(p->mode, &up->mode);
	return err;
}

static inline int __put_compat_ipc64_perm(struct ipc64_perm *p64,
					  struct compat_ipc64_perm __user *up64)
{
	int err;

	err  = __put_user(p64->key, &up64->key);
	err |= __put_user(p64->uid, &up64->uid);
	err |= __put_user(p64->gid, &up64->gid);
	err |= __put_user(p64->cuid, &up64->cuid);
	err |= __put_user(p64->cgid, &up64->cgid);
	err |= __put_user(p64->mode, &up64->mode);
	err |= __put_user(p64->seq, &up64->seq);
	return err;
}

static inline int __put_compat_ipc_perm(struct ipc64_perm *p,
					struct compat_ipc_perm __user *up)
{
	int err;
	__compat_uid_t u;
	__compat_gid_t g;

	err  = __put_user(p->key, &up->key);
	SET_UID(u, p->uid);
	err |= __put_user(u, &up->uid);
	SET_GID(g, p->gid);
	err |= __put_user(g, &up->gid);
	SET_UID(u, p->cuid);
	err |= __put_user(u, &up->cuid);
	SET_GID(g, p->cgid);
	err |= __put_user(g, &up->cgid);
	err |= __put_user(p->mode, &up->mode);
	err |= __put_user(p->seq, &up->seq);
	return err;
}

static inline int get_compat_semid64_ds(struct semid64_ds *s64,
					struct compat_semid64_ds __user *up64)
{
	if (!access_ok (VERIFY_READ, up64, sizeof(*up64)))
		return -EFAULT;
	return __get_compat_ipc64_perm(&s64->sem_perm, &up64->sem_perm);
}

static inline int get_compat_semid_ds(struct semid64_ds *s,
				      struct compat_semid_ds __user *up)
{
	if (!access_ok (VERIFY_READ, up, sizeof(*up)))
		return -EFAULT;
	return __get_compat_ipc_perm(&s->sem_perm, &up->sem_perm);
}

static inline int put_compat_semid64_ds(struct semid64_ds *s64,
					struct compat_semid64_ds __user *up64)
{
	int err;

	if (!access_ok (VERIFY_WRITE, up64, sizeof(*up64)))
		return -EFAULT;
	err  = __put_compat_ipc64_perm(&s64->sem_perm, &up64->sem_perm);
	err |= __put_user(s64->sem_otime, &up64->sem_otime);
	err |= __put_user(s64->sem_ctime, &up64->sem_ctime);
	err |= __put_user(s64->sem_nsems, &up64->sem_nsems);
	return err;
}

static inline int put_compat_semid_ds(struct semid64_ds *s,
				      struct compat_semid_ds __user *up)
{
	int err;

	if (!access_ok (VERIFY_WRITE, up, sizeof(*up)))
		return -EFAULT;
	err  = __put_compat_ipc_perm(&s->sem_perm, &up->sem_perm);
	err |= __put_user(s->sem_otime, &up->sem_otime);
	err |= __put_user(s->sem_ctime, &up->sem_ctime);
	err |= __put_user(s->sem_nsems, &up->sem_nsems);
	return err;
}

static long do_compat_semctl(int first, int second, int third, u32 pad)
{
	union semun fourth;
	int err, err2;
	struct semid64_ds s64;
	struct semid64_ds __user *up64;
	int version = compat_ipc_parse_version(&third);

	memset(&s64, 0, sizeof(s64));

	if ((third & (~IPC_64)) == SETVAL)
		fourth.val = (int) pad;
	else
		fourth.__pad = compat_ptr(pad);
	switch (third & (~IPC_64)) {
	case IPC_INFO:
	case IPC_RMID:
	case SEM_INFO:
	case GETVAL:
	case GETPID:
	case GETNCNT:
	case GETZCNT:
	case GETALL:
	case SETVAL:
	case SETALL:
		err = sys_semctl(first, second, third, fourth);
		break;

	case IPC_STAT:
	case SEM_STAT:
		up64 = compat_alloc_user_space(sizeof(s64));
		fourth.__pad = up64;
		err = sys_semctl(first, second, third, fourth);
		if (err < 0)
			break;
		if (copy_from_user(&s64, up64, sizeof(s64)))
			err2 = -EFAULT;
		else if (version == IPC_64)
			err2 = put_compat_semid64_ds(&s64, compat_ptr(pad));
		else
			err2 = put_compat_semid_ds(&s64, compat_ptr(pad));
		if (err2)
			err = -EFAULT;
		break;

	case IPC_SET:
		if (version == IPC_64) {
			err = get_compat_semid64_ds(&s64, compat_ptr(pad));
		} else {
			err = get_compat_semid_ds(&s64, compat_ptr(pad));
		}
		up64 = compat_alloc_user_space(sizeof(s64));
		if (copy_to_user(up64, &s64, sizeof(s64)))
			err = -EFAULT;
		if (err)
			break;

		fourth.__pad = up64;
		err = sys_semctl(first, second, third, fourth);
		break;

	default:
		err = -EINVAL;
		break;
	}
	return err;
}

#ifdef CONFIG_ARCH_WANT_OLD_COMPAT_IPC
long compat_sys_semctl(int first, int second, int third, void __user *uptr)
{
	u32 pad;

	if (!uptr)
		return -EINVAL;
	if (get_user(pad, (u32 __user *) uptr))
		return -EFAULT;
	return do_compat_semctl(first, second, third, pad);
}

long compat_sys_msgsnd(int first, int second, int third, void __user *uptr)
{
	struct compat_msgbuf __user *up = uptr;
	long type;

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

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

	return do_msgsnd(first, type, up->mtext, second, third);
}

long compat_sys_msgrcv(int first, int second, int msgtyp, int third,
			   int version, void __user *uptr)
{
	struct compat_msgbuf __user *up;
	long type;
	int err;

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

	if (!version) {
		struct compat_ipc_kludge ipck;
		err = -EINVAL;
		if (!uptr)
			goto out;
		err = -EFAULT;
		if (copy_from_user (&ipck, uptr, sizeof(ipck)))
			goto out;
		uptr = compat_ptr(ipck.msgp);
		msgtyp = ipck.msgtyp;
	}
	up = uptr;
	err = do_msgrcv(first, &type, up->mtext, second, msgtyp, third);
	if (err < 0)
		goto out;
	if (put_user(type, &up->mtype))
		err = -EFAULT;
out:
	return err;
}
#else
long compat_sys_semctl(int semid, int semnum, int cmd, int arg)
{
	return do_compat_semctl(semid, semnum, cmd, arg);
}

long compat_sys_msgsnd(int msqid, struct compat_msgbuf __user *msgp,
		       size_t msgsz, int msgflg)
{
	compat_long_t mtype;

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

long compat_sys_msgrcv(int msqid, struct compat_msgbuf __user *msgp,
		       size_t msgsz, long msgtyp, int msgflg)
{
	long err, mtype;

	err =  do_msgrcv(msqid, &mtype, msgp->mtext, msgsz, msgtyp, msgflg);
	if (err < 0)
		goto out;

	if (put_user(mtype, &msgp->mtype))
		err = -EFAULT;
 out:
	return err;
}
#endif

static inline int get_compat_msqid64(struct msqid64_ds *m64,
				     struct compat_msqid64_ds __user *up64)
{
	int err;

	if (!access_ok(VERIFY_READ, up64, sizeof(*up64)))
		return -EFAULT;
	err  = __get_compat_ipc64_perm(&m64->msg_perm, &up64->msg_perm);
	err |= __get_user(m64->msg_qbytes, &up64->msg_qbytes);
	return err;
}

static inline int get_compat_msqid(struct msqid64_ds *m,
				   struct compat_msqid_ds __user *up)
{
	int err;

	if (!access_ok(VERIFY_READ, up, sizeof(*up)))
		return -EFAULT;
	err  = __get_compat_ipc_perm(&m->msg_perm, &up->msg_perm);
	err |= __get_user(m->msg_qbytes, &up->msg_qbytes);
	return err;
}

static inline int put_compat_msqid64_ds(struct msqid64_ds *m64,
				 struct compat_msqid64_ds __user *up64)
{
	int err;

	if (!access_ok(VERIFY_WRITE, up64, sizeof(*up64)))
		return -EFAULT;
	err  = __put_compat_ipc64_perm(&m64->msg_perm, &up64->msg_perm);
	err |= __put_user(m64->msg_stime, &up64->msg_stime);
	err |= __put_user(m64->msg_rtime, &up64->msg_rtime);
	err |= __put_user(m64->msg_ctime, &up64->msg_ctime);
	err |= __put_user(m64->msg_cbytes, &up64->msg_cbytes);
	err |= __put_user(m64->msg_qnum, &up64->msg_qnum);
	err |= __put_user(m64->msg_qbytes, &up64->msg_qbytes);
	err |= __put_user(m64->msg_lspid, &up64->msg_lspid);
	err |= __put_user(m64->msg_lrpid, &up64->msg_lrpid);
	return err;
}

static inline int put_compat_msqid_ds(struct msqid64_ds *m,
				      struct compat_msqid_ds __user *up)
{
	int err;

	if (!access_ok(VERIFY_WRITE, up, sizeof(*up)))
		return -EFAULT;
	err  = __put_compat_ipc_perm(&m->msg_perm, &up->msg_perm);
	err |= __put_user(m->msg_stime, &up->msg_stime);
	err |= __put_user(m->msg_rtime, &up->msg_rtime);
	err |= __put_user(m->msg_ctime, &up->msg_ctime);
	err |= __put_user(m->msg_cbytes, &up->msg_cbytes);
	err |= __put_user(m->msg_qnum, &up->msg_qnum);
	err |= __put_user(m->msg_qbytes, &up->msg_qbytes);
	err |= __put_user(m->msg_lspid, &up->msg_lspid);
	err |= __put_user(m->msg_lrpid, &up->msg_lrpid);
	return err;
}

long compat_sys_msgctl(int first, int second, void __user *uptr)
{
	int err, err2;
	struct msqid64_ds m64;
	int version = compat_ipc_parse_version(&second);
	void __user *p;

	memset(&m64, 0, sizeof(m64));

	switch (second & (~IPC_64)) {
	case IPC_INFO:
	case IPC_RMID:
	case MSG_INFO:
		err = sys_msgctl(first, second, uptr);
		break;

	case IPC_SET:
		if (version == IPC_64) {
			err = get_compat_msqid64(&m64, uptr);
		} else {
			err = get_compat_msqid(&m64, uptr);
		}
		if (err)
			break;
		p = compat_alloc_user_space(sizeof(m64));
		if (copy_to_user(p, &m64, sizeof(m64)))
			err = -EFAULT;
		else
			err = sys_msgctl(first, second, p);
		break;

	case IPC_STAT:
	case MSG_STAT:
		p = compat_alloc_user_space(sizeof(m64));
		err = sys_msgctl(first, second, p);
		if (err < 0)
			break;
		if (copy_from_user(&m64, p, sizeof(m64)))
			err2 = -EFAULT;
		else if (version == IPC_64)
			err2 = put_compat_msqid64_ds(&m64, uptr);
		else
			err2 = put_compat_msqid_ds(&m64, uptr);
		if (err2)
			err = -EFAULT;
		break;

	default:
		err = -EINVAL;
		break;
	}
	return err;
}

#ifdef CONFIG_ARCH_WANT_OLD_COMPAT_IPC
long compat_sys_shmat(int first, int second, compat_uptr_t third, int version,
			void __user *uptr)
{
	int err;
	unsigned long raddr;
	compat_ulong_t __user *uaddr;

	if (version == 1)
		return -EINVAL;
	err = do_shmat(first, uptr, second, &raddr);
	if (err < 0)
		return err;
	uaddr = compat_ptr(third);
	return put_user(raddr, uaddr);
}
#else
long compat_sys_shmat(int shmid, compat_uptr_t shmaddr, int shmflg)
{
	unsigned long ret;
	long err;

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

static inline int get_compat_shmid64_ds(struct shmid64_ds *s64,
					struct compat_shmid64_ds __user *up64)
{
	if (!access_ok(VERIFY_READ, up64, sizeof(*up64)))
		return -EFAULT;
	return __get_compat_ipc64_perm(&s64->shm_perm, &up64->shm_perm);
}

static inline int get_compat_shmid_ds(struct shmid64_ds *s,
				      struct compat_shmid_ds __user *up)
{
	if (!access_ok(VERIFY_READ, up, sizeof(*up)))
		return -EFAULT;
	return __get_compat_ipc_perm(&s->shm_perm, &up->shm_perm);
}

static inline int put_compat_shmid64_ds(struct shmid64_ds *s64,
					struct compat_shmid64_ds __user *up64)
{
	int err;

	if (!access_ok(VERIFY_WRITE, up64, sizeof(*up64)))
		return -EFAULT;
	err  = __put_compat_ipc64_perm(&s64->shm_perm, &up64->shm_perm);
	err |= __put_user(s64->shm_atime, &up64->shm_atime);
	err |= __put_user(s64->shm_dtime, &up64->shm_dtime);
	err |= __put_user(s64->shm_ctime, &up64->shm_ctime);
	err |= __put_user(s64->shm_segsz, &up64->shm_segsz);
	err |= __put_user(s64->shm_nattch, &up64->shm_nattch);
	err |= __put_user(s64->shm_cpid, &up64->shm_cpid);
	err |= __put_user(s64->shm_lpid, &up64->shm_lpid);
	return err;
}

static inline int put_compat_shmid_ds(struct shmid64_ds *s,
				      struct compat_shmid_ds __user *up)
{
	int err;

	if (!access_ok(VERIFY_WRITE, up, sizeof(*up)))
		return -EFAULT;
	err  = __put_compat_ipc_perm(&s->shm_perm, &up->shm_perm);
	err |= __put_user(s->shm_atime, &up->shm_atime);
	err |= __put_user(s->shm_dtime, &up->shm_dtime);
	err |= __put_user(s->shm_ctime, &up->shm_ctime);
	err |= __put_user(s->shm_segsz, &up->shm_segsz);
	err |= __put_user(s->shm_nattch, &up->shm_nattch);
	err |= __put_user(s->shm_cpid, &up->shm_cpid);
	err |= __put_user(s->shm_lpid, &up->shm_lpid);
	return err;
}

static inline int put_compat_shminfo64(struct shminfo64 *smi,
				       struct compat_shminfo64 __user *up64)
{
	int err;

	if (!access_ok(VERIFY_WRITE, up64, sizeof(*up64)))
		return -EFAULT;
	if (smi->shmmax > INT_MAX)
		smi->shmmax = INT_MAX;
	err  = __put_user(smi->shmmax, &up64->shmmax);
	err |= __put_user(smi->shmmin, &up64->shmmin);
	err |= __put_user(smi->shmmni, &up64->shmmni);
	err |= __put_user(smi->shmseg, &up64->shmseg);
	err |= __put_user(smi->shmall, &up64->shmall);
	return err;
}

static inline int put_compat_shminfo(struct shminfo64 *smi,
				     struct shminfo __user *up)
{
	int err;

	if (!access_ok(VERIFY_WRITE, up, sizeof(*up)))
		return -EFAULT;
	if (smi->shmmax > INT_MAX)
		smi->shmmax = INT_MAX;
	err  = __put_user(smi->shmmax, &up->shmmax);
	err |= __put_user(smi->shmmin, &up->shmmin);
	err |= __put_user(smi->shmmni, &up->shmmni);
	err |= __put_user(smi->shmseg, &up->shmseg);
	err |= __put_user(smi->shmall, &up->shmall);
	return err;
}

static inline int put_compat_shm_info(struct shm_info __user *ip,
				      struct compat_shm_info __user *uip)
{
	int err;
	struct shm_info si;

	if (!access_ok(VERIFY_WRITE, uip, sizeof(*uip)) ||
	    copy_from_user(&si, ip, sizeof(si)))
		return -EFAULT;
	err  = __put_user(si.used_ids, &uip->used_ids);
	err |= __put_user(si.shm_tot, &uip->shm_tot);
	err |= __put_user(si.shm_rss, &uip->shm_rss);
	err |= __put_user(si.shm_swp, &uip->shm_swp);
	err |= __put_user(si.swap_attempts, &uip->swap_attempts);
	err |= __put_user(si.swap_successes, &uip->swap_successes);
	return err;
}

long compat_sys_shmctl(int first, int second, void __user *uptr)
{
	void __user *p;
	struct shmid64_ds s64;
	struct shminfo64 smi;
	int err, err2;
	int version = compat_ipc_parse_version(&second);

	memset(&s64, 0, sizeof(s64));

	switch (second & (~IPC_64)) {
	case IPC_RMID:
	case SHM_LOCK:
	case SHM_UNLOCK:
		err = sys_shmctl(first, second, uptr);
		break;

	case IPC_INFO:
		p = compat_alloc_user_space(sizeof(smi));
		err = sys_shmctl(first, second, p);
		if (err < 0)
			break;
		if (copy_from_user(&smi, p, sizeof(smi)))
			err2 = -EFAULT;
		else if (version == IPC_64)
			err2 = put_compat_shminfo64(&smi, uptr);
		else
			err2 = put_compat_shminfo(&smi, uptr);
		if (err2)
			err = -EFAULT;
		break;


	case IPC_SET:
		if (version == IPC_64) {
			err = get_compat_shmid64_ds(&s64, uptr);
		} else {
			err = get_compat_shmid_ds(&s64, uptr);
		}
		if (err)
			break;
		p = compat_alloc_user_space(sizeof(s64));
		if (copy_to_user(p, &s64, sizeof(s64)))
			err = -EFAULT;
		else
			err = sys_shmctl(first, second, p);
		break;

	case IPC_STAT:
	case SHM_STAT:
		p = compat_alloc_user_space(sizeof(s64));
		err = sys_shmctl(first, second, p);
		if (err < 0)
			break;
		if (copy_from_user(&s64, p, sizeof(s64)))
			err2 = -EFAULT;
		else if (version == IPC_64)
			err2 = put_compat_shmid64_ds(&s64, uptr);
		else
			err2 = put_compat_shmid_ds(&s64, uptr);
		if (err2)
			err = -EFAULT;
		break;

	case SHM_INFO:
		p = compat_alloc_user_space(sizeof(struct shm_info));
		err = sys_shmctl(first, second, p);
		if (err < 0)
			break;
		err2 = put_compat_shm_info(p, uptr);
		if (err2)
			err = -EFAULT;
		break;

	default:
		err = -EINVAL;
		break;
	}
	return err;
}

long compat_sys_semtimedop(int semid, struct sembuf __user *tsems,
		unsigned nsops, const struct compat_timespec __user *timeout)
{
	struct timespec __user *ts64 = NULL;
	if (timeout) {
		struct timespec ts;
		ts64 = compat_alloc_user_space(sizeof(*ts64));
		if (get_compat_timespec(&ts, timeout))
			return -EFAULT;
		if (copy_to_user(ts64, &ts, sizeof(ts)))
			return -EFAULT;
	}
	return sys_semtimedop(semid, tsems, nsops, ts64);
}