compat.c

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/*
 * 32 bit compatibility code for System V IPC
 *
 * Copyright (C) 1997,1998  Jakub Jelinek ([email protected])
 * Copyright (C) 1997       David S. Miller ([email protected])
 * Copyright (C) 1999       Arun Sharma <[email protected]>
 * Copyright (C) 2000       VA Linux Co
 * Copyright (C) 2000       Don Dugger <[email protected]>
 * Copyright (C) 2000           Hewlett-Packard Co.
 * Copyright (C) 2000           David Mosberger-Tang <[email protected]>
 * Copyright (C) 2000           Gerhard Tonn ([email protected])
 * 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 ([email protected])
 *
 * 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_COMPAT_IPC_PARSE_VERSION
    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,
               compat_ssize_t msgsz, int msgflg)
{
    compat_long_t mtype;

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

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

    err =  do_msgrcv(msqid, &mtype, msgp->mtext, (ssize_t)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;
}

#ifndef COMPAT_SHMLBA
#define COMPAT_SHMLBA   SHMLBA
#endif

#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, COMPAT_SHMLBA);
    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, COMPAT_SHMLBA);
    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);
}