compat_linux.c

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/*
 *  S390 version
 *    Copyright IBM Corp. 2000
 *    Author(s): Martin Schwidefsky ([email protected]),
 *               Gerhard Tonn ([email protected])   
 *               Thomas Spatzier ([email protected])
 *
 *  Conversion between 31bit and 64bit native syscalls.
 *
 * Heavily inspired by the 32-bit Sparc compat code which is 
 * Copyright (C) 1997,1998 Jakub Jelinek ([email protected])
 * Copyright (C) 1997 David S. Miller ([email protected])
 *
 */


#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/fs.h> 
#include <linux/mm.h> 
#include <linux/file.h> 
#include <linux/signal.h>
#include <linux/resource.h>
#include <linux/times.h>
#include <linux/smp.h>
#include <linux/sem.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/uio.h>
#include <linux/quota.h>
#include <linux/module.h>
#include <linux/poll.h>
#include <linux/personality.h>
#include <linux/stat.h>
#include <linux/filter.h>
#include <linux/highmem.h>
#include <linux/highuid.h>
#include <linux/mman.h>
#include <linux/ipv6.h>
#include <linux/in.h>
#include <linux/icmpv6.h>
#include <linux/syscalls.h>
#include <linux/sysctl.h>
#include <linux/binfmts.h>
#include <linux/capability.h>
#include <linux/compat.h>
#include <linux/vfs.h>
#include <linux/ptrace.h>
#include <linux/fadvise.h>
#include <linux/ipc.h>
#include <linux/slab.h>

#include <asm/types.h>
#include <asm/uaccess.h>

#include <net/scm.h>
#include <net/sock.h>

#include "compat_linux.h"

u32 psw32_user_bits = PSW32_MASK_DAT | PSW32_MASK_IO | PSW32_MASK_EXT |
              PSW32_DEFAULT_KEY | PSW32_MASK_BASE | PSW32_MASK_MCHECK |
              PSW32_MASK_PSTATE | PSW32_ASC_HOME;
 
/* For this source file, we want overflow handling. */

#undef high2lowuid
#undef high2lowgid
#undef low2highuid
#undef low2highgid
#undef SET_UID16
#undef SET_GID16
#undef NEW_TO_OLD_UID
#undef NEW_TO_OLD_GID
#undef SET_OLDSTAT_UID
#undef SET_OLDSTAT_GID
#undef SET_STAT_UID
#undef SET_STAT_GID

#define high2lowuid(uid) ((uid) > 65535) ? (u16)overflowuid : (u16)(uid)
#define high2lowgid(gid) ((gid) > 65535) ? (u16)overflowgid : (u16)(gid)
#define low2highuid(uid) ((uid) == (u16)-1) ? (uid_t)-1 : (uid_t)(uid)
#define low2highgid(gid) ((gid) == (u16)-1) ? (gid_t)-1 : (gid_t)(gid)
#define SET_UID16(var, uid) var = high2lowuid(uid)
#define SET_GID16(var, gid) var = high2lowgid(gid)
#define NEW_TO_OLD_UID(uid) high2lowuid(uid)
#define NEW_TO_OLD_GID(gid) high2lowgid(gid)
#define SET_OLDSTAT_UID(stat, uid)  (stat).st_uid = high2lowuid(uid)
#define SET_OLDSTAT_GID(stat, gid)  (stat).st_gid = high2lowgid(gid)
#define SET_STAT_UID(stat, uid)     (stat).st_uid = high2lowuid(uid)
#define SET_STAT_GID(stat, gid)     (stat).st_gid = high2lowgid(gid)

asmlinkage long sys32_chown16(const char __user * filename, u16 user, u16 group)
{
    return sys_chown(filename, low2highuid(user), low2highgid(group));
}

asmlinkage long sys32_lchown16(const char __user * filename, u16 user, u16 group)
{
    return sys_lchown(filename, low2highuid(user), low2highgid(group));
}

asmlinkage long sys32_fchown16(unsigned int fd, u16 user, u16 group)
{
    return sys_fchown(fd, low2highuid(user), low2highgid(group));
}

asmlinkage long sys32_setregid16(u16 rgid, u16 egid)
{
    return sys_setregid(low2highgid(rgid), low2highgid(egid));
}

asmlinkage long sys32_setgid16(u16 gid)
{
    return sys_setgid((gid_t)gid);
}

asmlinkage long sys32_setreuid16(u16 ruid, u16 euid)
{
    return sys_setreuid(low2highuid(ruid), low2highuid(euid));
}

asmlinkage long sys32_setuid16(u16 uid)
{
    return sys_setuid((uid_t)uid);
}

asmlinkage long sys32_setresuid16(u16 ruid, u16 euid, u16 suid)
{
    return sys_setresuid(low2highuid(ruid), low2highuid(euid),
        low2highuid(suid));
}

asmlinkage long sys32_getresuid16(u16 __user *ruidp, u16 __user *euidp, u16 __user *suidp)
{
    const struct cred *cred = current_cred();
    int retval;
    u16 ruid, euid, suid;

    ruid = high2lowuid(from_kuid_munged(cred->user_ns, cred->uid));
    euid = high2lowuid(from_kuid_munged(cred->user_ns, cred->euid));
    suid = high2lowuid(from_kuid_munged(cred->user_ns, cred->suid));

    if (!(retval   = put_user(ruid, ruidp)) &&
        !(retval   = put_user(euid, euidp)))
        retval = put_user(suid, suidp);

    return retval;
}

asmlinkage long sys32_setresgid16(u16 rgid, u16 egid, u16 sgid)
{
    return sys_setresgid(low2highgid(rgid), low2highgid(egid),
        low2highgid(sgid));
}

asmlinkage long sys32_getresgid16(u16 __user *rgidp, u16 __user *egidp, u16 __user *sgidp)
{
    const struct cred *cred = current_cred();
    int retval;
    u16 rgid, egid, sgid;

    rgid = high2lowgid(from_kgid_munged(cred->user_ns, cred->gid));
    egid = high2lowgid(from_kgid_munged(cred->user_ns, cred->egid));
    sgid = high2lowgid(from_kgid_munged(cred->user_ns, cred->sgid));

    if (!(retval   = put_user(rgid, rgidp)) &&
        !(retval   = put_user(egid, egidp)))
        retval = put_user(sgid, sgidp);

    return retval;
}

asmlinkage long sys32_setfsuid16(u16 uid)
{
    return sys_setfsuid((uid_t)uid);
}

asmlinkage long sys32_setfsgid16(u16 gid)
{
    return sys_setfsgid((gid_t)gid);
}

static int groups16_to_user(u16 __user *grouplist, struct group_info *group_info)
{
    struct user_namespace *user_ns = current_user_ns();
    int i;
    u16 group;
    kgid_t kgid;

    for (i = 0; i < group_info->ngroups; i++) {
        kgid = GROUP_AT(group_info, i);
        group = (u16)from_kgid_munged(user_ns, kgid);
        if (put_user(group, grouplist+i))
            return -EFAULT;
    }

    return 0;
}

static int groups16_from_user(struct group_info *group_info, u16 __user *grouplist)
{
    struct user_namespace *user_ns = current_user_ns();
    int i;
    u16 group;
    kgid_t kgid;

    for (i = 0; i < group_info->ngroups; i++) {
        if (get_user(group, grouplist+i))
            return  -EFAULT;

        kgid = make_kgid(user_ns, (gid_t)group);
        if (!gid_valid(kgid))
            return -EINVAL;

        GROUP_AT(group_info, i) = kgid;
    }

    return 0;
}

asmlinkage long sys32_getgroups16(int gidsetsize, u16 __user *grouplist)
{
    int i;

    if (gidsetsize < 0)
        return -EINVAL;

    get_group_info(current->cred->group_info);
    i = current->cred->group_info->ngroups;
    if (gidsetsize) {
        if (i > gidsetsize) {
            i = -EINVAL;
            goto out;
        }
        if (groups16_to_user(grouplist, current->cred->group_info)) {
            i = -EFAULT;
            goto out;
        }
    }
out:
    put_group_info(current->cred->group_info);
    return i;
}

asmlinkage long sys32_setgroups16(int gidsetsize, u16 __user *grouplist)
{
    struct group_info *group_info;
    int retval;

    if (!capable(CAP_SETGID))
        return -EPERM;
    if ((unsigned)gidsetsize > NGROUPS_MAX)
        return -EINVAL;

    group_info = groups_alloc(gidsetsize);
    if (!group_info)
        return -ENOMEM;
    retval = groups16_from_user(group_info, grouplist);
    if (retval) {
        put_group_info(group_info);
        return retval;
    }

    retval = set_current_groups(group_info);
    put_group_info(group_info);

    return retval;
}

asmlinkage long sys32_getuid16(void)
{
    return high2lowuid(from_kuid_munged(current_user_ns(), current_uid()));
}

asmlinkage long sys32_geteuid16(void)
{
    return high2lowuid(from_kuid_munged(current_user_ns(), current_euid()));
}

asmlinkage long sys32_getgid16(void)
{
    return high2lowgid(from_kgid_munged(current_user_ns(), current_gid()));
}

asmlinkage long sys32_getegid16(void)
{
    return high2lowgid(from_kgid_munged(current_user_ns(), current_egid()));
}

/*
 * sys32_ipc() is the de-multiplexer for the SysV IPC calls in 32bit emulation.
 *
 * This is really horribly ugly.
 */
#ifdef CONFIG_SYSVIPC
asmlinkage long sys32_ipc(u32 call, int first, int second, int third, u32 ptr)
{
    if (call >> 16)     /* hack for backward compatibility */
        return -EINVAL;
    switch (call) {
    case SEMTIMEDOP:
        return compat_sys_semtimedop(first, compat_ptr(ptr),
                         second, compat_ptr(third));
    case SEMOP:
        /* struct sembuf is the same on 32 and 64bit :)) */
        return sys_semtimedop(first, compat_ptr(ptr),
                      second, NULL);
    case SEMGET:
        return sys_semget(first, second, third);
    case SEMCTL:
        return compat_sys_semctl(first, second, third,
                     compat_ptr(ptr));
    case MSGSND:
        return compat_sys_msgsnd(first, second, third,
                     compat_ptr(ptr));
    case MSGRCV:
        return compat_sys_msgrcv(first, second, 0, third,
                     0, compat_ptr(ptr));
    case MSGGET:
        return sys_msgget((key_t) first, second);
    case MSGCTL:
        return compat_sys_msgctl(first, second, compat_ptr(ptr));
    case SHMAT:
        return compat_sys_shmat(first, second, third,
                    0, compat_ptr(ptr));
    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

asmlinkage long sys32_truncate64(const char __user * path, unsigned long high, unsigned long low)
{
    if ((int)high < 0)
        return -EINVAL;
    else
        return sys_truncate(path, (high << 32) | low);
}

asmlinkage long sys32_ftruncate64(unsigned int fd, unsigned long high, unsigned long low)
{
    if ((int)high < 0)
        return -EINVAL;
    else
        return sys_ftruncate(fd, (high << 32) | low);
}

asmlinkage long sys32_sched_rr_get_interval(compat_pid_t pid,
                struct compat_timespec __user *interval)
{
    struct timespec t;
    int ret;
    mm_segment_t old_fs = get_fs ();
    
    set_fs (KERNEL_DS);
    ret = sys_sched_rr_get_interval(pid,
                    (struct timespec __force __user *) &t);
    set_fs (old_fs);
    if (put_compat_timespec(&t, interval))
        return -EFAULT;
    return ret;
}

asmlinkage long sys32_rt_sigprocmask(int how, compat_sigset_t __user *set,
            compat_sigset_t __user *oset, size_t sigsetsize)
{
    sigset_t s;
    compat_sigset_t s32;
    int ret;
    mm_segment_t old_fs = get_fs();
    
    if (set) {
        if (copy_from_user (&s32, set, sizeof(compat_sigset_t)))
            return -EFAULT;
        s.sig[0] = s32.sig[0] | (((long)s32.sig[1]) << 32);
    }
    set_fs (KERNEL_DS);
    ret = sys_rt_sigprocmask(how,
                 set ? (sigset_t __force __user *) &s : NULL,
                 oset ? (sigset_t __force __user *) &s : NULL,
                 sigsetsize);
    set_fs (old_fs);
    if (ret) return ret;
    if (oset) {
        s32.sig[1] = (s.sig[0] >> 32);
        s32.sig[0] = s.sig[0];
        if (copy_to_user (oset, &s32, sizeof(compat_sigset_t)))
            return -EFAULT;
    }
    return 0;
}

asmlinkage long sys32_rt_sigpending(compat_sigset_t __user *set,
                size_t sigsetsize)
{
    sigset_t s;
    compat_sigset_t s32;
    int ret;
    mm_segment_t old_fs = get_fs();
        
    set_fs (KERNEL_DS);
    ret = sys_rt_sigpending((sigset_t __force __user *) &s, sigsetsize);
    set_fs (old_fs);
    if (!ret) {
        s32.sig[1] = (s.sig[0] >> 32);
        s32.sig[0] = s.sig[0];
        if (copy_to_user (set, &s32, sizeof(compat_sigset_t)))
            return -EFAULT;
    }
    return ret;
}

asmlinkage long
sys32_rt_sigqueueinfo(int pid, int sig, compat_siginfo_t __user *uinfo)
{
    siginfo_t info;
    int ret;
    mm_segment_t old_fs = get_fs();
    
    if (copy_siginfo_from_user32(&info, uinfo))
        return -EFAULT;
    set_fs (KERNEL_DS);
    ret = sys_rt_sigqueueinfo(pid, sig, (siginfo_t __force __user *) &info);
    set_fs (old_fs);
    return ret;
}

asmlinkage long sys32_pread64(unsigned int fd, char __user *ubuf,
                size_t count, u32 poshi, u32 poslo)
{
    if ((compat_ssize_t) count < 0)
        return -EINVAL;
    return sys_pread64(fd, ubuf, count, ((loff_t)AA(poshi) << 32) | AA(poslo));
}

asmlinkage long sys32_pwrite64(unsigned int fd, const char __user *ubuf,
                size_t count, u32 poshi, u32 poslo)
{
    if ((compat_ssize_t) count < 0)
        return -EINVAL;
    return sys_pwrite64(fd, ubuf, count, ((loff_t)AA(poshi) << 32) | AA(poslo));
}

asmlinkage compat_ssize_t sys32_readahead(int fd, u32 offhi, u32 offlo, s32 count)
{
    return sys_readahead(fd, ((loff_t)AA(offhi) << 32) | AA(offlo), count);
}

asmlinkage long sys32_sendfile(int out_fd, int in_fd, compat_off_t __user *offset, size_t count)
{
    mm_segment_t old_fs = get_fs();
    int ret;
    off_t of;
    
    if (offset && get_user(of, offset))
        return -EFAULT;
        
    set_fs(KERNEL_DS);
    ret = sys_sendfile(out_fd, in_fd,
               offset ? (off_t __force __user *) &of : NULL, count);
    set_fs(old_fs);
    
    if (offset && put_user(of, offset))
        return -EFAULT;
        
    return ret;
}

asmlinkage long sys32_sendfile64(int out_fd, int in_fd,
                compat_loff_t __user *offset, s32 count)
{
    mm_segment_t old_fs = get_fs();
    int ret;
    loff_t lof;
    
    if (offset && get_user(lof, offset))
        return -EFAULT;
        
    set_fs(KERNEL_DS);
    ret = sys_sendfile64(out_fd, in_fd,
                 offset ? (loff_t __force __user *) &lof : NULL,
                 count);
    set_fs(old_fs);
    
    if (offset && put_user(lof, offset))
        return -EFAULT;
        
    return ret;
}

struct stat64_emu31 {
    unsigned long long  st_dev;
    unsigned int    __pad1;
#define STAT64_HAS_BROKEN_ST_INO        1
    u32             __st_ino;
    unsigned int    st_mode;
    unsigned int    st_nlink;
    u32             st_uid;
    u32             st_gid;
    unsigned long long  st_rdev;
    unsigned int    __pad3;
    long            st_size;
    u32             st_blksize;
    unsigned char   __pad4[4];
    u32             __pad5;     /* future possible st_blocks high bits */
    u32             st_blocks;  /* Number 512-byte blocks allocated. */
    u32             st_atime;
    u32             __pad6;
    u32             st_mtime;
    u32             __pad7;
    u32             st_ctime;
    u32             __pad8;     /* will be high 32 bits of ctime someday */
    unsigned long   st_ino;
};  

static int cp_stat64(struct stat64_emu31 __user *ubuf, struct kstat *stat)
{
    struct stat64_emu31 tmp;

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

    tmp.st_dev = huge_encode_dev(stat->dev);
    tmp.st_ino = stat->ino;
    tmp.__st_ino = (u32)stat->ino;
    tmp.st_mode = stat->mode;
    tmp.st_nlink = (unsigned int)stat->nlink;
    tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);
    tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);
    tmp.st_rdev = huge_encode_dev(stat->rdev);
    tmp.st_size = stat->size;
    tmp.st_blksize = (u32)stat->blksize;
    tmp.st_blocks = (u32)stat->blocks;
    tmp.st_atime = (u32)stat->atime.tv_sec;
    tmp.st_mtime = (u32)stat->mtime.tv_sec;
    tmp.st_ctime = (u32)stat->ctime.tv_sec;

    return copy_to_user(ubuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; 
}

asmlinkage long sys32_stat64(const char __user * filename, struct stat64_emu31 __user * statbuf)
{
    struct kstat stat;
    int ret = vfs_stat(filename, &stat);
    if (!ret)
        ret = cp_stat64(statbuf, &stat);
    return ret;
}

asmlinkage long sys32_lstat64(const char __user * filename, struct stat64_emu31 __user * statbuf)
{
    struct kstat stat;
    int ret = vfs_lstat(filename, &stat);
    if (!ret)
        ret = cp_stat64(statbuf, &stat);
    return ret;
}

asmlinkage long sys32_fstat64(unsigned long fd, struct stat64_emu31 __user * statbuf)
{
    struct kstat stat;
    int ret = vfs_fstat(fd, &stat);
    if (!ret)
        ret = cp_stat64(statbuf, &stat);
    return ret;
}

asmlinkage long sys32_fstatat64(unsigned int dfd, const char __user *filename,
                struct stat64_emu31 __user* statbuf, int flag)
{
    struct kstat stat;
    int error;

    error = vfs_fstatat(dfd, filename, &stat, flag);
    if (error)
        return error;
    return cp_stat64(statbuf, &stat);
}

/*
 * Linux/i386 didn't use to be able to handle more than
 * 4 system call parameters, so these system calls used a memory
 * block for parameter passing..
 */

struct mmap_arg_struct_emu31 {
    compat_ulong_t addr;
    compat_ulong_t len;
    compat_ulong_t prot;
    compat_ulong_t flags;
    compat_ulong_t fd;
    compat_ulong_t offset;
};

asmlinkage unsigned long old32_mmap(struct mmap_arg_struct_emu31 __user *arg)
{
    struct mmap_arg_struct_emu31 a;

    if (copy_from_user(&a, arg, sizeof(a)))
        return -EFAULT;
    if (a.offset & ~PAGE_MASK)
        return -EINVAL;
    return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
                  a.offset >> PAGE_SHIFT);
}

asmlinkage long sys32_mmap2(struct mmap_arg_struct_emu31 __user *arg)
{
    struct mmap_arg_struct_emu31 a;

    if (copy_from_user(&a, arg, sizeof(a)))
        return -EFAULT;
    return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
}

asmlinkage long sys32_read(unsigned int fd, char __user * buf, size_t count)
{
    if ((compat_ssize_t) count < 0)
        return -EINVAL; 

    return sys_read(fd, buf, count);
}

asmlinkage long sys32_write(unsigned int fd, const char __user * buf, size_t count)
{
    if ((compat_ssize_t) count < 0)
        return -EINVAL; 

    return sys_write(fd, buf, count);
}

/*
 * 31 bit emulation wrapper functions for sys_fadvise64/fadvise64_64.
 * These need to rewrite the advise values for POSIX_FADV_{DONTNEED,NOREUSE}
 * because the 31 bit values differ from the 64 bit values.
 */

asmlinkage long
sys32_fadvise64(int fd, loff_t offset, size_t len, int advise)
{
    if (advise == 4)
        advise = POSIX_FADV_DONTNEED;
    else if (advise == 5)
        advise = POSIX_FADV_NOREUSE;
    return sys_fadvise64(fd, offset, len, advise);
}

struct fadvise64_64_args {
    int fd;
    long long offset;
    long long len;
    int advice;
};

asmlinkage long
sys32_fadvise64_64(struct fadvise64_64_args __user *args)
{
    struct fadvise64_64_args a;

    if ( copy_from_user(&a, args, sizeof(a)) )
        return -EFAULT;
    if (a.advice == 4)
        a.advice = POSIX_FADV_DONTNEED;
    else if (a.advice == 5)
        a.advice = POSIX_FADV_NOREUSE;
    return sys_fadvise64_64(a.fd, a.offset, a.len, a.advice);
}