NetBSD/sys/compat/linux/multiarch/linux_llseek.c

796 lines
19 KiB
C

/* $NetBSD: linux_llseek.c,v 1.13 1995/10/08 22:53:43 fvdl Exp $ */
/*
* Copyright (c) 1995 Frank van der Linden
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed for the NetBSD Project
* by Frank van der Linden
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/filedesc.h>
#include <sys/ioctl.h>
#include <sys/kernel.h>
#include <sys/mount.h>
#include <sys/malloc.h>
#include <sys/vnode.h>
#include <sys/tty.h>
#include <sys/conf.h>
#include <sys/syscallargs.h>
#include <compat/linux/linux_types.h>
#include <compat/linux/linux_signal.h>
#include <compat/linux/linux_syscallargs.h>
#include <compat/linux/linux_fcntl.h>
#include <compat/linux/linux_util.h>
/*
* Some file-related calls are handled here. The usual flag conversion
* an structure conversion is done, and alternate emul path searching.
*/
/*
* The next two functions convert between the Linux and NetBSD values
* of the flags used in open(2) and fcntl(2).
*/
static int
linux_to_bsd_ioflags(int lflags)
{
int res = 0;
res |= cvtto_bsd_mask(lflags, LINUX_O_WRONLY, O_WRONLY);
res |= cvtto_bsd_mask(lflags, LINUX_O_RDONLY, O_RDONLY);
res |= cvtto_bsd_mask(lflags, LINUX_O_RDWR, O_RDWR);
res |= cvtto_bsd_mask(lflags, LINUX_O_CREAT, O_CREAT);
res |= cvtto_bsd_mask(lflags, LINUX_O_EXCL, O_EXCL);
res |= cvtto_bsd_mask(lflags, LINUX_O_NOCTTY, O_NOCTTY);
res |= cvtto_bsd_mask(lflags, LINUX_O_TRUNC, O_TRUNC);
res |= cvtto_bsd_mask(lflags, LINUX_O_NDELAY, O_NDELAY);
res |= cvtto_bsd_mask(lflags, LINUX_O_SYNC, O_FSYNC);
res |= cvtto_bsd_mask(lflags, LINUX_FASYNC, O_ASYNC);
res |= cvtto_bsd_mask(lflags, LINUX_O_APPEND, O_APPEND);
return res;
}
static int
bsd_to_linux_ioflags(int bflags)
{
int res = 0;
res |= cvtto_linux_mask(bflags, O_WRONLY, LINUX_O_WRONLY);
res |= cvtto_linux_mask(bflags, O_RDONLY, LINUX_O_RDONLY);
res |= cvtto_linux_mask(bflags, O_RDWR, LINUX_O_RDWR);
res |= cvtto_linux_mask(bflags, O_CREAT, LINUX_O_CREAT);
res |= cvtto_linux_mask(bflags, O_EXCL, LINUX_O_EXCL);
res |= cvtto_linux_mask(bflags, O_NOCTTY, LINUX_O_NOCTTY);
res |= cvtto_linux_mask(bflags, O_TRUNC, LINUX_O_TRUNC);
res |= cvtto_linux_mask(bflags, O_NDELAY, LINUX_O_NDELAY);
res |= cvtto_linux_mask(bflags, O_FSYNC, LINUX_O_SYNC);
res |= cvtto_linux_mask(bflags, O_ASYNC, LINUX_FASYNC);
res |= cvtto_linux_mask(bflags, O_APPEND, LINUX_O_APPEND);
return res;
}
/*
* creat(2) is an obsolete function, but it's present as a Linux
* system call, so let's deal with it.
*
* Just call open(2) with the TRUNC, CREAT and WRONLY flags.
*/
int
linux_sys_creat(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct linux_sys_creat_args /* {
syscallarg(char *) path;
syscallarg(int) mode;
} */ *uap = v;
struct sys_open_args oa;
caddr_t sg;
sg = stackgap_init(p->p_emul);
LINUX_CHECK_ALT_CREAT(p, &sg, SCARG(uap, path));
SCARG(&oa, path) = SCARG(uap, path);
SCARG(&oa, flags) = O_CREAT | O_TRUNC | O_WRONLY;
SCARG(&oa, mode) = SCARG(uap, mode);
return sys_open(p, &oa, retval);
}
/*
* open(2). Take care of the different flag values, and let the
* NetBSD syscall do the real work. See if this operation
* gives the current process a controlling terminal.
* (XXX is this necessary?)
*/
int
linux_sys_open(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct linux_sys_open_args /* {
syscallarg(char *) path;
syscallarg(int) flags;
syscallarg(int) mode;
} */ *uap = v;
int error, fl;
struct sys_open_args boa;
caddr_t sg;
sg = stackgap_init(p->p_emul);
fl = linux_to_bsd_ioflags(SCARG(uap, flags));
if (fl & O_CREAT)
LINUX_CHECK_ALT_CREAT(p, &sg, SCARG(uap, path));
else
LINUX_CHECK_ALT_EXIST(p, &sg, SCARG(uap, path));
SCARG(&boa, path) = SCARG(uap, path);
SCARG(&boa, flags) = fl;
SCARG(&boa, mode) = SCARG(uap, mode);
if ((error = sys_open(p, &boa, retval)))
return error;
/*
* this bit from sunos_misc.c (and svr4_fcntl.c).
* If we are a session leader, and we don't have a controlling
* terminal yet, and the O_NOCTTY flag is not set, try to make
* this the controlling terminal.
*/
if (!(fl & O_NOCTTY) && SESS_LEADER(p) && !(p->p_flag & P_CONTROLT)) {
struct filedesc *fdp = p->p_fd;
struct file *fp = fdp->fd_ofiles[*retval];
/* ignore any error, just give it a try */
if (fp->f_type == DTYPE_VNODE)
(fp->f_ops->fo_ioctl) (fp, TIOCSCTTY, (caddr_t) 0, p);
}
return 0;
}
/*
* This appears to be part of a Linux attempt to switch to 64 bits file sizes.
*/
int
linux_sys_llseek(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct linux_sys_llseek_args /* {
syscallarg(int) fd;
syscallarg(uint32_t) ohigh;
syscallarg(uint32_t) olow;
syscallarg(caddr_t) res;
syscallarg(int) whence;
} */ *uap = v;
struct sys_lseek_args bla;
int error;
off_t off;
off = SCARG(uap, olow) | (((off_t) SCARG(uap, ohigh)) << 32);
SCARG(&bla, fd) = SCARG(uap, fd);
SCARG(&bla, offset) = off;
SCARG(&bla, whence) = SCARG(uap, whence);
if ((error = sys_lseek(p, &bla, retval)))
return error;
if ((error = copyout(retval, SCARG(uap, res), sizeof (off_t))))
return error;
retval[0] = 0;
return 0;
}
/*
* The next two functions take care of converting the flock
* structure back and forth between Linux and NetBSD format.
* The only difference in the structures is the order of
* the fields, and the 'whence' value.
*/
static void
bsd_to_linux_flock(bfp, lfp)
struct flock *bfp;
struct linux_flock *lfp;
{
lfp->l_start = bfp->l_start;
lfp->l_len = bfp->l_len;
lfp->l_pid = bfp->l_pid;
lfp->l_whence = bfp->l_whence;
switch (bfp->l_type) {
case F_RDLCK:
lfp->l_type = LINUX_F_RDLCK;
break;
case F_UNLCK:
lfp->l_type = LINUX_F_UNLCK;
break;
case F_WRLCK:
lfp->l_type = LINUX_F_WRLCK;
break;
}
}
static void
linux_to_bsd_flock(lfp, bfp)
struct linux_flock *lfp;
struct flock *bfp;
{
bfp->l_start = lfp->l_start;
bfp->l_len = lfp->l_len;
bfp->l_pid = lfp->l_pid;
bfp->l_whence = lfp->l_whence;
switch (lfp->l_type) {
case LINUX_F_RDLCK:
bfp->l_type = F_RDLCK;
break;
case LINUX_F_UNLCK:
bfp->l_type = F_UNLCK;
break;
case LINUX_F_WRLCK:
bfp->l_type = F_WRLCK;
break;
}
}
/*
* Most actions in the fcntl() call are straightforward; simply
* pass control to the NetBSD system call. A few commands need
* conversions after the actual system call has done its work,
* because the flag values and lock structure are different.
*/
int
linux_sys_fcntl(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct linux_sys_fcntl_args /* {
syscallarg(int) fd;
syscallarg(int) cmd;
syscallarg(void *) arg;
} */ *uap = v;
int fd, cmd, error, val;
caddr_t arg, sg;
struct linux_flock lfl;
struct flock *bfp, bfl;
struct sys_fcntl_args fca;
struct filedesc *fdp;
struct file *fp;
struct vnode *vp;
struct vattr va;
long pgid;
struct pgrp *pgrp;
struct tty *tp, *(*d_tty) __P((dev_t));
fd = SCARG(uap, fd);
cmd = SCARG(uap, cmd);
arg = (caddr_t) SCARG(uap, arg);
switch (cmd) {
case LINUX_F_DUPFD:
cmd = F_DUPFD;
break;
case LINUX_F_GETFD:
cmd = F_GETFD;
break;
case LINUX_F_SETFD:
cmd = F_SETFD;
break;
case LINUX_F_GETFL:
SCARG(&fca, fd) = fd;
SCARG(&fca, cmd) = F_GETFL;
SCARG(&fca, arg) = arg;
if ((error = sys_fcntl(p, &fca, retval)))
return error;
retval[0] = bsd_to_linux_ioflags(retval[0]);
return 0;
case LINUX_F_SETFL:
val = linux_to_bsd_ioflags((int)SCARG(uap, arg));
SCARG(&fca, fd) = fd;
SCARG(&fca, cmd) = F_SETFL;
SCARG(&fca, arg) = (caddr_t) val;
return sys_fcntl(p, &fca, retval);
case LINUX_F_GETLK:
sg = stackgap_init(p->p_emul);
bfp = (struct flock *) stackgap_alloc(&sg, sizeof *bfp);
SCARG(&fca, fd) = fd;
SCARG(&fca, cmd) = F_GETLK;
SCARG(&fca, arg) = bfp;
if ((error = sys_fcntl(p, &fca, retval)))
return error;
if ((error = copyin(bfp, &bfl, sizeof bfl)))
return error;
bsd_to_linux_flock(&bfl, &lfl);
return copyout(&lfl, arg, sizeof lfl);
break;
case LINUX_F_SETLK:
case LINUX_F_SETLKW:
cmd = (cmd == LINUX_F_SETLK ? F_SETLK : F_SETLKW);
if ((error = copyin(arg, &lfl, sizeof lfl)))
return error;
linux_to_bsd_flock(&lfl, &bfl);
sg = stackgap_init(p->p_emul);
bfp = (struct flock *) stackgap_alloc(&sg, sizeof *bfp);
if ((error = copyout(&bfl, bfp, sizeof bfl)))
return error;
SCARG(&fca, fd) = fd;
SCARG(&fca, cmd) = cmd;
SCARG(&fca, arg) = bfp;
return sys_fcntl(p, &fca, retval);
break;
case LINUX_F_SETOWN:
case LINUX_F_GETOWN:
/*
* We need to route around the normal fcntl() for these calls,
* since it uses TIOC{G,S}PGRP, which is too restrictive for
* Linux F_{G,S}ETOWN semantics. For sockets, this problem
* does not exist.
*/
fdp = p->p_fd;
if ((u_int)fd >= fdp->fd_nfiles ||
(fp = fdp->fd_ofiles[fd]) == NULL)
return EBADF;
if (fp->f_type == DTYPE_SOCKET) {
cmd = cmd == LINUX_F_SETOWN ? F_SETOWN : F_GETOWN;
break;
}
vp = (struct vnode *)fp->f_data;
if (vp->v_type != VCHR)
return EINVAL;
if ((error = VOP_GETATTR(vp, &va, p->p_ucred, p)))
return error;
d_tty = cdevsw[major(va.va_rdev)].d_tty;
if (!d_tty || (!(tp = (*d_tty)(va.va_rdev))))
return EINVAL;
if (cmd == LINUX_F_GETOWN) {
retval[0] = tp->t_pgrp ? tp->t_pgrp->pg_id : NO_PID;
return 0;
}
if ((long)arg <= 0) {
pgid = -(long)arg;
} else {
struct proc *p1 = pfind((long)arg);
if (p1 == 0)
return (ESRCH);
pgid = (long)p1->p_pgrp->pg_id;
}
pgrp = pgfind(pgid);
if (pgrp == NULL || pgrp->pg_session != p->p_session)
return EPERM;
tp->t_pgrp = pgrp;
return 0;
default:
return EOPNOTSUPP;
}
SCARG(&fca, fd) = fd;
SCARG(&fca, cmd) = cmd;
SCARG(&fca, arg) = arg;
return sys_fcntl(p, &fca, retval);
}
/*
* Convert a NetBSD stat structure to a Linux stat structure.
* Only the order of the fields and the padding in the structure
* is different. linux_fakedev is a machine-dependent function
* which optionally converts device driver major/minor numbers
* (XXX horrible, but what can you do against code that compares
* things against constant major device numbers? sigh)
*/
static void
bsd_to_linux_stat(bsp, lsp)
struct stat *bsp;
struct linux_stat *lsp;
{
lsp->lst_dev = bsp->st_dev;
lsp->lst_ino = bsp->st_ino;
lsp->lst_mode = bsp->st_mode;
lsp->lst_nlink = bsp->st_nlink;
lsp->lst_uid = bsp->st_uid;
lsp->lst_gid = bsp->st_gid;
lsp->lst_rdev = linux_fakedev(bsp->st_rdev);
lsp->lst_size = bsp->st_size;
lsp->lst_blksize = bsp->st_blksize;
lsp->lst_blocks = bsp->st_blocks;
lsp->lst_atime = bsp->st_atime;
lsp->lst_mtime = bsp->st_mtime;
lsp->lst_ctime = bsp->st_ctime;
}
/*
* The stat functions below are plain sailing. stat and lstat are handled
* by one function to avoid code duplication.
*/
int
linux_sys_fstat(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct linux_sys_fstat_args /* {
syscallarg(int) fd;
syscallarg(linux_stat *) sp;
} */ *uap = v;
struct sys_fstat_args fsa;
struct linux_stat tmplst;
struct stat *st,tmpst;
caddr_t sg;
int error;
sg = stackgap_init(p->p_emul);
st = stackgap_alloc(&sg, sizeof (struct stat));
SCARG(&fsa, fd) = SCARG(uap, fd);
SCARG(&fsa, sb) = st;
if ((error = sys_fstat(p, &fsa, retval)))
return error;
if ((error = copyin(st, &tmpst, sizeof tmpst)))
return error;
bsd_to_linux_stat(&tmpst, &tmplst);
if ((error = copyout(&tmplst, SCARG(uap, sp), sizeof tmplst)))
return error;
return 0;
}
static int
linux_stat1(p, uap, retval, dolstat)
struct proc *p;
struct linux_sys_stat_args *uap;
register_t *retval;
int dolstat;
{
struct sys_stat_args sa;
struct linux_stat tmplst;
struct stat *st, tmpst;
caddr_t sg;
int error;
sg = stackgap_init(p->p_emul);
LINUX_CHECK_ALT_EXIST(p, &sg, SCARG(uap, path));
st = stackgap_alloc(&sg, sizeof (struct stat));
SCARG(&sa, ub) = st;
SCARG(&sa, path) = SCARG(uap, path);
if ((error = (dolstat ? sys_lstat(p, &sa, retval) :
sys_stat(p, &sa, retval))))
return error;
if ((error = copyin(st, &tmpst, sizeof tmpst)))
return error;
bsd_to_linux_stat(&tmpst, &tmplst);
if ((error = copyout(&tmplst, SCARG(uap, sp), sizeof tmplst)))
return error;
return 0;
}
int
linux_sys_stat(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct linux_sys_stat_args /* {
syscallarg(char *) path;
syscallarg(struct linux_stat *) sp;
} */ *uap = v;
return linux_stat1(p, uap, retval, 0);
}
int
linux_sys_lstat(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct linux_sys_lstat_args /* {
syscallarg(char *) path;
syscallarg(struct linux_stat *) sp;
} */ *uap = v;
return linux_stat1(p, uap, retval, 1);
}
/*
* The following syscalls are mostly here because of the alternate path check.
*/
int
linux_sys_access(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct linux_sys_access_args /* {
syscallarg(char *) path;
syscallarg(int) flags;
} */ *uap = v;
caddr_t sg = stackgap_init(p->p_emul);
LINUX_CHECK_ALT_EXIST(p, &sg, SCARG(uap, path));
return sys_access(p, uap, retval);
}
int
linux_sys_unlink(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct linux_sys_unlink_args /* {
syscallarg(char *) path;
} */ *uap = v;
caddr_t sg = stackgap_init(p->p_emul);
LINUX_CHECK_ALT_EXIST(p, &sg, SCARG(uap, path));
return sys_unlink(p, uap, retval);
}
int
linux_sys_chdir(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct linux_sys_chdir_args /* {
syscallarg(char *) path;
} */ *uap = v;
caddr_t sg = stackgap_init(p->p_emul);
LINUX_CHECK_ALT_EXIST(p, &sg, SCARG(uap, path));
return sys_chdir(p, uap, retval);
}
int
linux_sys_mknod(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct linux_sys_mknod_args /* {
syscallarg(char *) path;
syscallarg(int) mode;
syscallarg(int) dev;
} */ *uap = v;
caddr_t sg = stackgap_init(p->p_emul);
struct sys_mkfifo_args bma;
LINUX_CHECK_ALT_CREAT(p, &sg, SCARG(uap, path));
/*
* BSD handles FIFOs seperately
*/
if (SCARG(uap, mode) & S_IFIFO) {
SCARG(&bma, path) = SCARG(uap, path);
SCARG(&bma, mode) = SCARG(uap, mode);
return sys_mkfifo(p, uap, retval);
} else
return sys_mknod(p, uap, retval);
}
int
linux_sys_chmod(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct linux_sys_chmod_args /* {
syscallarg(char *) path;
syscallarg(int) mode;
} */ *uap = v;
caddr_t sg = stackgap_init(p->p_emul);
LINUX_CHECK_ALT_EXIST(p, &sg, SCARG(uap, path));
return sys_chmod(p, uap, retval);
}
int
linux_sys_chown(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct linux_sys_chown_args /* {
syscallarg(char *) path;
syscallarg(int) uid;
syscallarg(int) gid;
} */ *uap = v;
struct sys_chown_args bca;
caddr_t sg = stackgap_init(p->p_emul);
LINUX_CHECK_ALT_EXIST(p, &sg, SCARG(uap, path));
SCARG(&bca, path) = SCARG(uap, path);
SCARG(&bca, uid) = ((linux_uid_t)SCARG(uap, uid) == (linux_uid_t)-1) ?
(uid_t)-1 : SCARG(uap, uid);
SCARG(&bca, gid) = ((linux_gid_t)SCARG(uap, gid) == (linux_gid_t)-1) ?
(gid_t)-1 : SCARG(uap, gid);
return sys_chown(p, &bca, retval);
}
int
linux_sys_fchown(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct linux_sys_fchown_args /* {
syscallarg(int) fd;
syscallarg(int) uid;
syscallarg(int) gid;
} */ *uap = v;
struct sys_fchown_args bfa;
SCARG(&bfa, fd) = SCARG(uap, fd);
SCARG(&bfa, uid) = ((linux_uid_t)SCARG(uap, uid) == (linux_uid_t)-1) ?
(uid_t)-1 : SCARG(uap, uid);
SCARG(&bfa, gid) = ((linux_gid_t)SCARG(uap, gid) == (linux_gid_t)-1) ?
(gid_t)-1 : SCARG(uap, gid);
return sys_fchown(p, &bfa, retval);
}
int
linux_sys_rename(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct linux_sys_rename_args /* {
syscallarg(char *) from;
syscallarg(char *) to;
} */ *uap = v;
caddr_t sg = stackgap_init(p->p_emul);
LINUX_CHECK_ALT_EXIST(p, &sg, SCARG(uap, from));
LINUX_CHECK_ALT_CREAT(p, &sg, SCARG(uap, to));
return sys_rename(p, uap, retval);
}
int
linux_sys_mkdir(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct linux_sys_mkdir_args /* {
syscallarg(char *) path;
syscallarg(int) mode;
} */ *uap = v;
caddr_t sg = stackgap_init(p->p_emul);
LINUX_CHECK_ALT_CREAT(p, &sg, SCARG(uap, path));
return sys_mkdir(p, uap, retval);
}
int
linux_sys_rmdir(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct linux_sys_rmdir_args /* {
syscallarg(char *) path;
} */ *uap = v;
caddr_t sg = stackgap_init(p->p_emul);
LINUX_CHECK_ALT_EXIST(p, &sg, SCARG(uap, path));
return sys_rmdir(p, uap, retval);
}
int
linux_sys_symlink(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct linux_sys_symlink_args /* {
syscallarg(char *) path;
syscallarg(char *) to;
} */ *uap = v;
caddr_t sg = stackgap_init(p->p_emul);
LINUX_CHECK_ALT_EXIST(p, &sg, SCARG(uap, path));
LINUX_CHECK_ALT_CREAT(p, &sg, SCARG(uap, to));
return sys_symlink(p, uap, retval);
}
int
linux_sys_readlink(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct linux_sys_readlink_args /* {
syscallarg(char *) name;
syscallarg(char *) buf;
syscallarg(int) count;
} */ *uap = v;
caddr_t sg = stackgap_init(p->p_emul);
LINUX_CHECK_ALT_EXIST(p, &sg, SCARG(uap, name));
return sys_readlink(p, uap, retval);
}
int
linux_sys_truncate(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct linux_sys_truncate_args /* {
syscallarg(char *) path;
syscallarg(long) length;
} */ *uap = v;
caddr_t sg = stackgap_init(p->p_emul);
LINUX_CHECK_ALT_EXIST(p, &sg, SCARG(uap, path));
return compat_43_sys_truncate(p, uap, retval);
}