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compat_util.c revision 1.40.6.1 
      1 /* 	$NetBSD: compat_util.c,v 1.40.6.1 2008/06/02 13:22:56 mjf Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1994 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Christos Zoulas and Frank van der Linden.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 __KERNEL_RCSID(0, "$NetBSD: compat_util.c,v 1.40.6.1 2008/06/02 13:22:56 mjf Exp $");
     34 
     35 #include <sys/param.h>
     36 #include <sys/systm.h>
     37 #include <sys/namei.h>
     38 #include <sys/proc.h>
     39 #include <sys/file.h>
     40 #include <sys/stat.h>
     41 #include <sys/filedesc.h>
     42 #include <sys/exec.h>
     43 #include <sys/ioctl.h>
     44 #include <sys/kernel.h>
     45 #include <sys/malloc.h>
     46 #include <sys/vnode.h>
     47 #include <sys/syslog.h>
     48 #include <sys/mount.h>
     49 
     50 #include <compat/common/compat_util.h>
     51 
     52 void
     53 emul_find_root(struct lwp *l, struct exec_package *epp)
     54 {
     55 	struct nameidata nd;
     56 	const char *emul_path;
     57 
     58 	if (epp->ep_emul_root != NULL)
     59 		/* We've already found it */
     60 		return;
     61 
     62 	emul_path = epp->ep_esch->es_emul->e_path;
     63 	if (emul_path == NULL)
     64 		/* Emulation doesn't have a root */
     65 		return;
     66 
     67 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, emul_path);
     68 	if (namei(&nd) != 0)
     69 		/* emulation root doesn't exist */
     70 		return;
     71 
     72 	epp->ep_emul_root = nd.ni_vp;
     73 }
     74 
     75 /*
     76  * Search the alternate path for dynamic binary interpreter. If not found
     77  * there, check if the interpreter exists in within 'proper' tree.
     78  */
     79 int
     80 emul_find_interp(struct lwp *l, struct exec_package *epp, const char *itp)
     81 {
     82 	int error;
     83 	struct nameidata nd;
     84 	unsigned int flags;
     85 
     86 	/* If we haven't found the emulation root already, do so now */
     87 	/* Maybe we should remember failures somehow ? */
     88 	if (epp->ep_esch->es_emul->e_path != 0 && epp->ep_emul_root == NULL)
     89 		emul_find_root(l, epp);
     90 
     91 	if (epp->ep_interp != NULL)
     92 		vrele(epp->ep_interp);
     93 
     94 	/* We need to use the emulation root for the new program,
     95 	 * not the one for the current process. */
     96 	if (epp->ep_emul_root == NULL)
     97 		flags = FOLLOW;
     98 	else {
     99 		nd.ni_erootdir = epp->ep_emul_root;
    100 		/* hack: Pass in the emulation path for ktrace calls */
    101 		nd.ni_next = epp->ep_esch->es_emul->e_path;
    102 		flags = FOLLOW | TRYEMULROOT | EMULROOTSET;
    103 	}
    104 
    105 	NDINIT(&nd, LOOKUP, flags, UIO_SYSSPACE, itp);
    106 	error = namei(&nd);
    107 	if (error != 0) {
    108 		epp->ep_interp = NULL;
    109 		return error;
    110 	}
    111 
    112 	/* Save interpreter in case we actually need to load it */
    113 	epp->ep_interp = nd.ni_vp;
    114 
    115 	return 0;
    116 }
    117 
    118 /*
    119  * Translate one set of flags to another, based on the entries in
    120  * the given table.  If 'leftover' is specified, it is filled in
    121  * with any flags which could not be translated.
    122  */
    123 unsigned long
    124 emul_flags_translate(const struct emul_flags_xtab *tab,
    125 		     unsigned long in, unsigned long *leftover)
    126 {
    127 	unsigned long out;
    128 
    129 	for (out = 0; tab->omask != 0; tab++) {
    130 		if ((in & tab->omask) == tab->oval) {
    131 			in &= ~tab->omask;
    132 			out |= tab->nval;
    133 		}
    134 	}
    135 	if (leftover != NULL)
    136 		*leftover = in;
    137 	return (out);
    138 }
    139 
    140 void
    141 compat_offseterr(struct vnode *vp, const char *msg)
    142 {
    143 	struct mount *mp;
    144 
    145 	mp = vp->v_mount;
    146 
    147 	log(LOG_ERR, "%s: dir offset too large on fs %s (mounted from %s)\n",
    148 	    msg, mp->mnt_stat.f_mntonname, mp->mnt_stat.f_mntfromname);
    149 	uprintf("%s: dir offset too large for emulated program\n", msg);
    150 }
    151