1 /* $NetBSD: compat_util.c,v 1.37 2007/07/13 21:04:29 dsl 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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 __KERNEL_RCSID(0, "$NetBSD: compat_util.c,v 1.37 2007/07/13 21:04:29 dsl Exp $"); 41 42 #include "opt_systrace.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/namei.h> 47 #include <sys/proc.h> 48 #include <sys/file.h> 49 #include <sys/stat.h> 50 #include <sys/filedesc.h> 51 #include <sys/exec.h> 52 #include <sys/ioctl.h> 53 #include <sys/kernel.h> 54 #include <sys/malloc.h> 55 #include <sys/vnode.h> 56 #include <sys/syslog.h> 57 #include <sys/mount.h> 58 59 60 #include <compat/common/compat_util.h> 61 62 void 63 emul_find_root(struct lwp *l, struct exec_package *epp) 64 { 65 struct nameidata nd; 66 const char *emul_path; 67 68 if (epp->ep_emul_root != NULL) 69 /* We've already found it */ 70 return; 71 72 emul_path = epp->ep_esch->es_emul->e_path; 73 if (emul_path == NULL) 74 /* Emulation doesn't have a root */ 75 return; 76 77 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, emul_path, l); 78 if (namei(&nd) != 0) 79 /* emulation root doesn't exist */ 80 return; 81 82 epp->ep_emul_root = nd.ni_vp; 83 } 84 85 /* 86 * Search the alternate path for dynamic binary interpreter. If not found 87 * there, check if the interpreter exists in within 'proper' tree. 88 */ 89 int 90 emul_find_interp(struct lwp *l, struct exec_package *epp, const char *itp) 91 { 92 int error; 93 struct nameidata nd; 94 unsigned int flags; 95 96 /* If we haven't found the emulation root already, do so now */ 97 /* Maybe we should remember failures somehow ? */ 98 if (epp->ep_esch->es_emul->e_path != 0 && epp->ep_emul_root == NULL) 99 emul_find_root(l, epp); 100 101 if (epp->ep_interp != NULL) 102 vrele(epp->ep_interp); 103 104 /* We need to use the emulation root for the new program, 105 * not the one for the current process. */ 106 if (epp->ep_emul_root == NULL) 107 flags = FOLLOW; 108 else { 109 nd.ni_erootdir = epp->ep_emul_root; 110 /* hack: Pass in the emulation path for ktrace calls */ 111 nd.ni_next = epp->ep_esch->es_emul->e_path; 112 flags = FOLLOW | TRYEMULROOT | EMULROOTSET; 113 } 114 115 NDINIT(&nd, LOOKUP, flags, UIO_SYSSPACE, itp, l); 116 error = namei(&nd); 117 if (error != 0) { 118 epp->ep_interp = NULL; 119 return error; 120 } 121 122 /* Save interpreter in case we actually need to load it */ 123 epp->ep_interp = nd.ni_vp; 124 125 return 0; 126 } 127 128 /* 129 * Translate one set of flags to another, based on the entries in 130 * the given table. If 'leftover' is specified, it is filled in 131 * with any flags which could not be translated. 132 */ 133 unsigned long 134 emul_flags_translate(const struct emul_flags_xtab *tab, 135 unsigned long in, unsigned long *leftover) 136 { 137 unsigned long out; 138 139 for (out = 0; tab->omask != 0; tab++) { 140 if ((in & tab->omask) == tab->oval) { 141 in &= ~tab->omask; 142 out |= tab->nval; 143 } 144 } 145 if (leftover != NULL) 146 *leftover = in; 147 return (out); 148 } 149 150 /* The only user left of the stackgap is the systrace code. */ 151 #if SYSTRACE 152 void * 153 stackgap_init(p, sz) 154 const struct proc *p; 155 size_t sz; 156 { 157 if (sz == 0) 158 sz = STACKGAPLEN; 159 if (sz > STACKGAPLEN) 160 panic("size %lu > STACKGAPLEN", (unsigned long)sz); 161 #define szsigcode ((void *)(p->p_emul->e_esigcode - p->p_emul->e_sigcode)) 162 return (void *)(((unsigned long)p->p_psstr - (unsigned long)szsigcode 163 - sz) & ~ALIGNBYTES); 164 #undef szsigcode 165 } 166 167 168 void * 169 stackgap_alloc(p, sgp, sz) 170 const struct proc *p; 171 void **sgp; 172 size_t sz; 173 { 174 void *n = *sgp; 175 void *nsgp; 176 const struct emul *e = p->p_emul; 177 int sigsize = e->e_esigcode - e->e_sigcode; 178 179 sz = ALIGN(sz); 180 nsgp = (char *)*sgp + sz; 181 if (nsgp > (void *)(((char *)p->p_psstr) - sigsize)) 182 return NULL; 183 *sgp = nsgp; 184 return n; 185 } 186 #endif 187 188 void 189 compat_offseterr(vp, msg) 190 struct vnode *vp; 191 const char *msg; 192 { 193 struct mount *mp; 194 195 mp = vp->v_mount; 196 197 log(LOG_ERR, "%s: dir offset too large on fs %s (mounted from %s)\n", 198 msg, mp->mnt_stat.f_mntonname, mp->mnt_stat.f_mntfromname); 199 uprintf("%s: dir offset too large for emulated program\n", msg); 200 } 201