1/* $NetBSD: subr_emul.c,v 1.2 2019/01/27 02:08:43 pgoyette Exp $ */ 2 3/*- 4 * Copyright (c) 1994, 2000, 2005, 2015 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 Maxime Villard. 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/* 33 * Copyright (c) 1996 Christopher G. Demetriou 34 * All rights reserved. 35 * 36 * Redistribution and use in source and binary forms, with or without 37 * modification, are permitted provided that the following conditions 38 * are met: 39 * 1. Redistributions of source code must retain the above copyright 40 * notice, this list of conditions and the following disclaimer. 41 * 2. Redistributions in binary form must reproduce the above copyright 42 * notice, this list of conditions and the following disclaimer in the 43 * documentation and/or other materials provided with the distribution. 44 * 3. The name of the author may not be used to endorse or promote products 45 * derived from this software without specific prior written permission 46 * 47 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 48 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 49 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 50 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 51 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 52 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 53 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 54 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 55 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 56 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 57 */ 58 59#include <sys/cdefs.h> 60__KERNEL_RCSID(1, "$NetBSD: subr_emul.c,v 1.2 2019/01/27 02:08:43 pgoyette Exp $"); 61 62#ifdef _KERNEL_OPT 63#include "opt_pax.h" 64#endif /* _KERNEL_OPT */ 65 66#include <sys/param.h> 67#include <sys/proc.h> 68#include <sys/vnode.h> 69#include <sys/namei.h> 70#include <sys/exec.h> 71 72#include <compat/common/compat_util.h> 73 74void 75emul_find_root(struct lwp *l, struct exec_package *epp) 76{ 77 struct vnode *vp; 78 const char *emul_path; 79 80 if (epp->ep_emul_root != NULL) 81 /* We've already found it */ 82 return; 83 84 emul_path = epp->ep_esch->es_emul->e_path; 85 if (emul_path == NULL) 86 /* Emulation doesn't have a root */ 87 return; 88 89 if (namei_simple_kernel(emul_path, NSM_FOLLOW_NOEMULROOT, &vp) != 0) 90 /* emulation root doesn't exist */ 91 return; 92 93 epp->ep_emul_root = vp; 94} 95 96/* 97 * Search the alternate path for dynamic binary interpreter. If not found 98 * there, check if the interpreter exists in within 'proper' tree. 99 */ 100int 101emul_find_interp(struct lwp *l, struct exec_package *epp, const char *itp) 102{ 103 int error; 104 struct pathbuf *pb; 105 struct nameidata nd; 106 unsigned int flags; 107 108 pb = pathbuf_create(itp); 109 if (pb == NULL) { 110 return ENOMEM; 111 } 112 113 /* If we haven't found the emulation root already, do so now */ 114 /* Maybe we should remember failures somehow ? */ 115 if (epp->ep_esch->es_emul->e_path != 0 && epp->ep_emul_root == NULL) 116 emul_find_root(l, epp); 117 118 if (epp->ep_interp != NULL) 119 vrele(epp->ep_interp); 120 121 /* We need to use the emulation root for the new program, 122 * not the one for the current process. */ 123 if (epp->ep_emul_root == NULL) 124 flags = FOLLOW; 125 else { 126 nd.ni_erootdir = epp->ep_emul_root; 127 /* hack: Pass in the emulation path for ktrace calls */ 128 nd.ni_next = epp->ep_esch->es_emul->e_path; 129 flags = FOLLOW | TRYEMULROOT | EMULROOTSET; 130 } 131 132 NDINIT(&nd, LOOKUP, flags, pb); 133 error = namei(&nd); 134 if (error != 0) { 135 epp->ep_interp = NULL; 136 pathbuf_destroy(pb); 137 return error; 138 } 139 140 /* Save interpreter in case we actually need to load it */ 141 epp->ep_interp = nd.ni_vp; 142 143 pathbuf_destroy(pb); 144 145 return 0; 146} 147