1 /* $NetBSD: subr_emul.c,v 1.4 2026/01/04 03:17:08 riastradh 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 1.4 2026/01/04 03:17:08 riastradh Exp $"); 61 62 #ifdef _KERNEL_OPT 63 #include "opt_pax.h" 64 #endif /* _KERNEL_OPT */ 65 66 #include <sys/param.h> 67 68 #include <sys/exec.h> 69 #include <sys/namei.h> 70 #include <sys/proc.h> 71 #include <sys/sdt.h> 72 #include <sys/vnode.h> 73 74 #include <compat/common/compat_util.h> 75 76 void 77 emul_find_root(struct lwp *l, struct exec_package *epp) 78 { 79 struct vnode *vp; 80 const char *emul_path; 81 82 if (epp->ep_emul_root != NULL) 83 /* We've already found it */ 84 return; 85 86 emul_path = epp->ep_esch->es_emul->e_path; 87 if (emul_path == NULL) 88 /* Emulation doesn't have a root */ 89 return; 90 91 if (namei_simple_kernel(emul_path, NSM_FOLLOW_NOEMULROOT, &vp) != 0) 92 /* emulation root doesn't exist */ 93 return; 94 95 epp->ep_emul_root = vp; 96 } 97 98 /* 99 * Search the alternate path for dynamic binary interpreter. If not found 100 * there, check if the interpreter exists in within 'proper' tree. 101 */ 102 int 103 emul_find_interp(struct lwp *l, struct exec_package *epp, const char *itp) 104 { 105 int error; 106 struct pathbuf *pb; 107 struct nameidata nd; 108 unsigned int flags; 109 110 pb = pathbuf_create(itp); 111 if (pb == NULL) { 112 return SET_ERROR(ENOMEM); 113 } 114 115 /* If we haven't found the emulation root already, do so now */ 116 /* Maybe we should remember failures somehow ? */ 117 if (epp->ep_esch->es_emul->e_path != 0 && epp->ep_emul_root == NULL) 118 emul_find_root(l, epp); 119 120 if (epp->ep_interp != NULL) 121 vrele(epp->ep_interp); 122 123 /* We need to use the emulation root for the new program, 124 * not the one for the current process. */ 125 if (epp->ep_emul_root == NULL) 126 flags = FOLLOW; 127 else { 128 nd.ni_erootdir = epp->ep_emul_root; 129 /* hack: Pass in the emulation path for ktrace calls */ 130 nd.ni_next = epp->ep_esch->es_emul->e_path; 131 flags = FOLLOW | TRYEMULROOT | EMULROOTSET; 132 } 133 134 NDINIT(&nd, LOOKUP, flags, pb); 135 error = namei(&nd); 136 if (error != 0) { 137 epp->ep_interp = NULL; 138 pathbuf_destroy(pb); 139 return error; 140 } 141 142 /* Save interpreter in case we actually need to load it */ 143 epp->ep_interp = nd.ni_vp; 144 145 pathbuf_destroy(pb); 146 147 return 0; 148 } 149
Indexes created Sat Feb 21 01:20:28 UTC 2026