1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* 28 * Copyright (c) 1988 AT&T 29 * All Rights Reserved 30 */ 31 /* 32 * Copyright (c) 2012, Joyent, Inc. All rights reserved. 33 * Copyright 2022 Oxide Computer Company 34 */ 35 36 /* 37 * i386 specific setup routine - relocate ld.so's symbols, setup its 38 * environment, map in loadable sections of the executable. 39 * 40 * Takes base address ld.so was loaded at, address of ld.so's dynamic 41 * structure, address of process environment pointers, address of auxiliary 42 * vector and * argv[0] (process name). 43 * If errors occur, send process signal - otherwise 44 * return executable's entry point to the bootstrap routine. 45 */ 46 47 #include <signal.h> 48 #include <stdlib.h> 49 #include <sys/auxv.h> 50 #include <sys/types.h> 51 #include <sys/stat.h> 52 #include <link.h> 53 #include <dlfcn.h> 54 #include "_rtld.h" 55 #include "_audit.h" 56 #include "msg.h" 57 58 /* VARARGS */ 59 unsigned long 60 _setup(Boot *ebp, Dyn *ld_dyn) 61 { 62 ulong_t reladdr, relcount, ld_base = 0; 63 ulong_t relent = 0; 64 ulong_t strtab, soname, interp_base = 0; 65 char *_rt_name, **_envp, **_argv; 66 int _syspagsz = 0, fd = -1; 67 uint_t _flags = 0; 68 uint_t hwcap[3] = { 0, 0, 0 }; 69 Dyn *dyn_ptr; 70 Phdr *phdr = NULL; 71 Rt_map *lmp; 72 auxv_t *auxv, *_auxv; 73 uid_t uid = (uid_t)-1, euid = (uid_t)-1; 74 gid_t gid = (gid_t)-1, egid = (gid_t)-1; 75 char *_platform = NULL, *_execname = NULL, *_emulator = NULL; 76 int auxflags = -1; 77 78 /* 79 * Scan the bootstrap structure to pick up the basics. 80 */ 81 for (; ebp->eb_tag != EB_NULL; ebp++) 82 switch (ebp->eb_tag) { 83 case EB_LDSO_BASE: 84 ld_base = (unsigned long)ebp->eb_un.eb_val; 85 break; 86 case EB_ARGV: 87 _argv = (char **)ebp->eb_un.eb_ptr; 88 break; 89 case EB_ENVP: 90 _envp = (char **)ebp->eb_un.eb_ptr; 91 break; 92 case EB_AUXV: 93 _auxv = (auxv_t *)ebp->eb_un.eb_ptr; 94 break; 95 case EB_PAGESIZE: 96 _syspagsz = (int)ebp->eb_un.eb_val; 97 break; 98 } 99 100 /* 101 * Search the aux. vector for the information passed by exec. 102 */ 103 for (auxv = _auxv; auxv->a_type != AT_NULL; auxv++) { 104 switch (auxv->a_type) { 105 case AT_EXECFD: 106 /* this is the old exec that passes a file descriptor */ 107 fd = (int)auxv->a_un.a_val; 108 break; 109 case AT_FLAGS: 110 /* processor flags (MAU available, etc) */ 111 _flags = auxv->a_un.a_val; 112 break; 113 case AT_PAGESZ: 114 /* system page size */ 115 _syspagsz = (int)auxv->a_un.a_val; 116 break; 117 case AT_PHDR: 118 /* address of the segment table */ 119 phdr = (Phdr *)auxv->a_un.a_ptr; 120 break; 121 case AT_BASE: 122 /* interpreter base address */ 123 if (ld_base == 0) 124 ld_base = auxv->a_un.a_val; 125 interp_base = auxv->a_un.a_val; 126 break; 127 case AT_SUN_UID: 128 /* effective user id for the executable */ 129 euid = (uid_t)auxv->a_un.a_val; 130 break; 131 case AT_SUN_RUID: 132 /* real user id for the executable */ 133 uid = (uid_t)auxv->a_un.a_val; 134 break; 135 case AT_SUN_GID: 136 /* effective group id for the executable */ 137 egid = (gid_t)auxv->a_un.a_val; 138 break; 139 case AT_SUN_RGID: 140 /* real group id for the executable */ 141 gid = (gid_t)auxv->a_un.a_val; 142 break; 143 case AT_SUN_PLATFORM: 144 /* platform name */ 145 _platform = auxv->a_un.a_ptr; 146 break; 147 case AT_SUN_EXECNAME: 148 /* full pathname of execed object */ 149 _execname = auxv->a_un.a_ptr; 150 break; 151 case AT_SUN_AUXFLAGS: 152 /* auxiliary flags */ 153 auxflags = (int)auxv->a_un.a_val; 154 break; 155 case AT_SUN_HWCAP: 156 /* hardware capabilities */ 157 hwcap[0] = (uint_t)auxv->a_un.a_val; 158 break; 159 case AT_SUN_HWCAP2: 160 /* hardware capabilities */ 161 hwcap[1] = (uint_t)auxv->a_un.a_val; 162 break; 163 case AT_SUN_HWCAP3: 164 /* hardware capabilities */ 165 hwcap[2] = (uint_t)auxv->a_un.a_val; 166 break; 167 case AT_SUN_EMULATOR: 168 /* name of emulation library, if any */ 169 _emulator = auxv->a_un.a_ptr; 170 break; 171 } 172 } 173 174 /* 175 * Get needed info from ld.so's dynamic structure. 176 */ 177 /* LINTED */ 178 dyn_ptr = (Dyn *)((char *)ld_dyn + ld_base); 179 for (ld_dyn = dyn_ptr; ld_dyn->d_tag != DT_NULL; ld_dyn++) { 180 switch (ld_dyn->d_tag) { 181 case DT_REL: 182 reladdr = ld_dyn->d_un.d_ptr + ld_base; 183 break; 184 case DT_RELCOUNT: 185 relcount = ld_dyn->d_un.d_val; 186 break; 187 case DT_RELENT: 188 relent = ld_dyn->d_un.d_val; 189 break; 190 case DT_STRTAB: 191 strtab = ld_dyn->d_un.d_ptr + ld_base; 192 break; 193 case DT_SONAME: 194 soname = ld_dyn->d_un.d_val; 195 break; 196 } 197 } 198 _rt_name = (char *)strtab + soname; 199 200 /* 201 * If we don't have a RELENT, just assume the size. 202 */ 203 if (relent == 0) 204 relent = sizeof (Rel); 205 206 /* 207 * As all global symbol references within ld.so.1 are protected 208 * (symbolic), only RELATIVE and JMPSLOT relocations should be left 209 * to process at runtime. Process all relative relocations now. 210 */ 211 for (; relcount; relcount--) { 212 ulong_t roffset; 213 214 roffset = ((Rel *)reladdr)->r_offset + ld_base; 215 *((ulong_t *)roffset) += ld_base; 216 reladdr += relent; 217 } 218 219 /* 220 * If an emulation library is being used, use that as the linker's 221 * effective executable name. The real executable is not linked by this 222 * linker. 223 */ 224 if (_emulator != NULL) { 225 _execname = _emulator; 226 rtld_flags2 |= RT_FL2_BRANDED; 227 } 228 229 /* 230 * Initialize the dyn_plt_ent_size field. It currently contains the 231 * size of the dyn_plt_template. It still needs to be aligned and have 232 * space for the 'dyn_data' area added. 233 */ 234 dyn_plt_ent_size = ROUND(dyn_plt_ent_size, M_WORD_ALIGN) + 235 sizeof (uintptr_t) + sizeof (uintptr_t) + sizeof (ulong_t) + 236 sizeof (ulong_t) + sizeof (Sym); 237 238 /* 239 * Continue with generic startup processing. 240 */ 241 if ((lmp = setup((char **)_envp, (auxv_t *)_auxv, _flags, _platform, 242 _syspagsz, _rt_name, ld_base, interp_base, fd, phdr, 243 _execname, _argv, uid, euid, gid, egid, auxflags, 244 hwcap)) == NULL) { 245 rtldexit(&lml_main, 1); 246 } 247 248 return (LM_ENTRY_PT(lmp)()); 249 } 250