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 2008 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 #pragma ident "%Z%%M% %I% %E% SMI" 33 34 /* 35 * i386 specific setup routine - relocate ld.so's symbols, setup its 36 * environment, map in loadable sections of the executable. 37 * 38 * Takes base address ld.so was loaded at, address of ld.so's dynamic 39 * structure, address of process environment pointers, address of auxiliary 40 * vector and * argv[0] (process name). 41 * If errors occur, send process signal - otherwise 42 * return executable's entry point to the bootstrap routine. 43 */ 44 45 #include <signal.h> 46 #include <stdlib.h> 47 #include <sys/auxv.h> 48 #include <sys/types.h> 49 #include <sys/stat.h> 50 #include <link.h> 51 #include <dlfcn.h> 52 #include <debug.h> 53 #include "_rtld.h" 54 #include "_audit.h" 55 #include "msg.h" 56 57 extern int _end; 58 extern int _etext; 59 60 61 /* 62 * Stub routine to prevent atexit_init() being extracted from libc_pic.a on 63 * i386 and added to ld.so.1. We don't need it. 64 */ 65 void 66 atexit_init() 67 { 68 } 69 70 /* VARARGS */ 71 unsigned long 72 _setup(Boot * ebp, Dyn * ld_dyn) 73 { 74 unsigned long reladdr, relcount, ld_base = 0; 75 unsigned long relent = 0; 76 unsigned long strtab, soname, interp_base = 0; 77 char *_rt_name, **_envp, **_argv; 78 int _syspagsz = 0, fd = -1, dz_fd = FD_UNAVAIL; 79 uint_t _flags = 0, hwcap_1 = 0; 80 Dyn * dyn_ptr; 81 Phdr * phdr = 0; 82 Rt_map * lmp; 83 auxv_t *auxv, *_auxv; 84 uid_t uid = (uid_t)-1, euid = (uid_t)-1; 85 gid_t gid = (gid_t)-1, egid = (gid_t)-1; 86 char *_platform = 0, *_execname = 0, *_emulator = 0; 87 int auxflags = -1; 88 /* 89 * Scan the bootstrap structure to pick up the basics. 90 */ 91 for (; ebp->eb_tag != EB_NULL; ebp++) 92 switch (ebp->eb_tag) { 93 case EB_LDSO_BASE: 94 ld_base = (unsigned long)ebp->eb_un.eb_val; 95 break; 96 case EB_ARGV: 97 _argv = (char **)ebp->eb_un.eb_ptr; 98 break; 99 case EB_ENVP: 100 _envp = (char **)ebp->eb_un.eb_ptr; 101 break; 102 case EB_AUXV: 103 _auxv = (auxv_t *)ebp->eb_un.eb_ptr; 104 break; 105 case EB_DEVZERO: 106 dz_fd = (int)ebp->eb_un.eb_val; 107 break; 108 case EB_PAGESIZE: 109 _syspagsz = (int)ebp->eb_un.eb_val; 110 break; 111 } 112 113 /* 114 * Search the aux. vector for the information passed by exec. 115 */ 116 for (auxv = _auxv; auxv->a_type != AT_NULL; auxv++) { 117 switch (auxv->a_type) { 118 case AT_EXECFD: 119 /* this is the old exec that passes a file descriptor */ 120 fd = (int)auxv->a_un.a_val; 121 break; 122 case AT_FLAGS: 123 /* processor flags (MAU available, etc) */ 124 _flags = auxv->a_un.a_val; 125 break; 126 case AT_PAGESZ: 127 /* system page size */ 128 _syspagsz = (int)auxv->a_un.a_val; 129 break; 130 case AT_PHDR: 131 /* address of the segment table */ 132 phdr = (Phdr *)auxv->a_un.a_ptr; 133 break; 134 case AT_BASE: 135 /* interpreter base address */ 136 if (ld_base == 0) 137 ld_base = auxv->a_un.a_val; 138 interp_base = auxv->a_un.a_val; 139 break; 140 case AT_SUN_UID: 141 /* effective user id for the executable */ 142 euid = (uid_t)auxv->a_un.a_val; 143 break; 144 case AT_SUN_RUID: 145 /* real user id for the executable */ 146 uid = (uid_t)auxv->a_un.a_val; 147 break; 148 case AT_SUN_GID: 149 /* effective group id for the executable */ 150 egid = (gid_t)auxv->a_un.a_val; 151 break; 152 case AT_SUN_RGID: 153 /* real group id for the executable */ 154 gid = (gid_t)auxv->a_un.a_val; 155 break; 156 #ifdef AT_SUN_PLATFORM /* Defined on SunOS 5.5 & greater. */ 157 case AT_SUN_PLATFORM: 158 /* platform name */ 159 _platform = auxv->a_un.a_ptr; 160 break; 161 #endif 162 #ifdef AT_SUN_EXECNAME /* Defined on SunOS 5.6 & greater. */ 163 case AT_SUN_EXECNAME: 164 /* full pathname of execed object */ 165 _execname = auxv->a_un.a_ptr; 166 break; 167 #endif 168 #ifdef AT_SUN_AUXFLAGS /* At the behest of PSARC 2002/188 */ 169 case AT_SUN_AUXFLAGS: 170 auxflags = (int)auxv->a_un.a_val; 171 break; 172 #endif 173 #ifdef AT_SUN_HWCAP /* Hardware capabilities */ 174 case AT_SUN_HWCAP: 175 hwcap_1 = (uint_t)auxv->a_un.a_val; 176 break; 177 #endif 178 #ifdef AT_SUN_EMULATOR /* Emulation library name */ 179 case AT_SUN_EMULATOR: 180 /* name of emulation library, if any */ 181 _emulator = auxv->a_un.a_ptr; 182 break; 183 #endif 184 } 185 } 186 187 /* 188 * Get needed info from ld.so's dynamic structure. 189 */ 190 /* LINTED */ 191 dyn_ptr = (Dyn *)((char *)ld_dyn + ld_base); 192 for (ld_dyn = dyn_ptr; ld_dyn->d_tag != DT_NULL; ld_dyn++) { 193 switch (ld_dyn->d_tag) { 194 case DT_REL: 195 reladdr = ld_dyn->d_un.d_ptr + ld_base; 196 break; 197 case DT_RELCOUNT: 198 relcount = ld_dyn->d_un.d_val; 199 break; 200 case DT_RELENT: 201 relent = ld_dyn->d_un.d_val; 202 break; 203 case DT_STRTAB: 204 strtab = ld_dyn->d_un.d_ptr + ld_base; 205 break; 206 case DT_SONAME: 207 soname = ld_dyn->d_un.d_val; 208 break; 209 } 210 } 211 _rt_name = (char *)strtab + soname; 212 213 /* 214 * If we don't have a RELENT, just assume 215 * the size. 216 */ 217 if (relent == 0) 218 relent = sizeof (Rel); 219 220 /* 221 * Relocate all symbols in ld.so. 222 * 223 * Because ld.so.1 is built with -Bsymbolic there should only be 224 * RELATIVE and JMPSLOT relocations, both of which get relative 225 * additions against them. 226 */ 227 for (; relcount; relcount--) { 228 ulong_t roffset; 229 230 roffset = ((Rel *)reladdr)->r_offset + ld_base; 231 *((ulong_t *)roffset) += ld_base; 232 reladdr += relent; 233 } 234 235 /* 236 * If an emulation library is being used, use that as the linker's 237 * effective executable name. The real executable is not linked by this 238 * linker. 239 */ 240 if (_emulator != NULL) { 241 _execname = _emulator; 242 rtld_flags2 |= RT_FL2_BRANDED; 243 } 244 245 /* 246 * Initialize the dyn_plt_ent_size field. It currently contains the 247 * size of the dyn_plt_template. It still needs to be aligned and have 248 * space for the 'dyn_data' area added. 249 */ 250 dyn_plt_ent_size = ROUND(dyn_plt_ent_size, M_WORD_ALIGN) + 251 sizeof (uintptr_t) + sizeof (uintptr_t) + sizeof (ulong_t) + 252 sizeof (ulong_t) + sizeof (Sym); 253 254 /* 255 * Continue with generic startup processing. 256 */ 257 if ((lmp = setup((char **)_envp, (auxv_t *)_auxv, _flags, _platform, 258 _syspagsz, _rt_name, dyn_ptr, ld_base, interp_base, fd, phdr, 259 _execname, _argv, dz_fd, uid, euid, gid, egid, NULL, auxflags, 260 hwcap_1)) == NULL) { 261 rtldexit(&lml_main, 1); 262 } 263 264 return (LM_ENTRY_PT(lmp)()); 265 } 266