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 * Copyright (c) 2012, Joyent, Inc. All rights reserved. 28 */ 29 30 /* 31 * amd64 specific setup routine - relocate ld.so's symbols, setup its 32 * environment, map in loadable sections of the executable. 33 * 34 * Takes base address ld.so was loaded at, address of ld.so's dynamic 35 * structure, address of process environment pointers, address of auxiliary 36 * vector and * argv[0] (process name). 37 * If errors occur, send process signal - otherwise 38 * return executable's entry point to the bootstrap routine. 39 */ 40 41 #include <signal.h> 42 #include <stdlib.h> 43 #include <sys/auxv.h> 44 #include <sys/types.h> 45 #include <sys/stat.h> 46 #include <link.h> 47 #include <dlfcn.h> 48 #include "_rtld.h" 49 #include "_audit.h" 50 #include "msg.h" 51 52 /* VARARGS */ 53 unsigned long 54 _setup(Boot *ebp, Dyn *ld_dyn) 55 { 56 ulong_t reladdr, relacount, ld_base = 0; 57 ulong_t relaent = 0, pltrelsz = 0; 58 ulong_t strtab, soname, interp_base = 0; 59 char *_rt_name, **_envp, **_argv; 60 int _syspagsz = 0, fd = -1; 61 uint_t _flags = 0; 62 uint_t hwcap[2] = { 0, 0 }; 63 Dyn *dyn_ptr; 64 Phdr *phdr = NULL; 65 Rt_map *lmp; 66 auxv_t *auxv, *_auxv; 67 uid_t uid = (uid_t)-1, euid = (uid_t)-1; 68 gid_t gid = (gid_t)-1, egid = (gid_t)-1; 69 char *_platform = NULL, *_execname = NULL, *_emulator = NULL; 70 int auxflags = -1; 71 72 /* 73 * Scan the bootstrap structure to pick up the basics. 74 */ 75 for (; ebp->eb_tag != EB_NULL; ebp++) 76 switch (ebp->eb_tag) { 77 case EB_LDSO_BASE: 78 ld_base = (unsigned long)ebp->eb_un.eb_val; 79 break; 80 case EB_ARGV: 81 _argv = (char **)ebp->eb_un.eb_ptr; 82 break; 83 case EB_ENVP: 84 _envp = (char **)ebp->eb_un.eb_ptr; 85 break; 86 case EB_AUXV: 87 _auxv = (auxv_t *)ebp->eb_un.eb_ptr; 88 break; 89 case EB_PAGESIZE: 90 _syspagsz = (int)ebp->eb_un.eb_val; 91 break; 92 } 93 94 /* 95 * Search the aux. vector for the information passed by exec. 96 */ 97 for (auxv = _auxv; auxv->a_type != AT_NULL; auxv++) { 98 switch (auxv->a_type) { 99 case AT_EXECFD: 100 /* this is the old exec that passes a file descriptor */ 101 fd = (int)auxv->a_un.a_val; 102 break; 103 case AT_FLAGS: 104 /* processor flags (MAU available, etc) */ 105 _flags = auxv->a_un.a_val; 106 break; 107 case AT_PAGESZ: 108 /* system page size */ 109 _syspagsz = (int)auxv->a_un.a_val; 110 break; 111 case AT_PHDR: 112 /* address of the segment table */ 113 phdr = (Phdr *)auxv->a_un.a_ptr; 114 break; 115 case AT_BASE: 116 /* interpreter base address */ 117 if (ld_base == 0) 118 ld_base = auxv->a_un.a_val; 119 interp_base = auxv->a_un.a_val; 120 break; 121 case AT_SUN_UID: 122 /* effective user id for the executable */ 123 euid = (uid_t)auxv->a_un.a_val; 124 break; 125 case AT_SUN_RUID: 126 /* real user id for the executable */ 127 uid = (uid_t)auxv->a_un.a_val; 128 break; 129 case AT_SUN_GID: 130 /* effective group id for the executable */ 131 egid = (gid_t)auxv->a_un.a_val; 132 break; 133 case AT_SUN_RGID: 134 /* real group id for the executable */ 135 gid = (gid_t)auxv->a_un.a_val; 136 break; 137 case AT_SUN_PLATFORM: 138 /* platform name */ 139 _platform = auxv->a_un.a_ptr; 140 break; 141 case AT_SUN_EXECNAME: 142 /* full pathname of execed object */ 143 _execname = auxv->a_un.a_ptr; 144 break; 145 case AT_SUN_AUXFLAGS: 146 /* auxiliary flags */ 147 auxflags = (int)auxv->a_un.a_val; 148 break; 149 case AT_SUN_HWCAP: 150 /* hardware capabilities */ 151 hwcap[0] = (uint_t)auxv->a_un.a_val; 152 break; 153 case AT_SUN_HWCAP2: 154 /* hardware capabilities */ 155 hwcap[1] = (uint_t)auxv->a_un.a_val; 156 break; 157 case AT_SUN_EMULATOR: 158 /* name of emulation library, if any */ 159 _emulator = auxv->a_un.a_ptr; 160 break; 161 } 162 } 163 164 /* 165 * Get needed info from ld.so's dynamic structure. 166 */ 167 /* LINTED */ 168 dyn_ptr = (Dyn *)((char *)ld_dyn + ld_base); 169 for (ld_dyn = dyn_ptr; ld_dyn->d_tag != DT_NULL; ld_dyn++) { 170 switch (ld_dyn->d_tag) { 171 case DT_RELA: 172 reladdr = ld_dyn->d_un.d_ptr + ld_base; 173 break; 174 case DT_RELACOUNT: 175 relacount = ld_dyn->d_un.d_val; 176 break; 177 case DT_RELAENT: 178 relaent = ld_dyn->d_un.d_val; 179 break; 180 case DT_PLTRELSZ: 181 pltrelsz = ld_dyn->d_un.d_val; 182 break; 183 case DT_STRTAB: 184 strtab = ld_dyn->d_un.d_ptr + ld_base; 185 break; 186 case DT_SONAME: 187 soname = ld_dyn->d_un.d_val; 188 break; 189 } 190 } 191 _rt_name = (char *)strtab + soname; 192 193 /* 194 * If we don't have a RELAENT, just assume the size. 195 */ 196 if (relaent == 0) 197 relaent = sizeof (Rela); 198 199 /* 200 * As all global symbol references within ld.so.1 are protected 201 * (symbolic), only RELATIVE and JMPSLOT relocations should be left 202 * to process at runtime. Process all relocations now. 203 */ 204 relacount += (pltrelsz / relaent); 205 for (; relacount; relacount--) { 206 ulong_t roffset; 207 208 roffset = ((Rela *)reladdr)->r_offset + ld_base; 209 *((ulong_t *)roffset) += ld_base + 210 ((Rela *)reladdr)->r_addend; 211 reladdr += relaent; 212 } 213 214 /* 215 * If an emulation library is being used, use that as the linker's 216 * effective executable name. The real executable is not linked by this 217 * linker. 218 */ 219 if (_emulator != NULL) { 220 _execname = _emulator; 221 rtld_flags2 |= RT_FL2_BRANDED; 222 } 223 224 /* 225 * Initialize the dyn_plt_ent_size field. It currently contains the 226 * size of the dyn_plt_template. It still needs to be aligned and have 227 * space for the 'dyn_data' area added. 228 */ 229 dyn_plt_ent_size = ROUND(dyn_plt_ent_size, M_WORD_ALIGN) + 230 sizeof (uintptr_t) + sizeof (uintptr_t) + sizeof (ulong_t) + 231 sizeof (ulong_t) + sizeof (Sym); 232 233 /* 234 * Continue with generic startup processing. 235 */ 236 if ((lmp = setup((char **)_envp, (auxv_t *)_auxv, _flags, _platform, 237 _syspagsz, _rt_name, ld_base, interp_base, fd, phdr, 238 _execname, _argv, uid, euid, gid, egid, NULL, auxflags, 239 hwcap)) == NULL) { 240 rtldexit(&lml_main, 1); 241 } 242 243 return (LM_ENTRY_PT(lmp)()); 244 } 245