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 2010 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #include <stdio.h> 28 #include <dlfcn.h> 29 #include <libelf.h> 30 #include <link.h> 31 #include <debug.h> 32 #include "msg.h" 33 #include "_libld.h" 34 35 /* 36 * Table which defines the default functions to be called by the library 37 * SUPPORT (-S <libname>). These functions can be redefined by the 38 * ld_support_loadso() routine. 39 */ 40 static Support_list support[LDS_NUM] = { 41 {MSG_ORIG(MSG_SUP_VERSION), NULL}, /* LDS_VERSION */ 42 {MSG_ORIG(MSG_SUP_INPUT_DONE), NULL}, /* LDS_INPUT_DONE */ 43 #if defined(_ELF64) 44 {MSG_ORIG(MSG_SUP_START_64), NULL}, /* LDS_START */ 45 {MSG_ORIG(MSG_SUP_ATEXIT_64), NULL}, /* LDS_ATEXIT */ 46 {MSG_ORIG(MSG_SUP_OPEN_64), NULL}, /* LDS_OPEN */ 47 {MSG_ORIG(MSG_SUP_FILE_64), NULL}, /* LDS_FILE */ 48 {MSG_ORIG(MSG_SUP_INSEC_64), NULL}, /* LDS_INSEC */ 49 {MSG_ORIG(MSG_SUP_SEC_64), NULL} /* LDS_SEC */ 50 #else /* Elf32 */ 51 {MSG_ORIG(MSG_SUP_START), NULL}, /* LDS_START */ 52 {MSG_ORIG(MSG_SUP_ATEXIT), NULL}, /* LDS_ATEXIT */ 53 {MSG_ORIG(MSG_SUP_OPEN), NULL}, /* LDS_OPEN */ 54 {MSG_ORIG(MSG_SUP_FILE), NULL}, /* LDS_FILE */ 55 {MSG_ORIG(MSG_SUP_INSEC), NULL}, /* LDS_INSEC */ 56 {MSG_ORIG(MSG_SUP_SEC), NULL} /* LDS_SEC */ 57 #endif 58 }; 59 60 /* 61 * Loads in a support shared object specified using the SGS_SUPPORT environment 62 * variable or the -S ld option, and determines which interface functions are 63 * provided by that object. 64 */ 65 uintptr_t 66 ld_sup_loadso(Ofl_desc *ofl, const char *obj) 67 { 68 void *handle, (*fptr)(); 69 uint_t interface, version = LD_SUP_VERSION1; 70 71 /* 72 * Load the required support library. If we are unable to load it fail 73 * with a fatal error. 74 */ 75 if ((handle = dlopen(obj, (RTLD_LAZY | RTLD_FIRST))) == NULL) { 76 eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_SUP_NOLOAD), 77 obj, dlerror()); 78 return (S_ERROR); 79 } 80 81 for (interface = 0; interface < LDS_NUM; interface++) { 82 Func_list fl; 83 84 if ((fptr = (void (*)())dlsym(handle, 85 support[interface].sup_name)) == NULL) 86 continue; 87 88 DBG_CALL(Dbg_support_load(ofl->ofl_lml, obj, 89 support[interface].sup_name)); 90 91 if (interface == LDS_VERSION) { 92 DBG_CALL(Dbg_support_action(ofl->ofl_lml, obj, 93 support[LDS_VERSION].sup_name, LDS_VERSION, 0)); 94 95 version = ((uint_t(*)())fptr)(LD_SUP_VCURRENT); 96 97 /* 98 * If version is LD_SUP_VNONE, unload the support 99 * library and act as if it was never requested. 100 * This provides the support library with a mechanism 101 * for opting out of the process. 102 * 103 * Note that this depends on LDS_VERSION being the 104 * first item in support[]. If this were not true, 105 * then other functions from the library might be 106 * entered into the function lists, and unloading 107 * the object would cause corruption. 108 */ 109 assert(LDS_VERSION == 0); 110 if (version == LD_SUP_VNONE) { 111 DBG_CALL(Dbg_support_vnone(ofl->ofl_lml, 112 obj)); 113 (void) dlclose(handle); 114 return (1); 115 } 116 117 /* 118 * If the support library has a version higher 119 * than we support, we are unable to accept it. 120 */ 121 if (version > LD_SUP_VCURRENT) { 122 eprintf(ofl->ofl_lml, ERR_FATAL, 123 MSG_INTL(MSG_SUP_BADVERSION), obj, 124 LD_SUP_VCURRENT, version); 125 (void) dlclose(handle); 126 return (S_ERROR); 127 } 128 } 129 130 fl.fl_obj = obj; 131 fl.fl_fptr = fptr; 132 fl.fl_version = version; 133 if (alist_append(&support[interface].sup_funcs, &fl, 134 sizeof (Func_list), AL_CNT_SUPPORT) == NULL) 135 return (S_ERROR); 136 } 137 return (1); 138 } 139 140 /* 141 * Wrapper routines for the ld support library calls. 142 */ 143 void 144 ld_sup_start(Ofl_desc *ofl, const Half etype, const char *caller) 145 { 146 Func_list *flp; 147 Aliste idx; 148 149 for (ALIST_TRAVERSE(support[LDS_START].sup_funcs, idx, flp)) { 150 DBG_CALL(Dbg_support_action(ofl->ofl_lml, flp->fl_obj, 151 support[LDS_START].sup_name, LDS_START, ofl->ofl_name)); 152 (*flp->fl_fptr)(ofl->ofl_name, etype, caller); 153 } 154 } 155 156 void 157 ld_sup_atexit(Ofl_desc *ofl, int ecode) 158 { 159 Func_list *flp; 160 Aliste idx; 161 162 for (ALIST_TRAVERSE(support[LDS_ATEXIT].sup_funcs, idx, flp)) { 163 DBG_CALL(Dbg_support_action(ofl->ofl_lml, flp->fl_obj, 164 support[LDS_ATEXIT].sup_name, LDS_ATEXIT, 0)); 165 (*flp->fl_fptr)(ecode); 166 } 167 } 168 169 void 170 ld_sup_open(Ofl_desc *ofl, const char **opath, const char **ofile, int *ofd, 171 int flags, Elf **oelf, Elf *ref, size_t off, const Elf_Kind ekind) 172 { 173 Func_list *flp; 174 Aliste idx; 175 176 for (ALIST_TRAVERSE(support[LDS_OPEN].sup_funcs, idx, flp)) { 177 const char *npath = *opath; 178 const char *nfile = *ofile; 179 Elf *nelf = *oelf; 180 int nfd = *ofd; 181 int _flags = 0; 182 183 /* 184 * This interface was introduced in VERSION3. Only call this 185 * function for libraries reporting support for version 3 or 186 * above. 187 */ 188 if (flp->fl_version < LD_SUP_VERSION3) 189 continue; 190 191 if (!(flags & FLG_IF_CMDLINE)) 192 _flags |= LD_SUP_DERIVED; 193 if (!(flags & FLG_IF_NEEDED)) 194 _flags |= LD_SUP_INHERITED; 195 if (flags & FLG_IF_EXTRACT) 196 _flags |= LD_SUP_EXTRACTED; 197 198 /* 199 * If the present object is an extracted archive member, make 200 * sure the archive offset is reset so that the caller can 201 * obtain an ELF descriptor to the same member (an elf_begin() 202 * moves the offset to the next member). 203 */ 204 if (flags & FLG_IF_EXTRACT) 205 (void) elf_rand(ref, off); 206 207 DBG_CALL(Dbg_support_action(ofl->ofl_lml, flp->fl_obj, 208 support[LDS_OPEN].sup_name, LDS_OPEN, *opath)); 209 (*flp->fl_fptr)(&npath, &nfile, &nfd, _flags, &nelf, ref, off, 210 ekind); 211 212 /* 213 * If the file descriptor, ELF descriptor, or file names have 214 * been modified, then diagnose the differences and return the 215 * new data. As a basic test, make sure the support library 216 * hasn't nulled out data ld(1) will try and dereference. 217 */ 218 if ((npath != *opath) || (nfd != *ofd) || (nelf != *oelf)) { 219 DBG_CALL(Dbg_file_modified(ofl->ofl_lml, flp->fl_obj, 220 *opath, npath, *ofd, nfd, *oelf, nelf)); 221 if (npath) 222 *opath = npath; 223 if (nfile) 224 *ofile = nfile; 225 *ofd = nfd; 226 *oelf = nelf; 227 } 228 } 229 } 230 231 void 232 ld_sup_file(Ofl_desc *ofl, const char *ifile, const Elf_Kind ekind, int flags, 233 Elf *elf) 234 { 235 Func_list *flp; 236 Aliste idx; 237 238 for (ALIST_TRAVERSE(support[LDS_FILE].sup_funcs, idx, flp)) { 239 int _flags = 0; 240 241 if (!(flags & FLG_IF_CMDLINE)) 242 _flags |= LD_SUP_DERIVED; 243 if (!(flags & FLG_IF_NEEDED)) 244 _flags |= LD_SUP_INHERITED; 245 if (flags & FLG_IF_EXTRACT) 246 _flags |= LD_SUP_EXTRACTED; 247 248 DBG_CALL(Dbg_support_action(ofl->ofl_lml, flp->fl_obj, 249 support[LDS_FILE].sup_name, LDS_FILE, ifile)); 250 (*flp->fl_fptr)(ifile, ekind, _flags, elf); 251 } 252 } 253 254 uintptr_t 255 ld_sup_input_section(Ofl_desc *ofl, Ifl_desc *ifl, const char *sname, 256 Shdr **oshdr, Word ndx, Elf_Scn *scn, Elf *elf) 257 { 258 Func_list *flp; 259 Aliste idx; 260 uint_t flags = 0; 261 Elf_Data *data = NULL; 262 263 for (ALIST_TRAVERSE(support[LDS_INSEC].sup_funcs, idx, flp)) { 264 Shdr *nshdr = *oshdr; 265 266 /* 267 * This interface was introduced in VERSION2. Only call this 268 * function for libraries reporting support for version 2 or 269 * above. 270 */ 271 if (flp->fl_version < LD_SUP_VERSION2) 272 continue; 273 274 if ((data == NULL) && 275 ((data = elf_getdata(scn, NULL)) == NULL)) { 276 eprintf(ofl->ofl_lml, ERR_ELF, 277 MSG_INTL(MSG_ELF_GETDATA), ifl->ifl_name); 278 ofl->ofl_flags |= FLG_OF_FATAL; 279 return (S_ERROR); 280 } 281 282 DBG_CALL(Dbg_support_action(ofl->ofl_lml, flp->fl_obj, 283 support[LDS_INSEC].sup_name, LDS_INSEC, sname)); 284 (*flp->fl_fptr)(sname, &nshdr, ndx, data, elf, &flags); 285 286 /* 287 * If the section header has been re-allocated (known to occur 288 * with libCCexcept.so), then diagnose the section header 289 * difference and return the new section header. 290 */ 291 if (nshdr != *oshdr) { 292 Ehdr *ehdr = ifl->ifl_ehdr; 293 294 DBG_CALL(Dbg_shdr_modified(ofl->ofl_lml, flp->fl_obj, 295 ehdr->e_ident[EI_OSABI], ehdr->e_machine, ndx, 296 *oshdr, nshdr, sname)); 297 *oshdr = nshdr; 298 } 299 } 300 return (0); 301 } 302 303 void 304 ld_sup_section(Ofl_desc *ofl, const char *scn, Shdr *shdr, Word ndx, 305 Elf_Data *data, Elf *elf) 306 { 307 Func_list *flp; 308 Aliste idx; 309 310 for (ALIST_TRAVERSE(support[LDS_SEC].sup_funcs, idx, flp)) { 311 DBG_CALL(Dbg_support_action(ofl->ofl_lml, flp->fl_obj, 312 support[LDS_SEC].sup_name, LDS_SEC, scn)); 313 (*flp->fl_fptr)(scn, shdr, ndx, data, elf); 314 } 315 } 316 317 void 318 ld_sup_input_done(Ofl_desc *ofl) 319 { 320 Func_list *flp; 321 Aliste idx; 322 uint_t flags = 0; 323 324 for (ALIST_TRAVERSE(support[LDS_INPUT_DONE].sup_funcs, idx, flp)) { 325 /* 326 * This interface was introduced in VERSION2. Only call this 327 * function for libraries reporting support for version 2 or 328 * above. 329 */ 330 if (flp->fl_version < LD_SUP_VERSION2) 331 continue; 332 333 DBG_CALL(Dbg_support_action(ofl->ofl_lml, flp->fl_obj, 334 support[LDS_INPUT_DONE].sup_name, LDS_INPUT_DONE, 0)); 335 (*flp->fl_fptr)(&flags); 336 } 337 } 338