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