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 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 /* 30 * Object file dependent suport for ELF objects. 31 */ 32 33 #include <sys/mman.h> 34 #include <stdio.h> 35 #include <unistd.h> 36 #include <libelf.h> 37 #include <string.h> 38 #include <dlfcn.h> 39 #include <debug.h> 40 #include <libld.h> 41 #include "_rtld.h" 42 #include "_audit.h" 43 #include "_elf.h" 44 45 static Rt_map *olmp = 0; 46 47 static Ehdr dehdr = { { ELFMAG0, ELFMAG1, ELFMAG2, ELFMAG3, 48 M_CLASS, M_DATA }, 0, M_MACH, EV_CURRENT }; 49 50 /* 51 * Process a relocatable object. The static object link map pointer is used as 52 * a flag to determine whether a concatenation is already in progress (ie. an 53 * LD_PRELOAD may specify a list of objects). The link map returned simply 54 * specifies an `object' flag which the caller can interpret and thus call 55 * elf_obj_fini() to complete the concatenation. 56 */ 57 static Rt_map * 58 elf_obj_init(Lm_list *lml, Aliste lmco, const char *name) 59 { 60 Ofl_desc * ofl; 61 62 /* 63 * Initialize an output file descriptor and the entrance criteria. 64 */ 65 if ((ofl = (Ofl_desc *)calloc(sizeof (Ofl_desc), 1)) == 0) 66 return (0); 67 68 ofl->ofl_dehdr = &dehdr; 69 70 ofl->ofl_flags = (FLG_OF_DYNAMIC | FLG_OF_SHAROBJ | FLG_OF_STRIP); 71 ofl->ofl_flags1 = (FLG_OF1_RELDYN | FLG_OF1_TEXTOFF | FLG_OF1_MEMORY); 72 ofl->ofl_lml = lml; 73 74 /* 75 * As ent_setup() will effectively lazy load the necessary support 76 * libraries, make sure ld.so.1 is initialized for plt relocations. 77 */ 78 if (elf_rtld_load() == 0) 79 return (0); 80 81 /* 82 * Configure libld.so to process objects of the desired target 83 * type (this is the first call to libld.so, which will effectively 84 * lazyload it). 85 */ 86 if (ld_init_target(lml, M_MACH) != 0) 87 return (0); 88 89 /* 90 * Obtain a generic set of entrance criteria 91 */ 92 if (ld_ent_setup(ofl, syspagsz) == S_ERROR) 93 return (0); 94 95 /* 96 * Generate a link map place holder and use the `rt_priv' element to 97 * maintain the output file descriptor. 98 */ 99 if ((olmp = (Rt_map *)calloc(sizeof (Rt_map), 1)) == 0) 100 return (0); 101 102 DBG_CALL(Dbg_file_elf(lml, name, 0, 0, 0, 0, lml->lm_lmidstr, lmco)); 103 FLAGS(olmp) |= FLG_RT_OBJECT; 104 olmp->rt_priv = (void *)ofl; 105 106 /* 107 * Initialize string tables. 108 */ 109 if (ld_init_strings(ofl) == S_ERROR) 110 return (0); 111 112 /* 113 * Assign the output file name to be the initial object that got us 114 * here. This name is being used for diagnostic purposes only as we 115 * don't actually generate an output file unless debugging is enabled. 116 */ 117 ofl->ofl_name = name; 118 ORIGNAME(olmp) = PATHNAME(olmp) = NAME(olmp) = (char *)name; 119 LIST(olmp) = lml; 120 121 lm_append(lml, lmco, olmp); 122 return (olmp); 123 } 124 125 /* 126 * Initial processing of a relocatable object. If this is the first object 127 * encountered we need to initialize some structures, then simply call the 128 * link-edit functionality to provide the initial processing of the file (ie. 129 * reads in sections and symbols, performs symbol resolution if more that one 130 * object file have been specified, and assigns input sections to output 131 * sections). 132 */ 133 Rt_map * 134 elf_obj_file(Lm_list *lml, Aliste lmco, const char *name, int fd) 135 { 136 Rej_desc rej; 137 138 /* 139 * If this is the first relocatable object (LD_PRELOAD could provide a 140 * list of objects), initialize an input file descriptor and a link map. 141 */ 142 if (!olmp) { 143 /* 144 * Load the link-editor library. 145 */ 146 if ((olmp = elf_obj_init(lml, lmco, name)) == 0) 147 return (0); 148 } 149 150 /* 151 * Proceed to process the input file. 152 */ 153 DBG_CALL(Dbg_util_nl(lml, DBG_NL_STD)); 154 if (ld_process_open(name, name, &fd, (Ofl_desc *)olmp->rt_priv, 155 NULL, &rej) == (Ifl_desc *)S_ERROR) 156 return (0); 157 return (olmp); 158 } 159 160 /* 161 * Finish relocatable object processing. Having already initially processed one 162 * or more objects, complete the generation of a shared object image by calling 163 * the appropriate link-edit functionality (refer to sgs/ld/common/main.c). 164 */ 165 Rt_map * 166 elf_obj_fini(Lm_list *lml, Rt_map *lmp, int *in_nfavl) 167 { 168 Ofl_desc *ofl = (Ofl_desc *)lmp->rt_priv; 169 Rt_map *nlmp; 170 Addr etext; 171 Ehdr *ehdr; 172 Phdr *phdr; 173 Mmap *mmaps; 174 uint_t phnum, mmapcnt; 175 Lm_cntl *lmc; 176 177 DBG_CALL(Dbg_util_nl(lml, DBG_NL_STD)); 178 179 if (ld_reloc_init(ofl) == S_ERROR) 180 return (0); 181 if (ld_sym_validate(ofl) == S_ERROR) 182 return (0); 183 if (ld_make_sections(ofl) == S_ERROR) 184 return (0); 185 if (ld_create_outfile(ofl) == S_ERROR) 186 return (0); 187 if ((etext = ld_update_outfile(ofl)) == (Addr)S_ERROR) 188 return (0); 189 if (ld_reloc_process(ofl) == S_ERROR) 190 return (0); 191 192 /* 193 * At this point we have a memory image of the shared object. The link 194 * editor would normally simply write this to the required output file. 195 * If we're debugging generate a standard temporary output file. 196 */ 197 DBG_CALL(Dbg_file_output(ofl)); 198 199 /* 200 * Allocate a mapping array to retain mapped segment information. 201 */ 202 ehdr = ofl->ofl_nehdr; 203 phdr = ofl->ofl_phdr; 204 if ((mmaps = calloc(ehdr->e_phnum, sizeof (Mmap))) == 0) 205 return (0); 206 for (mmapcnt = 0, phnum = 0; phnum < ehdr->e_phnum; phnum++) { 207 if (phdr[phnum].p_type != PT_LOAD) 208 continue; 209 210 mmaps[mmapcnt].m_vaddr = (caddr_t) 211 (phdr[phnum].p_vaddr + (ulong_t)ehdr); 212 mmaps[mmapcnt].m_msize = phdr[phnum].p_memsz; 213 mmaps[mmapcnt].m_fsize = phdr[phnum].p_filesz; 214 mmaps[mmapcnt].m_perm = (PROT_READ | PROT_WRITE | PROT_EXEC); 215 mmapcnt++; 216 } 217 218 /* 219 * Generate a new link map representing the memory image created. 220 */ 221 if ((nlmp = elf_new_lm(lml, ofl->ofl_name, ofl->ofl_name, 222 ofl->ofl_osdynamic->os_outdata->d_buf, (ulong_t)ehdr, 223 (ulong_t)ehdr + etext, CNTL(olmp), (ulong_t)ofl->ofl_size, 224 0, 0, 0, mmaps, mmapcnt, in_nfavl)) == 0) 225 return (0); 226 227 /* 228 * Remove this link map from the end of the link map list and copy its 229 * contents into the link map originally created for this file (we copy 230 * the contents rather than manipulate the link map pointers as parts 231 * of the dlopen code have remembered the original link map address). 232 */ 233 NEXT((Rt_map *)PREV(nlmp)) = 0; 234 /* LINTED */ 235 lmc = (Lm_cntl *)alist_item_by_offset(lml->lm_lists, CNTL(nlmp)); 236 lmc->lc_tail = (Rt_map *)PREV(nlmp); 237 if (CNTL(nlmp) == ALIST_OFF_DATA) 238 lml->lm_tail = (Rt_map *)PREV(nlmp); 239 lml->lm_obj--; 240 241 PREV(nlmp) = PREV(olmp); 242 NEXT(nlmp) = NEXT(olmp); 243 HANDLES(nlmp) = HANDLES(olmp); 244 GROUPS(nlmp) = GROUPS(olmp); 245 STDEV(nlmp) = STDEV(olmp); 246 STINO(nlmp) = STINO(olmp); 247 248 FLAGS(nlmp) |= ((FLAGS(olmp) & ~FLG_RT_OBJECT) | FLG_RT_IMGALLOC); 249 FLAGS1(nlmp) |= FLAGS1(olmp); 250 MODE(nlmp) |= MODE(olmp); 251 252 NAME(nlmp) = NAME(olmp); 253 PATHNAME(nlmp) = PATHNAME(olmp); 254 ORIGNAME(nlmp) = ORIGNAME(olmp); 255 DIRSZ(nlmp) = DIRSZ(olmp); 256 257 ld_ofl_cleanup(ofl); 258 free(olmp->rt_priv); 259 (void) memcpy(olmp, nlmp, sizeof (Rt_map)); 260 free(nlmp); 261 nlmp = olmp; 262 olmp = 0; 263 264 /* 265 * Now that we've allocated our permanent Rt_map structure, expand the 266 * PATHNAME() and insert it into the FullpathNode AVL tree 267 */ 268 if (FLAGS1(nlmp) & FL1_RT_RELATIVE) 269 (void) fullpath(nlmp, 0); 270 if (fpavl_insert(lml, nlmp, PATHNAME(nlmp), 0) == 0) 271 return (0); 272 273 /* 274 * If we're being audited tell the audit library of the file we've just 275 * opened. 276 */ 277 if ((lml->lm_tflags | FLAGS1(nlmp)) & LML_TFLG_AUD_MASK) { 278 if (audit_objopen(lmp, lmp) == 0) 279 return (0); 280 } 281 return (nlmp); 282 } 283