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