1 /* Interface for libebl. 2 Copyright (C) 2000-2010 Red Hat, Inc. 3 This file is part of Red Hat elfutils. 4 5 Red Hat elfutils is free software; you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by the 7 Free Software Foundation; version 2 of the License. 8 9 Red Hat elfutils is distributed in the hope that it will be useful, but 10 WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 General Public License for more details. 13 14 You should have received a copy of the GNU General Public License along 15 with Red Hat elfutils; if not, write to the Free Software Foundation, 16 Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. 17 18 In addition, as a special exception, Red Hat, Inc. gives You the 19 additional right to link the code of Red Hat elfutils with code licensed 20 under any Open Source Initiative certified open source license 21 (http://www.opensource.org/licenses/index.php) which requires the 22 distribution of source code with any binary distribution and to 23 distribute linked combinations of the two. Non-GPL Code permitted under 24 this exception must only link to the code of Red Hat elfutils through 25 those well defined interfaces identified in the file named EXCEPTION 26 found in the source code files (the "Approved Interfaces"). The files 27 of Non-GPL Code may instantiate templates or use macros or inline 28 functions from the Approved Interfaces without causing the resulting 29 work to be covered by the GNU General Public License. Only Red Hat, 30 Inc. may make changes or additions to the list of Approved Interfaces. 31 Red Hat's grant of this exception is conditioned upon your not adding 32 any new exceptions. If you wish to add a new Approved Interface or 33 exception, please contact Red Hat. You must obey the GNU General Public 34 License in all respects for all of the Red Hat elfutils code and other 35 code used in conjunction with Red Hat elfutils except the Non-GPL Code 36 covered by this exception. If you modify this file, you may extend this 37 exception to your version of the file, but you are not obligated to do 38 so. If you do not wish to provide this exception without modification, 39 you must delete this exception statement from your version and license 40 this file solely under the GPL without exception. 41 42 Red Hat elfutils is an included package of the Open Invention Network. 43 An included package of the Open Invention Network is a package for which 44 Open Invention Network licensees cross-license their patents. No patent 45 license is granted, either expressly or impliedly, by designation as an 46 included package. Should you wish to participate in the Open Invention 47 Network licensing program, please visit www.openinventionnetwork.com 48 <http://www.openinventionnetwork.com>. */ 49 50 #ifndef _LIBEBL_H 51 #define _LIBEBL_H 1 52 53 #include <gelf.h> 54 #include "libdw.h" 55 #include <stdbool.h> 56 #include <stddef.h> 57 #include <stdint.h> 58 59 #include "elf-knowledge.h" 60 61 62 /* Opaque type for the handle. */ 63 typedef struct ebl Ebl; 64 65 66 #ifdef __cplusplus 67 extern "C" { 68 #endif 69 70 /* Get backend handle for object associated with ELF handle. */ 71 extern Ebl *ebl_openbackend (Elf *elf); 72 /* Similar but without underlying ELF file. */ 73 extern Ebl *ebl_openbackend_machine (GElf_Half machine); 74 /* Similar but with emulation name given. */ 75 extern Ebl *ebl_openbackend_emulation (const char *emulation); 76 77 /* Free resources allocated for backend handle. */ 78 extern void ebl_closebackend (Ebl *bh); 79 80 81 /* Information about the descriptor. */ 82 83 /* Get ELF machine. */ 84 extern int ebl_get_elfmachine (Ebl *ebl) __attribute__ ((__pure__)); 85 86 /* Get ELF class. */ 87 extern int ebl_get_elfclass (Ebl *ebl) __attribute__ ((__pure__)); 88 89 /* Get ELF data encoding. */ 90 extern int ebl_get_elfdata (Ebl *ebl) __attribute__ ((__pure__)); 91 92 93 /* Function to call the callback functions including default ELF 94 handling. */ 95 96 /* Return backend name. */ 97 extern const char *ebl_backend_name (Ebl *ebl); 98 99 /* Return relocation type name. */ 100 extern const char *ebl_object_type_name (Ebl *ebl, int object, 101 char *buf, size_t len); 102 103 /* Return relocation type name. */ 104 extern const char *ebl_reloc_type_name (Ebl *ebl, int reloc, 105 char *buf, size_t len); 106 107 /* Check relocation type. */ 108 extern bool ebl_reloc_type_check (Ebl *ebl, int reloc); 109 110 /* Check relocation type use. */ 111 extern bool ebl_reloc_valid_use (Ebl *ebl, int reloc); 112 113 /* Check if relocation type is for simple absolute relocations. 114 Return ELF_T_{BYTE,HALF,SWORD,SXWORD} for a simple type, else ELF_T_NUM. */ 115 extern Elf_Type ebl_reloc_simple_type (Ebl *ebl, int reloc); 116 117 /* Return true if the symbol type is that referencing the GOT. E.g., 118 R_386_GOTPC. */ 119 extern bool ebl_gotpc_reloc_check (Ebl *ebl, int reloc); 120 121 /* Return segment type name. */ 122 extern const char *ebl_segment_type_name (Ebl *ebl, int segment, 123 char *buf, size_t len); 124 125 /* Return section type name. */ 126 extern const char *ebl_section_type_name (Ebl *ebl, int section, 127 char *buf, size_t len); 128 129 /* Return section name. */ 130 extern const char *ebl_section_name (Ebl *ebl, int section, int xsection, 131 char *buf, size_t len, 132 const char *scnnames[], size_t shnum); 133 134 /* Return machine flag names. */ 135 extern const char *ebl_machine_flag_name (Ebl *ebl, GElf_Word flags, 136 char *buf, size_t len); 137 138 /* Check whether machine flag is valid. */ 139 extern bool ebl_machine_flag_check (Ebl *ebl, GElf_Word flags); 140 141 /* Check whether SHF_MASKPROC flags are valid. */ 142 extern bool ebl_machine_section_flag_check (Ebl *ebl, GElf_Xword flags); 143 144 /* Check whether the section with the given index, header, and name 145 is a special machine section that is valid despite a combination 146 of flags or other details that are not generically valid. */ 147 extern bool ebl_check_special_section (Ebl *ebl, int ndx, 148 const GElf_Shdr *shdr, const char *name); 149 150 /* Return symbol type name. */ 151 extern const char *ebl_symbol_type_name (Ebl *ebl, int symbol, 152 char *buf, size_t len); 153 154 /* Return symbol binding name. */ 155 extern const char *ebl_symbol_binding_name (Ebl *ebl, int binding, 156 char *buf, size_t len); 157 158 /* Return dynamic tag name. */ 159 extern const char *ebl_dynamic_tag_name (Ebl *ebl, int64_t tag, 160 char *buf, size_t len); 161 162 /* Check dynamic tag. */ 163 extern bool ebl_dynamic_tag_check (Ebl *ebl, int64_t tag); 164 165 /* Check whether given symbol's st_value and st_size are OK despite failing 166 normal checks. */ 167 extern bool ebl_check_special_symbol (Ebl *ebl, GElf_Ehdr *ehdr, 168 const GElf_Sym *sym, const char *name, 169 const GElf_Shdr *destshdr); 170 171 /* Check whether only valid bits are set on the st_other symbol flag. */ 172 extern bool ebl_check_st_other_bits (Ebl *ebl, unsigned char st_other); 173 174 /* Return combined section header flags value. */ 175 extern GElf_Word ebl_sh_flags_combine (Ebl *ebl, GElf_Word flags1, 176 GElf_Word flags2); 177 178 /* Return symbolic representation of OS ABI. */ 179 extern const char *ebl_osabi_name (Ebl *ebl, int osabi, char *buf, size_t len); 180 181 182 /* Return name of the note section type for a core file. */ 183 extern const char *ebl_core_note_type_name (Ebl *ebl, uint32_t type, char *buf, 184 size_t len); 185 186 /* Return name of the note section type for an object file. */ 187 extern const char *ebl_object_note_type_name (Ebl *ebl, const char *name, 188 uint32_t type, char *buf, 189 size_t len); 190 191 /* Print information about object note if available. */ 192 extern void ebl_object_note (Ebl *ebl, const char *name, uint32_t type, 193 uint32_t descsz, const char *desc); 194 195 /* Check whether an attribute in a .gnu_attributes section is recognized. 196 Fills in *TAG_NAME with the name for this tag. 197 If VALUE is a known value for that tag, also fills in *VALUE_NAME. */ 198 extern bool ebl_check_object_attribute (Ebl *ebl, const char *vendor, 199 int tag, uint64_t value, 200 const char **tag_name, 201 const char **value_name); 202 203 204 /* Check section name for being that of a debug informatino section. */ 205 extern bool ebl_debugscn_p (Ebl *ebl, const char *name); 206 207 /* Check whether given relocation is a copy relocation. */ 208 extern bool ebl_copy_reloc_p (Ebl *ebl, int reloc); 209 210 /* Check whether given relocation is a no-op relocation. */ 211 extern bool ebl_none_reloc_p (Ebl *ebl, int reloc); 212 213 /* Check whether given relocation is a relative relocation. */ 214 extern bool ebl_relative_reloc_p (Ebl *ebl, int reloc); 215 216 /* Check whether section should be stripped. */ 217 extern bool ebl_section_strip_p (Ebl *ebl, const GElf_Ehdr *ehdr, 218 const GElf_Shdr *shdr, const char *name, 219 bool remove_comment, bool only_remove_debug); 220 221 /* Check if backend uses a bss PLT in this file. */ 222 extern bool ebl_bss_plt_p (Ebl *ebl, GElf_Ehdr *ehdr); 223 224 /* Return size of entry in SysV-style hash table. */ 225 extern int ebl_sysvhash_entrysize (Ebl *ebl); 226 227 /* Return location expression to find return value given a 228 DW_TAG_subprogram, DW_TAG_subroutine_type, or similar DIE describing 229 function itself (whose DW_AT_type attribute describes its return type). 230 Returns -1 for a libdw error (see dwarf_errno). 231 Returns -2 for an unrecognized type formation. 232 Returns zero if the function has no return value (e.g. "void" in C). 233 Otherwise, *LOCOPS gets a location expression to find the return value, 234 and returns the number of operations in the expression. The pointer is 235 permanently allocated at least as long as the Ebl handle is open. */ 236 extern int ebl_return_value_location (Ebl *ebl, 237 Dwarf_Die *functypedie, 238 const Dwarf_Op **locops); 239 240 /* Fill in register information given DWARF register numbers. 241 If NAME is null, return the maximum REGNO + 1 that has a name. 242 Otherwise, store in NAME the name for DWARF register number REGNO 243 and return the number of bytes written (including '\0' terminator). 244 Return -1 if NAMELEN is too short or REGNO is negative or too large. 245 Return 0 if REGNO is unused (a gap in the DWARF number assignment). 246 On success, set *SETNAME to a description like "integer" or "FPU" 247 fit for "%s registers" title display, and *PREFIX to the string 248 that precedes NAME in canonical assembler syntax (e.g. "%" or "$"). 249 The NAME string contains identifier characters only (maybe just digits). */ 250 extern ssize_t ebl_register_info (Ebl *ebl, 251 int regno, char *name, size_t namelen, 252 const char **prefix, const char **setname, 253 int *bits, int *type); 254 255 /* Fill in the DWARF register numbers for the registers used in system calls. 256 The SP and PC are what kernel reports call the user stack pointer and PC. 257 The CALLNO and ARGS are the system call number and incoming arguments. 258 Each of these is filled with the DWARF register number corresponding, 259 or -1 if there is none. Returns zero when the information is available. */ 260 extern int ebl_syscall_abi (Ebl *ebl, int *sp, int *pc, 261 int *callno, int args[6]); 262 263 /* Supply the ABI-specified state of DWARF CFI before CIE initial programs. 264 265 The DWARF 3.0 spec says that the default initial states of all registers 266 are "undefined", unless otherwise specified by the machine/compiler ABI. 267 268 This default is wrong for every machine with the CFI generated by GCC. 269 The EH unwinder does not really distinguish "same_value" and "undefined", 270 since it doesn't matter for unwinding (in either case there is no change 271 to make for that register). GCC generates CFI that says nothing at all 272 about registers it hasn't spilled somewhere. For our unwinder to give 273 the true story, the backend must supply an initial state that uses 274 "same_value" rules for all the callee-saves registers. 275 276 This can fill in the initial_instructions, initial_instructions_end 277 members of *ABI_INFO to point at a CFI instruction stream to process 278 before each CIE's initial instructions. It should set the 279 data_alignment_factor member if it affects the initial instructions. 280 281 As a shorthand for some common cases, for this instruction stream 282 we overload some CFI instructions that cannot be used in a CIE: 283 284 DW_CFA_restore -- Change default rule for all unmentioned 285 registers from undefined to same_value. 286 287 This function can also fill in ABI_INFO->return_address_register with the 288 DWARF register number that identifies the actual PC in machine state. 289 If there is no canonical DWARF register number with that meaning, it's 290 left unchanged (callers usually initialize with (Dwarf_Word) -1). 291 This value is not used by CFI per se. */ 292 extern int ebl_abi_cfi (Ebl *ebl, Dwarf_CIE *abi_info) 293 __nonnull_attribute__ (2); 294 295 /* ELF string table handling. */ 296 struct Ebl_Strtab; 297 struct Ebl_Strent; 298 299 /* Create new ELF string table object in memory. */ 300 extern struct Ebl_Strtab *ebl_strtabinit (bool nullstr); 301 302 /* Free resources allocated for ELF string table ST. */ 303 extern void ebl_strtabfree (struct Ebl_Strtab *st); 304 305 /* Add string STR (length LEN is != 0) to ELF string table ST. */ 306 extern struct Ebl_Strent *ebl_strtabadd (struct Ebl_Strtab *st, 307 const char *str, size_t len); 308 309 /* Finalize string table ST and store size and memory location information 310 in DATA. */ 311 extern void ebl_strtabfinalize (struct Ebl_Strtab *st, Elf_Data *data); 312 313 /* Get offset in string table for string associated with SE. */ 314 extern size_t ebl_strtaboffset (struct Ebl_Strent *se); 315 316 /* Return the string associated with SE. */ 317 extern const char *ebl_string (struct Ebl_Strent *se); 318 319 320 /* ELF wide char string table handling. */ 321 struct Ebl_WStrtab; 322 struct Ebl_WStrent; 323 324 /* Create new ELF wide char string table object in memory. */ 325 extern struct Ebl_WStrtab *ebl_wstrtabinit (bool nullstr); 326 327 /* Free resources allocated for ELF wide char string table ST. */ 328 extern void ebl_wstrtabfree (struct Ebl_WStrtab *st); 329 330 /* Add string STR (length LEN is != 0) to ELF string table ST. */ 331 extern struct Ebl_WStrent *ebl_wstrtabadd (struct Ebl_WStrtab *st, 332 const wchar_t *str, size_t len); 333 334 /* Finalize string table ST and store size and memory location information 335 in DATA. */ 336 extern void ebl_wstrtabfinalize (struct Ebl_WStrtab *st, Elf_Data *data); 337 338 /* Get offset in wide char string table for string associated with SE. */ 339 extern size_t ebl_wstrtaboffset (struct Ebl_WStrent *se); 340 341 342 /* Generic string table handling. */ 343 struct Ebl_GStrtab; 344 struct Ebl_GStrent; 345 346 /* Create new string table object in memory. */ 347 extern struct Ebl_GStrtab *ebl_gstrtabinit (unsigned int width, bool nullstr); 348 349 /* Free resources allocated for string table ST. */ 350 extern void ebl_gstrtabfree (struct Ebl_GStrtab *st); 351 352 /* Add string STR (length LEN is != 0) to string table ST. */ 353 extern struct Ebl_GStrent *ebl_gstrtabadd (struct Ebl_GStrtab *st, 354 const char *str, size_t len); 355 356 /* Finalize string table ST and store size and memory location information 357 in DATA. */ 358 extern void ebl_gstrtabfinalize (struct Ebl_GStrtab *st, Elf_Data *data); 359 360 /* Get offset in wide char string table for string associated with SE. */ 361 extern size_t ebl_gstrtaboffset (struct Ebl_GStrent *se); 362 363 364 /* Register map info. */ 365 typedef struct 366 { 367 Dwarf_Half offset; /* Byte offset in register data block. */ 368 Dwarf_Half regno; /* DWARF register number. */ 369 uint8_t bits; /* Bits of data for one register. */ 370 uint8_t pad; /* Bytes of padding after register's data. */ 371 Dwarf_Half count; /* Consecutive register numbers here. */ 372 } Ebl_Register_Location; 373 374 /* Non-register data items in core notes. */ 375 typedef struct 376 { 377 const char *name; /* Printable identifier. */ 378 const char *group; /* Identifier for category of related items. */ 379 Dwarf_Half offset; /* Byte offset in note data. */ 380 Dwarf_Half count; 381 Elf_Type type; 382 char format; 383 bool thread_identifier; 384 } Ebl_Core_Item; 385 386 /* Describe the format of a core file note with the given header and NAME. 387 NAME is not guaranteed terminated, it's NHDR->n_namesz raw bytes. */ 388 extern int ebl_core_note (Ebl *ebl, const GElf_Nhdr *nhdr, const char *name, 389 GElf_Word *regs_offset, size_t *nregloc, 390 const Ebl_Register_Location **reglocs, 391 size_t *nitems, const Ebl_Core_Item **items) 392 __nonnull_attribute__ (1, 2, 3, 4, 5, 6, 7, 8); 393 394 /* Describe the auxv type number. */ 395 extern int ebl_auxv_info (Ebl *ebl, GElf_Xword a_type, 396 const char **name, const char **format) 397 __nonnull_attribute__ (1, 3, 4); 398 399 400 #ifdef __cplusplus 401 } 402 #endif 403 404 #endif /* libebl.h */ 405
