1 /* Internal definitions for libdwfl.
2 Copyright (C) 2005-2011 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 _LIBDWFLP_H
51 #define _LIBDWFLP_H 1
52
53 #ifndef PACKAGE_NAME
54 # include <config.h>
55 #endif
56 #include <libdwfl.h>
57 #include <libebl.h>
58 #include <assert.h>
59 #include <errno.h>
60 #include <stdbool.h>
61 #include <stdlib.h>
62 #include <string.h>
63
64 #include "../libdw/libdwP.h" /* We need its INTDECLs. */
65
66 /* gettext helper macros. */
67 #define _(Str) dgettext ("elfutils", Str)
68
69 #define DWFL_ERRORS \
70 DWFL_ERROR (NOERROR, N_("no error")) \
71 DWFL_ERROR (UNKNOWN_ERROR, N_("unknown error")) \
72 DWFL_ERROR (NOMEM, N_("out of memory")) \
73 DWFL_ERROR (ERRNO, N_("See errno")) \
74 DWFL_ERROR (LIBELF, N_("See elf_errno")) \
75 DWFL_ERROR (LIBDW, N_("See dwarf_errno")) \
76 DWFL_ERROR (LIBEBL, N_("See ebl_errno (XXX missing)")) \
77 DWFL_ERROR (ZLIB, N_("gzip decompression failed")) \
78 DWFL_ERROR (BZLIB, N_("bzip2 decompression failed")) \
79 DWFL_ERROR (LZMA, N_("LZMA decompression failed")) \
80 DWFL_ERROR (UNKNOWN_MACHINE, N_("no support library found for machine")) \
81 DWFL_ERROR (NOREL, N_("Callbacks missing for ET_REL file")) \
82 DWFL_ERROR (BADRELTYPE, N_("Unsupported relocation type")) \
83 DWFL_ERROR (BADRELOFF, N_("r_offset is bogus")) \
84 DWFL_ERROR (BADSTROFF, N_("offset out of range")) \
85 DWFL_ERROR (RELUNDEF, N_("relocation refers to undefined symbol")) \
86 DWFL_ERROR (CB, N_("Callback returned failure")) \
87 DWFL_ERROR (NO_DWARF, N_("No DWARF information found")) \
88 DWFL_ERROR (NO_SYMTAB, N_("No symbol table found")) \
89 DWFL_ERROR (NO_PHDR, N_("No ELF program headers")) \
90 DWFL_ERROR (OVERLAP, N_("address range overlaps an existing module")) \
91 DWFL_ERROR (ADDR_OUTOFRANGE, N_("address out of range")) \
92 DWFL_ERROR (NO_MATCH, N_("no matching address range")) \
93 DWFL_ERROR (TRUNCATED, N_("image truncated")) \
94 DWFL_ERROR (ALREADY_ELF, N_("ELF file opened")) \
95 DWFL_ERROR (BADELF, N_("not a valid ELF file")) \
96 DWFL_ERROR (WEIRD_TYPE, N_("cannot handle DWARF type description")) \
97 DWFL_ERROR (WRONG_ID_ELF, N_("ELF file does not match build ID")) \
98 DWFL_ERROR (BAD_PRELINK, N_("corrupt .gnu.prelink_undo section data"))
99
100 #define DWFL_ERROR(name, text) DWFL_E_##name,
101 typedef enum { DWFL_ERRORS DWFL_E_NUM } Dwfl_Error;
102 #undef DWFL_ERROR
103
104 #define OTHER_ERROR(name) ((unsigned int) DWFL_E_##name << 16)
105 #define DWFL_E(name, errno) (OTHER_ERROR (name) | (errno))
106
107 extern int __libdwfl_canon_error (Dwfl_Error) internal_function;
108 extern void __libdwfl_seterrno (Dwfl_Error) internal_function;
109
110 struct Dwfl
111 {
112 const Dwfl_Callbacks *callbacks;
113
114 Dwfl_Module *modulelist; /* List in order used by full traversals. */
115
116 GElf_Addr offline_next_address;
117
118 GElf_Addr segment_align; /* Smallest granularity of segments. */
119
120 /* Binary search table in three parallel malloc'd arrays. */
121 size_t lookup_elts; /* Elements in use. */
122 size_t lookup_alloc; /* Elements allococated. */
123 GElf_Addr *lookup_addr; /* Start address of segment. */
124 Dwfl_Module **lookup_module; /* Module associated with segment, or null. */
125 int *lookup_segndx; /* User segment index, or -1. */
126
127 /* Cache from last dwfl_report_segment call. */
128 const void *lookup_tail_ident;
129 GElf_Off lookup_tail_vaddr;
130 GElf_Off lookup_tail_offset;
131 int lookup_tail_ndx;
132 };
133
134 #define OFFLINE_REDZONE 0x10000
135
136 struct dwfl_file
137 {
138 char *name;
139 int fd;
140 bool valid; /* The build ID note has been matched. */
141 bool relocated; /* Partial relocation of all sections done. */
142
143 Elf *elf;
144
145 /* This is the lowest p_vaddr in this ELF file, aligned to p_align.
146 For a file without phdrs, this is zero. */
147 GElf_Addr vaddr;
148
149 /* This is an address chosen for synchronization between the main file
150 and the debug file. See dwfl_module_getdwarf.c for how it's chosen. */
151 GElf_Addr address_sync;
152 };
153
154 struct Dwfl_Module
155 {
156 Dwfl *dwfl;
157 struct Dwfl_Module *next; /* Link on Dwfl.modulelist. */
158
159 void *userdata;
160
161 char *name; /* Iterator name for this module. */
162 GElf_Addr low_addr, high_addr;
163
164 struct dwfl_file main, debug;
165 GElf_Addr main_bias;
166 Ebl *ebl;
167 GElf_Half e_type; /* GElf_Ehdr.e_type cache. */
168 Dwfl_Error elferr; /* Previous failure to open main file. */
169
170 struct dwfl_relocation *reloc_info; /* Relocatable sections. */
171
172 struct dwfl_file *symfile; /* Either main or debug. */
173 Elf_Data *symdata; /* Data in the ELF symbol table section. */
174 size_t syments; /* sh_size / sh_entsize of that section. */
175 int first_global; /* Index of first global symbol of table. */
176 Elf_Data *symstrdata; /* Data for its string table. */
177 Elf_Data *symxndxdata; /* Data in the extended section index table. */
178
179 Dwarf *dw; /* libdw handle for its debugging info. */
180
181 Dwfl_Error symerr; /* Previous failure to load symbols. */
182 Dwfl_Error dwerr; /* Previous failure to load DWARF. */
183
184 /* Known CU's in this module. */
185 struct dwfl_cu *first_cu, **cu;
186
187 void *lazy_cu_root; /* Table indexed by Dwarf_Off of CU. */
188
189 struct dwfl_arange *aranges; /* Mapping of addresses in module to CUs. */
190
191 void *build_id_bits; /* malloc'd copy of build ID bits. */
192 GElf_Addr build_id_vaddr; /* Address where they reside, 0 if unknown. */
193 int build_id_len; /* -1 for prior failure, 0 if unset. */
194
195 unsigned int ncu;
196 unsigned int lazycu; /* Possible users, deleted when none left. */
197 unsigned int naranges;
198
199 Dwarf_CFI *dwarf_cfi; /* Cached DWARF CFI for this module. */
200 Dwarf_CFI *eh_cfi; /* Cached EH CFI for this module. */
201
202 int segment; /* Index of first segment table entry. */
203 bool gc; /* Mark/sweep flag. */
204 };
205
206
207
208 /* Information cached about each CU in Dwfl_Module.dw. */
209 struct dwfl_cu
210 {
211 /* This caches libdw information about the CU. It's also the
212 address passed back to users, so we take advantage of the
213 fact that it's placed first to cast back. */
214 Dwarf_Die die;
215
216 Dwfl_Module *mod; /* Pointer back to containing module. */
217
218 struct dwfl_cu *next; /* CU immediately following in the file. */
219
220 struct Dwfl_Lines *lines;
221 };
222
223 struct Dwfl_Lines
224 {
225 struct dwfl_cu *cu;
226
227 /* This is what the opaque Dwfl_Line * pointers we pass to users are.
228 We need to recover pointers to our struct dwfl_cu and a record in
229 libdw's Dwarf_Line table. To minimize the memory used in addition
230 to libdw's Dwarf_Lines buffer, we just point to our own index in
231 this table, and have one pointer back to the CU. The indices here
232 match those in libdw's Dwarf_CU.lines->info table. */
233 struct Dwfl_Line
234 {
235 unsigned int idx; /* My index in the dwfl_cu.lines table. */
236 } idx[0];
237 };
238
239 static inline struct dwfl_cu *
dwfl_linecu_inline(const Dwfl_Line * line)240 dwfl_linecu_inline (const Dwfl_Line *line)
241 {
242 const struct Dwfl_Lines *lines = ((const void *) line
243 - offsetof (struct Dwfl_Lines,
244 idx[line->idx]));
245 return lines->cu;
246 }
247 #define dwfl_linecu dwfl_linecu_inline
248
249 static inline GElf_Addr
dwfl_adjusted_address(Dwfl_Module * mod,GElf_Addr addr)250 dwfl_adjusted_address (Dwfl_Module *mod, GElf_Addr addr)
251 {
252 return addr + mod->main_bias;
253 }
254
255 static inline GElf_Addr
dwfl_deadjust_address(Dwfl_Module * mod,GElf_Addr addr)256 dwfl_deadjust_address (Dwfl_Module *mod, GElf_Addr addr)
257 {
258 return addr - mod->main_bias;
259 }
260
261 static inline Dwarf_Addr
dwfl_adjusted_dwarf_addr(Dwfl_Module * mod,Dwarf_Addr addr)262 dwfl_adjusted_dwarf_addr (Dwfl_Module *mod, Dwarf_Addr addr)
263 {
264 return dwfl_adjusted_address (mod, (addr
265 - mod->debug.address_sync
266 + mod->main.address_sync));
267 }
268
269 static inline Dwarf_Addr
dwfl_deadjust_dwarf_addr(Dwfl_Module * mod,Dwarf_Addr addr)270 dwfl_deadjust_dwarf_addr (Dwfl_Module *mod, Dwarf_Addr addr)
271 {
272 return (dwfl_deadjust_address (mod, addr)
273 - mod->main.address_sync
274 + mod->debug.address_sync);
275 }
276
277 static inline GElf_Addr
dwfl_adjusted_st_value(Dwfl_Module * mod,GElf_Addr addr)278 dwfl_adjusted_st_value (Dwfl_Module *mod, GElf_Addr addr)
279 {
280 if (mod->symfile == &mod->main)
281 return dwfl_adjusted_address (mod, addr);
282 return dwfl_adjusted_dwarf_addr (mod, addr);
283 }
284
285 static inline GElf_Addr
dwfl_deadjust_st_value(Dwfl_Module * mod,GElf_Addr addr)286 dwfl_deadjust_st_value (Dwfl_Module *mod, GElf_Addr addr)
287 {
288 if (mod->symfile == &mod->main)
289 return dwfl_deadjust_address (mod, addr);
290 return dwfl_deadjust_dwarf_addr (mod, addr);
291 }
292
293 /* This describes a contiguous address range that lies in a single CU.
294 We condense runs of Dwarf_Arange entries for the same CU into this. */
295 struct dwfl_arange
296 {
297 struct dwfl_cu *cu;
298 size_t arange; /* Index in Dwarf_Aranges. */
299 };
300
301
302
303 extern void __libdwfl_module_free (Dwfl_Module *mod) internal_function;
304
305 /* Find the main ELF file, update MOD->elferr and/or MOD->main.elf. */
306 extern void __libdwfl_getelf (Dwfl_Module *mod) internal_function;
307
308 /* Process relocations in debugging sections in an ET_REL file.
309 FILE must be opened with ELF_C_READ_MMAP_PRIVATE or ELF_C_READ,
310 to make it possible to relocate the data in place (or ELF_C_RDWR or
311 ELF_C_RDWR_MMAP if you intend to modify the Elf file on disk). After
312 this, dwarf_begin_elf on FILE will read the relocated data.
313
314 When DEBUG is false, apply partial relocation to all sections. */
315 extern Dwfl_Error __libdwfl_relocate (Dwfl_Module *mod, Elf *file, bool debug)
316 internal_function;
317
318 /* Process (simple) relocations in arbitrary section TSCN of an ET_REL file.
319 RELOCSCN is SHT_REL or SHT_RELA and TSCN is its sh_info target section. */
320 extern Dwfl_Error __libdwfl_relocate_section (Dwfl_Module *mod, Elf *relocated,
321 Elf_Scn *relocscn, Elf_Scn *tscn,
322 bool partial)
323 internal_function;
324
325 /* Adjust *VALUE from section-relative to absolute.
326 MOD->dwfl->callbacks->section_address is called to determine the actual
327 address of a loaded section. */
328 extern Dwfl_Error __libdwfl_relocate_value (Dwfl_Module *mod, Elf *elf,
329 size_t *shstrndx_cache,
330 Elf32_Word shndx,
331 GElf_Addr *value)
332 internal_function;
333
334
335 /* Ensure that MOD->ebl is set up. */
336 extern Dwfl_Error __libdwfl_module_getebl (Dwfl_Module *mod) internal_function;
337
338 /* Install a new Dwarf_CFI in *SLOT (MOD->eh_cfi or MOD->dwarf_cfi). */
339 extern Dwarf_CFI *__libdwfl_set_cfi (Dwfl_Module *mod, Dwarf_CFI **slot,
340 Dwarf_CFI *cfi)
341 internal_function;
342
343 /* Iterate through all the CU's in the module. Start by passing a null
344 LASTCU, and then pass the last *CU returned. Success return with null
345 *CU no more CUs. */
346 extern Dwfl_Error __libdwfl_nextcu (Dwfl_Module *mod, struct dwfl_cu *lastcu,
347 struct dwfl_cu **cu) internal_function;
348
349 /* Find the CU by address. */
350 extern Dwfl_Error __libdwfl_addrcu (Dwfl_Module *mod, Dwarf_Addr addr,
351 struct dwfl_cu **cu) internal_function;
352
353 /* Ensure that CU->lines (and CU->cu->lines) is set up. */
354 extern Dwfl_Error __libdwfl_cu_getsrclines (struct dwfl_cu *cu)
355 internal_function;
356
357 /* Look in ELF for an NT_GNU_BUILD_ID note. If SET is true, store it
358 in MOD and return its length. If SET is false, instead compare it
359 to that stored in MOD and return 2 if they match, 1 if they do not.
360 Returns -1 for errors, 0 if no note is found. */
361 extern int __libdwfl_find_build_id (Dwfl_Module *mod, bool set, Elf *elf)
362 internal_function;
363
364 /* Open a main or debuginfo file by its build ID, returns the fd. */
365 extern int __libdwfl_open_by_build_id (Dwfl_Module *mod, bool debug,
366 char **file_name) internal_function;
367
368 extern uint32_t __libdwfl_crc32 (uint32_t crc, unsigned char *buf, size_t len)
369 attribute_hidden;
370 extern int __libdwfl_crc32_file (int fd, uint32_t *resp) attribute_hidden;
371
372
373 /* Meat of dwfl_report_elf, given elf_begin just called.
374 Consumes ELF on success, not on failure. */
375 extern Dwfl_Module *__libdwfl_report_elf (Dwfl *dwfl, const char *name,
376 const char *file_name, int fd,
377 Elf *elf, GElf_Addr base, bool sanity)
378 internal_function;
379
380 /* Meat of dwfl_report_offline. */
381 extern Dwfl_Module *__libdwfl_report_offline (Dwfl *dwfl, const char *name,
382 const char *file_name,
383 int fd, bool closefd,
384 int (*predicate) (const char *,
385 const char *))
386 internal_function;
387
388 /* Decompression wrappers: decompress whole file into memory. */
389 extern Dwfl_Error __libdw_gunzip (int fd, off64_t start_offset,
390 void *mapped, size_t mapped_size,
391 void **whole, size_t *whole_size)
392 internal_function;
393 extern Dwfl_Error __libdw_bunzip2 (int fd, off64_t start_offset,
394 void *mapped, size_t mapped_size,
395 void **whole, size_t *whole_size)
396 internal_function;
397 extern Dwfl_Error __libdw_unlzma (int fd, off64_t start_offset,
398 void *mapped, size_t mapped_size,
399 void **whole, size_t *whole_size)
400 internal_function;
401
402 /* Skip the image header before a file image: updates *START_OFFSET. */
403 extern Dwfl_Error __libdw_image_header (int fd, off64_t *start_offset,
404 void *mapped, size_t mapped_size)
405 internal_function;
406
407 /* Open Elf handle on *FDP. This handles decompression and checks
408 elf_kind. Succeed only for ELF_K_ELF, or also ELF_K_AR if ARCHIVE_OK.
409 Returns DWFL_E_NOERROR and sets *ELFP on success, resets *FDP to -1 if
410 it's no longer used. Resets *FDP on failure too iff CLOSE_ON_FAIL. */
411 extern Dwfl_Error __libdw_open_file (int *fdp, Elf **elfp,
412 bool close_on_fail, bool archive_ok)
413 internal_function;
414
415 /* These are working nicely for --core, but are not ready to be
416 exported interfaces quite yet. */
417
418 /* Type of callback function ...
419 */
420 typedef bool Dwfl_Memory_Callback (Dwfl *dwfl, int segndx,
421 void **buffer, size_t *buffer_available,
422 GElf_Addr vaddr, size_t minread, void *arg);
423
424 /* Type of callback function ...
425 */
426 typedef bool Dwfl_Module_Callback (Dwfl_Module *mod, void **userdata,
427 const char *name, Dwarf_Addr base,
428 void **buffer, size_t *buffer_available,
429 GElf_Off cost, GElf_Off worthwhile,
430 GElf_Off whole, GElf_Off contiguous,
431 void *arg, Elf **elfp);
432
433 /* ...
434 */
435 extern int dwfl_segment_report_module (Dwfl *dwfl, int ndx, const char *name,
436 Dwfl_Memory_Callback *memory_callback,
437 void *memory_callback_arg,
438 Dwfl_Module_Callback *read_eagerly,
439 void *read_eagerly_arg);
440
441 /* Report a module for entry in the dynamic linker's struct link_map list.
442 For each link_map entry, if an existing module resides at its address,
443 this just modifies that module's name and suggested file name. If
444 no such module exists, this calls dwfl_report_elf on the l_name string.
445
446 If AUXV is not null, it points to AUXV_SIZE bytes of auxiliary vector
447 data as contained in an NT_AUXV note or read from a /proc/pid/auxv
448 file. When this is available, it guides the search. If AUXV is null
449 or the memory it points to is not accessible, then this search can
450 only find where to begin if the correct executable file was
451 previously reported and preloaded as with dwfl_report_elf.
452
453 Returns the number of modules found, or -1 for errors. */
454 extern int dwfl_link_map_report (Dwfl *dwfl, const void *auxv, size_t auxv_size,
455 Dwfl_Memory_Callback *memory_callback,
456 void *memory_callback_arg);
457
458
459 /* Avoid PLT entries. */
460 INTDECL (dwfl_begin)
461 INTDECL (dwfl_errmsg)
462 INTDECL (dwfl_errno)
463 INTDECL (dwfl_addrmodule)
464 INTDECL (dwfl_addrsegment)
465 INTDECL (dwfl_addrdwarf)
466 INTDECL (dwfl_addrdie)
467 INTDECL (dwfl_core_file_report)
468 INTDECL (dwfl_getmodules)
469 INTDECL (dwfl_module_addrdie)
470 INTDECL (dwfl_module_address_section)
471 INTDECL (dwfl_module_addrsym)
472 INTDECL (dwfl_module_build_id)
473 INTDECL (dwfl_module_getdwarf)
474 INTDECL (dwfl_module_getelf)
475 INTDECL (dwfl_module_getsym)
476 INTDECL (dwfl_module_getsymtab)
477 INTDECL (dwfl_module_getsrc)
478 INTDECL (dwfl_module_report_build_id)
479 INTDECL (dwfl_report_elf)
480 INTDECL (dwfl_report_begin)
481 INTDECL (dwfl_report_begin_add)
482 INTDECL (dwfl_report_module)
483 INTDECL (dwfl_report_segment)
484 INTDECL (dwfl_report_offline)
485 INTDECL (dwfl_report_end)
486 INTDECL (dwfl_build_id_find_elf)
487 INTDECL (dwfl_build_id_find_debuginfo)
488 INTDECL (dwfl_standard_find_debuginfo)
489 INTDECL (dwfl_link_map_report)
490 INTDECL (dwfl_linux_kernel_find_elf)
491 INTDECL (dwfl_linux_kernel_module_section_address)
492 INTDECL (dwfl_linux_proc_report)
493 INTDECL (dwfl_linux_proc_maps_report)
494 INTDECL (dwfl_linux_proc_find_elf)
495 INTDECL (dwfl_linux_kernel_report_kernel)
496 INTDECL (dwfl_linux_kernel_report_modules)
497 INTDECL (dwfl_linux_kernel_report_offline)
498 INTDECL (dwfl_offline_section_address)
499 INTDECL (dwfl_module_relocate_address)
500 INTDECL (dwfl_module_dwarf_cfi)
501 INTDECL (dwfl_module_eh_cfi)
502
503 /* Leading arguments standard to callbacks passed a Dwfl_Module. */
504 #define MODCB_ARGS(mod) (mod), &(mod)->userdata, (mod)->name, (mod)->low_addr
505 #define CBFAIL (errno ? DWFL_E (ERRNO, errno) : DWFL_E_CB);
506
507
508 /* The default used by dwfl_standard_find_debuginfo. */
509 #define DEFAULT_DEBUGINFO_PATH ":.debug:/usr/lib/debug"
510
511
512 #endif /* libdwflP.h */
513