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0e5d83e3 JJ |
1 | /* Frame unwinder for frames using the libunwind library. |
2 | ||
6aba47ca | 3 | Copyright (C) 2003, 2004, 2006, 2007 Free Software Foundation, Inc. |
0e5d83e3 JJ |
4 | |
5 | Written by Jeff Johnston, contributed by Red Hat Inc. | |
6 | ||
7 | This file is part of GDB. | |
8 | ||
9 | This program is free software; you can redistribute it and/or modify | |
10 | it under the terms of the GNU General Public License as published by | |
11 | the Free Software Foundation; either version 2 of the License, or | |
12 | (at your option) any later version. | |
13 | ||
14 | This program is distributed in the hope that it will be useful, | |
15 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | GNU General Public License for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
20 | along with this program; if not, write to the Free Software | |
197e01b6 EZ |
21 | Foundation, Inc., 51 Franklin Street, Fifth Floor, |
22 | Boston, MA 02110-1301, USA. */ | |
0e5d83e3 JJ |
23 | |
24 | #include "defs.h" | |
25 | ||
26 | #include "inferior.h" | |
27 | #include "frame.h" | |
28 | #include "frame-base.h" | |
29 | #include "frame-unwind.h" | |
30 | #include "gdbcore.h" | |
31 | #include "gdbtypes.h" | |
32 | #include "symtab.h" | |
33 | #include "objfiles.h" | |
34 | #include "regcache.h" | |
35 | ||
36 | #include <dlfcn.h> | |
37 | ||
38 | #include "gdb_assert.h" | |
39 | #include "gdb_string.h" | |
40 | ||
41 | #include "libunwind-frame.h" | |
42 | ||
43 | #include "complaints.h" | |
44 | ||
45 | static int libunwind_initialized; | |
46 | static struct gdbarch_data *libunwind_descr_handle; | |
47 | ||
0e5d83e3 JJ |
48 | /* Required function pointers from libunwind. */ |
49 | static int (*unw_get_reg_p) (unw_cursor_t *, unw_regnum_t, unw_word_t *); | |
50 | static int (*unw_get_fpreg_p) (unw_cursor_t *, unw_regnum_t, unw_fpreg_t *); | |
51 | static int (*unw_get_saveloc_p) (unw_cursor_t *, unw_regnum_t, unw_save_loc_t *); | |
c5a27d9c | 52 | static int (*unw_is_signal_frame_p) (unw_cursor_t *); |
0e5d83e3 JJ |
53 | static int (*unw_step_p) (unw_cursor_t *); |
54 | static int (*unw_init_remote_p) (unw_cursor_t *, unw_addr_space_t, void *); | |
55 | static unw_addr_space_t (*unw_create_addr_space_p) (unw_accessors_t *, int); | |
56 | static int (*unw_search_unwind_table_p) (unw_addr_space_t, unw_word_t, unw_dyn_info_t *, | |
57 | unw_proc_info_t *, int, void *); | |
503ff15d KB |
58 | static unw_word_t (*unw_find_dyn_list_p) (unw_addr_space_t, unw_dyn_info_t *, |
59 | void *); | |
0e5d83e3 JJ |
60 | |
61 | ||
62 | struct libunwind_frame_cache | |
63 | { | |
64 | CORE_ADDR base; | |
65 | CORE_ADDR func_addr; | |
66 | unw_cursor_t cursor; | |
67 | }; | |
68 | ||
69 | /* We need to qualify the function names with a platform-specific prefix to match | |
70 | the names used by the libunwind library. The UNW_OBJ macro is provided by the | |
71 | libunwind.h header file. */ | |
72 | #define STRINGIFY2(name) #name | |
73 | #define STRINGIFY(name) STRINGIFY2(name) | |
74 | ||
38e400fa JJ |
75 | #ifndef LIBUNWIND_SO |
76 | #define LIBUNWIND_SO "libunwind-" STRINGIFY(UNW_TARGET) ".so" | |
77 | #endif | |
78 | ||
0e5d83e3 JJ |
79 | static char *get_reg_name = STRINGIFY(UNW_OBJ(get_reg)); |
80 | static char *get_fpreg_name = STRINGIFY(UNW_OBJ(get_fpreg)); | |
81 | static char *get_saveloc_name = STRINGIFY(UNW_OBJ(get_save_loc)); | |
c5a27d9c | 82 | static char *is_signal_frame_name = STRINGIFY(UNW_OBJ(is_signal_frame)); |
0e5d83e3 JJ |
83 | static char *step_name = STRINGIFY(UNW_OBJ(step)); |
84 | static char *init_remote_name = STRINGIFY(UNW_OBJ(init_remote)); | |
85 | static char *create_addr_space_name = STRINGIFY(UNW_OBJ(create_addr_space)); | |
86 | static char *search_unwind_table_name = STRINGIFY(UNW_OBJ(search_unwind_table)); | |
87 | static char *find_dyn_list_name = STRINGIFY(UNW_OBJ(find_dyn_list)); | |
88 | ||
89 | static struct libunwind_descr * | |
90 | libunwind_descr (struct gdbarch *gdbarch) | |
91 | { | |
92 | return gdbarch_data (gdbarch, libunwind_descr_handle); | |
93 | } | |
94 | ||
95 | static void * | |
96 | libunwind_descr_init (struct gdbarch *gdbarch) | |
97 | { | |
98 | struct libunwind_descr *descr = GDBARCH_OBSTACK_ZALLOC (gdbarch, | |
99 | struct libunwind_descr); | |
100 | return descr; | |
101 | } | |
102 | ||
103 | void | |
104 | libunwind_frame_set_descr (struct gdbarch *gdbarch, struct libunwind_descr *descr) | |
105 | { | |
106 | struct libunwind_descr *arch_descr; | |
107 | ||
108 | gdb_assert (gdbarch != NULL); | |
109 | ||
110 | arch_descr = gdbarch_data (gdbarch, libunwind_descr_handle); | |
111 | ||
112 | if (arch_descr == NULL) | |
113 | { | |
114 | /* First time here. Must initialize data area. */ | |
115 | arch_descr = libunwind_descr_init (gdbarch); | |
030f20e1 | 116 | deprecated_set_gdbarch_data (gdbarch, libunwind_descr_handle, arch_descr); |
0e5d83e3 JJ |
117 | } |
118 | ||
119 | /* Copy new descriptor info into arch descriptor. */ | |
120 | arch_descr->gdb2uw = descr->gdb2uw; | |
121 | arch_descr->uw2gdb = descr->uw2gdb; | |
122 | arch_descr->is_fpreg = descr->is_fpreg; | |
123 | arch_descr->accessors = descr->accessors; | |
c5a27d9c | 124 | arch_descr->special_accessors = descr->special_accessors; |
0e5d83e3 JJ |
125 | } |
126 | ||
127 | static struct libunwind_frame_cache * | |
128 | libunwind_frame_cache (struct frame_info *next_frame, void **this_cache) | |
129 | { | |
130 | unw_accessors_t *acc; | |
131 | unw_addr_space_t as; | |
132 | unw_word_t fp; | |
133 | unw_regnum_t uw_sp_regnum; | |
134 | struct libunwind_frame_cache *cache; | |
135 | struct libunwind_descr *descr; | |
136 | int i, ret; | |
137 | ||
138 | if (*this_cache) | |
139 | return *this_cache; | |
140 | ||
141 | /* Allocate a new cache. */ | |
142 | cache = FRAME_OBSTACK_ZALLOC (struct libunwind_frame_cache); | |
143 | ||
93d42b30 DJ |
144 | /* We can assume we are unwinding a normal frame. Even if this is |
145 | for a signal trampoline, ia64 signal "trampolines" use a normal | |
146 | subroutine call to start the signal handler. */ | |
147 | cache->func_addr = frame_func_unwind (next_frame, NORMAL_FRAME); | |
c5a27d9c JJ |
148 | if (cache->func_addr == 0 |
149 | && frame_relative_level (next_frame) > 0 | |
150 | && get_frame_type (next_frame) != SIGTRAMP_FRAME) | |
151 | return NULL; | |
0e5d83e3 JJ |
152 | |
153 | /* Get a libunwind cursor to the previous frame. We do this by initializing | |
154 | a cursor. Libunwind treats a new cursor as the top of stack and will get | |
155 | the current register set via the libunwind register accessor. Now, we | |
156 | provide the platform-specific accessors and we set up the register accessor to use | |
157 | the frame register unwinding interfaces so that we properly get the registers for | |
158 | the current frame rather than the top. We then use the unw_step function to | |
159 | move the libunwind cursor back one frame. We can later use this cursor to find previous | |
160 | registers via the unw_get_reg interface which will invoke libunwind's special logic. */ | |
161 | descr = libunwind_descr (get_frame_arch (next_frame)); | |
162 | acc = descr->accessors; | |
163 | as = unw_create_addr_space_p (acc, | |
164 | TARGET_BYTE_ORDER == BFD_ENDIAN_BIG | |
165 | ? __BIG_ENDIAN | |
166 | : __LITTLE_ENDIAN); | |
167 | ||
168 | unw_init_remote_p (&cache->cursor, as, next_frame); | |
c5a27d9c JJ |
169 | if (unw_step_p (&cache->cursor) < 0) |
170 | return NULL; | |
0e5d83e3 JJ |
171 | |
172 | /* To get base address, get sp from previous frame. */ | |
173 | uw_sp_regnum = descr->gdb2uw (SP_REGNUM); | |
174 | ret = unw_get_reg_p (&cache->cursor, uw_sp_regnum, &fp); | |
175 | if (ret < 0) | |
8a3fe4f8 | 176 | error (_("Can't get libunwind sp register.")); |
0e5d83e3 JJ |
177 | |
178 | cache->base = (CORE_ADDR)fp; | |
179 | ||
180 | *this_cache = cache; | |
181 | return cache; | |
182 | } | |
183 | ||
503ff15d KB |
184 | unw_word_t |
185 | libunwind_find_dyn_list (unw_addr_space_t as, unw_dyn_info_t *di, void *arg) | |
0e5d83e3 | 186 | { |
503ff15d | 187 | return unw_find_dyn_list_p (as, di, arg); |
0e5d83e3 JJ |
188 | } |
189 | ||
190 | static const struct frame_unwind libunwind_frame_unwind = | |
191 | { | |
192 | NORMAL_FRAME, | |
193 | libunwind_frame_this_id, | |
194 | libunwind_frame_prev_register | |
195 | }; | |
196 | ||
197 | /* Verify if there is sufficient libunwind information for the frame to use | |
198 | libunwind frame unwinding. */ | |
199 | const struct frame_unwind * | |
200 | libunwind_frame_sniffer (struct frame_info *next_frame) | |
201 | { | |
202 | unw_cursor_t cursor; | |
203 | unw_accessors_t *acc; | |
204 | unw_addr_space_t as; | |
205 | struct libunwind_descr *descr; | |
206 | int i, ret; | |
207 | ||
208 | /* To test for libunwind unwind support, initialize a cursor to the current frame and try to back | |
209 | up. We use this same method when setting up the frame cache (see libunwind_frame_cache()). | |
210 | If libunwind returns success for this operation, it means that it has found sufficient | |
211 | libunwind unwinding information to do so. */ | |
212 | ||
213 | descr = libunwind_descr (get_frame_arch (next_frame)); | |
214 | acc = descr->accessors; | |
215 | as = unw_create_addr_space_p (acc, | |
216 | TARGET_BYTE_ORDER == BFD_ENDIAN_BIG | |
217 | ? __BIG_ENDIAN | |
218 | : __LITTLE_ENDIAN); | |
219 | ||
220 | ret = unw_init_remote_p (&cursor, as, next_frame); | |
221 | ||
c5a27d9c JJ |
222 | if (ret < 0) |
223 | return NULL; | |
224 | ||
225 | ||
226 | /* Check to see if we have libunwind info by checking if we are in a | |
227 | signal frame. If it doesn't return an error, we have libunwind info | |
228 | and can use libunwind. */ | |
229 | ret = unw_is_signal_frame_p (&cursor); | |
0e5d83e3 JJ |
230 | |
231 | if (ret < 0) | |
232 | return NULL; | |
233 | ||
234 | return &libunwind_frame_unwind; | |
235 | } | |
236 | ||
237 | void | |
238 | libunwind_frame_this_id (struct frame_info *next_frame, void **this_cache, | |
239 | struct frame_id *this_id) | |
240 | { | |
241 | struct libunwind_frame_cache *cache = | |
242 | libunwind_frame_cache (next_frame, this_cache); | |
243 | ||
c5a27d9c JJ |
244 | if (cache != NULL) |
245 | (*this_id) = frame_id_build (cache->base, cache->func_addr); | |
246 | else | |
247 | (*this_id) = null_frame_id; | |
0e5d83e3 JJ |
248 | } |
249 | ||
250 | void | |
251 | libunwind_frame_prev_register (struct frame_info *next_frame, void **this_cache, | |
252 | int regnum, int *optimizedp, | |
253 | enum lval_type *lvalp, CORE_ADDR *addrp, | |
f1b4b38e | 254 | int *realnump, gdb_byte *valuep) |
0e5d83e3 JJ |
255 | { |
256 | struct libunwind_frame_cache *cache = | |
257 | libunwind_frame_cache (next_frame, this_cache); | |
258 | ||
259 | void *ptr; | |
260 | unw_cursor_t *c; | |
261 | unw_save_loc_t sl; | |
262 | int i, ret; | |
263 | unw_word_t intval; | |
264 | unw_fpreg_t fpval; | |
265 | unw_regnum_t uw_regnum; | |
266 | struct libunwind_descr *descr; | |
267 | ||
c5a27d9c JJ |
268 | if (cache == NULL) |
269 | return; | |
270 | ||
0e5d83e3 JJ |
271 | /* Convert from gdb register number to libunwind register number. */ |
272 | descr = libunwind_descr (get_frame_arch (next_frame)); | |
273 | uw_regnum = descr->gdb2uw (regnum); | |
274 | ||
275 | gdb_assert (regnum >= 0); | |
276 | ||
277 | if (!target_has_registers) | |
8a3fe4f8 | 278 | error (_("No registers.")); |
0e5d83e3 JJ |
279 | |
280 | *optimizedp = 0; | |
281 | *addrp = 0; | |
282 | *lvalp = not_lval; | |
283 | *realnump = -1; | |
284 | ||
6672f2ae AS |
285 | if (valuep) |
286 | memset (valuep, 0, register_size (current_gdbarch, regnum)); | |
0e5d83e3 JJ |
287 | |
288 | if (uw_regnum < 0) | |
289 | return; | |
290 | ||
291 | /* To get the previous register, we use the libunwind register APIs with | |
292 | the cursor we have already pushed back to the previous frame. */ | |
293 | ||
294 | if (descr->is_fpreg (uw_regnum)) | |
295 | { | |
296 | ret = unw_get_fpreg_p (&cache->cursor, uw_regnum, &fpval); | |
297 | ptr = &fpval; | |
298 | } | |
299 | else | |
300 | { | |
301 | ret = unw_get_reg_p (&cache->cursor, uw_regnum, &intval); | |
302 | ptr = &intval; | |
303 | } | |
304 | ||
305 | if (ret < 0) | |
306 | return; | |
307 | ||
6672f2ae AS |
308 | if (valuep) |
309 | memcpy (valuep, ptr, register_size (current_gdbarch, regnum)); | |
0e5d83e3 JJ |
310 | |
311 | if (unw_get_saveloc_p (&cache->cursor, uw_regnum, &sl) < 0) | |
312 | return; | |
313 | ||
314 | switch (sl.type) | |
315 | { | |
316 | case UNW_SLT_NONE: | |
317 | *optimizedp = 1; | |
318 | break; | |
319 | ||
320 | case UNW_SLT_MEMORY: | |
321 | *lvalp = lval_memory; | |
322 | *addrp = sl.u.addr; | |
323 | break; | |
324 | ||
325 | case UNW_SLT_REG: | |
326 | *lvalp = lval_register; | |
327 | *realnump = regnum; | |
328 | break; | |
329 | } | |
330 | } | |
331 | ||
332 | CORE_ADDR | |
333 | libunwind_frame_base_address (struct frame_info *next_frame, void **this_cache) | |
334 | { | |
335 | struct libunwind_frame_cache *cache = | |
336 | libunwind_frame_cache (next_frame, this_cache); | |
337 | ||
c5a27d9c JJ |
338 | if (cache == NULL) |
339 | return (CORE_ADDR)NULL; | |
0e5d83e3 JJ |
340 | return cache->base; |
341 | } | |
342 | ||
343 | /* The following is a glue routine to call the libunwind unwind table | |
344 | search function to get unwind information for a specified ip address. */ | |
345 | int | |
346 | libunwind_search_unwind_table (void *as, long ip, void *di, | |
347 | void *pi, int need_unwind_info, void *args) | |
348 | { | |
349 | return unw_search_unwind_table_p (*(unw_addr_space_t *)as, (unw_word_t )ip, | |
350 | di, pi, need_unwind_info, args); | |
351 | } | |
352 | ||
c5a27d9c JJ |
353 | /* Verify if we are in a sigtramp frame and we can use libunwind to unwind. */ |
354 | const struct frame_unwind * | |
355 | libunwind_sigtramp_frame_sniffer (struct frame_info *next_frame) | |
356 | { | |
357 | unw_cursor_t cursor; | |
358 | unw_accessors_t *acc; | |
359 | unw_addr_space_t as; | |
360 | struct libunwind_descr *descr; | |
361 | int i, ret; | |
362 | ||
363 | /* To test for libunwind unwind support, initialize a cursor to the | |
364 | current frame and try to back up. We use this same method when | |
365 | setting up the frame cache (see libunwind_frame_cache()). If | |
366 | libunwind returns success for this operation, it means that it | |
367 | has found sufficient libunwind unwinding information to do | |
368 | so. */ | |
369 | ||
370 | descr = libunwind_descr (get_frame_arch (next_frame)); | |
371 | acc = descr->accessors; | |
372 | as = unw_create_addr_space_p (acc, | |
373 | TARGET_BYTE_ORDER == BFD_ENDIAN_BIG | |
374 | ? __BIG_ENDIAN | |
375 | : __LITTLE_ENDIAN); | |
376 | ||
377 | ret = unw_init_remote_p (&cursor, as, next_frame); | |
378 | ||
379 | if (ret < 0) | |
380 | return NULL; | |
381 | ||
382 | /* Check to see if we are in a signal frame. */ | |
383 | ret = unw_is_signal_frame_p (&cursor); | |
384 | if (ret > 0) | |
385 | return &libunwind_frame_unwind; | |
386 | ||
387 | return NULL; | |
388 | } | |
389 | ||
390 | /* The following routine is for accessing special registers of the top frame. | |
391 | A special set of accessors must be given that work without frame info. | |
392 | This is used by ia64 to access the rse registers r32-r127. While they | |
393 | are usually located at BOF, this is not always true and only the libunwind | |
394 | info can decipher where they actually are. */ | |
395 | int | |
396 | libunwind_get_reg_special (struct gdbarch *gdbarch, int regnum, void *buf) | |
397 | { | |
398 | unw_cursor_t cursor; | |
399 | unw_accessors_t *acc; | |
400 | unw_addr_space_t as; | |
401 | struct libunwind_descr *descr; | |
402 | int ret; | |
403 | unw_regnum_t uw_regnum; | |
404 | unw_word_t intval; | |
405 | unw_fpreg_t fpval; | |
406 | void *ptr; | |
407 | ||
408 | ||
409 | descr = libunwind_descr (gdbarch); | |
410 | acc = descr->special_accessors; | |
411 | as = unw_create_addr_space_p (acc, | |
412 | TARGET_BYTE_ORDER == BFD_ENDIAN_BIG | |
413 | ? __BIG_ENDIAN | |
414 | : __LITTLE_ENDIAN); | |
415 | ||
416 | ret = unw_init_remote_p (&cursor, as, NULL); | |
417 | if (ret < 0) | |
418 | return -1; | |
419 | ||
420 | uw_regnum = descr->gdb2uw (regnum); | |
421 | ||
422 | if (descr->is_fpreg (uw_regnum)) | |
423 | { | |
424 | ret = unw_get_fpreg_p (&cursor, uw_regnum, &fpval); | |
425 | ptr = &fpval; | |
426 | } | |
427 | else | |
428 | { | |
429 | ret = unw_get_reg_p (&cursor, uw_regnum, &intval); | |
430 | ptr = &intval; | |
431 | } | |
432 | ||
433 | if (ret < 0) | |
434 | return -1; | |
435 | ||
436 | if (buf) | |
437 | memcpy (buf, ptr, register_size (current_gdbarch, regnum)); | |
438 | ||
439 | return 0; | |
440 | } | |
441 | ||
0e5d83e3 JJ |
442 | static int |
443 | libunwind_load (void) | |
444 | { | |
445 | void *handle; | |
446 | ||
447 | handle = dlopen (LIBUNWIND_SO, RTLD_NOW); | |
448 | if (handle == NULL) | |
449 | return 0; | |
450 | ||
451 | /* Initialize pointers to the dynamic library functions we will use. */ | |
452 | ||
453 | unw_get_reg_p = dlsym (handle, get_reg_name); | |
454 | if (unw_get_reg_p == NULL) | |
455 | return 0; | |
456 | ||
457 | unw_get_fpreg_p = dlsym (handle, get_fpreg_name); | |
458 | if (unw_get_fpreg_p == NULL) | |
459 | return 0; | |
460 | ||
461 | unw_get_saveloc_p = dlsym (handle, get_saveloc_name); | |
462 | if (unw_get_saveloc_p == NULL) | |
463 | return 0; | |
464 | ||
c5a27d9c JJ |
465 | unw_is_signal_frame_p = dlsym (handle, is_signal_frame_name); |
466 | if (unw_is_signal_frame_p == NULL) | |
467 | return 0; | |
468 | ||
0e5d83e3 JJ |
469 | unw_step_p = dlsym (handle, step_name); |
470 | if (unw_step_p == NULL) | |
471 | return 0; | |
472 | ||
473 | unw_init_remote_p = dlsym (handle, init_remote_name); | |
474 | if (unw_init_remote_p == NULL) | |
475 | return 0; | |
476 | ||
477 | unw_create_addr_space_p = dlsym (handle, create_addr_space_name); | |
478 | if (unw_create_addr_space_p == NULL) | |
479 | return 0; | |
480 | ||
481 | unw_search_unwind_table_p = dlsym (handle, search_unwind_table_name); | |
482 | if (unw_search_unwind_table_p == NULL) | |
483 | return 0; | |
484 | ||
485 | unw_find_dyn_list_p = dlsym (handle, find_dyn_list_name); | |
486 | if (unw_find_dyn_list_p == NULL) | |
487 | return 0; | |
488 | ||
489 | return 1; | |
490 | } | |
491 | ||
492 | int | |
493 | libunwind_is_initialized (void) | |
494 | { | |
495 | return libunwind_initialized; | |
496 | } | |
497 | ||
498 | /* Provide a prototype to silence -Wmissing-prototypes. */ | |
499 | void _initialize_libunwind_frame (void); | |
500 | ||
501 | void | |
502 | _initialize_libunwind_frame (void) | |
503 | { | |
030f20e1 | 504 | libunwind_descr_handle = gdbarch_data_register_post_init (libunwind_descr_init); |
0e5d83e3 JJ |
505 | |
506 | libunwind_initialized = libunwind_load (); | |
507 | } |