Commit | Line | Data |
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be4d1333 MS |
1 | /* Generate a core file for the inferior process. |
2 | Copyright 2001, 2002 Free Software Foundation, Inc. | |
3 | ||
4 | This file is part of GDB. | |
5 | ||
6 | This program is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2 of the License, or | |
9 | (at your option) any later version. | |
10 | ||
11 | This program is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with this program; if not, write to the Free Software | |
18 | Foundation, Inc., 59 Temple Place - Suite 330, | |
19 | Boston, MA 02111-1307, USA. */ | |
20 | ||
21 | #include "defs.h" | |
c18be923 | 22 | #include "cli/cli-decode.h" |
be4d1333 MS |
23 | #include "inferior.h" |
24 | #include "gdbcore.h" | |
25 | #include "elf-bfd.h" | |
26 | #include <sys/procfs.h> | |
27 | #include "symfile.h" | |
28 | #include "objfiles.h" | |
29 | ||
30 | static char *default_gcore_target (void); | |
31 | static enum bfd_architecture default_gcore_arch (void); | |
32 | static unsigned long default_gcore_mach (void); | |
33 | static int gcore_memory_sections (bfd *); | |
34 | ||
35 | /* Function: gcore_command | |
36 | Generate a core file from the inferior process. */ | |
37 | ||
38 | static void | |
39 | gcore_command (char *args, int from_tty) | |
40 | { | |
41 | struct cleanup *old_chain; | |
42 | char *corefilename, corefilename_buffer[40]; | |
43 | asection *note_sec; | |
44 | bfd *obfd; | |
45 | void *note_data = NULL; | |
46 | int note_size = 0; | |
47 | ||
48 | /* No use generating a corefile without a target process. */ | |
49 | if (!(target_has_execution)) | |
50 | noprocess (); | |
51 | ||
52 | if (args && *args) | |
53 | corefilename = args; | |
54 | else | |
55 | { | |
56 | /* Default corefile name is "core.PID". */ | |
57 | sprintf (corefilename_buffer, "core.%d", PIDGET (inferior_ptid)); | |
58 | corefilename = corefilename_buffer; | |
59 | } | |
60 | ||
61 | if (info_verbose) | |
62 | fprintf_filtered (gdb_stdout, | |
63 | "Opening corefile '%s' for output.\n", corefilename); | |
64 | ||
65 | /* Open the output file. */ | |
66 | if (!(obfd = bfd_openw (corefilename, NULL /*default_gcore_target ()*/))) | |
67 | { | |
68 | error ("Failed to open '%s' for output.", corefilename); | |
69 | } | |
70 | ||
71 | /* Need a cleanup that will close the file (FIXME: delete it?). */ | |
72 | old_chain = make_cleanup_bfd_close (obfd); | |
73 | ||
74 | bfd_set_format (obfd, bfd_core); | |
75 | bfd_set_arch_mach (obfd, default_gcore_arch (), default_gcore_mach ()); | |
76 | ||
77 | /* An external target method must build the notes section. */ | |
78 | note_data = (char *) target_make_corefile_notes (obfd, ¬e_size); | |
79 | ||
80 | /* Create the note section. */ | |
81 | if (note_data != NULL && note_size != 0) | |
82 | { | |
83 | if ((note_sec = bfd_make_section_anyway (obfd, "note0")) == NULL) | |
84 | error ("Failed to create 'note' section for corefile: %s", | |
85 | bfd_errmsg (bfd_get_error ())); | |
86 | ||
87 | bfd_set_section_vma (obfd, note_sec, 0); | |
88 | bfd_set_section_flags (obfd, note_sec, | |
89 | SEC_HAS_CONTENTS | SEC_READONLY | SEC_ALLOC); | |
90 | bfd_set_section_alignment (obfd, note_sec, 0); | |
91 | bfd_set_section_size (obfd, note_sec, note_size); | |
92 | } | |
93 | ||
94 | /* Now create the memory/load sections. */ | |
95 | if (gcore_memory_sections (obfd) == 0) | |
96 | error ("gcore: failed to get corefile memory sections from target."); | |
97 | ||
98 | /* Write out the contents of the note section. */ | |
99 | if (note_data != NULL && note_size != 0) | |
100 | { | |
101 | if (!bfd_set_section_contents (obfd, note_sec, note_data, 0, note_size)) | |
102 | { | |
103 | warning ("writing note section (%s)", | |
104 | bfd_errmsg (bfd_get_error ())); | |
105 | } | |
106 | } | |
107 | ||
108 | /* Succeeded. */ | |
109 | fprintf_filtered (gdb_stdout, | |
110 | "Saved corefile %s\n", corefilename); | |
111 | ||
112 | /* Clean-ups will close the output file and free malloc memory. */ | |
113 | do_cleanups (old_chain); | |
114 | return; | |
115 | } | |
116 | ||
117 | static unsigned long | |
118 | default_gcore_mach (void) | |
119 | { | |
120 | #ifdef TARGET_ARCHITECTURE | |
121 | const struct bfd_arch_info * bfdarch = TARGET_ARCHITECTURE; | |
122 | ||
123 | if (bfdarch != NULL) | |
124 | return bfdarch->mach; | |
125 | #endif | |
126 | if (exec_bfd == NULL) | |
127 | error ("Can't find default bfd machine type (need execfile)."); | |
128 | ||
129 | return bfd_get_mach (exec_bfd); | |
130 | } | |
131 | ||
132 | static enum bfd_architecture | |
133 | default_gcore_arch (void) | |
134 | { | |
135 | #ifdef TARGET_ARCHITECTURE | |
136 | const struct bfd_arch_info * bfdarch = TARGET_ARCHITECTURE; | |
137 | ||
138 | if (bfdarch != NULL) | |
139 | return bfdarch->arch; | |
140 | #endif | |
141 | if (exec_bfd == NULL) | |
142 | error ("Can't find bfd architecture for corefile (need execfile)."); | |
143 | ||
144 | return bfd_get_arch (exec_bfd); | |
145 | } | |
146 | ||
147 | static char * | |
148 | default_gcore_target (void) | |
149 | { | |
150 | /* FIXME -- this may only work for ELF targets. */ | |
151 | if (exec_bfd == NULL) | |
152 | error ("Can't find default bfd target for corefile (need execfile)."); | |
153 | ||
154 | return bfd_get_target (exec_bfd); | |
155 | } | |
156 | ||
157 | /* | |
158 | * Default method for stack segment (preemptable by target). | |
159 | */ | |
160 | ||
161 | static int (*override_derive_stack_segment) (bfd_vma *, bfd_vma *); | |
162 | ||
163 | extern void | |
164 | preempt_derive_stack_segment (int (*override_func) (bfd_vma *, bfd_vma *)) | |
165 | { | |
166 | override_derive_stack_segment = override_func; | |
167 | } | |
168 | ||
169 | /* Function: default_derive_stack_segment | |
170 | Derive a reasonable stack segment by unwinding the target stack. | |
171 | ||
172 | Returns 0 for failure, 1 for success. */ | |
173 | ||
174 | static int | |
175 | default_derive_stack_segment (bfd_vma *bottom, bfd_vma *top) | |
176 | { | |
177 | bfd_vma tmp_vma; | |
178 | struct frame_info *fi, *tmp_fi; | |
179 | ||
180 | if (bottom == NULL || top == NULL) | |
181 | return 0; /* Paranoia. */ | |
182 | ||
183 | if (!target_has_stack || !target_has_registers) | |
184 | return 0; /* Can't succeed without stack and registers. */ | |
185 | ||
186 | if ((fi = get_current_frame ()) == NULL) | |
187 | return 0; /* Can't succeed without current frame. */ | |
188 | ||
189 | /* Save frame pointer of TOS frame. */ | |
190 | *top = fi->frame; | |
191 | /* If current stack pointer is more "inner", use that instead. */ | |
192 | if (INNER_THAN (read_sp (), *top)) | |
193 | *top = read_sp (); | |
194 | ||
195 | /* Find prev-most frame. */ | |
196 | while ((tmp_fi = get_prev_frame (fi)) != NULL) | |
197 | fi = tmp_fi; | |
198 | ||
199 | /* Save frame pointer of prev-most frame. */ | |
200 | *bottom = fi->frame; | |
201 | ||
202 | /* Now canonicalize their order, so that 'bottom' is a lower address | |
203 | (as opposed to a lower stack frame). */ | |
204 | if (*bottom > *top) | |
205 | { | |
206 | tmp_vma = *top; | |
207 | *top = *bottom; | |
208 | *bottom = tmp_vma; | |
209 | } | |
210 | ||
211 | return 1; /* success */ | |
212 | } | |
213 | ||
214 | static int | |
215 | derive_stack_segment (bfd_vma *bottom, bfd_vma *top) | |
216 | { | |
217 | if (override_derive_stack_segment) | |
218 | return override_derive_stack_segment (bottom, top); | |
219 | else | |
220 | return default_derive_stack_segment (bottom, top); | |
221 | } | |
222 | ||
223 | /* | |
224 | * Default method for heap segment (preemptable by target). | |
225 | */ | |
226 | ||
227 | static int (*override_derive_heap_segment) (bfd *, bfd_vma *, bfd_vma *); | |
228 | ||
229 | extern void | |
230 | preempt_derive_heap_segment (int (*override_func) (bfd *, | |
231 | bfd_vma *, bfd_vma *)) | |
232 | { | |
233 | override_derive_heap_segment = override_func; | |
234 | } | |
235 | ||
236 | /* Function: default_derive_heap_segment | |
237 | Derive a reasonable heap segment by looking at sbrk and | |
238 | the static data sections. | |
239 | ||
240 | Returns 0 for failure, 1 for success. */ | |
241 | ||
242 | static int | |
243 | default_derive_heap_segment (bfd *abfd, bfd_vma *bottom, bfd_vma *top) | |
244 | { | |
245 | bfd_vma top_of_data_memory = 0; | |
246 | bfd_vma top_of_heap = 0; | |
247 | bfd_size_type sec_size; | |
248 | struct value *zero, *sbrk; | |
249 | bfd_vma sec_vaddr; | |
250 | asection *sec; | |
251 | ||
252 | if (bottom == NULL || top == NULL) | |
253 | return 0; /* Paranoia. */ | |
254 | ||
255 | if (!target_has_execution) | |
256 | return 0; /* This function depends on being able | |
257 | to call a function in the inferior. */ | |
258 | ||
259 | /* Assumption: link map is arranged as follows (low to high addresses): | |
260 | text sections | |
261 | data sections (including bss) | |
262 | heap | |
263 | */ | |
264 | ||
265 | for (sec = abfd->sections; sec; sec = sec->next) | |
266 | { | |
267 | if (bfd_get_section_flags (abfd, sec) & SEC_DATA || | |
268 | strcmp (".bss", bfd_get_section_name (abfd, sec)) == 0) | |
269 | { | |
270 | sec_vaddr = bfd_get_section_vma (abfd, sec); | |
271 | sec_size = bfd_get_section_size_before_reloc (sec); | |
272 | if (sec_vaddr + sec_size > top_of_data_memory) | |
273 | top_of_data_memory = sec_vaddr + sec_size; | |
274 | } | |
275 | } | |
276 | /* Now get the top-of-heap by calling sbrk in the inferior. */ | |
277 | if ((sbrk = find_function_in_inferior ("sbrk")) == NULL) | |
278 | return 0; | |
279 | if ((zero = value_from_longest (builtin_type_int, (LONGEST) 0)) == NULL) | |
280 | return 0; | |
281 | if ((sbrk = call_function_by_hand (sbrk, 1, &zero)) == NULL) | |
282 | return 0; | |
283 | top_of_heap = value_as_long (sbrk); | |
284 | ||
285 | /* Return results. */ | |
286 | if (top_of_heap > top_of_data_memory) | |
287 | { | |
288 | *bottom = top_of_data_memory; | |
289 | *top = top_of_heap; | |
290 | return 1; /* success */ | |
291 | } | |
292 | else | |
293 | return 0; /* No additional heap space needs to be saved. */ | |
294 | } | |
295 | ||
296 | static int | |
297 | derive_heap_segment (bfd *abfd, bfd_vma *bottom, bfd_vma *top) | |
298 | { | |
299 | if (override_derive_heap_segment) | |
300 | return override_derive_heap_segment (abfd, bottom, top); | |
301 | else | |
302 | return default_derive_heap_segment (abfd, bottom, top); | |
303 | } | |
304 | ||
305 | /* ARGSUSED */ | |
306 | static void | |
307 | make_output_phdrs (bfd *obfd, asection *osec, void *ignored) | |
308 | { | |
309 | int p_flags = 0; | |
310 | int p_type; | |
311 | ||
312 | /* FIXME: these constants may only be applicable for ELF. */ | |
313 | if (strncmp (osec->name, "load", 4) == 0) | |
314 | p_type = PT_LOAD; | |
315 | else | |
316 | p_type = PT_NOTE; | |
317 | ||
318 | p_flags |= PF_R; /* Segment is readable. */ | |
319 | if (!(bfd_get_section_flags (obfd, osec) & SEC_READONLY)) | |
320 | p_flags |= PF_W; /* Segment is writable. */ | |
321 | if (bfd_get_section_flags (obfd, osec) & SEC_CODE) | |
322 | p_flags |= PF_X; /* Segment is executable. */ | |
323 | ||
324 | bfd_record_phdr (obfd, p_type, 1, p_flags, 0, 0, | |
325 | 0, 0, 1, &osec); | |
326 | } | |
327 | ||
328 | static asection * | |
329 | make_mem_sec (bfd *obfd, | |
330 | bfd_vma addr, | |
331 | bfd_size_type size, | |
332 | unsigned int flags, | |
333 | unsigned int alignment) | |
334 | { | |
335 | asection *osec; | |
336 | ||
337 | if ((osec = bfd_make_section_anyway (obfd, "load")) == NULL) | |
338 | { | |
339 | warning ("Couldn't make gcore segment: %s", | |
340 | bfd_errmsg (bfd_get_error ())); | |
341 | return NULL; | |
342 | } | |
343 | ||
344 | if (info_verbose) | |
345 | { | |
346 | fprintf_filtered (gdb_stdout, | |
347 | "Save segment, %ld bytes at 0x%s\n", | |
348 | size, paddr_nz (addr)); | |
349 | } | |
350 | ||
351 | bfd_set_section_size (obfd, osec, size); | |
352 | bfd_set_section_vma (obfd, osec, addr); | |
353 | osec->lma = 0; /* FIXME: there should be a macro for this! */ | |
354 | bfd_set_section_alignment (obfd, osec, alignment); | |
355 | bfd_set_section_flags (obfd, osec, | |
356 | flags | SEC_LOAD | SEC_ALLOC | SEC_HAS_CONTENTS); | |
357 | return osec; | |
358 | } | |
359 | ||
360 | static int | |
361 | gcore_create_callback (CORE_ADDR vaddr, | |
362 | unsigned long size, | |
363 | int read, int write, int exec, | |
364 | void *data) | |
365 | { | |
366 | flagword flags = 0; | |
367 | ||
368 | if (write == 0) | |
369 | { | |
370 | flags |= SEC_READONLY; | |
371 | /* Set size == zero for readonly sections. */ | |
372 | size = 0; | |
373 | } | |
374 | if (exec) | |
375 | { | |
376 | flags |= SEC_CODE; | |
377 | } | |
378 | else | |
379 | { | |
380 | flags |= SEC_DATA; | |
381 | } | |
382 | ||
383 | return ((make_mem_sec ((bfd *) data, vaddr, size, flags, 0)) == NULL); | |
384 | } | |
385 | ||
386 | static int | |
387 | objfile_find_memory_regions (int (*func) (CORE_ADDR, | |
388 | unsigned long, | |
389 | int, int, int, | |
390 | void *), | |
391 | void *obfd) | |
392 | { | |
393 | /* Use objfile data to create memory sections. */ | |
394 | struct objfile *objfile; | |
395 | struct obj_section *objsec; | |
396 | bfd_vma temp_bottom, temp_top; | |
397 | ||
398 | /* Call callback function for each objfile section. */ | |
399 | ALL_OBJSECTIONS (objfile, objsec) | |
400 | { | |
401 | bfd *ibfd = objfile->obfd; | |
402 | asection *isec = objsec->the_bfd_section; | |
403 | flagword flags = bfd_get_section_flags (ibfd, isec); | |
404 | int ret; | |
405 | ||
406 | if ((flags & SEC_ALLOC) || (flags & SEC_LOAD)) | |
407 | { | |
408 | int size = bfd_section_size (ibfd, isec); | |
409 | int ret; | |
410 | ||
411 | if ((ret = (*func) (objsec->addr, | |
412 | bfd_section_size (ibfd, isec), | |
413 | 1, /* All sections will be readable. */ | |
414 | (flags & SEC_READONLY) == 0, /* writable */ | |
415 | (flags & SEC_CODE) != 0, /* executable */ | |
416 | obfd)) != 0) | |
417 | return ret; | |
418 | } | |
419 | } | |
420 | ||
421 | /* Make a stack segment. */ | |
422 | if (derive_stack_segment (&temp_bottom, &temp_top)) | |
423 | (*func) (temp_bottom, | |
424 | temp_top - temp_bottom, | |
425 | 1, /* Stack section will be readable */ | |
426 | 1, /* Stack section will be writable */ | |
427 | 0, /* Stack section will not be executable */ | |
428 | obfd); | |
429 | ||
430 | /* Make a heap segment. */ | |
431 | if (derive_heap_segment (exec_bfd, &temp_bottom, &temp_top)) | |
432 | (*func) (temp_bottom, | |
433 | temp_top - temp_bottom, | |
434 | 1, /* Heap section will be readable */ | |
435 | 1, /* Heap section will be writable */ | |
436 | 0, /* Heap section will not be executable */ | |
437 | obfd); | |
438 | return 0; | |
439 | } | |
440 | ||
441 | static void | |
442 | gcore_copy_callback (bfd *obfd, asection *osec, void *ignored) | |
443 | { | |
444 | bfd_size_type size = bfd_section_size (obfd, osec); | |
445 | struct cleanup *old_chain = NULL; | |
446 | void *memhunk; | |
447 | ||
448 | if (size == 0) | |
449 | return; /* Read-only sections are marked as zero-size. | |
450 | We don't have to copy their contents. */ | |
451 | if (strncmp ("load", bfd_get_section_name (obfd, osec), 4) != 0) | |
452 | return; /* Only interested in "load" sections. */ | |
453 | ||
454 | if ((memhunk = xmalloc (size)) == NULL) | |
455 | error ("Not enough memory to create corefile."); | |
456 | old_chain = make_cleanup (xfree, memhunk); | |
457 | ||
458 | if (target_read_memory (bfd_section_vma (obfd, osec), | |
459 | memhunk, size) != 0) | |
460 | warning ("Memory read failed for corefile section, %ld bytes at 0x%s\n", | |
461 | (long) size, paddr (bfd_section_vma (obfd, osec))); | |
462 | if (!bfd_set_section_contents (obfd, osec, memhunk, 0, size)) | |
463 | warning ("Failed to write corefile contents (%s).", | |
464 | bfd_errmsg (bfd_get_error ())); | |
465 | ||
466 | do_cleanups (old_chain); /* frees the xmalloc buffer */ | |
467 | } | |
468 | ||
469 | static int | |
470 | gcore_memory_sections (bfd *obfd) | |
471 | { | |
472 | if (target_find_memory_regions (gcore_create_callback, obfd) != 0) | |
473 | return 0; /* FIXME error return/msg? */ | |
474 | ||
475 | /* Record phdrs for section-to-segment mapping. */ | |
476 | bfd_map_over_sections (obfd, make_output_phdrs, NULL); | |
477 | ||
478 | /* Copy memory region contents. */ | |
479 | bfd_map_over_sections (obfd, gcore_copy_callback, NULL); | |
480 | ||
481 | return 1; /* success */ | |
482 | } | |
483 | ||
484 | void | |
485 | _initialize_gcore (void) | |
486 | { | |
487 | add_com ("generate-core-file", class_files, gcore_command, | |
488 | "Save a core file with the current state of the debugged process.\n\ | |
489 | Argument is optional filename. Default filename is 'core.<process_id>'."); | |
490 | ||
491 | add_com_alias ("gcore", "generate-core-file", class_files, 1); | |
492 | exec_set_find_memory_regions (objfile_find_memory_regions); | |
493 | } |