1 /* Generate a core file for the inferior process.
3 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 51 Franklin Street, Fifth Floor,
21 Boston, MA 02110-1301, USA. */
31 #include "cli/cli-decode.h"
33 #include "gdb_assert.h"
35 /* The largest amount of memory to read from the target at once. We
36 must throttle it to limit the amount of memory used by GDB during
37 generate-core-file for programs with large resident data. */
38 #define MAX_COPY_BYTES (1024 * 1024)
40 static char *default_gcore_target (void);
41 static enum bfd_architecture default_gcore_arch (void);
42 static unsigned long default_gcore_mach (void);
43 static int gcore_memory_sections (bfd *);
45 /* Generate a core file from the inferior process. */
48 gcore_command (char *args, int from_tty)
50 struct cleanup *old_chain;
51 char *corefilename, corefilename_buffer[40];
52 asection *note_sec = NULL;
54 void *note_data = NULL;
57 /* No use generating a corefile without a target process. */
58 if (!target_has_execution)
65 /* Default corefile name is "core.PID". */
66 sprintf (corefilename_buffer, "core.%d", PIDGET (inferior_ptid));
67 corefilename = corefilename_buffer;
71 fprintf_filtered (gdb_stdout,
72 "Opening corefile '%s' for output.\n", corefilename);
74 /* Open the output file. */
75 obfd = bfd_openw (corefilename, default_gcore_target ());
77 error (_("Failed to open '%s' for output."), corefilename);
79 /* Need a cleanup that will close the file (FIXME: delete it?). */
80 old_chain = make_cleanup_bfd_close (obfd);
82 bfd_set_format (obfd, bfd_core);
83 bfd_set_arch_mach (obfd, default_gcore_arch (), default_gcore_mach ());
85 /* An external target method must build the notes section. */
86 note_data = target_make_corefile_notes (obfd, ¬e_size);
88 /* Create the note section. */
89 if (note_data != NULL && note_size != 0)
91 note_sec = bfd_make_section_anyway (obfd, "note0");
93 error (_("Failed to create 'note' section for corefile: %s"),
94 bfd_errmsg (bfd_get_error ()));
96 bfd_set_section_vma (obfd, note_sec, 0);
97 bfd_set_section_flags (obfd, note_sec,
98 SEC_HAS_CONTENTS | SEC_READONLY | SEC_ALLOC);
99 bfd_set_section_alignment (obfd, note_sec, 0);
100 bfd_set_section_size (obfd, note_sec, note_size);
103 /* Now create the memory/load sections. */
104 if (gcore_memory_sections (obfd) == 0)
105 error (_("gcore: failed to get corefile memory sections from target."));
107 /* Write out the contents of the note section. */
108 if (note_data != NULL && note_size != 0)
110 if (!bfd_set_section_contents (obfd, note_sec, note_data, 0, note_size))
111 warning (_("writing note section (%s)"), bfd_errmsg (bfd_get_error ()));
115 fprintf_filtered (gdb_stdout, "Saved corefile %s\n", corefilename);
117 /* Clean-ups will close the output file and free malloc memory. */
118 do_cleanups (old_chain);
123 default_gcore_mach (void)
125 #if 1 /* See if this even matters... */
128 #ifdef TARGET_ARCHITECTURE
129 const struct bfd_arch_info *bfdarch = TARGET_ARCHITECTURE;
132 return bfdarch->mach;
133 #endif /* TARGET_ARCHITECTURE */
134 if (exec_bfd == NULL)
135 error (_("Can't find default bfd machine type (need execfile)."));
137 return bfd_get_mach (exec_bfd);
141 static enum bfd_architecture
142 default_gcore_arch (void)
144 #ifdef TARGET_ARCHITECTURE
145 const struct bfd_arch_info * bfdarch = TARGET_ARCHITECTURE;
148 return bfdarch->arch;
150 if (exec_bfd == NULL)
151 error (_("Can't find bfd architecture for corefile (need execfile)."));
153 return bfd_get_arch (exec_bfd);
157 default_gcore_target (void)
159 /* FIXME: This may only work for ELF targets. */
160 if (exec_bfd == NULL)
163 return bfd_get_target (exec_bfd);
166 /* Derive a reasonable stack segment by unwinding the target stack,
167 and store its limits in *BOTTOM and *TOP. Return non-zero if
171 derive_stack_segment (bfd_vma *bottom, bfd_vma *top)
173 struct frame_info *fi, *tmp_fi;
178 /* Can't succeed without stack and registers. */
179 if (!target_has_stack || !target_has_registers)
182 /* Can't succeed without current frame. */
183 fi = get_current_frame ();
187 /* Save frame pointer of TOS frame. */
188 *top = get_frame_base (fi);
189 /* If current stack pointer is more "inner", use that instead. */
190 if (INNER_THAN (read_sp (), *top))
193 /* Find prev-most frame. */
194 while ((tmp_fi = get_prev_frame (fi)) != NULL)
197 /* Save frame pointer of prev-most frame. */
198 *bottom = get_frame_base (fi);
200 /* Now canonicalize their order, so that BOTTOM is a lower address
201 (as opposed to a lower stack frame). */
214 /* Derive a reasonable heap segment for ABFD by looking at sbrk and
215 the static data sections. Store its limits in *BOTTOM and *TOP.
216 Return non-zero if successful. */
219 derive_heap_segment (bfd *abfd, bfd_vma *bottom, bfd_vma *top)
221 bfd_vma top_of_data_memory = 0;
222 bfd_vma top_of_heap = 0;
223 bfd_size_type sec_size;
224 struct value *zero, *sbrk;
231 /* This function depends on being able to call a function in the
233 if (!target_has_execution)
236 /* The following code assumes that the link map is arranged as
237 follows (low to high addresses):
239 ---------------------------------
241 ---------------------------------
242 | data sections (including bss) |
243 ---------------------------------
245 --------------------------------- */
247 for (sec = abfd->sections; sec; sec = sec->next)
249 if (bfd_get_section_flags (abfd, sec) & SEC_DATA
250 || strcmp (".bss", bfd_section_name (abfd, sec)) == 0)
252 sec_vaddr = bfd_get_section_vma (abfd, sec);
253 sec_size = bfd_get_section_size (sec);
254 if (sec_vaddr + sec_size > top_of_data_memory)
255 top_of_data_memory = sec_vaddr + sec_size;
259 /* Now get the top-of-heap by calling sbrk in the inferior. */
260 if (lookup_minimal_symbol ("sbrk", NULL, NULL) != NULL)
262 sbrk = find_function_in_inferior ("sbrk");
266 else if (lookup_minimal_symbol ("_sbrk", NULL, NULL) != NULL)
268 sbrk = find_function_in_inferior ("_sbrk");
275 zero = value_from_longest (builtin_type_int, 0);
277 sbrk = call_function_by_hand (sbrk, 1, &zero);
280 top_of_heap = value_as_long (sbrk);
282 /* Return results. */
283 if (top_of_heap > top_of_data_memory)
285 *bottom = top_of_data_memory;
290 /* No additional heap space needs to be saved. */
295 make_output_phdrs (bfd *obfd, asection *osec, void *ignored)
300 /* FIXME: these constants may only be applicable for ELF. */
301 if (strncmp (bfd_section_name (obfd, osec), "load", 4) == 0)
306 p_flags |= PF_R; /* Segment is readable. */
307 if (!(bfd_get_section_flags (obfd, osec) & SEC_READONLY))
308 p_flags |= PF_W; /* Segment is writable. */
309 if (bfd_get_section_flags (obfd, osec) & SEC_CODE)
310 p_flags |= PF_X; /* Segment is executable. */
312 bfd_record_phdr (obfd, p_type, 1, p_flags, 0, 0, 0, 0, 1, &osec);
316 gcore_create_callback (CORE_ADDR vaddr, unsigned long size,
317 int read, int write, int exec, void *data)
321 flagword flags = SEC_ALLOC | SEC_HAS_CONTENTS | SEC_LOAD;
323 /* If the memory segment has no permissions set, ignore it, otherwise
324 when we later try to access it for read/write, we'll get an error
325 or jam the kernel. */
326 if (read == 0 && write == 0 && exec == 0)
330 fprintf_filtered (gdb_stdout, "Ignore segment, %s bytes at 0x%s\n",
331 paddr_d (size), paddr_nz (vaddr));
339 /* See if this region of memory lies inside a known file on disk.
340 If so, we can avoid copying its contents by clearing SEC_LOAD. */
341 struct objfile *objfile;
342 struct obj_section *objsec;
344 ALL_OBJSECTIONS (objfile, objsec)
346 bfd *abfd = objfile->obfd;
347 asection *asec = objsec->the_bfd_section;
348 bfd_vma align = (bfd_vma) 1 << bfd_get_section_alignment (abfd,
350 bfd_vma start = objsec->addr & -align;
351 bfd_vma end = (objsec->endaddr + align - 1) & -align;
352 /* Match if either the entire memory region lies inside the
353 section (i.e. a mapping covering some pages of a large
354 segment) or the entire section lies inside the memory region
355 (i.e. a mapping covering multiple small sections).
357 This BFD was synthesized from reading target memory,
358 we don't want to omit that. */
359 if (((vaddr >= start && vaddr + size <= end)
360 || (start >= vaddr && end <= vaddr + size))
361 && !(bfd_get_file_flags (abfd) & BFD_IN_MEMORY))
364 goto keep; /* break out of two nested for loops */
369 flags |= SEC_READONLY;
377 osec = bfd_make_section_anyway (obfd, "load");
380 warning (_("Couldn't make gcore segment: %s"),
381 bfd_errmsg (bfd_get_error ()));
387 fprintf_filtered (gdb_stdout, "Save segment, %s bytes at 0x%s\n",
388 paddr_d (size), paddr_nz (vaddr));
391 bfd_set_section_size (obfd, osec, size);
392 bfd_set_section_vma (obfd, osec, vaddr);
393 bfd_section_lma (obfd, osec) = 0; /* ??? bfd_set_section_lma? */
394 bfd_set_section_flags (obfd, osec, flags);
399 objfile_find_memory_regions (int (*func) (CORE_ADDR, unsigned long,
400 int, int, int, void *),
403 /* Use objfile data to create memory sections. */
404 struct objfile *objfile;
405 struct obj_section *objsec;
406 bfd_vma temp_bottom, temp_top;
408 /* Call callback function for each objfile section. */
409 ALL_OBJSECTIONS (objfile, objsec)
411 bfd *ibfd = objfile->obfd;
412 asection *isec = objsec->the_bfd_section;
413 flagword flags = bfd_get_section_flags (ibfd, isec);
416 if ((flags & SEC_ALLOC) || (flags & SEC_LOAD))
418 int size = bfd_section_size (ibfd, isec);
421 ret = (*func) (objsec->addr, bfd_section_size (ibfd, isec),
422 1, /* All sections will be readable. */
423 (flags & SEC_READONLY) == 0, /* Writable. */
424 (flags & SEC_CODE) != 0, /* Executable. */
431 /* Make a stack segment. */
432 if (derive_stack_segment (&temp_bottom, &temp_top))
433 (*func) (temp_bottom, temp_top - temp_bottom,
434 1, /* Stack section will be readable. */
435 1, /* Stack section will be writable. */
436 0, /* Stack section will not be executable. */
439 /* Make a heap segment. */
440 if (derive_heap_segment (exec_bfd, &temp_bottom, &temp_top))
441 (*func) (temp_bottom, temp_top - temp_bottom,
442 1, /* Heap section will be readable. */
443 1, /* Heap section will be writable. */
444 0, /* Heap section will not be executable. */
451 gcore_copy_callback (bfd *obfd, asection *osec, void *ignored)
453 bfd_size_type size, total_size = bfd_section_size (obfd, osec);
455 struct cleanup *old_chain = NULL;
458 /* Read-only sections are marked; we don't have to copy their contents. */
459 if ((bfd_get_section_flags (obfd, osec) & SEC_LOAD) == 0)
462 /* Only interested in "load" sections. */
463 if (strncmp ("load", bfd_section_name (obfd, osec), 4) != 0)
466 size = min (total_size, MAX_COPY_BYTES);
467 memhunk = xmalloc (size);
468 /* ??? This is crap since xmalloc should never return NULL. */
470 error (_("Not enough memory to create corefile."));
471 old_chain = make_cleanup (xfree, memhunk);
473 while (total_size > 0)
475 if (size > total_size)
478 if (target_read_memory (bfd_section_vma (obfd, osec) + offset,
481 warning (_("Memory read failed for corefile section, %s bytes at 0x%s."),
482 paddr_d (size), paddr (bfd_section_vma (obfd, osec)));
485 if (!bfd_set_section_contents (obfd, osec, memhunk, offset, size))
487 warning (_("Failed to write corefile contents (%s)."),
488 bfd_errmsg (bfd_get_error ()));
496 do_cleanups (old_chain); /* Frees MEMHUNK. */
500 gcore_memory_sections (bfd *obfd)
502 if (target_find_memory_regions (gcore_create_callback, obfd) != 0)
503 return 0; /* FIXME: error return/msg? */
505 /* Record phdrs for section-to-segment mapping. */
506 bfd_map_over_sections (obfd, make_output_phdrs, NULL);
508 /* Copy memory region contents. */
509 bfd_map_over_sections (obfd, gcore_copy_callback, NULL);
515 _initialize_gcore (void)
517 add_com ("generate-core-file", class_files, gcore_command, _("\
518 Save a core file with the current state of the debugged process.\n\
519 Argument is optional filename. Default filename is 'core.<process_id>'."));
521 add_com_alias ("gcore", "generate-core-file", class_files, 1);
522 exec_set_find_memory_regions (objfile_find_memory_regions);