1 /* Generate a core file for the inferior process.
3 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
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 3 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, see <http://www.gnu.org/licenses/>. */
29 #include "cli/cli-decode.h"
31 #include "gdb_assert.h"
33 /* The largest amount of memory to read from the target at once. We
34 must throttle it to limit the amount of memory used by GDB during
35 generate-core-file for programs with large resident data. */
36 #define MAX_COPY_BYTES (1024 * 1024)
38 static char *default_gcore_target (void);
39 static enum bfd_architecture
default_gcore_arch (void);
40 static unsigned long default_gcore_mach (void);
41 static int gcore_memory_sections (bfd
*);
43 /* Generate a core file from the inferior process. */
46 gcore_command (char *args
, int from_tty
)
48 struct cleanup
*old_chain
;
49 char *corefilename
, corefilename_buffer
[40];
50 asection
*note_sec
= NULL
;
52 void *note_data
= NULL
;
55 /* No use generating a corefile without a target process. */
56 if (!target_has_execution
)
63 /* Default corefile name is "core.PID". */
64 sprintf (corefilename_buffer
, "core.%d", PIDGET (inferior_ptid
));
65 corefilename
= corefilename_buffer
;
69 fprintf_filtered (gdb_stdout
,
70 "Opening corefile '%s' for output.\n", corefilename
);
72 /* Open the output file. */
73 obfd
= bfd_openw (corefilename
, default_gcore_target ());
75 error (_("Failed to open '%s' for output."), corefilename
);
77 /* Need a cleanup that will close the file (FIXME: delete it?). */
78 old_chain
= make_cleanup_bfd_close (obfd
);
80 bfd_set_format (obfd
, bfd_core
);
81 bfd_set_arch_mach (obfd
, default_gcore_arch (), default_gcore_mach ());
83 /* An external target method must build the notes section. */
84 note_data
= target_make_corefile_notes (obfd
, ¬e_size
);
86 /* Create the note section. */
87 if (note_data
!= NULL
&& note_size
!= 0)
89 note_sec
= bfd_make_section_anyway_with_flags (obfd
, "note0",
94 error (_("Failed to create 'note' section for corefile: %s"),
95 bfd_errmsg (bfd_get_error ()));
97 bfd_set_section_vma (obfd
, note_sec
, 0);
98 bfd_set_section_alignment (obfd
, note_sec
, 0);
99 bfd_set_section_size (obfd
, note_sec
, note_size
);
102 /* Now create the memory/load sections. */
103 if (gcore_memory_sections (obfd
) == 0)
104 error (_("gcore: failed to get corefile memory sections from target."));
106 /* Write out the contents of the note section. */
107 if (note_data
!= NULL
&& note_size
!= 0)
109 if (!bfd_set_section_contents (obfd
, note_sec
, note_data
, 0, note_size
))
110 warning (_("writing note section (%s)"), bfd_errmsg (bfd_get_error ()));
114 fprintf_filtered (gdb_stdout
, "Saved corefile %s\n", corefilename
);
116 /* Clean-ups will close the output file and free malloc memory. */
117 do_cleanups (old_chain
);
122 default_gcore_mach (void)
124 #if 1 /* See if this even matters... */
128 const struct bfd_arch_info
*bfdarch
= gdbarch_bfd_arch_info (current_gdbarch
);
131 return bfdarch
->mach
;
132 if (exec_bfd
== NULL
)
133 error (_("Can't find default bfd machine type (need execfile)."));
135 return bfd_get_mach (exec_bfd
);
139 static enum bfd_architecture
140 default_gcore_arch (void)
142 const struct bfd_arch_info
* bfdarch
= gdbarch_bfd_arch_info
146 return bfdarch
->arch
;
147 if (exec_bfd
== NULL
)
148 error (_("Can't find bfd architecture for corefile (need execfile)."));
150 return bfd_get_arch (exec_bfd
);
154 default_gcore_target (void)
156 /* FIXME: This may only work for ELF targets. */
157 if (exec_bfd
== NULL
)
160 return bfd_get_target (exec_bfd
);
163 /* Derive a reasonable stack segment by unwinding the target stack,
164 and store its limits in *BOTTOM and *TOP. Return non-zero if
168 derive_stack_segment (bfd_vma
*bottom
, bfd_vma
*top
)
170 struct frame_info
*fi
, *tmp_fi
;
175 /* Can't succeed without stack and registers. */
176 if (!target_has_stack
|| !target_has_registers
)
179 /* Can't succeed without current frame. */
180 fi
= get_current_frame ();
184 /* Save frame pointer of TOS frame. */
185 *top
= get_frame_base (fi
);
186 /* If current stack pointer is more "inner", use that instead. */
187 if (gdbarch_inner_than (get_frame_arch (fi
), get_frame_sp (fi
), *top
))
188 *top
= get_frame_sp (fi
);
190 /* Find prev-most frame. */
191 while ((tmp_fi
= get_prev_frame (fi
)) != NULL
)
194 /* Save frame pointer of prev-most frame. */
195 *bottom
= get_frame_base (fi
);
197 /* Now canonicalize their order, so that BOTTOM is a lower address
198 (as opposed to a lower stack frame). */
211 /* Derive a reasonable heap segment for ABFD by looking at sbrk and
212 the static data sections. Store its limits in *BOTTOM and *TOP.
213 Return non-zero if successful. */
216 derive_heap_segment (bfd
*abfd
, bfd_vma
*bottom
, bfd_vma
*top
)
218 struct objfile
*sbrk_objf
;
219 struct gdbarch
*gdbarch
;
220 bfd_vma top_of_data_memory
= 0;
221 bfd_vma top_of_heap
= 0;
222 bfd_size_type sec_size
;
223 struct value
*zero
, *sbrk
;
230 /* This function depends on being able to call a function in the
232 if (!target_has_execution
)
235 /* The following code assumes that the link map is arranged as
236 follows (low to high addresses):
238 ---------------------------------
240 ---------------------------------
241 | data sections (including bss) |
242 ---------------------------------
244 --------------------------------- */
246 for (sec
= abfd
->sections
; sec
; sec
= sec
->next
)
248 if (bfd_get_section_flags (abfd
, sec
) & SEC_DATA
249 || strcmp (".bss", bfd_section_name (abfd
, sec
)) == 0)
251 sec_vaddr
= bfd_get_section_vma (abfd
, sec
);
252 sec_size
= bfd_get_section_size (sec
);
253 if (sec_vaddr
+ sec_size
> top_of_data_memory
)
254 top_of_data_memory
= sec_vaddr
+ sec_size
;
258 /* Now get the top-of-heap by calling sbrk in the inferior. */
259 if (lookup_minimal_symbol ("sbrk", NULL
, NULL
) != NULL
)
261 sbrk
= find_function_in_inferior ("sbrk", &sbrk_objf
);
265 else if (lookup_minimal_symbol ("_sbrk", NULL
, NULL
) != NULL
)
267 sbrk
= find_function_in_inferior ("_sbrk", &sbrk_objf
);
274 gdbarch
= get_objfile_arch (sbrk_objf
);
275 zero
= value_from_longest (builtin_type (gdbarch
)->builtin_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 plongest (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
= obj_section_addr (objsec
) & -align
;
351 bfd_vma end
= (obj_section_endaddr (objsec
) + 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 flags
|= SEC_NEVER_LOAD
;
365 goto keep
; /* break out of two nested for loops */
370 flags
|= SEC_READONLY
;
378 osec
= bfd_make_section_anyway_with_flags (obfd
, "load", flags
);
381 warning (_("Couldn't make gcore segment: %s"),
382 bfd_errmsg (bfd_get_error ()));
388 fprintf_filtered (gdb_stdout
, "Save segment, %s bytes at 0x%s\n",
389 plongest (size
), paddr_nz (vaddr
));
392 bfd_set_section_size (obfd
, osec
, size
);
393 bfd_set_section_vma (obfd
, osec
, vaddr
);
394 bfd_section_lma (obfd
, osec
) = 0; /* ??? bfd_set_section_lma? */
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
) (obj_section_addr (objsec
), 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 plongest (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
);