| /* Generate a core file for the inferior process. |
| |
| Copyright (C) 2001-2012 Free Software Foundation, Inc. |
| |
| This file is part of GDB. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| |
| #include "defs.h" |
| #include "elf-bfd.h" |
| #include "infcall.h" |
| #include "inferior.h" |
| #include "gdbcore.h" |
| #include "objfiles.h" |
| #include "solib.h" |
| #include "symfile.h" |
| #include "arch-utils.h" |
| #include "completer.h" |
| #include "gcore.h" |
| #include "cli/cli-decode.h" |
| #include "gdb_assert.h" |
| #include <fcntl.h> |
| #include "regcache.h" |
| #include "regset.h" |
| |
| /* The largest amount of memory to read from the target at once. We |
| must throttle it to limit the amount of memory used by GDB during |
| generate-core-file for programs with large resident data. */ |
| #define MAX_COPY_BYTES (1024 * 1024) |
| |
| static const char *default_gcore_target (void); |
| static enum bfd_architecture default_gcore_arch (void); |
| static unsigned long default_gcore_mach (void); |
| static int gcore_memory_sections (bfd *); |
| |
| /* create_gcore_bfd -- helper for gcore_command (exported). |
| Open a new bfd core file for output, and return the handle. */ |
| |
| bfd * |
| create_gcore_bfd (char *filename) |
| { |
| bfd *obfd = bfd_openw (filename, default_gcore_target ()); |
| |
| if (!obfd) |
| error (_("Failed to open '%s' for output."), filename); |
| bfd_set_format (obfd, bfd_core); |
| bfd_set_arch_mach (obfd, default_gcore_arch (), default_gcore_mach ()); |
| return obfd; |
| } |
| |
| /* write_gcore_file -- helper for gcore_command (exported). |
| Compose and write the corefile data to the core file. */ |
| |
| |
| void |
| write_gcore_file (bfd *obfd) |
| { |
| void *note_data = NULL; |
| int note_size = 0; |
| asection *note_sec = NULL; |
| |
| /* An external target method must build the notes section. */ |
| /* FIXME: uweigand/2011-10-06: All architectures that support core file |
| generation should be converted to gdbarch_make_corefile_notes; at that |
| point, the target vector method can be removed. */ |
| if (!gdbarch_make_corefile_notes_p (target_gdbarch)) |
| note_data = target_make_corefile_notes (obfd, ¬e_size); |
| else |
| note_data = gdbarch_make_corefile_notes (target_gdbarch, obfd, ¬e_size); |
| |
| if (note_data == NULL || note_size == 0) |
| error (_("Target does not support core file generation.")); |
| |
| /* Create the note section. */ |
| note_sec = bfd_make_section_anyway_with_flags (obfd, "note0", |
| SEC_HAS_CONTENTS |
| | SEC_READONLY |
| | SEC_ALLOC); |
| if (note_sec == NULL) |
| error (_("Failed to create 'note' section for corefile: %s"), |
| bfd_errmsg (bfd_get_error ())); |
| |
| bfd_set_section_vma (obfd, note_sec, 0); |
| bfd_set_section_alignment (obfd, note_sec, 0); |
| bfd_set_section_size (obfd, note_sec, note_size); |
| |
| /* Now create the memory/load sections. */ |
| if (gcore_memory_sections (obfd) == 0) |
| error (_("gcore: failed to get corefile memory sections from target.")); |
| |
| /* Write out the contents of the note section. */ |
| if (!bfd_set_section_contents (obfd, note_sec, note_data, 0, note_size)) |
| warning (_("writing note section (%s)"), bfd_errmsg (bfd_get_error ())); |
| } |
| |
| static void |
| do_bfd_delete_cleanup (void *arg) |
| { |
| bfd *obfd = arg; |
| const char *filename = obfd->filename; |
| |
| bfd_close (arg); |
| unlink (filename); |
| } |
| |
| /* gcore_command -- implements the 'gcore' command. |
| Generate a core file from the inferior process. */ |
| |
| static void |
| gcore_command (char *args, int from_tty) |
| { |
| struct cleanup *old_chain; |
| char *corefilename, corefilename_buffer[40]; |
| bfd *obfd; |
| |
| /* No use generating a corefile without a target process. */ |
| if (!target_has_execution) |
| noprocess (); |
| |
| if (args && *args) |
| corefilename = args; |
| else |
| { |
| /* Default corefile name is "core.PID". */ |
| sprintf (corefilename_buffer, "core.%d", PIDGET (inferior_ptid)); |
| corefilename = corefilename_buffer; |
| } |
| |
| if (info_verbose) |
| fprintf_filtered (gdb_stdout, |
| "Opening corefile '%s' for output.\n", corefilename); |
| |
| /* Open the output file. */ |
| obfd = create_gcore_bfd (corefilename); |
| |
| /* Need a cleanup that will close and delete the file. */ |
| old_chain = make_cleanup (do_bfd_delete_cleanup, obfd); |
| |
| /* Call worker function. */ |
| write_gcore_file (obfd); |
| |
| /* Succeeded. */ |
| fprintf_filtered (gdb_stdout, "Saved corefile %s\n", corefilename); |
| |
| discard_cleanups (old_chain); |
| bfd_close (obfd); |
| } |
| |
| static unsigned long |
| default_gcore_mach (void) |
| { |
| #if 1 /* See if this even matters... */ |
| return 0; |
| #else |
| |
| const struct bfd_arch_info *bfdarch = gdbarch_bfd_arch_info (target_gdbarch); |
| |
| if (bfdarch != NULL) |
| return bfdarch->mach; |
| if (exec_bfd == NULL) |
| error (_("Can't find default bfd machine type (need execfile).")); |
| |
| return bfd_get_mach (exec_bfd); |
| #endif /* 1 */ |
| } |
| |
| static enum bfd_architecture |
| default_gcore_arch (void) |
| { |
| const struct bfd_arch_info *bfdarch = gdbarch_bfd_arch_info (target_gdbarch); |
| |
| if (bfdarch != NULL) |
| return bfdarch->arch; |
| if (exec_bfd == NULL) |
| error (_("Can't find bfd architecture for corefile (need execfile).")); |
| |
| return bfd_get_arch (exec_bfd); |
| } |
| |
| static const char * |
| default_gcore_target (void) |
| { |
| /* The gdbarch may define a target to use for core files. */ |
| if (gdbarch_gcore_bfd_target_p (target_gdbarch)) |
| return gdbarch_gcore_bfd_target (target_gdbarch); |
| |
| /* Otherwise, try to fall back to the exec_bfd target. This will probably |
| not work for non-ELF targets. */ |
| if (exec_bfd == NULL) |
| return NULL; |
| else |
| return bfd_get_target (exec_bfd); |
| } |
| |
| /* Derive a reasonable stack segment by unwinding the target stack, |
| and store its limits in *BOTTOM and *TOP. Return non-zero if |
| successful. */ |
| |
| static int |
| derive_stack_segment (bfd_vma *bottom, bfd_vma *top) |
| { |
| struct frame_info *fi, *tmp_fi; |
| |
| gdb_assert (bottom); |
| gdb_assert (top); |
| |
| /* Can't succeed without stack and registers. */ |
| if (!target_has_stack || !target_has_registers) |
| return 0; |
| |
| /* Can't succeed without current frame. */ |
| fi = get_current_frame (); |
| if (fi == NULL) |
| return 0; |
| |
| /* Save frame pointer of TOS frame. */ |
| *top = get_frame_base (fi); |
| /* If current stack pointer is more "inner", use that instead. */ |
| if (gdbarch_inner_than (get_frame_arch (fi), get_frame_sp (fi), *top)) |
| *top = get_frame_sp (fi); |
| |
| /* Find prev-most frame. */ |
| while ((tmp_fi = get_prev_frame (fi)) != NULL) |
| fi = tmp_fi; |
| |
| /* Save frame pointer of prev-most frame. */ |
| *bottom = get_frame_base (fi); |
| |
| /* Now canonicalize their order, so that BOTTOM is a lower address |
| (as opposed to a lower stack frame). */ |
| if (*bottom > *top) |
| { |
| bfd_vma tmp_vma; |
| |
| tmp_vma = *top; |
| *top = *bottom; |
| *bottom = tmp_vma; |
| } |
| |
| return 1; |
| } |
| |
| /* call_target_sbrk -- |
| helper function for derive_heap_segment. */ |
| |
| static bfd_vma |
| call_target_sbrk (int sbrk_arg) |
| { |
| struct objfile *sbrk_objf; |
| struct gdbarch *gdbarch; |
| bfd_vma top_of_heap; |
| struct value *target_sbrk_arg; |
| struct value *sbrk_fn, *ret; |
| bfd_vma tmp; |
| |
| if (lookup_minimal_symbol ("sbrk", NULL, NULL) != NULL) |
| { |
| sbrk_fn = find_function_in_inferior ("sbrk", &sbrk_objf); |
| if (sbrk_fn == NULL) |
| return (bfd_vma) 0; |
| } |
| else if (lookup_minimal_symbol ("_sbrk", NULL, NULL) != NULL) |
| { |
| sbrk_fn = find_function_in_inferior ("_sbrk", &sbrk_objf); |
| if (sbrk_fn == NULL) |
| return (bfd_vma) 0; |
| } |
| else |
| return (bfd_vma) 0; |
| |
| gdbarch = get_objfile_arch (sbrk_objf); |
| target_sbrk_arg = value_from_longest (builtin_type (gdbarch)->builtin_int, |
| sbrk_arg); |
| gdb_assert (target_sbrk_arg); |
| ret = call_function_by_hand (sbrk_fn, 1, &target_sbrk_arg); |
| if (ret == NULL) |
| return (bfd_vma) 0; |
| |
| tmp = value_as_long (ret); |
| if ((LONGEST) tmp <= 0 || (LONGEST) tmp == 0xffffffff) |
| return (bfd_vma) 0; |
| |
| top_of_heap = tmp; |
| return top_of_heap; |
| } |
| |
| /* Derive a reasonable heap segment for ABFD by looking at sbrk and |
| the static data sections. Store its limits in *BOTTOM and *TOP. |
| Return non-zero if successful. */ |
| |
| static int |
| derive_heap_segment (bfd *abfd, bfd_vma *bottom, bfd_vma *top) |
| { |
| bfd_vma top_of_data_memory = 0; |
| bfd_vma top_of_heap = 0; |
| bfd_size_type sec_size; |
| bfd_vma sec_vaddr; |
| asection *sec; |
| |
| gdb_assert (bottom); |
| gdb_assert (top); |
| |
| /* This function depends on being able to call a function in the |
| inferior. */ |
| if (!target_has_execution) |
| return 0; |
| |
| /* The following code assumes that the link map is arranged as |
| follows (low to high addresses): |
| |
| --------------------------------- |
| | text sections | |
| --------------------------------- |
| | data sections (including bss) | |
| --------------------------------- |
| | heap | |
| --------------------------------- */ |
| |
| for (sec = abfd->sections; sec; sec = sec->next) |
| { |
| if (bfd_get_section_flags (abfd, sec) & SEC_DATA |
| || strcmp (".bss", bfd_section_name (abfd, sec)) == 0) |
| { |
| sec_vaddr = bfd_get_section_vma (abfd, sec); |
| sec_size = bfd_get_section_size (sec); |
| if (sec_vaddr + sec_size > top_of_data_memory) |
| top_of_data_memory = sec_vaddr + sec_size; |
| } |
| } |
| |
| top_of_heap = call_target_sbrk (0); |
| if (top_of_heap == (bfd_vma) 0) |
| return 0; |
| |
| /* Return results. */ |
| if (top_of_heap > top_of_data_memory) |
| { |
| *bottom = top_of_data_memory; |
| *top = top_of_heap; |
| return 1; |
| } |
| |
| /* No additional heap space needs to be saved. */ |
| return 0; |
| } |
| |
| static void |
| make_output_phdrs (bfd *obfd, asection *osec, void *ignored) |
| { |
| int p_flags = 0; |
| int p_type = 0; |
| |
| /* FIXME: these constants may only be applicable for ELF. */ |
| if (strncmp (bfd_section_name (obfd, osec), "load", 4) == 0) |
| p_type = PT_LOAD; |
| else if (strncmp (bfd_section_name (obfd, osec), "note", 4) == 0) |
| p_type = PT_NOTE; |
| else |
| p_type = PT_NULL; |
| |
| p_flags |= PF_R; /* Segment is readable. */ |
| if (!(bfd_get_section_flags (obfd, osec) & SEC_READONLY)) |
| p_flags |= PF_W; /* Segment is writable. */ |
| if (bfd_get_section_flags (obfd, osec) & SEC_CODE) |
| p_flags |= PF_X; /* Segment is executable. */ |
| |
| bfd_record_phdr (obfd, p_type, 1, p_flags, 0, 0, 0, 0, 1, &osec); |
| } |
| |
| static int |
| gcore_create_callback (CORE_ADDR vaddr, unsigned long size, |
| int read, int write, int exec, void *data) |
| { |
| bfd *obfd = data; |
| asection *osec; |
| flagword flags = SEC_ALLOC | SEC_HAS_CONTENTS | SEC_LOAD; |
| |
| /* If the memory segment has no permissions set, ignore it, otherwise |
| when we later try to access it for read/write, we'll get an error |
| or jam the kernel. */ |
| if (read == 0 && write == 0 && exec == 0) |
| { |
| if (info_verbose) |
| { |
| fprintf_filtered (gdb_stdout, "Ignore segment, %s bytes at %s\n", |
| plongest (size), paddress (target_gdbarch, vaddr)); |
| } |
| |
| return 0; |
| } |
| |
| if (write == 0 && !solib_keep_data_in_core (vaddr, size)) |
| { |
| /* See if this region of memory lies inside a known file on disk. |
| If so, we can avoid copying its contents by clearing SEC_LOAD. */ |
| struct objfile *objfile; |
| struct obj_section *objsec; |
| |
| ALL_OBJSECTIONS (objfile, objsec) |
| { |
| bfd *abfd = objfile->obfd; |
| asection *asec = objsec->the_bfd_section; |
| bfd_vma align = (bfd_vma) 1 << bfd_get_section_alignment (abfd, |
| asec); |
| bfd_vma start = obj_section_addr (objsec) & -align; |
| bfd_vma end = (obj_section_endaddr (objsec) + align - 1) & -align; |
| |
| /* Match if either the entire memory region lies inside the |
| section (i.e. a mapping covering some pages of a large |
| segment) or the entire section lies inside the memory region |
| (i.e. a mapping covering multiple small sections). |
| |
| This BFD was synthesized from reading target memory, |
| we don't want to omit that. */ |
| if (((vaddr >= start && vaddr + size <= end) |
| || (start >= vaddr && end <= vaddr + size)) |
| && !(bfd_get_file_flags (abfd) & BFD_IN_MEMORY)) |
| { |
| flags &= ~(SEC_LOAD | SEC_HAS_CONTENTS); |
| goto keep; /* Break out of two nested for loops. */ |
| } |
| } |
| |
| keep: |
| flags |= SEC_READONLY; |
| } |
| |
| if (exec) |
| flags |= SEC_CODE; |
| else |
| flags |= SEC_DATA; |
| |
| osec = bfd_make_section_anyway_with_flags (obfd, "load", flags); |
| if (osec == NULL) |
| { |
| warning (_("Couldn't make gcore segment: %s"), |
| bfd_errmsg (bfd_get_error ())); |
| return 1; |
| } |
| |
| if (info_verbose) |
| { |
| fprintf_filtered (gdb_stdout, "Save segment, %s bytes at %s\n", |
| plongest (size), paddress (target_gdbarch, vaddr)); |
| } |
| |
| bfd_set_section_size (obfd, osec, size); |
| bfd_set_section_vma (obfd, osec, vaddr); |
| bfd_section_lma (obfd, osec) = 0; /* ??? bfd_set_section_lma? */ |
| return 0; |
| } |
| |
| static int |
| objfile_find_memory_regions (find_memory_region_ftype func, void *obfd) |
| { |
| /* Use objfile data to create memory sections. */ |
| struct objfile *objfile; |
| struct obj_section *objsec; |
| bfd_vma temp_bottom, temp_top; |
| |
| /* Call callback function for each objfile section. */ |
| ALL_OBJSECTIONS (objfile, objsec) |
| { |
| bfd *ibfd = objfile->obfd; |
| asection *isec = objsec->the_bfd_section; |
| flagword flags = bfd_get_section_flags (ibfd, isec); |
| |
| if ((flags & SEC_ALLOC) || (flags & SEC_LOAD)) |
| { |
| int size = bfd_section_size (ibfd, isec); |
| int ret; |
| |
| ret = (*func) (obj_section_addr (objsec), size, |
| 1, /* All sections will be readable. */ |
| (flags & SEC_READONLY) == 0, /* Writable. */ |
| (flags & SEC_CODE) != 0, /* Executable. */ |
| obfd); |
| if (ret != 0) |
| return ret; |
| } |
| } |
| |
| /* Make a stack segment. */ |
| if (derive_stack_segment (&temp_bottom, &temp_top)) |
| (*func) (temp_bottom, temp_top - temp_bottom, |
| 1, /* Stack section will be readable. */ |
| 1, /* Stack section will be writable. */ |
| 0, /* Stack section will not be executable. */ |
| obfd); |
| |
| /* Make a heap segment. */ |
| if (derive_heap_segment (exec_bfd, &temp_bottom, &temp_top)) |
| (*func) (temp_bottom, temp_top - temp_bottom, |
| 1, /* Heap section will be readable. */ |
| 1, /* Heap section will be writable. */ |
| 0, /* Heap section will not be executable. */ |
| obfd); |
| |
| return 0; |
| } |
| |
| static void |
| gcore_copy_callback (bfd *obfd, asection *osec, void *ignored) |
| { |
| bfd_size_type size, total_size = bfd_section_size (obfd, osec); |
| file_ptr offset = 0; |
| struct cleanup *old_chain = NULL; |
| void *memhunk; |
| |
| /* Read-only sections are marked; we don't have to copy their contents. */ |
| if ((bfd_get_section_flags (obfd, osec) & SEC_LOAD) == 0) |
| return; |
| |
| /* Only interested in "load" sections. */ |
| if (strncmp ("load", bfd_section_name (obfd, osec), 4) != 0) |
| return; |
| |
| size = min (total_size, MAX_COPY_BYTES); |
| memhunk = xmalloc (size); |
| old_chain = make_cleanup (xfree, memhunk); |
| |
| while (total_size > 0) |
| { |
| if (size > total_size) |
| size = total_size; |
| |
| if (target_read_memory (bfd_section_vma (obfd, osec) + offset, |
| memhunk, size) != 0) |
| { |
| warning (_("Memory read failed for corefile " |
| "section, %s bytes at %s."), |
| plongest (size), |
| paddress (target_gdbarch, bfd_section_vma (obfd, osec))); |
| break; |
| } |
| if (!bfd_set_section_contents (obfd, osec, memhunk, offset, size)) |
| { |
| warning (_("Failed to write corefile contents (%s)."), |
| bfd_errmsg (bfd_get_error ())); |
| break; |
| } |
| |
| total_size -= size; |
| offset += size; |
| } |
| |
| do_cleanups (old_chain); /* Frees MEMHUNK. */ |
| } |
| |
| static int |
| gcore_memory_sections (bfd *obfd) |
| { |
| /* Try gdbarch method first, then fall back to target method. */ |
| if (!gdbarch_find_memory_regions_p (target_gdbarch) |
| || gdbarch_find_memory_regions (target_gdbarch, |
| gcore_create_callback, obfd) != 0) |
| { |
| if (target_find_memory_regions (gcore_create_callback, obfd) != 0) |
| return 0; /* FIXME: error return/msg? */ |
| } |
| |
| /* Record phdrs for section-to-segment mapping. */ |
| bfd_map_over_sections (obfd, make_output_phdrs, NULL); |
| |
| /* Copy memory region contents. */ |
| bfd_map_over_sections (obfd, gcore_copy_callback, NULL); |
| |
| return 1; |
| } |
| |
| /* Provide a prototype to silence -Wmissing-prototypes. */ |
| extern initialize_file_ftype _initialize_gcore; |
| |
| void |
| _initialize_gcore (void) |
| { |
| add_com ("generate-core-file", class_files, gcore_command, _("\ |
| Save a core file with the current state of the debugged process.\n\ |
| Argument is optional filename. Default filename is 'core.<process_id>'.")); |
| |
| add_com_alias ("gcore", "generate-core-file", class_files, 1); |
| exec_set_find_memory_regions (objfile_find_memory_regions); |
| } |