diff options
Diffstat (limited to 'contrib/gdb/gdb/gcore.c')
| -rw-r--r-- | contrib/gdb/gdb/gcore.c | 501 |
1 files changed, 501 insertions, 0 deletions
diff --git a/contrib/gdb/gdb/gcore.c b/contrib/gdb/gdb/gcore.c new file mode 100644 index 0000000..b551372 --- /dev/null +++ b/contrib/gdb/gdb/gcore.c @@ -0,0 +1,501 @@ +/* Generate a core file for the inferior process. + + Copyright 2001, 2002, 2003, 2004 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 2 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, write to the Free Software + Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include "defs.h" +#include "elf-bfd.h" +#include "infcall.h" +#include "inferior.h" +#include "gdbcore.h" +#include "objfiles.h" +#include "symfile.h" + +#include "cli/cli-decode.h" + +#include "gdb_assert.h" + +static 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 *); + +/* 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]; + asection *note_sec = NULL; + bfd *obfd; + void *note_data = NULL; + int note_size = 0; + + /* 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 = bfd_openw (corefilename, default_gcore_target ()); + if (!obfd) + error ("Failed to open '%s' for output.", corefilename); + + /* Need a cleanup that will close the file (FIXME: delete it?). */ + old_chain = make_cleanup_bfd_close (obfd); + + bfd_set_format (obfd, bfd_core); + bfd_set_arch_mach (obfd, default_gcore_arch (), default_gcore_mach ()); + + /* An external target method must build the notes section. */ + note_data = target_make_corefile_notes (obfd, ¬e_size); + + /* Create the note section. */ + if (note_data != NULL && note_size != 0) + { + note_sec = bfd_make_section_anyway (obfd, "note0"); + 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_flags (obfd, note_sec, + SEC_HAS_CONTENTS | SEC_READONLY | SEC_ALLOC); + 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 (note_data != NULL && note_size != 0) + { + if (!bfd_set_section_contents (obfd, note_sec, note_data, 0, note_size)) + warning ("writing note section (%s)", bfd_errmsg (bfd_get_error ())); + } + + /* Succeeded. */ + fprintf_filtered (gdb_stdout, "Saved corefile %s\n", corefilename); + + /* Clean-ups will close the output file and free malloc memory. */ + do_cleanups (old_chain); + return; +} + +static unsigned long +default_gcore_mach (void) +{ +#if 1 /* See if this even matters... */ + return 0; +#else +#ifdef TARGET_ARCHITECTURE + const struct bfd_arch_info *bfdarch = TARGET_ARCHITECTURE; + + if (bfdarch != NULL) + return bfdarch->mach; +#endif /* TARGET_ARCHITECTURE */ + 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) +{ +#ifdef TARGET_ARCHITECTURE + const struct bfd_arch_info * bfdarch = TARGET_ARCHITECTURE; + + if (bfdarch != NULL) + return bfdarch->arch; +#endif + if (exec_bfd == NULL) + error ("Can't find bfd architecture for corefile (need execfile)."); + + return bfd_get_arch (exec_bfd); +} + +static char * +default_gcore_target (void) +{ + /* FIXME: This may only work for 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 (INNER_THAN (read_sp (), *top)) + *top = read_sp (); + + /* 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; +} + +/* 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; + struct value *zero, *sbrk; + 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_before_reloc (sec); + if (sec_vaddr + sec_size > top_of_data_memory) + top_of_data_memory = sec_vaddr + sec_size; + } + } + + /* Now get the top-of-heap by calling sbrk in the inferior. */ + if (lookup_minimal_symbol ("sbrk", NULL, NULL) != NULL) + { + sbrk = find_function_in_inferior ("sbrk"); + if (sbrk == NULL) + return 0; + } + else if (lookup_minimal_symbol ("_sbrk", NULL, NULL) != NULL) + { + sbrk = find_function_in_inferior ("_sbrk"); + if (sbrk == NULL) + return 0; + } + else + return 0; + + zero = value_from_longest (builtin_type_int, 0); + gdb_assert (zero); + sbrk = call_function_by_hand (sbrk, 1, &zero); + if (sbrk == NULL) + return 0; + top_of_heap = value_as_long (sbrk); + + /* 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; + + /* FIXME: these constants may only be applicable for ELF. */ + if (strncmp (bfd_section_name (obfd, osec), "load", 4) == 0) + p_type = PT_LOAD; + else + p_type = PT_NOTE; + + 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 0x%s\n", + paddr_d (size), paddr_nz (vaddr)); + } + + return 0; + } + + if (write == 0) + { + /* 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 = objsec->addr & -align; + bfd_vma end = (objsec->endaddr + 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; + 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 (obfd, "load"); + 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 0x%s\n", + paddr_d (size), paddr_nz (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? */ + bfd_set_section_flags (obfd, osec, flags); + return 0; +} + +static int +objfile_find_memory_regions (int (*func) (CORE_ADDR, unsigned long, + int, int, int, void *), + 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); + int ret; + + if ((flags & SEC_ALLOC) || (flags & SEC_LOAD)) + { + int size = bfd_section_size (ibfd, isec); + int ret; + + ret = (*func) (objsec->addr, bfd_section_size (ibfd, isec), + 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 = bfd_section_size (obfd, osec); + 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; + + memhunk = xmalloc (size); + /* ??? This is crap since xmalloc should never return NULL. */ + if (memhunk == NULL) + error ("Not enough memory to create corefile."); + old_chain = make_cleanup (xfree, memhunk); + + if (target_read_memory (bfd_section_vma (obfd, osec), + memhunk, size) != 0) + warning ("Memory read failed for corefile section, %s bytes at 0x%s\n", + paddr_d (size), paddr (bfd_section_vma (obfd, osec))); + if (!bfd_set_section_contents (obfd, osec, memhunk, 0, size)) + warning ("Failed to write corefile contents (%s).", + bfd_errmsg (bfd_get_error ())); + + do_cleanups (old_chain); /* Frees MEMHUNK. */ +} + +static int +gcore_memory_sections (bfd *obfd) +{ + 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; +} + +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); +} |
