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FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
| Current File : //usr/src/contrib/gdb/gdb/gcore.c |
/* 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 (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);
}