mirror of
https://sourceware.org/git/binutils-gdb.git
synced 2024-12-03 04:12:10 +08:00
3437254d7b
We have a case in solib-svr4.c where we could reuse symfile-mem.c's vDSO range lookup. Since symfile-mem.c is not present in all configurations solib-svr4.c is, move that lookup to a gdbarch hook. This has the minor (good) side effect that we stop even trying the target_auxv_search lookup against targets that don't have a concept of a vDSO, in case symfile-mem.c happens to be linked in the build (--enable-targets=all). Tested on x86_64 Fedora 20. gdb/ 2014-10-10 Pedro Alves <palves@redhat.com> * arch-utils.c (default_vsyscall_range): New function. * arch-utils.h (default_vsyscall_range): New declaration. * gdbarch.sh (vsyscall_range): New hook. * gdbarch.h, gdbarch.c: Regenerate. * linux-tdep.c (linux_vsyscall_range): New function. (linux_init_abi): Install linux_vsyscall_range as vsyscall_range gdbarch hook. * memrange.c (address_in_mem_range): New function. * memrange.h (address_in_mem_range): New declaration. * symfile-mem.c (find_vdso_size): Delete function. (add_vsyscall_page): Use gdbarch_vsyscall_range.
255 lines
8.2 KiB
C
255 lines
8.2 KiB
C
/* Reading symbol files from memory.
|
||
|
||
Copyright (C) 1986-2014 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/>. */
|
||
|
||
/* This file defines functions (and commands to exercise those
|
||
functions) for reading debugging information from object files
|
||
whose images are mapped directly into the inferior's memory. For
|
||
example, the Linux kernel maps a "syscall DSO" into each process's
|
||
address space; this DSO provides kernel-specific code for some
|
||
system calls.
|
||
|
||
At the moment, BFD only has functions for parsing object files from
|
||
memory for the ELF format, even though the general idea isn't
|
||
ELF-specific. This means that BFD only provides the functions GDB
|
||
needs when configured for ELF-based targets. So these functions
|
||
may only be compiled on ELF-based targets.
|
||
|
||
GDB has no idea whether it has been configured for an ELF-based
|
||
target or not: it just tries to handle whatever files it is given.
|
||
But this means there are no preprocessor symbols on which we could
|
||
make these functions' compilation conditional.
|
||
|
||
So, for the time being, we put these functions alone in this file,
|
||
and have .mt files reference them as appropriate. In the future, I
|
||
hope BFD will provide a format-independent bfd_from_remote_memory
|
||
entry point. */
|
||
|
||
|
||
#include "defs.h"
|
||
#include "symtab.h"
|
||
#include "gdbcore.h"
|
||
#include "objfiles.h"
|
||
#include "gdbcmd.h"
|
||
#include "target.h"
|
||
#include "value.h"
|
||
#include "symfile.h"
|
||
#include "observer.h"
|
||
#include "auxv.h"
|
||
#include "elf/common.h"
|
||
#include "gdb_bfd.h"
|
||
|
||
/* Verify parameters of target_read_memory_bfd and target_read_memory are
|
||
compatible. */
|
||
|
||
gdb_static_assert (sizeof (CORE_ADDR) == sizeof (bfd_vma));
|
||
gdb_static_assert (sizeof (gdb_byte) == sizeof (bfd_byte));
|
||
gdb_static_assert (sizeof (ssize_t) <= sizeof (bfd_size_type));
|
||
|
||
/* Provide bfd/ compatible prototype for target_read_memory. Casting would not
|
||
be enough as LEN width may differ. */
|
||
|
||
static int
|
||
target_read_memory_bfd (bfd_vma memaddr, bfd_byte *myaddr, bfd_size_type len)
|
||
{
|
||
/* MYADDR must be already allocated for the LEN size so it has to fit in
|
||
ssize_t. */
|
||
gdb_assert ((ssize_t) len == len);
|
||
|
||
return target_read_memory (memaddr, myaddr, len);
|
||
}
|
||
|
||
/* Read inferior memory at ADDR to find the header of a loaded object file
|
||
and read its in-core symbols out of inferior memory. SIZE, if
|
||
non-zero, is the known size of the object. TEMPL is a bfd
|
||
representing the target's format. NAME is the name to use for this
|
||
symbol file in messages; it can be NULL or a malloc-allocated string
|
||
which will be attached to the BFD. */
|
||
static struct objfile *
|
||
symbol_file_add_from_memory (struct bfd *templ, CORE_ADDR addr,
|
||
size_t size, char *name, int from_tty)
|
||
{
|
||
struct objfile *objf;
|
||
struct bfd *nbfd;
|
||
struct bfd_section *sec;
|
||
bfd_vma loadbase;
|
||
struct section_addr_info *sai;
|
||
unsigned int i;
|
||
struct cleanup *cleanup;
|
||
|
||
if (bfd_get_flavour (templ) != bfd_target_elf_flavour)
|
||
error (_("add-symbol-file-from-memory not supported for this target"));
|
||
|
||
nbfd = bfd_elf_bfd_from_remote_memory (templ, addr, size, &loadbase,
|
||
target_read_memory_bfd);
|
||
if (nbfd == NULL)
|
||
error (_("Failed to read a valid object file image from memory."));
|
||
|
||
gdb_bfd_ref (nbfd);
|
||
xfree (bfd_get_filename (nbfd));
|
||
if (name == NULL)
|
||
nbfd->filename = xstrdup ("shared object read from target memory");
|
||
else
|
||
nbfd->filename = name;
|
||
|
||
cleanup = make_cleanup_bfd_unref (nbfd);
|
||
|
||
if (!bfd_check_format (nbfd, bfd_object))
|
||
error (_("Got object file from memory but can't read symbols: %s."),
|
||
bfd_errmsg (bfd_get_error ()));
|
||
|
||
sai = alloc_section_addr_info (bfd_count_sections (nbfd));
|
||
make_cleanup (xfree, sai);
|
||
i = 0;
|
||
for (sec = nbfd->sections; sec != NULL; sec = sec->next)
|
||
if ((bfd_get_section_flags (nbfd, sec) & (SEC_ALLOC|SEC_LOAD)) != 0)
|
||
{
|
||
sai->other[i].addr = bfd_get_section_vma (nbfd, sec) + loadbase;
|
||
sai->other[i].name = (char *) bfd_get_section_name (nbfd, sec);
|
||
sai->other[i].sectindex = sec->index;
|
||
++i;
|
||
}
|
||
sai->num_sections = i;
|
||
|
||
objf = symbol_file_add_from_bfd (nbfd, bfd_get_filename (nbfd),
|
||
from_tty ? SYMFILE_VERBOSE : 0,
|
||
sai, OBJF_SHARED, NULL);
|
||
|
||
add_target_sections_of_objfile (objf);
|
||
|
||
/* This might change our ideas about frames already looked at. */
|
||
reinit_frame_cache ();
|
||
|
||
do_cleanups (cleanup);
|
||
return objf;
|
||
}
|
||
|
||
|
||
static void
|
||
add_symbol_file_from_memory_command (char *args, int from_tty)
|
||
{
|
||
CORE_ADDR addr;
|
||
struct bfd *templ;
|
||
|
||
if (args == NULL)
|
||
error (_("add-symbol-file-from-memory requires an expression argument"));
|
||
|
||
addr = parse_and_eval_address (args);
|
||
|
||
/* We need some representative bfd to know the target we are looking at. */
|
||
if (symfile_objfile != NULL)
|
||
templ = symfile_objfile->obfd;
|
||
else
|
||
templ = exec_bfd;
|
||
if (templ == NULL)
|
||
error (_("Must use symbol-file or exec-file "
|
||
"before add-symbol-file-from-memory."));
|
||
|
||
symbol_file_add_from_memory (templ, addr, 0, NULL, from_tty);
|
||
}
|
||
|
||
/* Arguments for symbol_file_add_from_memory_wrapper. */
|
||
|
||
struct symbol_file_add_from_memory_args
|
||
{
|
||
struct bfd *bfd;
|
||
CORE_ADDR sysinfo_ehdr;
|
||
size_t size;
|
||
char *name;
|
||
int from_tty;
|
||
};
|
||
|
||
/* Wrapper function for symbol_file_add_from_memory, for
|
||
catch_exceptions. */
|
||
|
||
static int
|
||
symbol_file_add_from_memory_wrapper (struct ui_out *uiout, void *data)
|
||
{
|
||
struct symbol_file_add_from_memory_args *args = data;
|
||
|
||
symbol_file_add_from_memory (args->bfd, args->sysinfo_ehdr, args->size,
|
||
args->name, args->from_tty);
|
||
return 0;
|
||
}
|
||
|
||
/* Try to add the symbols for the vsyscall page, if there is one.
|
||
This function is called via the inferior_created observer. */
|
||
|
||
static void
|
||
add_vsyscall_page (struct target_ops *target, int from_tty)
|
||
{
|
||
struct mem_range vsyscall_range;
|
||
|
||
if (gdbarch_vsyscall_range (target_gdbarch (), &vsyscall_range))
|
||
{
|
||
struct bfd *bfd;
|
||
struct symbol_file_add_from_memory_args args;
|
||
|
||
if (core_bfd != NULL)
|
||
bfd = core_bfd;
|
||
else if (exec_bfd != NULL)
|
||
bfd = exec_bfd;
|
||
else
|
||
/* FIXME: cagney/2004-05-06: Should not require an existing
|
||
BFD when trying to create a run-time BFD of the VSYSCALL
|
||
page in the inferior. Unfortunately that's the current
|
||
interface so for the moment bail. Introducing a
|
||
``bfd_runtime'' (a BFD created using the loaded image) file
|
||
format should fix this. */
|
||
{
|
||
warning (_("Could not load vsyscall page "
|
||
"because no executable was specified\n"
|
||
"try using the \"file\" command first."));
|
||
return;
|
||
}
|
||
args.bfd = bfd;
|
||
args.sysinfo_ehdr = vsyscall_range.start;
|
||
args.size = vsyscall_range.length;
|
||
|
||
args.name = xstrprintf ("system-supplied DSO at %s",
|
||
paddress (target_gdbarch (), vsyscall_range.start));
|
||
/* Pass zero for FROM_TTY, because the action of loading the
|
||
vsyscall DSO was not triggered by the user, even if the user
|
||
typed "run" at the TTY. */
|
||
args.from_tty = 0;
|
||
catch_exceptions (current_uiout, symbol_file_add_from_memory_wrapper,
|
||
&args, RETURN_MASK_ALL);
|
||
}
|
||
}
|
||
|
||
|
||
|
||
/* Provide a prototype to silence -Wmissing-prototypes. */
|
||
extern initialize_file_ftype _initialize_symfile_mem;
|
||
|
||
void
|
||
_initialize_symfile_mem (void)
|
||
{
|
||
add_cmd ("add-symbol-file-from-memory", class_files,
|
||
add_symbol_file_from_memory_command,
|
||
_("Load the symbols out of memory from a "
|
||
"dynamically loaded object file.\n"
|
||
"Give an expression for the address "
|
||
"of the file's shared object file header."),
|
||
&cmdlist);
|
||
|
||
/* Want to know of each new inferior so that its vsyscall info can
|
||
be extracted. */
|
||
observer_attach_inferior_created (add_vsyscall_page);
|
||
}
|