binutils-gdb/binutils/addr2line.c
Andi Kleen fd3c53675c Support symbol+offset lookup in addr2line
The Linux kernel usually ouputs symbol+offset instead of plain code
addresses these days, to avoid leaking ASLR secrets and to handle
dynamically loaded modules.

Converting those with addr2line is somewhat involved: it requires
looking up the symbol first using nm and then manually compute the
offset, and then pass it to addr2line.

This patch implements the necessary steps directly in addr2line,
by looking up the symbol (with demangling if needed) and computing
the offset.

It's possible that a symbol is ambigious with a hex number. In this
case it uses the symbol lookup if the string contains a +. When it isn't
ambigious the + is optional.
2022-02-03 18:41:56 -08:00

584 lines
15 KiB
C
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/* addr2line.c -- convert addresses to line number and function name
Copyright (C) 1997-2022 Free Software Foundation, Inc.
Contributed by Ulrich Lauther <Ulrich.Lauther@mchp.siemens.de>
This file is part of GNU Binutils.
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, 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, 51 Franklin Street - Fifth Floor, Boston,
MA 02110-1301, USA. */
/* Derived from objdump.c and nm.c by Ulrich.Lauther@mchp.siemens.de
Usage:
addr2line [options] addr addr ...
or
addr2line [options]
both forms write results to stdout, the second form reads addresses
to be converted from stdin. */
#include "sysdep.h"
#include "bfd.h"
#include "getopt.h"
#include "libiberty.h"
#include "demangle.h"
#include "bucomm.h"
#include "elf-bfd.h"
#include "safe-ctype.h"
static bool unwind_inlines; /* -i, unwind inlined functions. */
static bool with_addresses; /* -a, show addresses. */
static bool with_functions; /* -f, show function names. */
static bool do_demangle; /* -C, demangle names. */
static bool pretty_print; /* -p, print on one line. */
static bool base_names; /* -s, strip directory names. */
/* Flags passed to the name demangler. */
static int demangle_flags = DMGL_PARAMS | DMGL_ANSI;
static int naddr; /* Number of addresses to process. */
static char **addr; /* Hex addresses to process. */
static long symcount;
static asymbol **syms; /* Symbol table. */
static struct option long_options[] =
{
{"addresses", no_argument, NULL, 'a'},
{"basenames", no_argument, NULL, 's'},
{"demangle", optional_argument, NULL, 'C'},
{"exe", required_argument, NULL, 'e'},
{"functions", no_argument, NULL, 'f'},
{"inlines", no_argument, NULL, 'i'},
{"pretty-print", no_argument, NULL, 'p'},
{"recurse-limit", no_argument, NULL, 'R'},
{"recursion-limit", no_argument, NULL, 'R'},
{"no-recurse-limit", no_argument, NULL, 'r'},
{"no-recursion-limit", no_argument, NULL, 'r'},
{"section", required_argument, NULL, 'j'},
{"target", required_argument, NULL, 'b'},
{"help", no_argument, NULL, 'H'},
{"version", no_argument, NULL, 'V'},
{0, no_argument, 0, 0}
};
static void usage (FILE *, int);
static void slurp_symtab (bfd *);
static void find_address_in_section (bfd *, asection *, void *);
static void find_offset_in_section (bfd *, asection *);
static void translate_addresses (bfd *, asection *);
/* Print a usage message to STREAM and exit with STATUS. */
static void
usage (FILE *stream, int status)
{
fprintf (stream, _("Usage: %s [option(s)] [addr(s)]\n"), program_name);
fprintf (stream, _(" Convert addresses into line number/file name pairs.\n"));
fprintf (stream, _(" If no addresses are specified on the command line, they will be read from stdin\n"));
fprintf (stream, _(" The options are:\n\
@<file> Read options from <file>\n\
-a --addresses Show addresses\n\
-b --target=<bfdname> Set the binary file format\n\
-e --exe=<executable> Set the input file name (default is a.out)\n\
-i --inlines Unwind inlined functions\n\
-j --section=<name> Read section-relative offsets instead of addresses\n\
-p --pretty-print Make the output easier to read for humans\n\
-s --basenames Strip directory names\n\
-f --functions Show function names\n\
-C --demangle[=style] Demangle function names\n\
-R --recurse-limit Enable a limit on recursion whilst demangling. [Default]\n\
-r --no-recurse-limit Disable a limit on recursion whilst demangling\n\
-h --help Display this information\n\
-v --version Display the program's version\n\
\n"));
list_supported_targets (program_name, stream);
if (REPORT_BUGS_TO[0] && status == 0)
fprintf (stream, _("Report bugs to %s\n"), REPORT_BUGS_TO);
exit (status);
}
/* Read in the symbol table. */
static void
slurp_symtab (bfd *abfd)
{
long storage;
bool dynamic = false;
if ((bfd_get_file_flags (abfd) & HAS_SYMS) == 0)
return;
storage = bfd_get_symtab_upper_bound (abfd);
if (storage == 0)
{
storage = bfd_get_dynamic_symtab_upper_bound (abfd);
dynamic = true;
}
if (storage < 0)
bfd_fatal (bfd_get_filename (abfd));
syms = (asymbol **) xmalloc (storage);
if (dynamic)
symcount = bfd_canonicalize_dynamic_symtab (abfd, syms);
else
symcount = bfd_canonicalize_symtab (abfd, syms);
if (symcount < 0)
bfd_fatal (bfd_get_filename (abfd));
/* If there are no symbols left after canonicalization and
we have not tried the dynamic symbols then give them a go. */
if (symcount == 0
&& ! dynamic
&& (storage = bfd_get_dynamic_symtab_upper_bound (abfd)) > 0)
{
free (syms);
syms = xmalloc (storage);
symcount = bfd_canonicalize_dynamic_symtab (abfd, syms);
}
/* PR 17512: file: 2a1d3b5b.
Do not pretend that we have some symbols when we don't. */
if (symcount <= 0)
{
free (syms);
syms = NULL;
}
}
/* These global variables are used to pass information between
translate_addresses and find_address_in_section. */
static bfd_vma pc;
static const char *filename;
static const char *functionname;
static unsigned int line;
static unsigned int discriminator;
static bool found;
/* Look for an address in a section. This is called via
bfd_map_over_sections. */
static void
find_address_in_section (bfd *abfd, asection *section,
void *data ATTRIBUTE_UNUSED)
{
bfd_vma vma;
bfd_size_type size;
if (found)
return;
if ((bfd_section_flags (section) & SEC_ALLOC) == 0)
return;
vma = bfd_section_vma (section);
if (pc < vma)
return;
size = bfd_section_size (section);
if (pc >= vma + size)
return;
found = bfd_find_nearest_line_discriminator (abfd, section, syms, pc - vma,
&filename, &functionname,
&line, &discriminator);
}
/* Look for an offset in a section. This is directly called. */
static void
find_offset_in_section (bfd *abfd, asection *section)
{
bfd_size_type size;
if (found)
return;
if ((bfd_section_flags (section) & SEC_ALLOC) == 0)
return;
size = bfd_section_size (section);
if (pc >= size)
return;
found = bfd_find_nearest_line_discriminator (abfd, section, syms, pc,
&filename, &functionname,
&line, &discriminator);
}
/* Lookup a symbol with offset in symbol table. */
static bfd_vma
lookup_symbol (bfd *abfd, char *sym, size_t offset)
{
long i;
for (i = 0; i < symcount; i++)
{
if (!strcmp (syms[i]->name, sym))
return syms[i]->value + offset + bfd_asymbol_section (syms[i])->vma;
}
/* Try again mangled */
for (i = 0; i < symcount; i++)
{
char *d = bfd_demangle (abfd, syms[i]->name, demangle_flags);
bool match = d && !strcmp (d, sym);
free (d);
if (match)
return syms[i]->value + offset + bfd_asymbol_section (syms[i])->vma;
}
return 0;
}
/* Split an symbol+offset expression. adr is modified. */
static bool
is_symbol (char *adr, char **symp, size_t *offset)
{
char *end;
while (ISSPACE (*adr))
adr++;
if (ISDIGIT (*adr) || *adr == 0)
return false;
/* Could be either symbol or hex number. Check if it has +. */
if (TOUPPER(*adr) >= 'A' && TOUPPER(*adr) <= 'F' && !strchr (adr, '+'))
return false;
*symp = adr;
while (*adr && !ISSPACE (*adr) && *adr != '+')
adr++;
end = adr;
while (ISSPACE (*adr))
adr++;
*offset = 0;
if (*adr == '+')
{
adr++;
*offset = strtoul(adr, NULL, 0);
}
*end = 0;
return true;
}
/* Read hexadecimal or symbolic with offset addresses from stdin, translate into
file_name:line_number and optionally function name. */
static void
translate_addresses (bfd *abfd, asection *section)
{
int read_stdin = (naddr == 0);
char *adr;
char addr_hex[100];
char *symp;
size_t offset;
for (;;)
{
if (read_stdin)
{
if (fgets (addr_hex, sizeof addr_hex, stdin) == NULL)
break;
adr = addr_hex;
}
else
{
if (naddr <= 0)
break;
--naddr;
adr = *addr++;
}
if (is_symbol (adr, &symp, &offset))
pc = lookup_symbol (abfd, symp, offset);
else
pc = bfd_scan_vma (adr, NULL, 16);
if (bfd_get_flavour (abfd) == bfd_target_elf_flavour)
{
const struct elf_backend_data *bed = get_elf_backend_data (abfd);
bfd_vma sign = (bfd_vma) 1 << (bed->s->arch_size - 1);
pc &= (sign << 1) - 1;
if (bed->sign_extend_vma)
pc = (pc ^ sign) - sign;
}
if (with_addresses)
{
printf ("0x");
bfd_printf_vma (abfd, pc);
if (pretty_print)
printf (": ");
else
printf ("\n");
}
found = false;
if (section)
find_offset_in_section (abfd, section);
else
bfd_map_over_sections (abfd, find_address_in_section, NULL);
if (! found)
{
if (with_functions)
{
if (pretty_print)
printf ("?? ");
else
printf ("??\n");
}
printf ("??:0\n");
}
else
{
while (1)
{
if (with_functions)
{
const char *name;
char *alloc = NULL;
name = functionname;
if (name == NULL || *name == '\0')
name = "??";
else if (do_demangle)
{
alloc = bfd_demangle (abfd, name, demangle_flags);
if (alloc != NULL)
name = alloc;
}
printf ("%s", name);
if (pretty_print)
/* Note for translators: This printf is used to join the
function name just printed above to the line number/
file name pair that is about to be printed below. Eg:
foo at 123:bar.c */
printf (_(" at "));
else
printf ("\n");
free (alloc);
}
if (base_names && filename != NULL)
{
char *h;
h = strrchr (filename, '/');
if (h != NULL)
filename = h + 1;
}
printf ("%s:", filename ? filename : "??");
if (line != 0)
{
if (discriminator != 0)
printf ("%u (discriminator %u)\n", line, discriminator);
else
printf ("%u\n", line);
}
else
printf ("?\n");
if (!unwind_inlines)
found = false;
else
found = bfd_find_inliner_info (abfd, &filename, &functionname,
&line);
if (! found)
break;
if (pretty_print)
/* Note for translators: This printf is used to join the
line number/file name pair that has just been printed with
the line number/file name pair that is going to be printed
by the next iteration of the while loop. Eg:
123:bar.c (inlined by) 456:main.c */
printf (_(" (inlined by) "));
}
}
/* fflush() is essential for using this command as a server
child process that reads addresses from a pipe and responds
with line number information, processing one address at a
time. */
fflush (stdout);
}
}
/* Process a file. Returns an exit value for main(). */
static int
process_file (const char *file_name, const char *section_name,
const char *target)
{
bfd *abfd;
asection *section;
char **matching;
if (get_file_size (file_name) < 1)
return 1;
abfd = bfd_openr (file_name, target);
if (abfd == NULL)
bfd_fatal (file_name);
/* Decompress sections. */
abfd->flags |= BFD_DECOMPRESS;
if (bfd_check_format (abfd, bfd_archive))
fatal (_("%s: cannot get addresses from archive"), file_name);
if (! bfd_check_format_matches (abfd, bfd_object, &matching))
{
bfd_nonfatal (bfd_get_filename (abfd));
if (bfd_get_error () == bfd_error_file_ambiguously_recognized)
{
list_matching_formats (matching);
free (matching);
}
xexit (1);
}
if (section_name != NULL)
{
section = bfd_get_section_by_name (abfd, section_name);
if (section == NULL)
fatal (_("%s: cannot find section %s"), file_name, section_name);
}
else
section = NULL;
slurp_symtab (abfd);
translate_addresses (abfd, section);
free (syms);
syms = NULL;
bfd_close (abfd);
return 0;
}
int
main (int argc, char **argv)
{
const char *file_name;
const char *section_name;
char *target;
int c;
#ifdef HAVE_LC_MESSAGES
setlocale (LC_MESSAGES, "");
#endif
setlocale (LC_CTYPE, "");
bindtextdomain (PACKAGE, LOCALEDIR);
textdomain (PACKAGE);
program_name = *argv;
xmalloc_set_program_name (program_name);
bfd_set_error_program_name (program_name);
expandargv (&argc, &argv);
if (bfd_init () != BFD_INIT_MAGIC)
fatal (_("fatal error: libbfd ABI mismatch"));
set_default_bfd_target ();
file_name = NULL;
section_name = NULL;
target = NULL;
while ((c = getopt_long (argc, argv, "ab:Ce:rRsfHhij:pVv", long_options, (int *) 0))
!= EOF)
{
switch (c)
{
case 0:
break; /* We've been given a long option. */
case 'a':
with_addresses = true;
break;
case 'b':
target = optarg;
break;
case 'C':
do_demangle = true;
if (optarg != NULL)
{
enum demangling_styles style;
style = cplus_demangle_name_to_style (optarg);
if (style == unknown_demangling)
fatal (_("unknown demangling style `%s'"),
optarg);
cplus_demangle_set_style (style);
}
break;
case 'r':
demangle_flags |= DMGL_NO_RECURSE_LIMIT;
break;
case 'R':
demangle_flags &= ~ DMGL_NO_RECURSE_LIMIT;
break;
case 'e':
file_name = optarg;
break;
case 's':
base_names = true;
break;
case 'f':
with_functions = true;
break;
case 'p':
pretty_print = true;
break;
case 'v':
case 'V':
print_version ("addr2line");
break;
case 'h':
case 'H':
usage (stdout, 0);
break;
case 'i':
unwind_inlines = true;
break;
case 'j':
section_name = optarg;
break;
default:
usage (stderr, 1);
break;
}
}
if (file_name == NULL)
file_name = "a.out";
addr = argv + optind;
naddr = argc - optind;
return process_file (file_name, section_name, target);
}