/* Unwinding of frames like gstack/pstack.
Copyright (C) 2013-2014 Red Hat, Inc.
This file is part of elfutils.
This file 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.
elfutils 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 <config.h>
#include <assert.h>
#include <argp.h>
#include <error.h>
#include <stdlib.h>
#include <inttypes.h>
#include <stdio.h>
#include <stdio_ext.h>
#include <string.h>
#include <locale.h>
#include <fcntl.h>
#include ELFUTILS_HEADER(dwfl)
#include <dwarf.h>
#include <system.h>
/* Name and version of program. */
static void print_version (FILE *stream, struct argp_state *state);
ARGP_PROGRAM_VERSION_HOOK_DEF = print_version;
/* Bug report address. */
ARGP_PROGRAM_BUG_ADDRESS_DEF = PACKAGE_BUGREPORT;
/* non-printable argp options. */
#define OPT_DEBUGINFO 0x100
#define OPT_COREFILE 0x101
static bool show_activation = false;
static bool show_module = false;
static bool show_build_id = false;
static bool show_source = false;
static bool show_one_tid = false;
static bool show_quiet = false;
static bool show_raw = false;
static bool show_modules = false;
static bool show_debugname = false;
static bool show_inlines = false;
static int maxframes = 256;
struct frame
{
Dwarf_Addr pc;
bool isactivation;
};
struct frames
{
int frames;
int allocated;
struct frame *frame;
};
static Dwfl *dwfl = NULL;
static pid_t pid = 0;
static int core_fd = -1;
static Elf *core = NULL;
static const char *exec = NULL;
static char *debuginfo_path = NULL;
static const Dwfl_Callbacks proc_callbacks =
{
.find_elf = dwfl_linux_proc_find_elf,
.find_debuginfo = dwfl_standard_find_debuginfo,
.debuginfo_path = &debuginfo_path,
};
static const Dwfl_Callbacks core_callbacks =
{
.find_elf = dwfl_build_id_find_elf,
.find_debuginfo = dwfl_standard_find_debuginfo,
.debuginfo_path = &debuginfo_path,
};
#ifdef USE_DEMANGLE
static size_t demangle_buffer_len = 0;
static char *demangle_buffer = NULL;
#endif
/* Whether any frames have been shown at all. Determines exit status. */
static bool frames_shown = false;
/* Program exit codes. All frames shown without any errors is GOOD.
Some frames shown with some non-fatal errors is an ERROR. A fatal
error or no frames shown at all is BAD. A command line USAGE exit
is generated by argp_error. */
#define EXIT_OK 0
#define EXIT_ERROR 1
#define EXIT_BAD 2
#define EXIT_USAGE 64
static int
get_addr_width (Dwfl_Module *mod)
{
// Try to find the address wide if possible.
static int width = 0;
if (width == 0 && mod)
{
Dwarf_Addr bias;
Elf *elf = dwfl_module_getelf (mod, &bias);
if (elf)
{
GElf_Ehdr ehdr_mem;
GElf_Ehdr *ehdr = gelf_getehdr (elf, &ehdr_mem);
if (ehdr)
width = ehdr->e_ident[EI_CLASS] == ELFCLASS32 ? 8 : 16;
}
}
if (width == 0)
width = 16;
return width;
}
static int
module_callback (Dwfl_Module *mod, void **userdata __attribute__((unused)),
const char *name, Dwarf_Addr start,
void *arg __attribute__((unused)))
{
/* Forces resolving of main elf and debug files. */
Dwarf_Addr bias;
Elf *elf = dwfl_module_getelf (mod, &bias);
Dwarf *dwarf = dwfl_module_getdwarf (mod, &bias);
Dwarf_Addr end;
const char *mainfile;
const char *debugfile;
const char *modname = dwfl_module_info (mod, NULL, NULL, &end, NULL,
NULL, &mainfile, &debugfile);
assert (strcmp (modname, name) == 0);
int width = get_addr_width (mod);
printf ("0x%0*" PRIx64 "-0x%0*" PRIx64 " %s\n",
width, start, width, end, basename (name));
const unsigned char *id;
GElf_Addr id_vaddr;
int id_len = dwfl_module_build_id (mod, &id, &id_vaddr);
if (id_len > 0)
{
printf (" [");
do
printf ("%02" PRIx8, *id++);
while (--id_len > 0);
printf ("]\n");
}
if (elf != NULL)
printf (" %s\n", mainfile != NULL ? mainfile : "-");
if (dwarf != NULL)
printf (" %s\n", debugfile != NULL ? debugfile : "-");
return DWARF_CB_OK;
}
static int
frame_callback (Dwfl_Frame *state, void *arg)
{
struct frames *frames = (struct frames *) arg;
int nr = frames->frames;
if (! dwfl_frame_pc (state, &frames->frame[nr].pc,
&frames->frame[nr].isactivation))
return -1;
frames->frames++;
if (frames->frames == maxframes)
return DWARF_CB_ABORT;
if (frames->frames == frames->allocated)
{
frames->allocated *= 2;
frames->frame = realloc (frames->frame,
sizeof (struct frame) * frames->allocated);
if (frames->frame == NULL)
error (EXIT_BAD, errno, "realloc frames.frame");
}
return DWARF_CB_OK;
}
static const char*
die_name (Dwarf_Die *die)
{
Dwarf_Attribute attr;
const char *name;
name = dwarf_formstring (dwarf_attr_integrate (die,
DW_AT_MIPS_linkage_name,
&attr)
?: dwarf_attr_integrate (die,
DW_AT_linkage_name,
&attr));
if (name == NULL)
name = dwarf_diename (die);
return name;
}
static void
print_frame (int nr, Dwarf_Addr pc, bool isactivation,
Dwarf_Addr pc_adjusted, Dwfl_Module *mod,
const char *symname, Dwarf_Die *cudie,
Dwarf_Die *die)
{
int width = get_addr_width (mod);
printf ("#%-2u 0x%0*" PRIx64, nr, width, (uint64_t) pc);
if (show_activation)
printf ("%4s", ! isactivation ? "- 1" : "");
if (symname != NULL)
{
#ifdef USE_DEMANGLE
// Require GNU v3 ABI by the "_Z" prefix.
if (! show_raw && symname[0] == '_' && symname[1] == 'Z')
{
int status = -1;
char *dsymname = __cxa_demangle (symname, demangle_buffer,
&demangle_buffer_len, &status);
if (status == 0)
symname = demangle_buffer = dsymname;
}
#endif
printf (" %s", symname);
}
const char* fname;
Dwarf_Addr start;
fname = dwfl_module_info(mod, NULL, &start,
NULL, NULL, NULL, NULL, NULL);
if (show_module)
{
if (fname != NULL)
printf (" - %s", fname);
}
if (show_build_id)
{
const unsigned char *id;
GElf_Addr id_vaddr;
int id_len = dwfl_module_build_id (mod, &id, &id_vaddr);
if (id_len > 0)
{
printf ("\n [");
do
printf ("%02" PRIx8, *id++);
while (--id_len > 0);
printf ("]@0x%0" PRIx64 "+0x%" PRIx64,
start, pc_adjusted - start);
}
}
if (show_source)
{
int line, col;
const char* sname;
line = col = -1;
sname = NULL;
if (die != NULL)
{
Dwarf_Files *files;
if (dwarf_getsrcfiles (cudie, &files, NULL) == 0)
{
Dwarf_Attribute attr;
Dwarf_Word val;
if (dwarf_formudata (dwarf_attr (die, DW_AT_call_file, &attr),
&val) == 0)
{
sname = dwarf_filesrc (files, val, NULL, NULL);
if (dwarf_formudata (dwarf_attr (die, DW_AT_call_line,
&attr), &val) == 0)
{
line = val;
if (dwarf_formudata (dwarf_attr (die, DW_AT_call_column,
&attr), &val) == 0)
col = val;
}
}
}
}
else
{
Dwfl_Line *lineobj = dwfl_module_getsrc(mod, pc_adjusted);
if (lineobj)
sname = dwfl_lineinfo (lineobj, NULL, &line, &col, NULL, NULL);
}
if (sname != NULL)
{
printf ("\n %s", sname);
if (line > 0)
{
printf (":%d", line);
if (col > 0)
printf (":%d", col);
}
}
}
printf ("\n");
}
static void
print_inline_frames (int *nr, Dwarf_Addr pc, bool isactivation,
Dwarf_Addr pc_adjusted, Dwfl_Module *mod,
const char *symname, Dwarf_Die *cudie, Dwarf_Die *die)
{
Dwarf_Die *scopes = NULL;
int nscopes = dwarf_getscopes_die (die, &scopes);
if (nscopes > 0)
{
/* scopes[0] == die, the lowest level, for which we already have
the name. This is the actual source location where it
happened. */
print_frame ((*nr)++, pc, isactivation, pc_adjusted, mod, symname,
NULL, NULL);
/* last_scope is the source location where the next frame/function
call was done. */
Dwarf_Die *last_scope = &scopes[0];
for (int i = 1; i < nscopes && (maxframes == 0 || *nr < maxframes); i++)
{
Dwarf_Die *scope = &scopes[i];
int tag = dwarf_tag (scope);
if (tag != DW_TAG_inlined_subroutine
&& tag != DW_TAG_entry_point
&& tag != DW_TAG_subprogram)
continue;
symname = die_name (scope);
print_frame ((*nr)++, pc, isactivation, pc_adjusted, mod, symname,
cudie, last_scope);
/* Found the "top-level" in which everything was inlined? */
if (tag == DW_TAG_subprogram)
break;
last_scope = scope;
}
}
free (scopes);
}
static void
print_frames (struct frames *frames, pid_t tid, int dwflerr, const char *what)
{
if (frames->frames > 0)
frames_shown = true;
printf ("TID %d:\n", tid);
int frame_nr = 0;
for (int nr = 0; nr < frames->frames && (maxframes == 0
|| frame_nr < maxframes); nr++)
{
Dwarf_Addr pc = frames->frame[nr].pc;
bool isactivation = frames->frame[nr].isactivation;
Dwarf_Addr pc_adjusted = pc - (isactivation ? 0 : 1);
/* Get PC->SYMNAME. */
Dwfl_Module *mod = dwfl_addrmodule (dwfl, pc_adjusted);
const char *symname = NULL;
Dwarf_Die die_mem;
Dwarf_Die *die = NULL;
Dwarf_Die *cudie = NULL;
if (mod && ! show_quiet)
{
if (show_debugname)
{
Dwarf_Addr bias = 0;
Dwarf_Die *scopes = NULL;
cudie = dwfl_module_addrdie (mod, pc_adjusted, &bias);
int nscopes = dwarf_getscopes (cudie, pc_adjusted - bias,
&scopes);
/* Find the first function-like DIE with a name in scope. */
for (int i = 0; symname == NULL && i < nscopes; i++)
{
Dwarf_Die *scope = &scopes[i];
int tag = dwarf_tag (scope);
if (tag == DW_TAG_subprogram
|| tag == DW_TAG_inlined_subroutine
|| tag == DW_TAG_entry_point)
symname = die_name (scope);
if (symname != NULL)
{
die_mem = *scope;
die = &die_mem;
}
}
free (scopes);
}
if (symname == NULL)
symname = dwfl_module_addrname (mod, pc_adjusted);
}
if (show_inlines && die != NULL)
print_inline_frames (&frame_nr, pc, isactivation, pc_adjusted, mod,
symname, cudie, die);
else
print_frame (frame_nr++, pc, isactivation, pc_adjusted, mod, symname,
NULL, NULL);
}
if (frames->frames > 0 && frame_nr == maxframes)
error (0, 0, "tid %d: shown max number of frames "
"(%d, use -n 0 for unlimited)", tid, maxframes);
else if (dwflerr != 0)
{
if (frames->frames > 0)
{
unsigned nr = frames->frames - 1;
Dwarf_Addr pc = frames->frame[nr].pc;
bool isactivation = frames->frame[nr].isactivation;
Dwarf_Addr pc_adjusted = pc - (isactivation ? 0 : 1);
Dwfl_Module *mod = dwfl_addrmodule (dwfl, pc_adjusted);
const char *mainfile = NULL;
const char *modname = dwfl_module_info (mod, NULL, NULL, NULL, NULL,
NULL, &mainfile, NULL);
if (modname == NULL || modname[0] == '\0')
{
if (mainfile != NULL)
modname = mainfile;
else
modname = "<unknown>";
}
error (0, 0, "%s tid %d at 0x%" PRIx64 " in %s: %s", what, tid,
pc_adjusted, modname, dwfl_errmsg (dwflerr));
}
else
error (0, 0, "%s tid %d: %s", what, tid, dwfl_errmsg (dwflerr));
}
}
static int
thread_callback (Dwfl_Thread *thread, void *thread_arg)
{
struct frames *frames = (struct frames *) thread_arg;
pid_t tid = dwfl_thread_tid (thread);
int err = 0;
frames->frames = 0;
switch (dwfl_thread_getframes (thread, frame_callback, thread_arg))
{
case DWARF_CB_OK:
case DWARF_CB_ABORT:
break;
case -1:
err = dwfl_errno ();
break;
default:
abort ();
}
print_frames (frames, tid, err, "dwfl_thread_getframes");
return DWARF_CB_OK;
}
static void
print_version (FILE *stream, struct argp_state *state __attribute__ ((unused)))
{
fprintf (stream, "stack (%s) %s\n", PACKAGE_NAME, PACKAGE_VERSION);
}
static error_t
parse_opt (int key, char *arg __attribute__ ((unused)),
struct argp_state *state)
{
switch (key)
{
case 'p':
pid = atoi (arg);
if (pid == 0)
argp_error (state, N_("-p PID should be a positive process id."));
break;
case OPT_COREFILE:
core_fd = open (arg, O_RDONLY);
if (core_fd < 0)
error (EXIT_BAD, errno, N_("Cannot open core file '%s'"), arg);
elf_version (EV_CURRENT);
core = elf_begin (core_fd, ELF_C_READ_MMAP, NULL);
if (core == NULL)
error (EXIT_BAD, 0, "core '%s' elf_begin: %s", arg, elf_errmsg(-1));
break;
case 'e':
exec = arg;
break;
case OPT_DEBUGINFO:
debuginfo_path = arg;
break;
case 'm':
show_module = true;
break;
case 's':
show_source = true;
break;
case 'a':
show_activation = true;
break;
case 'd':
show_debugname = true;
break;
case 'i':
show_inlines = show_debugname = true;
break;
case 'v':
show_activation = show_source = show_module = show_debugname = true;
show_inlines = true;
break;
case 'b':
show_build_id = true;
break;
case 'q':
show_quiet = true;
break;
case 'r':
show_raw = true;
break;
case '1':
show_one_tid = true;
break;
case 'n':
maxframes = atoi (arg);
if (maxframes < 0)
{
argp_error (state, N_("-n MAXFRAMES should be 0 or higher."));
return EINVAL;
}
break;
case 'l':
show_modules = true;
break;
case ARGP_KEY_END:
if (core == NULL && exec != NULL)
argp_error (state,
N_("-e EXEC needs a core given by --core."));
if (pid == 0 && show_one_tid == true)
argp_error (state,
N_("-1 needs a thread id given by -p."));
if ((pid == 0 && core == NULL) || (pid != 0 && core != NULL))
argp_error (state,
N_("One of -p PID or --core COREFILE should be given."));
if (pid != 0)
{
dwfl = dwfl_begin (&proc_callbacks);
if (dwfl == NULL)
error (EXIT_BAD, 0, "dwfl_begin: %s", dwfl_errmsg (-1));
int err = dwfl_linux_proc_report (dwfl, pid);
if (err < 0)
error (EXIT_BAD, 0, "dwfl_linux_proc_report pid %d: %s", pid,
dwfl_errmsg (-1));
else if (err > 0)
error (EXIT_BAD, err, "dwfl_linux_proc_report pid %d", pid);
}
if (core != NULL)
{
dwfl = dwfl_begin (&core_callbacks);
if (dwfl == NULL)
error (EXIT_BAD, 0, "dwfl_begin: %s", dwfl_errmsg (-1));
if (dwfl_core_file_report (dwfl, core, exec) < 0)
error (EXIT_BAD, 0, "dwfl_core_file_report: %s", dwfl_errmsg (-1));
}
if (dwfl_report_end (dwfl, NULL, NULL) != 0)
error (EXIT_BAD, 0, "dwfl_report_end: %s", dwfl_errmsg (-1));
if (pid != 0)
{
int err = dwfl_linux_proc_attach (dwfl, pid, false);
if (err < 0)
error (EXIT_BAD, 0, "dwfl_linux_proc_attach pid %d: %s", pid,
dwfl_errmsg (-1));
else if (err > 0)
error (EXIT_BAD, err, "dwfl_linux_proc_attach pid %d", pid);
}
if (core != NULL)
{
if (dwfl_core_file_attach (dwfl, core) < 0)
error (EXIT_BAD, 0, "dwfl_core_file_report: %s", dwfl_errmsg (-1));
}
/* Makes sure we are properly attached. */
if (dwfl_pid (dwfl) < 0)
error (EXIT_BAD, 0, "dwfl_pid: %s\n", dwfl_errmsg (-1));
break;
default:
return ARGP_ERR_UNKNOWN;
}
return 0;
}
int
main (int argc, char **argv)
{
/* We use no threads here which can interfere with handling a stream. */
__fsetlocking (stdin, FSETLOCKING_BYCALLER);
__fsetlocking (stdout, FSETLOCKING_BYCALLER);
__fsetlocking (stderr, FSETLOCKING_BYCALLER);
/* Set locale. */
(void) setlocale (LC_ALL, "");
const struct argp_option options[] =
{
{ NULL, 0, NULL, 0, N_("Input selection options:"), 0 },
{ "pid", 'p', "PID", 0,
N_("Show stack of process PID"), 0 },
{ "core", OPT_COREFILE, "COREFILE", 0,
N_("Show stack found in COREFILE"), 0 },
{ "executable", 'e', "EXEC", 0, N_("(optional) EXECUTABLE that produced COREFILE"), 0 },
{ "debuginfo-path", OPT_DEBUGINFO, "PATH", 0,
N_("Search path for separate debuginfo files"), 0 },
{ NULL, 0, NULL, 0, N_("Output selection options:"), 0 },
{ "activation", 'a', NULL, 0,
N_("Additionally show frame activation"), 0 },
{ "debugname", 'd', NULL, 0,
N_("Additionally try to lookup DWARF debuginfo name for frame address"),
0 },
{ "inlines", 'i', NULL, 0,
N_("Additionally show inlined function frames using DWARF debuginfo if available (implies -d)"), 0 },
{ "module", 'm', NULL, 0,
N_("Additionally show module file information"), 0 },
{ "source", 's', NULL, 0,
N_("Additionally show source file information"), 0 },
{ "verbose", 'v', NULL, 0,
N_("Show all additional information (activation, debugname, inlines, module and source)"), 0 },
{ "quiet", 'q', NULL, 0,
N_("Do not resolve address to function symbol name"), 0 },
{ "raw", 'r', NULL, 0,
N_("Show raw function symbol names, do not try to demangle names"), 0 },
{ "build-id", 'b', NULL, 0,
N_("Show module build-id, load address and pc offset"), 0 },
{ NULL, '1', NULL, 0,
N_("Show the backtrace of only one thread"), 0 },
{ NULL, 'n', "MAXFRAMES", 0,
N_("Show at most MAXFRAMES per thread (default 256, use 0 for unlimited)"), 0 },
{ "list-modules", 'l', NULL, 0,
N_("Show module memory map with build-id, elf and debug files detected"), 0 },
{ NULL, 0, NULL, 0, NULL, 0 }
};
const struct argp argp =
{
.options = options,
.parser = parse_opt,
.doc = N_("Print a stack for each thread in a process or core file.\v\
Program exits with return code 0 if all frames were shown without \
any errors. If some frames were shown, but there were some non-fatal \
errors, possibly causing an incomplete backtrace, the program exits \
with return code 1. If no frames could be shown, or a fatal error \
occured the program exits with return code 2. If the program was \
invoked with bad or missing arguments it will exit with return code 64.")
};
argp_parse (&argp, argc, argv, 0, NULL, NULL);
if (show_modules)
{
printf ("PID %d - %s module memory map\n", dwfl_pid (dwfl),
pid != 0 ? "process" : "core");
if (dwfl_getmodules (dwfl, module_callback, NULL, 0) != 0)
error (EXIT_BAD, 0, "dwfl_getmodules: %s", dwfl_errmsg (-1));
}
struct frames frames;
/* When maxframes is zero, then 2048 is just the initial allocation
that will be increased using realloc in framecallback (). */
frames.allocated = maxframes == 0 ? 2048 : maxframes;
frames.frames = 0;
frames.frame = malloc (sizeof (struct frame) * frames.allocated);
if (frames.frame == NULL)
error (EXIT_BAD, errno, "malloc frames.frame");
if (show_one_tid)
{
int err = 0;
switch (dwfl_getthread_frames (dwfl, pid, frame_callback, &frames))
{
case DWARF_CB_OK:
case DWARF_CB_ABORT:
break;
case -1:
err = dwfl_errno ();
break;
default:
abort ();
}
print_frames (&frames, pid, err, "dwfl_getthread_frames");
}
else
{
printf ("PID %d - %s\n", dwfl_pid (dwfl), pid != 0 ? "process" : "core");
switch (dwfl_getthreads (dwfl, thread_callback, &frames))
{
case DWARF_CB_OK:
case DWARF_CB_ABORT:
break;
case -1:
error (0, 0, "dwfl_getthreads: %s", dwfl_errmsg (-1));
break;
default:
abort ();
}
}
free (frames.frame);
dwfl_end (dwfl);
if (core != NULL)
elf_end (core);
if (core_fd != -1)
close (core_fd);
#ifdef USE_DEMANGLE
free (demangle_buffer);
#endif
if (! frames_shown)
error (EXIT_BAD, 0, N_("Couldn't show any frames."));
return error_message_count != 0 ? EXIT_ERROR : EXIT_OK;
}