strace/unwind.c
Masatake YAMATO dd7e62f1e7 unwind: split unwind code into front-end and back-end
This opens the way for alternative unwinder back-ends.

* unwind.h: New file, defines the unwinder back-end interface.
* unwind.c: Move all libunwind related code ...
* unwind-libunwind.c: ... here.
* Makefile.am [USE_LIBUNWIND] (strace_SOURCES): Add unwind.h
and unwind-libunwind.c.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
2018-04-05 01:40:00 +00:00

341 lines
7.8 KiB
C

/*
* Copyright (c) 2013 Luca Clementi <luca.clementi@gmail.com>
* Copyright (c) 2013-2018 The strace developers.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "defs.h"
#include "mmap_cache.h"
#include "unwind.h"
#ifdef USE_DEMANGLE
# if defined HAVE_DEMANGLE_H
# include <demangle.h>
# elif defined HAVE_LIBIBERTY_DEMANGLE_H
# include <libiberty/demangle.h>
# endif
#endif
/*
* Type used in stacktrace capturing
*/
struct call_t {
struct call_t *next;
char *output_line;
};
struct unwind_queue_t {
struct call_t *tail;
struct call_t *head;
};
static void queue_print(struct unwind_queue_t *queue);
static const char asprintf_error_str[] = "???";
void
unwind_init(void)
{
if (unwinder.init)
unwinder.init();
mmap_cache_enable();
}
void
unwind_tcb_init(struct tcb *tcp)
{
if (tcp->unwind_queue)
return;
tcp->unwind_queue = xmalloc(sizeof(*tcp->unwind_queue));
tcp->unwind_queue->head = NULL;
tcp->unwind_queue->tail = NULL;
tcp->unwind_ctx = unwinder.tcb_init(tcp);
}
void
unwind_tcb_fin(struct tcb *tcp)
{
queue_print(tcp->unwind_queue);
free(tcp->unwind_queue);
tcp->unwind_queue = NULL;
unwinder.tcb_fin(tcp);
tcp->unwind_ctx = NULL;
}
/*
* printing an entry in stack to stream or buffer
*/
/*
* we want to keep the format used by backtrace_symbols from the glibc
*
* ./a.out() [0x40063d]
* ./a.out() [0x4006bb]
* ./a.out() [0x4006c6]
* /lib64/libc.so.6(__libc_start_main+0xed) [0x7fa2f8a5976d]
* ./a.out() [0x400569]
*/
#define STACK_ENTRY_SYMBOL_FMT(SYM) \
" > %s(%s+0x%lx) [0x%lx]\n", \
binary_filename, \
(SYM), \
(unsigned long) function_offset, \
true_offset
#define STACK_ENTRY_NOSYMBOL_FMT \
" > %s() [0x%lx]\n", \
binary_filename, true_offset
#define STACK_ENTRY_BUG_FMT \
" > BUG IN %s\n"
#define STACK_ENTRY_ERROR_WITH_OFFSET_FMT \
" > %s [0x%lx]\n", error, true_offset
#define STACK_ENTRY_ERROR_FMT \
" > %s\n", error
static void
print_call_cb(void *dummy,
const char *binary_filename,
const char *symbol_name,
unwind_function_offset_t function_offset,
unsigned long true_offset)
{
if (symbol_name && (symbol_name[0] != '\0')) {
#ifdef USE_DEMANGLE
char *demangled_name =
cplus_demangle(symbol_name,
DMGL_AUTO | DMGL_PARAMS);
#endif
tprintf(STACK_ENTRY_SYMBOL_FMT(
#ifdef USE_DEMANGLE
demangled_name ? demangled_name :
#endif
symbol_name));
#ifdef USE_DEMANGLE
free(demangled_name);
#endif
}
else if (binary_filename)
tprintf(STACK_ENTRY_NOSYMBOL_FMT);
else
tprintf(STACK_ENTRY_BUG_FMT, __func__);
line_ended();
}
static void
print_error_cb(void *dummy,
const char *error,
unsigned long true_offset)
{
if (true_offset)
tprintf(STACK_ENTRY_ERROR_WITH_OFFSET_FMT);
else
tprintf(STACK_ENTRY_ERROR_FMT);
line_ended();
}
static char *
sprint_call_or_error(const char *binary_filename,
const char *symbol_name,
unwind_function_offset_t function_offset,
unsigned long true_offset,
const char *error)
{
char *output_line = NULL;
int n;
if (symbol_name) {
#ifdef USE_DEMANGLE
char *demangled_name =
cplus_demangle(symbol_name,
DMGL_AUTO | DMGL_PARAMS);
#endif
n = asprintf(&output_line,
STACK_ENTRY_SYMBOL_FMT(
#ifdef USE_DEMANGLE
demangled_name ? demangled_name :
#endif
symbol_name));
#ifdef USE_DEMANGLE
free(demangled_name);
#endif
}
else if (binary_filename)
n = asprintf(&output_line, STACK_ENTRY_NOSYMBOL_FMT);
else if (error)
n = true_offset
? asprintf(&output_line, STACK_ENTRY_ERROR_WITH_OFFSET_FMT)
: asprintf(&output_line, STACK_ENTRY_ERROR_FMT);
else
n = asprintf(&output_line, STACK_ENTRY_BUG_FMT, __func__);
if (n < 0) {
perror_func_msg("asprintf");
output_line = (char *) asprintf_error_str;
}
return output_line;
}
/*
* queue manipulators
*/
static void
queue_put(struct unwind_queue_t *queue,
const char *binary_filename,
const char *symbol_name,
unwind_function_offset_t function_offset,
unsigned long true_offset,
const char *error)
{
struct call_t *call;
call = xmalloc(sizeof(*call));
call->output_line = sprint_call_or_error(binary_filename,
symbol_name,
function_offset,
true_offset,
error);
call->next = NULL;
if (!queue->head) {
queue->head = call;
queue->tail = call;
} else {
queue->tail->next = call;
queue->tail = call;
}
}
static void
queue_put_call(void *queue,
const char *binary_filename,
const char *symbol_name,
unwind_function_offset_t function_offset,
unsigned long true_offset)
{
queue_put(queue,
binary_filename,
symbol_name,
function_offset,
true_offset,
NULL);
}
static void
queue_put_error(void *queue,
const char *error,
unsigned long ip)
{
queue_put(queue, NULL, NULL, 0, ip, error);
}
static void
queue_print(struct unwind_queue_t *queue)
{
struct call_t *call, *tmp;
queue->tail = NULL;
call = queue->head;
queue->head = NULL;
while (call) {
tmp = call;
call = call->next;
tprints(tmp->output_line);
line_ended();
if (tmp->output_line != asprintf_error_str)
free(tmp->output_line);
tmp->output_line = NULL;
tmp->next = NULL;
free(tmp);
}
}
/*
* printing stack
*/
void
unwind_tcb_print(struct tcb *tcp)
{
#if SUPPORTED_PERSONALITIES > 1
if (tcp->currpers != DEFAULT_PERSONALITY) {
/* disable stack trace */
return;
}
#endif
if (tcp->unwind_queue->head) {
debug_func_msg("head: tcp=%p, queue=%p",
tcp, tcp->unwind_queue->head);
queue_print(tcp->unwind_queue);
} else switch (mmap_cache_rebuild_if_invalid(tcp, __func__)) {
case MMAP_CACHE_REBUILD_RENEWED:
unwinder.tcb_flush_cache(tcp);
ATTRIBUTE_FALLTHROUGH;
case MMAP_CACHE_REBUILD_READY:
debug_func_msg("walk: tcp=%p, queue=%p",
tcp, tcp->unwind_queue->head);
unwinder.tcb_walk(tcp, print_call_cb, print_error_cb, NULL);
break;
default:
/* Do nothing */
;
}
}
/*
* capturing stack
*/
void
unwind_tcb_capture(struct tcb *tcp)
{
#if SUPPORTED_PERSONALITIES > 1
if (tcp->currpers != DEFAULT_PERSONALITY) {
/* disable stack trace */
return;
}
#endif
if (tcp->unwind_queue->head)
error_msg_and_die("bug: unprinted entries in queue");
switch (mmap_cache_rebuild_if_invalid(tcp, __func__)) {
case MMAP_CACHE_REBUILD_RENEWED:
unwinder.tcb_flush_cache(tcp);
ATTRIBUTE_FALLTHROUGH;
case MMAP_CACHE_REBUILD_READY:
unwinder.tcb_walk(tcp, queue_put_call, queue_put_error,
tcp->unwind_queue);
debug_func_msg("tcp=%p, queue=%p",
tcp, tcp->unwind_queue->head);
break;
default:
/* Do nothing */
;
}
}