mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-25 04:01:10 +00:00
d5dff793af
Other architectures also had bugs, or did unnecessary work.
160 lines
4.1 KiB
C
160 lines
4.1 KiB
C
/* Return backtrace of current program state.
|
|
Copyright (C) 2013-2015 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by David S. Miller <davem@davemloft.net>
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Library General Public License as
|
|
published by the Free Software Foundation; either version 2 of the
|
|
License, or (at your option) any later version.
|
|
|
|
The GNU C Library 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
|
|
Library General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public
|
|
License along with the GNU C Library; see the file COPYING.LIB. If
|
|
not, see <http://www.gnu.org/licenses/>. */
|
|
|
|
#include <execinfo.h>
|
|
#include <stddef.h>
|
|
#include <sysdep.h>
|
|
#include <sys/trap.h>
|
|
#include <dlfcn.h>
|
|
#include <unwind.h>
|
|
#include <backtrace.h>
|
|
|
|
struct layout
|
|
{
|
|
unsigned long locals[8];
|
|
unsigned long ins[6];
|
|
unsigned long next;
|
|
void *return_address;
|
|
};
|
|
|
|
struct trace_arg
|
|
{
|
|
void **array;
|
|
_Unwind_Word cfa;
|
|
int cnt;
|
|
int size;
|
|
};
|
|
|
|
#ifdef SHARED
|
|
static _Unwind_Reason_Code (*unwind_backtrace) (_Unwind_Trace_Fn, void *);
|
|
static _Unwind_Ptr (*unwind_getip) (struct _Unwind_Context *);
|
|
static _Unwind_Word (*unwind_getcfa) (struct _Unwind_Context *);
|
|
static void *libgcc_handle;
|
|
|
|
/* Dummy version in case libgcc_s does not contain the real code. */
|
|
static _Unwind_Word
|
|
dummy_getcfa (struct _Unwind_Context *ctx __attribute__ ((unused)))
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
init (void)
|
|
{
|
|
libgcc_handle = __libc_dlopen ("libgcc_s.so.1");
|
|
|
|
if (libgcc_handle == NULL)
|
|
return;
|
|
|
|
unwind_backtrace = __libc_dlsym (libgcc_handle, "_Unwind_Backtrace");
|
|
unwind_getip = __libc_dlsym (libgcc_handle, "_Unwind_GetIP");
|
|
if (unwind_getip == NULL)
|
|
unwind_backtrace = NULL;
|
|
unwind_getcfa = (__libc_dlsym (libgcc_handle, "_Unwind_GetCFA")
|
|
?: dummy_getcfa);
|
|
}
|
|
#else
|
|
# define unwind_backtrace _Unwind_Backtrace
|
|
# define unwind_getip _Unwind_GetIP
|
|
# define unwind_getcfa _Unwind_GetCFA
|
|
#endif
|
|
|
|
static _Unwind_Reason_Code
|
|
backtrace_helper (struct _Unwind_Context *ctx, void *a)
|
|
{
|
|
struct trace_arg *arg = a;
|
|
_Unwind_Ptr ip;
|
|
|
|
/* We are first called with address in the __backtrace function.
|
|
Skip it. */
|
|
if (arg->cnt != -1)
|
|
{
|
|
ip = unwind_getip (ctx);
|
|
arg->array[arg->cnt] = (void *) ip;
|
|
|
|
/* Check whether we make any progress. */
|
|
_Unwind_Word cfa = unwind_getcfa (ctx);
|
|
|
|
if (arg->cnt > 0 && arg->array[arg->cnt - 1] == arg->array[arg->cnt]
|
|
&& cfa == arg->cfa)
|
|
return _URC_END_OF_STACK;
|
|
arg->cfa = cfa;
|
|
}
|
|
if (++arg->cnt == arg->size)
|
|
return _URC_END_OF_STACK;
|
|
return _URC_NO_REASON;
|
|
}
|
|
|
|
int
|
|
__backtrace (void **array, int size)
|
|
{
|
|
struct trace_arg arg = { .array = array, .cfa = 0, .size = size, .cnt = -1 };
|
|
bool use_unwinder;
|
|
int count;
|
|
|
|
if (size <= 0)
|
|
return 0;
|
|
|
|
use_unwinder = true;
|
|
#ifdef SHARED
|
|
__libc_once_define (static, once);
|
|
|
|
__libc_once (once, init);
|
|
if (unwind_backtrace == NULL)
|
|
use_unwinder = false;
|
|
#endif
|
|
|
|
if (use_unwinder == false)
|
|
{
|
|
struct layout *current;
|
|
unsigned long fp, i7;
|
|
|
|
asm volatile ("mov %%fp, %0" : "=r"(fp));
|
|
asm volatile ("mov %%i7, %0" : "=r"(i7));
|
|
current = (struct layout *) (fp + BACKTRACE_STACK_BIAS);
|
|
|
|
array[0] = (void *) i7;
|
|
|
|
if (size == 1)
|
|
return 1;
|
|
|
|
backtrace_flush_register_windows();
|
|
for (count = 1; count < size; count++)
|
|
{
|
|
array[count] = current->return_address;
|
|
if (!current->next)
|
|
break;
|
|
current = (struct layout *) (current->next + BACKTRACE_STACK_BIAS);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
unwind_backtrace (backtrace_helper, &arg);
|
|
|
|
/* _Unwind_Backtrace seems to put NULL address above
|
|
_start. Fix it up here. */
|
|
if (arg.cnt > 1 && arg.array[arg.cnt - 1] == NULL)
|
|
--arg.cnt;
|
|
count = arg.cnt != -1 ? arg.cnt : 0;
|
|
}
|
|
return count;
|
|
}
|
|
weak_alias (__backtrace, backtrace)
|
|
libc_hidden_def (__backtrace)
|