146 lines
4.0 KiB
C
146 lines
4.0 KiB
C
/* Return backtrace of current program state.
|
|
Copyright (C) 2000, 2001, 2003, 2004, 2005 Free Software Foundation, Inc.
|
|
Contributed by Martin Schwidefsky <schwidefsky@de.ibm.com>.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 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
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, write to the Free
|
|
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
02111-1307 USA. */
|
|
|
|
#include <bits/libc-lock.h>
|
|
#include <dlfcn.h>
|
|
#include <execinfo.h>
|
|
#include <stddef.h>
|
|
#include <stdlib.h>
|
|
#include <unwind.h>
|
|
|
|
/* This is a global variable set at program start time. It marks the
|
|
highest used stack address. */
|
|
extern void *__libc_stack_end;
|
|
|
|
|
|
/* This is the stack layout we see for every non-leaf function.
|
|
size offset
|
|
%r15 -> +------------------+
|
|
4 | back chain | 0
|
|
4 | end of stack | 4
|
|
8 | glue | 8
|
|
8 | scratch | 16
|
|
40 | save area r6-r15 | 24
|
|
16 | save area f4,f6 | 64
|
|
16 | empty | 80
|
|
+------------------+
|
|
r14 in the save area holds the return address.
|
|
*/
|
|
|
|
struct layout
|
|
{
|
|
int back_chain;
|
|
int end_of_stack;
|
|
int glue[2];
|
|
int scratch[2];
|
|
int save_grps[10];
|
|
int save_fp[4];
|
|
int empty[2];
|
|
};
|
|
|
|
struct trace_arg
|
|
{
|
|
void **array;
|
|
int cnt, size;
|
|
};
|
|
|
|
#ifdef SHARED
|
|
static _Unwind_Reason_Code (*unwind_backtrace) (_Unwind_Trace_Fn, void *);
|
|
static _Unwind_Ptr (*unwind_getip) (struct _Unwind_Context *);
|
|
|
|
static void
|
|
init (void)
|
|
{
|
|
void *handle = __libc_dlopen ("libgcc_s.so.1");
|
|
|
|
if (handle == NULL)
|
|
return;
|
|
|
|
unwind_backtrace = __libc_dlsym (handle, "_Unwind_Backtrace");
|
|
unwind_getip = __libc_dlsym (handle, "_Unwind_GetIP");
|
|
if (unwind_getip == NULL)
|
|
unwind_backtrace = NULL;
|
|
}
|
|
#else
|
|
# define unwind_backtrace _Unwind_Backtrace
|
|
# define unwind_getip _Unwind_GetIP
|
|
#endif
|
|
|
|
static int
|
|
__backchain_backtrace (void **array, int size)
|
|
{
|
|
/* We assume that all the code is generated with frame pointers set. */
|
|
struct layout *stack;
|
|
int cnt = 0;
|
|
|
|
asm ("LR %0,%%r15" : "=d" (stack) );
|
|
/* We skip the call to this function, it makes no sense to record it. */
|
|
stack = (struct layout *) stack->back_chain;
|
|
while (cnt < size)
|
|
{
|
|
if (stack == NULL || (void *) stack > __libc_stack_end)
|
|
/* This means the address is out of range. Note that for the
|
|
toplevel we see a frame pointer with value NULL which clearly is
|
|
out of range. */
|
|
break;
|
|
|
|
array[cnt++] = (void *) (stack->save_grps[8] & 0x7fffffff);
|
|
|
|
stack = (struct layout *) stack->back_chain;
|
|
}
|
|
|
|
return cnt;
|
|
}
|
|
|
|
static _Unwind_Reason_Code
|
|
backtrace_helper (struct _Unwind_Context *ctx, void *a)
|
|
{
|
|
struct trace_arg *arg = a;
|
|
|
|
/* We are first called with address in the __backtrace function.
|
|
Skip it. */
|
|
if (arg->cnt != -1)
|
|
arg->array[arg->cnt] = (void *) unwind_getip (ctx);
|
|
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, .size = size, .cnt = -1 };
|
|
#ifdef SHARED
|
|
__libc_once_define (static, once);
|
|
|
|
__libc_once (once, init);
|
|
#endif
|
|
if (unwind_backtrace == NULL)
|
|
return __backchain_backtrace (array, size);
|
|
|
|
if (size >= 1)
|
|
unwind_backtrace (backtrace_helper, &arg);
|
|
|
|
return arg.cnt != -1 ? arg.cnt : 0;
|
|
}
|
|
|
|
weak_alias (__backtrace, backtrace)
|
|
libc_hidden_def (__backtrace)
|