glibc/sysdeps/arm/backtrace.c
Florian Weimer fac75a690e arm: Implement backtrace on top of <unwind-link.h>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-03-01 15:58:45 +01:00

90 lines
2.5 KiB
C

/* Return backtrace of current program state.
Copyright (C) 2008-2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Kazu Hirata <kazu@codesourcery.com>, 2008.
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, see
<https://www.gnu.org/licenses/>. */
#include <execinfo.h>
#include <stdlib.h>
#include <unwind-link.h>
struct trace_arg
{
void **array;
struct unwind_link *unwind_link;
int cnt, size;
};
#ifdef SHARED
/* This function is identical to "_Unwind_GetGR", except that it uses
"unwind_vrs_get" instead of "_Unwind_VRS_Get". */
static inline _Unwind_Word
unwind_getgr (struct unwind_link *unwind_link,
_Unwind_Context *context, int regno)
{
_uw val;
UNWIND_LINK_PTR (unwind_link, _Unwind_VRS_Get)
(context, _UVRSC_CORE, regno, _UVRSD_UINT32, &val);
return val;
}
/* This macro is identical to the _Unwind_GetIP macro, except that it
uses "unwind_getgr" instead of "_Unwind_GetGR". */
#define unwind_getip(context) \
(unwind_getgr (arg->unwind_link, context, 15) & ~(_Unwind_Word)1)
#else /* !SHARED */
# define unwind_getip _Unwind_GetIP
#endif
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,
.unwind_link = __libc_unwind_link_get (),
.size = size,
.cnt = -1
};
if (size <= 0 || arg.unwind_link == NULL)
return 0;
UNWIND_LINK_PTR (arg.unwind_link, _Unwind_Backtrace)
(backtrace_helper, &arg);
if (arg.cnt > 1 && arg.array[arg.cnt - 1] == NULL)
--arg.cnt;
return arg.cnt != -1 ? arg.cnt : 0;
}
weak_alias (__backtrace, backtrace)
libc_hidden_def (__backtrace)