nuttx/libs/libc/debug/lib_backtrace.c
chao.an 27dd771336 libc/execinfo: add backtrace support based on EABI Unwinder
1. Flags < -funwind-tables > is required
2. Keep the section ".exidx" in linker script

Signed-off-by: chao.an <anchao@xiaomi.com>
2021-04-19 04:45:04 -07:00

129 lines
3.4 KiB
C

/****************************************************************************
* libs/libc/debug/lib_backtrace.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <execinfo.h>
#include <unwind.h>
/****************************************************************************
* Private Data Types
****************************************************************************/
struct trace_arg
{
FAR void **array;
_Unwind_Word cfa;
int cnt;
int size;
};
/****************************************************************************
* Private Functions
****************************************************************************/
static inline weak_function
FAR void *unwind_arch_adjustment(FAR void *prev, FAR void *addr)
{
return addr;
}
static _Unwind_Reason_Code
backtrace_helper(FAR struct _Unwind_Context *ctx, FAR void *a)
{
FAR 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] = (FAR void *)_Unwind_GetIP(ctx);
if (arg->cnt > 0)
{
arg->array[arg->cnt]
= unwind_arch_adjustment(arg->array[arg->cnt - 1],
arg->array[arg->cnt]);
}
/* 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;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/* Store up to SIZE return address of the current program state in
* ARRAY and return the exact number of values stored.
*/
int backtrace(FAR void **buffer, int size)
{
struct trace_arg arg;
arg.array = buffer;
arg.cfa = 0;
arg.size = size;
arg.cnt = -1;
if (size <= 0)
{
return 0;
}
_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;
}
return arg.cnt != -1 ? arg.cnt : 0;
}