42f0cc34fa
If Unwind_Backtrace is broken, ctx.n will still contain ~0, and we will
return that which poor behavior for the user, so return 0 instead.
We could document ~0 to be an error, but that would deviate from the
Linux behavior which is not desirable. Noted by Poul-Henning Kamp
PR: 209842
77 lines
2.3 KiB
C
77 lines
2.3 KiB
C
/* $NetBSD: unwind.c,v 1.3 2019/01/30 22:46:49 mrg Exp $ */
|
|
|
|
/*-
|
|
* Copyright (c) 2012 The NetBSD Foundation, Inc.
|
|
* All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to The NetBSD Foundation
|
|
* by Christos Zoulas.
|
|
*
|
|
* 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.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
|
|
* ``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 FOUNDATION OR CONTRIBUTORS
|
|
* 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 <sys/cdefs.h>
|
|
#include <sys/types.h>
|
|
#include <stdio.h>
|
|
|
|
#include "unwind.h"
|
|
#include "execinfo.h"
|
|
|
|
struct tracer_context {
|
|
void **arr;
|
|
size_t len;
|
|
size_t n;
|
|
};
|
|
|
|
static _Unwind_Reason_Code
|
|
tracer(struct _Unwind_Context *ctx, void *arg)
|
|
{
|
|
struct tracer_context *t = arg;
|
|
if (t->n == (size_t)~0) {
|
|
/* Skip backtrace frame */
|
|
t->n = 0;
|
|
return 0;
|
|
}
|
|
if (t->n < t->len)
|
|
t->arr[t->n++] = (void *)_Unwind_GetIP(ctx);
|
|
else
|
|
return _URC_END_OF_STACK;
|
|
return _URC_NO_REASON;
|
|
}
|
|
|
|
size_t
|
|
backtrace(void **arr, size_t len)
|
|
{
|
|
struct tracer_context ctx;
|
|
|
|
ctx.arr = arr;
|
|
ctx.len = len;
|
|
ctx.n = (size_t)~0;
|
|
|
|
_Unwind_Backtrace(tracer, &ctx);
|
|
if (ctx.n == (size_t)~0)
|
|
ctx.n = 0;
|
|
else if (ctx.n > 0)
|
|
ctx.arr[--ctx.n] = NULL; /* Skip frame below __start */
|
|
|
|
return ctx.n;
|
|
}
|