1*499fe48dSConrad Meyer /* $NetBSD: unwind.c,v 1.3 2019/01/30 22:46:49 mrg Exp $ */ 2287472b3SEd Maste 3287472b3SEd Maste /*- 4287472b3SEd Maste * Copyright (c) 2012 The NetBSD Foundation, Inc. 5287472b3SEd Maste * All rights reserved. 6287472b3SEd Maste * 7287472b3SEd Maste * This code is derived from software contributed to The NetBSD Foundation 8287472b3SEd Maste * by Christos Zoulas. 9287472b3SEd Maste * 10287472b3SEd Maste * Redistribution and use in source and binary forms, with or without 11287472b3SEd Maste * modification, are permitted provided that the following conditions 12287472b3SEd Maste * are met: 13287472b3SEd Maste * 1. Redistributions of source code must retain the above copyright 14287472b3SEd Maste * notice, this list of conditions and the following disclaimer. 15287472b3SEd Maste * 2. Redistributions in binary form must reproduce the above copyright 16287472b3SEd Maste * notice, this list of conditions and the following disclaimer in the 17287472b3SEd Maste * documentation and/or other materials provided with the distribution. 18287472b3SEd Maste * 19287472b3SEd Maste * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20287472b3SEd Maste * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21287472b3SEd Maste * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22287472b3SEd Maste * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23287472b3SEd Maste * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24287472b3SEd Maste * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25287472b3SEd Maste * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26287472b3SEd Maste * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27287472b3SEd Maste * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28287472b3SEd Maste * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29287472b3SEd Maste * POSSIBILITY OF SUCH DAMAGE. 30287472b3SEd Maste */ 31287472b3SEd Maste #include <sys/cdefs.h> 32287472b3SEd Maste #include <sys/types.h> 33287472b3SEd Maste #include <stdio.h> 34287472b3SEd Maste 35287472b3SEd Maste #include "unwind.h" 36287472b3SEd Maste #include "execinfo.h" 37287472b3SEd Maste 38287472b3SEd Maste struct tracer_context { 39287472b3SEd Maste void **arr; 40287472b3SEd Maste size_t len; 41287472b3SEd Maste size_t n; 42287472b3SEd Maste }; 43287472b3SEd Maste 44287472b3SEd Maste static _Unwind_Reason_Code 45287472b3SEd Maste tracer(struct _Unwind_Context *ctx, void *arg) 46287472b3SEd Maste { 47287472b3SEd Maste struct tracer_context *t = arg; 48287472b3SEd Maste if (t->n == (size_t)~0) { 49287472b3SEd Maste /* Skip backtrace frame */ 50287472b3SEd Maste t->n = 0; 51287472b3SEd Maste return 0; 52287472b3SEd Maste } 53287472b3SEd Maste if (t->n < t->len) 54*499fe48dSConrad Meyer t->arr[t->n++] = (void *)_Unwind_GetIP(ctx); 55*499fe48dSConrad Meyer else 56*499fe48dSConrad Meyer return _URC_END_OF_STACK; 57*499fe48dSConrad Meyer return _URC_NO_REASON; 58287472b3SEd Maste } 59287472b3SEd Maste 60287472b3SEd Maste size_t 61287472b3SEd Maste backtrace(void **arr, size_t len) 62287472b3SEd Maste { 63287472b3SEd Maste struct tracer_context ctx; 64287472b3SEd Maste 65287472b3SEd Maste ctx.arr = arr; 66287472b3SEd Maste ctx.len = len; 67287472b3SEd Maste ctx.n = (size_t)~0; 68287472b3SEd Maste 69287472b3SEd Maste _Unwind_Backtrace(tracer, &ctx); 70287472b3SEd Maste if (ctx.n != (size_t)~0 && ctx.n > 0) 71287472b3SEd Maste ctx.arr[--ctx.n] = NULL; /* Skip frame below __start */ 72287472b3SEd Maste 73287472b3SEd Maste return ctx.n; 74287472b3SEd Maste } 75