1*287472b3SEd Maste /* $NetBSD: unwind.c,v 1.1 2012/05/26 22:02:29 christos Exp $ */ 2*287472b3SEd Maste 3*287472b3SEd Maste /*- 4*287472b3SEd Maste * Copyright (c) 2012 The NetBSD Foundation, Inc. 5*287472b3SEd Maste * All rights reserved. 6*287472b3SEd Maste * 7*287472b3SEd Maste * This code is derived from software contributed to The NetBSD Foundation 8*287472b3SEd Maste * by Christos Zoulas. 9*287472b3SEd Maste * 10*287472b3SEd Maste * Redistribution and use in source and binary forms, with or without 11*287472b3SEd Maste * modification, are permitted provided that the following conditions 12*287472b3SEd Maste * are met: 13*287472b3SEd Maste * 1. Redistributions of source code must retain the above copyright 14*287472b3SEd Maste * notice, this list of conditions and the following disclaimer. 15*287472b3SEd Maste * 2. Redistributions in binary form must reproduce the above copyright 16*287472b3SEd Maste * notice, this list of conditions and the following disclaimer in the 17*287472b3SEd Maste * documentation and/or other materials provided with the distribution. 18*287472b3SEd Maste * 19*287472b3SEd Maste * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20*287472b3SEd Maste * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21*287472b3SEd Maste * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22*287472b3SEd Maste * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23*287472b3SEd Maste * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24*287472b3SEd Maste * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25*287472b3SEd Maste * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26*287472b3SEd Maste * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27*287472b3SEd Maste * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28*287472b3SEd Maste * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29*287472b3SEd Maste * POSSIBILITY OF SUCH DAMAGE. 30*287472b3SEd Maste */ 31*287472b3SEd Maste #include <sys/cdefs.h> 32*287472b3SEd Maste #include <sys/types.h> 33*287472b3SEd Maste #include <stdio.h> 34*287472b3SEd Maste 35*287472b3SEd Maste #include "unwind.h" 36*287472b3SEd Maste #include "execinfo.h" 37*287472b3SEd Maste 38*287472b3SEd Maste struct tracer_context { 39*287472b3SEd Maste void **arr; 40*287472b3SEd Maste size_t len; 41*287472b3SEd Maste size_t n; 42*287472b3SEd Maste }; 43*287472b3SEd Maste 44*287472b3SEd Maste static _Unwind_Reason_Code 45*287472b3SEd Maste tracer(struct _Unwind_Context *ctx, void *arg) 46*287472b3SEd Maste { 47*287472b3SEd Maste struct tracer_context *t = arg; 48*287472b3SEd Maste if (t->n == (size_t)~0) { 49*287472b3SEd Maste /* Skip backtrace frame */ 50*287472b3SEd Maste t->n = 0; 51*287472b3SEd Maste return 0; 52*287472b3SEd Maste } 53*287472b3SEd Maste if (t->n < t->len) 54*287472b3SEd Maste t->arr[t->n++] = _Unwind_GetIP(ctx); 55*287472b3SEd Maste return 0; 56*287472b3SEd Maste } 57*287472b3SEd Maste 58*287472b3SEd Maste size_t 59*287472b3SEd Maste backtrace(void **arr, size_t len) 60*287472b3SEd Maste { 61*287472b3SEd Maste struct tracer_context ctx; 62*287472b3SEd Maste 63*287472b3SEd Maste ctx.arr = arr; 64*287472b3SEd Maste ctx.len = len; 65*287472b3SEd Maste ctx.n = (size_t)~0; 66*287472b3SEd Maste 67*287472b3SEd Maste _Unwind_Backtrace(tracer, &ctx); 68*287472b3SEd Maste if (ctx.n != (size_t)~0 && ctx.n > 0) 69*287472b3SEd Maste ctx.arr[--ctx.n] = NULL; /* Skip frame below __start */ 70*287472b3SEd Maste 71*287472b3SEd Maste return ctx.n; 72*287472b3SEd Maste } 73