1 /*- 2 * Copyright (c) 2015 The FreeBSD Foundation 3 * All rights reserved. 4 * 5 * This software was developed by Semihalf under 6 * the sponsorship of the FreeBSD Foundation. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 #include <sys/param.h> 33 #include <sys/proc.h> 34 35 #include <machine/stack.h> 36 #include <machine/vmparam.h> 37 38 bool 39 unwind_frame(struct thread *td, struct unwind_state *frame) 40 { 41 uintptr_t fp; 42 43 fp = frame->fp; 44 45 if (!kstack_contains(td, fp, sizeof(uintptr_t) * 2)) 46 return (false); 47 48 /* FP to previous frame (X29) */ 49 frame->fp = ((uintptr_t *)fp)[0]; 50 /* LR (X30) */ 51 frame->pc = ((uintptr_t *)fp)[1] - 4; 52 53 return (true); 54 } 55