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