xref: /freebsd/sys/arm64/arm64/unwind.c (revision ec965063070e5753c166cf592c9336444b74720a)
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/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 #include <sys/param.h>
32 #include <sys/proc.h>
33 
34 #include <machine/stack.h>
35 #include <machine/vmparam.h>
36 
37 bool
38 unwind_frame(struct thread *td, struct unwind_state *frame)
39 {
40 	uintptr_t fp;
41 
42 	fp = frame->fp;
43 
44 	if (!__is_aligned(fp, sizeof(fp)) ||
45 	    !kstack_contains(td, fp, sizeof(fp) * 2))
46 		return (false);
47 
48 	/* FP to previous frame (X29) */
49 	frame->fp = ((uintptr_t *)fp)[0];
50 	/* LR (X30) */
51 	frame->pc = ADDR_MAKE_CANONICAL(((uintptr_t *)fp)[1] - 4);
52 
53 	return (true);
54 }
55