xref: /freebsd/sys/arm/arm/stack_machdep.c (revision 0957b409)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2005 Antoine Brodin
5  * All rights reserved.
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 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/proc.h>
35 #include <sys/stack.h>
36 
37 #include <machine/vmparam.h>
38 #include <machine/pcb.h>
39 #include <machine/stack.h>
40 
41 /*
42  * This code makes assumptions about the stack layout. These are correct
43  * when using APCS (the old ABI), but are no longer true with AAPCS and the
44  * ARM EABI. There is also an issue with clang and llvm when building for
45  * APCS where it lays out the stack incorrectly. Because of this we disable
46  * this when building for ARM EABI or when building with clang.
47  */
48 
49 extern vm_offset_t kernel_vm_end;
50 
51 static void
52 stack_capture(struct stack *st, u_int32_t *frame)
53 {
54 }
55 
56 void
57 stack_save_td(struct stack *st, struct thread *td)
58 {
59 	u_int32_t *frame;
60 
61 	if (TD_IS_SWAPPED(td))
62 		panic("stack_save_td: swapped");
63 	if (TD_IS_RUNNING(td))
64 		panic("stack_save_td: running");
65 
66 	/*
67 	 * This register, the frame pointer, is incorrect for the ARM EABI
68 	 * as it doesn't have a frame pointer, however it's value is not used
69 	 * when building for EABI.
70 	 */
71 	frame = (u_int32_t *)td->td_pcb->pcb_regs.sf_r11;
72 	stack_zero(st);
73 	stack_capture(st, frame);
74 }
75 
76 int
77 stack_save_td_running(struct stack *st, struct thread *td)
78 {
79 
80 	return (EOPNOTSUPP);
81 }
82 
83 void
84 stack_save(struct stack *st)
85 {
86 	u_int32_t *frame;
87 
88 	frame = (u_int32_t *)__builtin_frame_address(0);
89 	stack_zero(st);
90 	stack_capture(st, frame);
91 }
92