1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2019 Ian Lepore <ian@freebsd.org>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD$");
30
31#include <sys/types.h>
32#include <sys/systm.h>
33#include <sys/lock.h>
34#include <sys/mutex.h>
35#include <sys/proc.h>
36#include <sys/stack.h>
37
38#include <machine/pcb.h>
39#include <machine/stack.h>
40
41static void
42stack_capture(struct stack *st, struct unwind_state *state)
43{
44
45	stack_zero(st);
46	while (unwind_stack_one(state, 0) == 0) {
47		if (stack_put(st, state->registers[PC]) == -1)
48			break;
49	}
50}
51
52void
53stack_save(struct stack *st)
54{
55	struct unwind_state state;
56	uint32_t sp;
57
58	/* Read the stack pointer */
59	__asm __volatile("mov %0, sp" : "=&r" (sp));
60
61	state.registers[FP] = (uint32_t)__builtin_frame_address(0);
62	state.registers[SP] = sp;
63	state.registers[LR] = (uint32_t)__builtin_return_address(0);
64	state.registers[PC] = (uint32_t)stack_save;
65
66	stack_capture(st, &state);
67}
68
69int
70stack_save_td(struct stack *st, struct thread *td)
71{
72	struct unwind_state state;
73
74	THREAD_LOCK_ASSERT(td, MA_OWNED);
75	KASSERT(!TD_IS_SWAPPED(td),
76	    ("stack_save_td: thread %p is swapped", td));
77
78	if (TD_IS_RUNNING(td))
79		return (EOPNOTSUPP);
80
81	state.registers[FP] = td->td_pcb->pcb_regs.sf_r11;
82	state.registers[SP] = td->td_pcb->pcb_regs.sf_sp;
83	state.registers[LR] = td->td_pcb->pcb_regs.sf_lr;
84	state.registers[PC] = td->td_pcb->pcb_regs.sf_pc;
85
86	stack_capture(st, &state);
87	return (0);
88}
89