xref: /freebsd/sys/arm/arm/stack_machdep.c (revision 06c3fb27)
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/types.h>
29 #include <sys/systm.h>
30 #include <sys/lock.h>
31 #include <sys/mutex.h>
32 #include <sys/proc.h>
33 #include <sys/stack.h>
34 
35 #include <machine/pcb.h>
36 #include <machine/stack.h>
37 
38 static void
39 stack_capture(struct stack *st, struct unwind_state *state)
40 {
41 
42 	stack_zero(st);
43 	while (unwind_stack_one(state, 0) == 0) {
44 		if (stack_put(st, state->registers[PC]) == -1)
45 			break;
46 	}
47 }
48 
49 void
50 stack_save(struct stack *st)
51 {
52 	struct unwind_state state;
53 	uint32_t sp;
54 
55 	/* Read the stack pointer */
56 	__asm __volatile("mov %0, sp" : "=&r" (sp));
57 
58 	state.registers[FP] = (uint32_t)__builtin_frame_address(0);
59 	state.registers[SP] = sp;
60 	state.registers[LR] = (uint32_t)__builtin_return_address(0);
61 	state.registers[PC] = (uint32_t)stack_save;
62 
63 	stack_capture(st, &state);
64 }
65 
66 int
67 stack_save_td(struct stack *st, struct thread *td)
68 {
69 	struct unwind_state state;
70 
71 	THREAD_LOCK_ASSERT(td, MA_OWNED);
72 	KASSERT(!TD_IS_SWAPPED(td),
73 	    ("stack_save_td: thread %p is swapped", td));
74 
75 	if (TD_IS_RUNNING(td))
76 		return (EOPNOTSUPP);
77 
78 	state.registers[FP] = td->td_pcb->pcb_regs.sf_r11;
79 	state.registers[SP] = td->td_pcb->pcb_regs.sf_sp;
80 	state.registers[LR] = td->td_pcb->pcb_regs.sf_lr;
81 	state.registers[PC] = td->td_pcb->pcb_regs.sf_pc;
82 
83 	stack_capture(st, &state);
84 	return (0);
85 }
86