1/*
2 * This file is part of ltrace.
3 * Copyright (C) 2014 Petr Machata, Red Hat, Inc.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation; either version 2 of the
8 * License, or (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13 * General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
18 * 02110-1301 USA
19 */
20
21#include <sys/ptrace.h>
22#include <asm/ptrace.h>
23#include <linux/uio.h>
24#include <assert.h>
25#include <stdlib.h>
26#include <stdio.h>
27
28#include "backend.h"
29#include "proc.h"
30
31#define PC_OFF (32 * 4)
32
33int
34aarch64_read_gregs(struct process *proc, struct user_pt_regs *regs)
35{
36	*regs = (struct user_pt_regs) {};
37	struct iovec iovec;
38	iovec.iov_base = regs;
39	iovec.iov_len = sizeof *regs;
40	return ptrace(PTRACE_GETREGSET, proc->pid, NT_PRSTATUS, &iovec) < 0
41		? -1 : 0;
42}
43
44int
45aarch64_write_gregs(struct process *proc, struct user_pt_regs *regs)
46{
47	struct iovec iovec;
48	iovec.iov_base = regs;
49	iovec.iov_len = sizeof *regs;
50	return ptrace(PTRACE_SETREGSET, proc->pid, NT_PRSTATUS, &iovec) < 0
51		? -1 : 0;
52}
53
54int
55aarch64_read_fregs(struct process *proc, struct user_fpsimd_state *regs)
56{
57	*regs = (struct user_fpsimd_state) {};
58	struct iovec iovec;
59	iovec.iov_base = regs;
60	iovec.iov_len = sizeof *regs;
61	return ptrace(PTRACE_GETREGSET, proc->pid, NT_FPREGSET, &iovec) < 0
62		? -1 : 0;
63}
64
65arch_addr_t
66get_instruction_pointer(struct process *proc)
67{
68	struct user_pt_regs regs;
69	if (aarch64_read_gregs(proc, &regs) < 0) {
70		fprintf(stderr, "get_instruction_pointer: "
71			"Couldn't read registers of %d.\n", proc->pid);
72		return 0;
73	}
74
75	/*
76	char buf[128];
77	sprintf(buf, "cat /proc/%d/maps", proc->pid);
78	system(buf);
79	*/
80
81	/* XXX double cast */
82	return (arch_addr_t) (uintptr_t) regs.pc;
83}
84
85void
86set_instruction_pointer(struct process *proc, arch_addr_t addr)
87{
88	struct user_pt_regs regs;
89	if (aarch64_read_gregs(proc, &regs) < 0) {
90		fprintf(stderr, "get_instruction_pointer: "
91			"Couldn't read registers of %d.\n", proc->pid);
92		return;
93	}
94
95	/* XXX double cast */
96	regs.pc = (uint64_t) (uintptr_t) addr;
97
98	if (aarch64_write_gregs(proc, &regs) < 0) {
99		fprintf(stderr, "get_instruction_pointer: "
100			"Couldn't write registers of %d.\n", proc->pid);
101		return;
102	}
103}
104
105arch_addr_t
106get_stack_pointer(struct process *proc)
107{
108	struct user_pt_regs regs;
109	if (aarch64_read_gregs(proc, &regs) < 0) {
110		fprintf(stderr, "get_stack_pointer: "
111			"Couldn't read registers of %d.\n", proc->pid);
112		return 0;
113	}
114
115	/* XXX double cast */
116	return (arch_addr_t) (uintptr_t) regs.sp;
117}
118
119arch_addr_t
120get_return_addr(struct process *proc, arch_addr_t stack_pointer)
121{
122	struct user_pt_regs regs;
123	if (aarch64_read_gregs(proc, &regs) < 0) {
124		fprintf(stderr, "get_return_addr: "
125			"Couldn't read registers of %d.\n", proc->pid);
126		return 0;
127	}
128
129	/* XXX double cast */
130	return (arch_addr_t) (uintptr_t) regs.regs[30];
131}
132