1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Mapping of DWARF debug register numbers into register names.
4 *
5 * Copyright (C) 2010 Will Deacon, ARM Ltd.
6 */
7
8#include <errno.h>
9#include <stddef.h>
10#include <string.h>
11#include <dwarf-regs.h>
12#include <linux/ptrace.h> /* for struct user_pt_regs */
13#include <linux/stringify.h>
14
15struct pt_regs_dwarfnum {
16	const char *name;
17	unsigned int dwarfnum;
18};
19
20#define REG_DWARFNUM_NAME(r, num) {.name = r, .dwarfnum = num}
21#define GPR_DWARFNUM_NAME(num) \
22	{.name = __stringify(%x##num), .dwarfnum = num}
23#define REG_DWARFNUM_END {.name = NULL, .dwarfnum = 0}
24#define DWARFNUM2OFFSET(index) \
25	(index * sizeof((struct user_pt_regs *)0)->regs[0])
26
27/*
28 * Reference:
29 * http://infocenter.arm.com/help/topic/com.arm.doc.ihi0057b/IHI0057B_aadwarf64.pdf
30 */
31static const struct pt_regs_dwarfnum regdwarfnum_table[] = {
32	GPR_DWARFNUM_NAME(0),
33	GPR_DWARFNUM_NAME(1),
34	GPR_DWARFNUM_NAME(2),
35	GPR_DWARFNUM_NAME(3),
36	GPR_DWARFNUM_NAME(4),
37	GPR_DWARFNUM_NAME(5),
38	GPR_DWARFNUM_NAME(6),
39	GPR_DWARFNUM_NAME(7),
40	GPR_DWARFNUM_NAME(8),
41	GPR_DWARFNUM_NAME(9),
42	GPR_DWARFNUM_NAME(10),
43	GPR_DWARFNUM_NAME(11),
44	GPR_DWARFNUM_NAME(12),
45	GPR_DWARFNUM_NAME(13),
46	GPR_DWARFNUM_NAME(14),
47	GPR_DWARFNUM_NAME(15),
48	GPR_DWARFNUM_NAME(16),
49	GPR_DWARFNUM_NAME(17),
50	GPR_DWARFNUM_NAME(18),
51	GPR_DWARFNUM_NAME(19),
52	GPR_DWARFNUM_NAME(20),
53	GPR_DWARFNUM_NAME(21),
54	GPR_DWARFNUM_NAME(22),
55	GPR_DWARFNUM_NAME(23),
56	GPR_DWARFNUM_NAME(24),
57	GPR_DWARFNUM_NAME(25),
58	GPR_DWARFNUM_NAME(26),
59	GPR_DWARFNUM_NAME(27),
60	GPR_DWARFNUM_NAME(28),
61	GPR_DWARFNUM_NAME(29),
62	REG_DWARFNUM_NAME("%lr", 30),
63	REG_DWARFNUM_NAME("%sp", 31),
64	REG_DWARFNUM_END,
65};
66
67/**
68 * get_arch_regstr() - lookup register name from it's DWARF register number
69 * @n:	the DWARF register number
70 *
71 * get_arch_regstr() returns the name of the register in struct
72 * regdwarfnum_table from it's DWARF register number. If the register is not
73 * found in the table, this returns NULL;
74 */
75const char *get_arch_regstr(unsigned int n)
76{
77	const struct pt_regs_dwarfnum *roff;
78	for (roff = regdwarfnum_table; roff->name != NULL; roff++)
79		if (roff->dwarfnum == n)
80			return roff->name;
81	return NULL;
82}
83
84int regs_query_register_offset(const char *name)
85{
86	const struct pt_regs_dwarfnum *roff;
87
88	for (roff = regdwarfnum_table; roff->name != NULL; roff++)
89		if (!strcmp(roff->name, name))
90			return DWARFNUM2OFFSET(roff->dwarfnum);
91	return -EINVAL;
92}
93