1 /*
2  * Mapping of DWARF debug register numbers into register names.
3  *
4  * Copyright (C) 2010 Will Deacon, ARM Ltd.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 
11 #include <errno.h>
12 #include <stddef.h>
13 #include <string.h>
14 #include <dwarf-regs.h>
15 #include <linux/ptrace.h> /* for struct user_pt_regs */
16 #include <linux/stringify.h>
17 #include "util.h"
18 
19 struct pt_regs_dwarfnum {
20 	const char *name;
21 	unsigned int dwarfnum;
22 };
23 
24 #define REG_DWARFNUM_NAME(r, num) {.name = r, .dwarfnum = num}
25 #define GPR_DWARFNUM_NAME(num) \
26 	{.name = __stringify(%x##num), .dwarfnum = num}
27 #define REG_DWARFNUM_END {.name = NULL, .dwarfnum = 0}
28 #define DWARFNUM2OFFSET(index) \
29 	(index * sizeof((struct user_pt_regs *)0)->regs[0])
30 
31 /*
32  * Reference:
33  * http://infocenter.arm.com/help/topic/com.arm.doc.ihi0057b/IHI0057B_aadwarf64.pdf
34  */
35 static const struct pt_regs_dwarfnum regdwarfnum_table[] = {
36 	GPR_DWARFNUM_NAME(0),
37 	GPR_DWARFNUM_NAME(1),
38 	GPR_DWARFNUM_NAME(2),
39 	GPR_DWARFNUM_NAME(3),
40 	GPR_DWARFNUM_NAME(4),
41 	GPR_DWARFNUM_NAME(5),
42 	GPR_DWARFNUM_NAME(6),
43 	GPR_DWARFNUM_NAME(7),
44 	GPR_DWARFNUM_NAME(8),
45 	GPR_DWARFNUM_NAME(9),
46 	GPR_DWARFNUM_NAME(10),
47 	GPR_DWARFNUM_NAME(11),
48 	GPR_DWARFNUM_NAME(12),
49 	GPR_DWARFNUM_NAME(13),
50 	GPR_DWARFNUM_NAME(14),
51 	GPR_DWARFNUM_NAME(15),
52 	GPR_DWARFNUM_NAME(16),
53 	GPR_DWARFNUM_NAME(17),
54 	GPR_DWARFNUM_NAME(18),
55 	GPR_DWARFNUM_NAME(19),
56 	GPR_DWARFNUM_NAME(20),
57 	GPR_DWARFNUM_NAME(21),
58 	GPR_DWARFNUM_NAME(22),
59 	GPR_DWARFNUM_NAME(23),
60 	GPR_DWARFNUM_NAME(24),
61 	GPR_DWARFNUM_NAME(25),
62 	GPR_DWARFNUM_NAME(26),
63 	GPR_DWARFNUM_NAME(27),
64 	GPR_DWARFNUM_NAME(28),
65 	GPR_DWARFNUM_NAME(29),
66 	REG_DWARFNUM_NAME("%lr", 30),
67 	REG_DWARFNUM_NAME("%sp", 31),
68 	REG_DWARFNUM_END,
69 };
70 
71 /**
72  * get_arch_regstr() - lookup register name from it's DWARF register number
73  * @n:	the DWARF register number
74  *
75  * get_arch_regstr() returns the name of the register in struct
76  * regdwarfnum_table from it's DWARF register number. If the register is not
77  * found in the table, this returns NULL;
78  */
79 const char *get_arch_regstr(unsigned int n)
80 {
81 	const struct pt_regs_dwarfnum *roff;
82 	for (roff = regdwarfnum_table; roff->name != NULL; roff++)
83 		if (roff->dwarfnum == n)
84 			return roff->name;
85 	return NULL;
86 }
87 
88 int regs_query_register_offset(const char *name)
89 {
90 	const struct pt_regs_dwarfnum *roff;
91 
92 	for (roff = regdwarfnum_table; roff->name != NULL; roff++)
93 		if (!strcmp(roff->name, name))
94 			return DWARFNUM2OFFSET(roff->dwarfnum);
95 	return -EINVAL;
96 }
97