1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Mapping of DWARF debug register numbers into register names.
4 *
5 * Copyright (C) 2010 Ian Munsie, IBM Corporation.
6 */
7
8 #include <stddef.h>
9 #include <errno.h>
10 #include <string.h>
11 #include <dwarf-regs.h>
12 #include <linux/ptrace.h>
13 #include <linux/kernel.h>
14 #include <linux/stringify.h>
15
16 struct pt_regs_dwarfnum {
17 const char *name;
18 unsigned int dwarfnum;
19 unsigned int ptregs_offset;
20 };
21
22 #define REG_DWARFNUM_NAME(r, num) \
23 {.name = __stringify(%)__stringify(r), .dwarfnum = num, \
24 .ptregs_offset = offsetof(struct pt_regs, r)}
25 #define GPR_DWARFNUM_NAME(num) \
26 {.name = __stringify(%gpr##num), .dwarfnum = num, \
27 .ptregs_offset = offsetof(struct pt_regs, gpr[num])}
28 #define REG_DWARFNUM_END {.name = NULL, .dwarfnum = 0, .ptregs_offset = 0}
29
30 /*
31 * Reference:
32 * http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi-1.9.html
33 */
34 static const struct pt_regs_dwarfnum regdwarfnum_table[] = {
35 GPR_DWARFNUM_NAME(0),
36 GPR_DWARFNUM_NAME(1),
37 GPR_DWARFNUM_NAME(2),
38 GPR_DWARFNUM_NAME(3),
39 GPR_DWARFNUM_NAME(4),
40 GPR_DWARFNUM_NAME(5),
41 GPR_DWARFNUM_NAME(6),
42 GPR_DWARFNUM_NAME(7),
43 GPR_DWARFNUM_NAME(8),
44 GPR_DWARFNUM_NAME(9),
45 GPR_DWARFNUM_NAME(10),
46 GPR_DWARFNUM_NAME(11),
47 GPR_DWARFNUM_NAME(12),
48 GPR_DWARFNUM_NAME(13),
49 GPR_DWARFNUM_NAME(14),
50 GPR_DWARFNUM_NAME(15),
51 GPR_DWARFNUM_NAME(16),
52 GPR_DWARFNUM_NAME(17),
53 GPR_DWARFNUM_NAME(18),
54 GPR_DWARFNUM_NAME(19),
55 GPR_DWARFNUM_NAME(20),
56 GPR_DWARFNUM_NAME(21),
57 GPR_DWARFNUM_NAME(22),
58 GPR_DWARFNUM_NAME(23),
59 GPR_DWARFNUM_NAME(24),
60 GPR_DWARFNUM_NAME(25),
61 GPR_DWARFNUM_NAME(26),
62 GPR_DWARFNUM_NAME(27),
63 GPR_DWARFNUM_NAME(28),
64 GPR_DWARFNUM_NAME(29),
65 GPR_DWARFNUM_NAME(30),
66 GPR_DWARFNUM_NAME(31),
67 REG_DWARFNUM_NAME(msr, 66),
68 REG_DWARFNUM_NAME(ctr, 109),
69 REG_DWARFNUM_NAME(link, 108),
70 REG_DWARFNUM_NAME(xer, 101),
71 REG_DWARFNUM_NAME(dar, 119),
72 REG_DWARFNUM_NAME(dsisr, 118),
73 REG_DWARFNUM_END,
74 };
75
76 /**
77 * get_arch_regstr() - lookup register name from it's DWARF register number
78 * @n: the DWARF register number
79 *
80 * get_arch_regstr() returns the name of the register in struct
81 * regdwarfnum_table from it's DWARF register number. If the register is not
82 * found in the table, this returns NULL;
83 */
84 const char *get_arch_regstr(unsigned int n)
85 {
86 const struct pt_regs_dwarfnum *roff;
87 for (roff = regdwarfnum_table; roff->name != NULL; roff++)
88 if (roff->dwarfnum == n)
89 return roff->name;
90 return NULL;
91 }
92
93 int regs_query_register_offset(const char *name)
94 {
95 const struct pt_regs_dwarfnum *roff;
96 for (roff = regdwarfnum_table; roff->name != NULL; roff++)
97 if (!strcmp(roff->name, name))
98 return roff->ptregs_offset;
99 return -EINVAL;
100 }
101
102 #define PPC_OP(op) (((op) >> 26) & 0x3F)
103 #define PPC_RA(a) (((a) >> 16) & 0x1f)
104 #define PPC_RT(t) (((t) >> 21) & 0x1f)
105 #define PPC_RB(b) (((b) >> 11) & 0x1f)
106 #define PPC_D(D) ((D) & 0xfffe)
107 #define PPC_DS(DS) ((DS) & 0xfffc)
108 #define OP_LD 58
109 #define OP_STD 62
110
111 static int get_source_reg(u32 raw_insn)
112 {
113 return PPC_RA(raw_insn);
114 }
115
116 static int get_target_reg(u32 raw_insn)
117 {
118 return PPC_RT(raw_insn);
119 }
120
121 static int get_offset_opcode(u32 raw_insn)
122 {
123 int opcode = PPC_OP(raw_insn);
124
125 /* DS- form */
126 if ((opcode == OP_LD) || (opcode == OP_STD))
127 return PPC_DS(raw_insn);
128 else
129 return PPC_D(raw_insn);
130 }
131
132 /*
133 * Fills the required fields for op_loc depending on if it
134 * is a source or target.
135 * D form: ins RT,D(RA) -> src_reg1 = RA, offset = D, dst_reg1 = RT
136 * DS form: ins RT,DS(RA) -> src_reg1 = RA, offset = DS, dst_reg1 = RT
137 * X form: ins RT,RA,RB -> src_reg1 = RA, src_reg2 = RB, dst_reg1 = RT
138 */
139 void get_powerpc_regs(u32 raw_insn, int is_source,
140 struct annotated_op_loc *op_loc)
141 {
142 if (is_source)
143 op_loc->reg1 = get_source_reg(raw_insn);
144 else
145 op_loc->reg1 = get_target_reg(raw_insn);
146
147 if (op_loc->multi_regs)
148 op_loc->reg2 = PPC_RB(raw_insn);
149
150 /* TODO: Implement offset handling for X Form */
151 if ((op_loc->mem_ref) && (PPC_OP(raw_insn) != 31))
152 op_loc->offset = get_offset_opcode(raw_insn);
153 }
154
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