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   */
get_arch_regstr(unsigned int n)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  
regs_query_register_offset(const char * name)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