1// SPDX-License-Identifier: GPL-2.0-or-later
2
3#include <stdio.h>
4#include <stdlib.h>
5#include <objtool/check.h>
6#include <objtool/elf.h>
7#include <objtool/arch.h>
8#include <objtool/warn.h>
9#include <objtool/builtin.h>
10#include <objtool/endianness.h>
11
12int arch_ftrace_match(char *name)
13{
14 return !strcmp(s1: name, s2: "_mcount");
15}
16
17unsigned long arch_dest_reloc_offset(int addend)
18{
19 return addend;
20}
21
22bool arch_callee_saved_reg(unsigned char reg)
23{
24 return false;
25}
26
27int arch_decode_hint_reg(u8 sp_reg, int *base)
28{
29 exit(status: -1);
30}
31
32const char *arch_nop_insn(int len)
33{
34 exit(status: -1);
35}
36
37const char *arch_ret_insn(int len)
38{
39 exit(status: -1);
40}
41
42int arch_decode_instruction(struct objtool_file *file, const struct section *sec,
43 unsigned long offset, unsigned int maxlen,
44 struct instruction *insn)
45{
46 unsigned int opcode;
47 enum insn_type typ;
48 unsigned long imm;
49 u32 ins;
50
51 ins = bswap_if_needed(file->elf, *(u32 *)(sec->data->d_buf + offset));
52 opcode = ins >> 26;
53 typ = INSN_OTHER;
54 imm = 0;
55
56 switch (opcode) {
57 case 18: /* b[l][a] */
58 if (ins == 0x48000005) /* bl .+4 */
59 typ = INSN_OTHER;
60 else if (ins & 1) /* bl[a] */
61 typ = INSN_CALL;
62 else /* b[a] */
63 typ = INSN_JUMP_UNCONDITIONAL;
64
65 imm = ins & 0x3fffffc;
66 if (imm & 0x2000000)
67 imm -= 0x4000000;
68 imm |= ins & 2; /* AA flag */
69 break;
70 }
71
72 if (opcode == 1)
73 insn->len = 8;
74 else
75 insn->len = 4;
76
77 insn->type = typ;
78 insn->immediate = imm;
79
80 return 0;
81}
82
83unsigned long arch_jump_destination(struct instruction *insn)
84{
85 if (insn->immediate & 2)
86 return insn->immediate & ~2;
87
88 return insn->offset + insn->immediate;
89}
90
91bool arch_pc_relative_reloc(struct reloc *reloc)
92{
93 /*
94 * The powerpc build only allows certain relocation types, see
95 * relocs_check.sh, and none of those accepted are PC relative.
96 */
97 return false;
98}
99
100void arch_initial_func_cfi_state(struct cfi_init_state *state)
101{
102 int i;
103
104 for (i = 0; i < CFI_NUM_REGS; i++) {
105 state->regs[i].base = CFI_UNDEFINED;
106 state->regs[i].offset = 0;
107 }
108
109 /* initial CFA (call frame address) */
110 state->cfa.base = CFI_SP;
111 state->cfa.offset = 0;
112
113 /* initial LR (return address) */
114 state->regs[CFI_RA].base = CFI_CFA;
115 state->regs[CFI_RA].offset = 0;
116}
117
118unsigned int arch_reloc_size(struct reloc *reloc)
119{
120 switch (reloc_type(reloc)) {
121 case R_PPC_REL32:
122 case R_PPC_ADDR32:
123 case R_PPC_UADDR32:
124 case R_PPC_PLT32:
125 case R_PPC_PLTREL32:
126 return 4;
127 default:
128 return 8;
129 }
130}
131

source code of linux/tools/objtool/arch/powerpc/decode.c