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 12 int arch_ftrace_match(char *name) 13 { 14 return !strcmp(name, "_mcount"); 15 } 16 17 unsigned long arch_dest_reloc_offset(int addend) 18 { 19 return addend; 20 } 21 22 bool arch_callee_saved_reg(unsigned char reg) 23 { 24 return false; 25 } 26 27 int arch_decode_hint_reg(u8 sp_reg, int *base) 28 { 29 exit(-1); 30 } 31 32 const char *arch_nop_insn(int len) 33 { 34 exit(-1); 35 } 36 37 const char *arch_ret_insn(int len) 38 { 39 exit(-1); 40 } 41 42 int 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 83 unsigned 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 91 bool 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 } 99 100 void 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 } 117 118 unsigned 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