diff options
Diffstat (limited to 'tools/objtool/arch/x86/decode.c')
| -rw-r--r-- | tools/objtool/arch/x86/decode.c | 302 |
1 files changed, 185 insertions, 117 deletions
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c index a62e032863a8..4b504fc90bbb 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -11,6 +11,7 @@ #include "../../../arch/x86/lib/inat.c" #include "../../../arch/x86/lib/insn.c" +#include "../../check.h" #include "../../elf.h" #include "../../arch.h" #include "../../warn.h" @@ -26,7 +27,7 @@ static unsigned char op_to_cfi_reg[][2] = { {CFI_DI, CFI_R15}, }; -static int is_x86_64(struct elf *elf) +static int is_x86_64(const struct elf *elf) { switch (elf->ehdr.e_machine) { case EM_X86_64: @@ -66,16 +67,34 @@ bool arch_callee_saved_reg(unsigned char reg) } } -int arch_decode_instruction(struct elf *elf, struct section *sec, +unsigned long arch_dest_rela_offset(int addend) +{ + return addend + 4; +} + +unsigned long arch_jump_destination(struct instruction *insn) +{ + return insn->offset + insn->len + insn->immediate; +} + +#define ADD_OP(op) \ + if (!(op = calloc(1, sizeof(*op)))) \ + return -1; \ + else for (list_add_tail(&op->list, ops_list); op; op = NULL) + +int arch_decode_instruction(const struct elf *elf, const struct section *sec, unsigned long offset, unsigned int maxlen, unsigned int *len, enum insn_type *type, - unsigned long *immediate, struct stack_op *op) + unsigned long *immediate, + struct list_head *ops_list) { struct insn insn; int x86_64, sign; unsigned char op1, op2, rex = 0, rex_b = 0, rex_r = 0, rex_w = 0, rex_x = 0, modrm = 0, modrm_mod = 0, modrm_rm = 0, modrm_reg = 0, sib = 0; + struct stack_op *op = NULL; + struct symbol *sym; x86_64 = is_x86_64(elf); if (x86_64 == -1) @@ -85,7 +104,7 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, insn_get_length(&insn); if (!insn_complete(&insn)) { - WARN_FUNC("can't decode instruction", sec, offset); + WARN("can't decode instruction at %s:0x%lx", sec->name, offset); return -1; } @@ -123,40 +142,44 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, if (rex_w && !rex_b && modrm_mod == 3 && modrm_rm == 4) { /* add/sub reg, %rsp */ - *type = INSN_STACK; - op->src.type = OP_SRC_ADD; - op->src.reg = op_to_cfi_reg[modrm_reg][rex_r]; - op->dest.type = OP_DEST_REG; - op->dest.reg = CFI_SP; + ADD_OP(op) { + op->src.type = OP_SRC_ADD; + op->src.reg = op_to_cfi_reg[modrm_reg][rex_r]; + op->dest.type = OP_DEST_REG; + op->dest.reg = CFI_SP; + } } break; case 0x50 ... 0x57: /* push reg */ - *type = INSN_STACK; - op->src.type = OP_SRC_REG; - op->src.reg = op_to_cfi_reg[op1 & 0x7][rex_b]; - op->dest.type = OP_DEST_PUSH; + ADD_OP(op) { + op->src.type = OP_SRC_REG; + op->src.reg = op_to_cfi_reg[op1 & 0x7][rex_b]; + op->dest.type = OP_DEST_PUSH; + } break; case 0x58 ... 0x5f: /* pop reg */ - *type = INSN_STACK; - op->src.type = OP_SRC_POP; - op->dest.type = OP_DEST_REG; - op->dest.reg = op_to_cfi_reg[op1 & 0x7][rex_b]; + ADD_OP(op) { + op->src.type = OP_SRC_POP; + op->dest.type = OP_DEST_REG; + op->dest.reg = op_to_cfi_reg[op1 & 0x7][rex_b]; + } break; case 0x68: case 0x6a: /* push immediate */ - *type = INSN_STACK; - op->src.type = OP_SRC_CONST; - op->dest.type = OP_DEST_PUSH; + ADD_OP(op) { + op->src.type = OP_SRC_CONST; + op->dest.type = OP_DEST_PUSH; + } break; case 0x70 ... 0x7f: @@ -170,12 +193,13 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, if (modrm == 0xe4) { /* and imm, %rsp */ - *type = INSN_STACK; - op->src.type = OP_SRC_AND; - op->src.reg = CFI_SP; - op->src.offset = insn.immediate.value; - op->dest.type = OP_DEST_REG; - op->dest.reg = CFI_SP; + ADD_OP(op) { + op->src.type = OP_SRC_AND; + op->src.reg = CFI_SP; + op->src.offset = insn.immediate.value; + op->dest.type = OP_DEST_REG; + op->dest.reg = CFI_SP; + } break; } @@ -187,34 +211,37 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, break; /* add/sub imm, %rsp */ - *type = INSN_STACK; - op->src.type = OP_SRC_ADD; - op->src.reg = CFI_SP; - op->src.offset = insn.immediate.value * sign; - op->dest.type = OP_DEST_REG; - op->dest.reg = CFI_SP; + ADD_OP(op) { + op->src.type = OP_SRC_ADD; + op->src.reg = CFI_SP; + op->src.offset = insn.immediate.value * sign; + op->dest.type = OP_DEST_REG; + op->dest.reg = CFI_SP; + } break; case 0x89: if (rex_w && !rex_r && modrm_mod == 3 && modrm_reg == 4) { /* mov %rsp, reg */ - *type = INSN_STACK; - op->src.type = OP_SRC_REG; - op->src.reg = CFI_SP; - op->dest.type = OP_DEST_REG; - op->dest.reg = op_to_cfi_reg[modrm_rm][rex_b]; + ADD_OP(op) { + op->src.type = OP_SRC_REG; + op->src.reg = CFI_SP; + op->dest.type = OP_DEST_REG; + op->dest.reg = op_to_cfi_reg[modrm_rm][rex_b]; + } break; } if (rex_w && !rex_b && modrm_mod == 3 && modrm_rm == 4) { /* mov reg, %rsp */ - *type = INSN_STACK; - op->src.type = OP_SRC_REG; - op->src.reg = op_to_cfi_reg[modrm_reg][rex_r]; - op->dest.type = OP_DEST_REG; - op->dest.reg = CFI_SP; + ADD_OP(op) { + op->src.type = OP_SRC_REG; + op->src.reg = op_to_cfi_reg[modrm_reg][rex_r]; + op->dest.type = OP_DEST_REG; + op->dest.reg = CFI_SP; + } break; } @@ -224,22 +251,24 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, (modrm_mod == 1 || modrm_mod == 2) && modrm_rm == 5) { /* mov reg, disp(%rbp) */ - *type = INSN_STACK; - op->src.type = OP_SRC_REG; - op->src.reg = op_to_cfi_reg[modrm_reg][rex_r]; - op->dest.type = OP_DEST_REG_INDIRECT; - op->dest.reg = CFI_BP; - op->dest.offset = insn.displacement.value; + ADD_OP(op) { + op->src.type = OP_SRC_REG; + op->src.reg = op_to_cfi_reg[modrm_reg][rex_r]; + op->dest.type = OP_DEST_REG_INDIRECT; + op->dest.reg = CFI_BP; + op->dest.offset = insn.displacement.value; + } } else if (rex_w && !rex_b && modrm_rm == 4 && sib == 0x24) { /* mov reg, disp(%rsp) */ - *type = INSN_STACK; - op->src.type = OP_SRC_REG; - op->src.reg = op_to_cfi_reg[modrm_reg][rex_r]; - op->dest.type = OP_DEST_REG_INDIRECT; - op->dest.reg = CFI_SP; - op->dest.offset = insn.displacement.value; + ADD_OP(op) { + op->src.type = OP_SRC_REG; + op->src.reg = op_to_cfi_reg[modrm_reg][rex_r]; + op->dest.type = OP_DEST_REG_INDIRECT; + op->dest.reg = CFI_SP; + op->dest.offset = insn.displacement.value; + } } break; @@ -248,23 +277,25 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, if (rex_w && !rex_b && modrm_mod == 1 && modrm_rm == 5) { /* mov disp(%rbp), reg */ - *type = INSN_STACK; - op->src.type = OP_SRC_REG_INDIRECT; - op->src.reg = CFI_BP; - op->src.offset = insn.displacement.value; - op->dest.type = OP_DEST_REG; - op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r]; + ADD_OP(op) { + op->src.type = OP_SRC_REG_INDIRECT; + op->src.reg = CFI_BP; + op->src.offset = insn.displacement.value; + op->dest.type = OP_DEST_REG; + op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r]; + } } else if (rex_w && !rex_b && sib == 0x24 && modrm_mod != 3 && modrm_rm == 4) { /* mov disp(%rsp), reg */ - *type = INSN_STACK; - op->src.type = OP_SRC_REG_INDIRECT; - op->src.reg = CFI_SP; - op->src.offset = insn.displacement.value; - op->dest.type = OP_DEST_REG; - op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r]; + ADD_OP(op) { + op->src.type = OP_SRC_REG_INDIRECT; + op->src.reg = CFI_SP; + op->src.offset = insn.displacement.value; + op->dest.type = OP_DEST_REG; + op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r]; + } } break; @@ -272,28 +303,30 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, case 0x8d: if (sib == 0x24 && rex_w && !rex_b && !rex_x) { - *type = INSN_STACK; - if (!insn.displacement.value) { - /* lea (%rsp), reg */ - op->src.type = OP_SRC_REG; - } else { - /* lea disp(%rsp), reg */ - op->src.type = OP_SRC_ADD; - op->src.offset = insn.displacement.value; + ADD_OP(op) { + if (!insn.displacement.value) { + /* lea (%rsp), reg */ + op->src.type = OP_SRC_REG; + } else { + /* lea disp(%rsp), reg */ + op->src.type = OP_SRC_ADD; + op->src.offset = insn.displacement.value; + } + op->src.reg = CFI_SP; + op->dest.type = OP_DEST_REG; + op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r]; } - op->src.reg = CFI_SP; - op->dest.type = OP_DEST_REG; - op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r]; } else if (rex == 0x48 && modrm == 0x65) { /* lea disp(%rbp), %rsp */ - *type = INSN_STACK; - op->src.type = OP_SRC_ADD; - op->src.reg = CFI_BP; - op->src.offset = insn.displacement.value; - op->dest.type = OP_DEST_REG; - op->dest.reg = CFI_SP; + ADD_OP(op) { + op->src.type = OP_SRC_ADD; + op->src.reg = CFI_BP; + op->src.offset = insn.displacement.value; + op->dest.type = OP_DEST_REG; + op->dest.reg = CFI_SP; + } } else if (rex == 0x49 && modrm == 0x62 && insn.displacement.value == -8) { @@ -304,12 +337,13 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, * Restoring rsp back to its original value after a * stack realignment. */ - *type = INSN_STACK; - op->src.type = OP_SRC_ADD; - op->src.reg = CFI_R10; - op->src.offset = -8; - op->dest.type = OP_DEST_REG; - op->dest.reg = CFI_SP; + ADD_OP(op) { + op->src.type = OP_SRC_ADD; + op->src.reg = CFI_R10; + op->src.offset = -8; + op->dest.type = OP_DEST_REG; + op->dest.reg = CFI_SP; + } } else if (rex == 0x49 && modrm == 0x65 && insn.displacement.value == -16) { @@ -320,21 +354,23 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, * Restoring rsp back to its original value after a * stack realignment. */ - *type = INSN_STACK; - op->src.type = OP_SRC_ADD; - op->src.reg = CFI_R13; - op->src.offset = -16; - op->dest.type = OP_DEST_REG; - op->dest.reg = CFI_SP; + ADD_OP(op) { + op->src.type = OP_SRC_ADD; + op->src.reg = CFI_R13; + op->src.offset = -16; + op->dest.type = OP_DEST_REG; + op->dest.reg = CFI_SP; + } } break; case 0x8f: /* pop to mem */ - *type = INSN_STACK; - op->src.type = OP_SRC_POP; - op->dest.type = OP_DEST_MEM; + ADD_OP(op) { + op->src.type = OP_SRC_POP; + op->dest.type = OP_DEST_MEM; + } break; case 0x90: @@ -343,16 +379,18 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, case 0x9c: /* pushf */ - *type = INSN_STACK; - op->src.type = OP_SRC_CONST; - op->dest.type = OP_DEST_PUSHF; + ADD_OP(op) { + op->src.type = OP_SRC_CONST; + op->dest.type = OP_DEST_PUSHF; + } break; case 0x9d: /* popf */ - *type = INSN_STACK; - op->src.type = OP_SRC_POPF; - op->dest.type = OP_DEST_MEM; + ADD_OP(op) { + op->src.type = OP_SRC_POPF; + op->dest.type = OP_DEST_MEM; + } break; case 0x0f: @@ -387,16 +425,18 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, } else if (op2 == 0xa0 || op2 == 0xa8) { /* push fs/gs */ - *type = INSN_STACK; - op->src.type = OP_SRC_CONST; - op->dest.type = OP_DEST_PUSH; + ADD_OP(op) { + op->src.type = OP_SRC_CONST; + op->dest.type = OP_DEST_PUSH; + } } else if (op2 == 0xa1 || op2 == 0xa9) { /* pop fs/gs */ - *type = INSN_STACK; - op->src.type = OP_SRC_POP; - op->dest.type = OP_DEST_MEM; + ADD_OP(op) { + op->src.type = OP_SRC_POP; + op->dest.type = OP_DEST_MEM; + } } break; @@ -409,8 +449,8 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, * mov bp, sp * pop bp */ - *type = INSN_STACK; - op->dest.type = OP_DEST_LEAVE; + ADD_OP(op) + op->dest.type = OP_DEST_LEAVE; break; @@ -429,14 +469,41 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, *type = INSN_RETURN; break; + case 0xcf: /* iret */ + /* + * Handle sync_core(), which has an IRET to self. + * All other IRET are in STT_NONE entry code. + */ + sym = find_symbol_containing(sec, offset); + if (sym && sym->type == STT_FUNC) { + ADD_OP(op) { + /* add $40, %rsp */ + op->src.type = OP_SRC_ADD; + op->src.reg = CFI_SP; + op->src.offset = 5*8; + op->dest.type = OP_DEST_REG; + op->dest.reg = CFI_SP; + } + break; + } + + /* fallthrough */ + case 0xca: /* retf */ case 0xcb: /* retf */ - case 0xcf: /* iret */ *type = INSN_CONTEXT_SWITCH; break; case 0xe8: *type = INSN_CALL; + /* + * For the impact on the stack, a CALL behaves like + * a PUSH of an immediate value (the return address). + */ + ADD_OP(op) { + op->src.type = OP_SRC_CONST; + op->dest.type = OP_DEST_PUSH; + } break; case 0xfc: @@ -464,9 +531,10 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, else if (modrm_reg == 6) { /* push from mem */ - *type = INSN_STACK; - op->src.type = OP_SRC_CONST; - op->dest.type = OP_DEST_PUSH; + ADD_OP(op) { + op->src.type = OP_SRC_CONST; + op->dest.type = OP_DEST_PUSH; + } } break; @@ -480,7 +548,7 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, return 0; } -void arch_initial_func_cfi_state(struct cfi_state *state) +void arch_initial_func_cfi_state(struct cfi_init_state *state) { int i; |