From 7d989fcadd6e225a61d6490dd15bdbdfc8a53d5c Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 23 Apr 2020 13:22:10 +0200 Subject: [PATCH] objtool: Rework allocating stack_ops on decode Wrap each stack_op in a macro that allocates and adds it to the list. This simplifies trying to figure out what to do with the pre-allocated stack_op at the end. Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Alexandre Chartre Reviewed-by: Miroslav Benes Acked-by: Josh Poimboeuf Link: https://lkml.kernel.org/r/20200428191659.736151601@infradead.org --- tools/objtool/arch/x86/decode.c | 251 +++++++++++++++++++++++----------------- 1 file changed, 147 insertions(+), 104 deletions(-) diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c index c45a0b4..97e66c7 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -77,6 +77,11 @@ 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, @@ -88,7 +93,7 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, 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; + struct stack_op *op = NULL; x86_64 = is_x86_64(elf); if (x86_64 == -1) @@ -129,10 +134,6 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, if (insn.sib.nbytes) sib = insn.sib.bytes[0]; - op = calloc(1, sizeof(*op)); - if (!op) - return -1; - switch (op1) { case 0x1: @@ -141,10 +142,12 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, /* 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; @@ -152,9 +155,11 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, /* 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; @@ -162,9 +167,11 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, /* 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; @@ -172,8 +179,10 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, 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: @@ -188,11 +197,13 @@ int arch_decode_instruction(const struct elf *elf, const 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; } @@ -205,11 +216,13 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, /* 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: @@ -217,10 +230,12 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, /* 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; } @@ -228,10 +243,12 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, /* 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; } @@ -242,21 +259,25 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, /* 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; @@ -266,22 +287,26 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, /* 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; @@ -290,27 +315,31 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, 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) { @@ -322,11 +351,13 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, * 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) { @@ -338,11 +369,13 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, * 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; @@ -350,8 +383,10 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, 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: @@ -361,15 +396,19 @@ int arch_decode_instruction(const struct elf *elf, const 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: @@ -405,15 +444,19 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, /* 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; @@ -427,7 +470,8 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, * pop bp */ *type = INSN_STACK; - op->dest.type = OP_DEST_LEAVE; + ADD_OP(op) + op->dest.type = OP_DEST_LEAVE; break; @@ -449,12 +493,14 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, case 0xcf: /* iret */ *type = INSN_EXCEPTION_RETURN; - /* 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; + 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; case 0xca: /* retf */ @@ -492,8 +538,10 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, /* 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; @@ -504,11 +552,6 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, *immediate = insn.immediate.nbytes ? insn.immediate.value : 0; - if (*type == INSN_STACK || *type == INSN_EXCEPTION_RETURN) - list_add_tail(&op->list, ops_list); - else - free(op); - return 0; } -- 2.7.4