The following commit has been merged into the objtool/core branch of tip: Commit-ID: 7e1b2eb05787d1c7f18445b7cfdfc612e827ca7b Gitweb: https://git.kernel.org/tip/7e1b2eb05787d1c7f18445b7cfdfc612e827ca7b Author: Peter Zijlstra <pet...@infradead.org> AuthorDate: Fri, 12 Feb 2021 09:13:00 +01:00 Committer: Peter Zijlstra <pet...@infradead.org> CommitterDate: Wed, 03 Mar 2021 09:38:31 +01:00
objtool,x86: More ModRM sugar Better helpers to decode ModRM. Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Acked-by: Josh Poimboeuf <jpoim...@redhat.com> Link: https://lkml.kernel.org/r/YCZB/ljatfxqq...@hirez.programming.kicks-ass.net --- tools/objtool/arch/x86/decode.c | 28 +++++++++++++++++----------- 1 file changed, 17 insertions(+), 11 deletions(-) diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c index b42e5ec..431bafb 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -82,15 +82,21 @@ unsigned long arch_jump_destination(struct instruction *insn) * 01 | [r/m + d8] |[S+d]| [r/m + d8] | * 10 | [r/m + d32] |[S+D]| [r/m + d32] | * 11 | r/ m | - * */ + +#define mod_is_mem() (modrm_mod != 3) +#define mod_is_reg() (modrm_mod == 3) + #define is_RIP() ((modrm_rm & 7) == CFI_BP && modrm_mod == 0) -#define have_SIB() ((modrm_rm & 7) == CFI_SP && modrm_mod != 3) +#define have_SIB() ((modrm_rm & 7) == CFI_SP && mod_is_mem()) #define rm_is(reg) (have_SIB() ? \ sib_base == (reg) && sib_index == CFI_SP : \ modrm_rm == (reg)) +#define rm_is_mem(reg) (mod_is_mem() && !is_RIP() && rm_is(reg)) +#define rm_is_reg(reg) (mod_is_reg() && modrm_rm == (reg)) + 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, @@ -154,7 +160,7 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, case 0x1: case 0x29: - if (rex_w && modrm_mod == 3 && modrm_rm == CFI_SP) { + if (rex_w && rm_is_reg(CFI_SP)) { /* add/sub reg, %rsp */ ADD_OP(op) { @@ -219,7 +225,7 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, break; /* %rsp target only */ - if (!(modrm_mod == 3 && modrm_rm == CFI_SP)) + if (!rm_is_reg(CFI_SP)) break; imm = insn.immediate.value; @@ -272,7 +278,7 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, if (modrm_reg == CFI_SP) { - if (modrm_mod == 3) { + if (mod_is_reg()) { /* mov %rsp, reg */ ADD_OP(op) { op->src.type = OP_SRC_REG; @@ -308,7 +314,7 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, break; } - if (modrm_mod == 3 && modrm_rm == CFI_SP) { + if (rm_is_reg(CFI_SP)) { /* mov reg, %rsp */ ADD_OP(op) { @@ -325,7 +331,7 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, if (!rex_w) break; - if ((modrm_mod == 1 || modrm_mod == 2) && modrm_rm == CFI_BP) { + if (rm_is_mem(CFI_BP)) { /* mov reg, disp(%rbp) */ ADD_OP(op) { @@ -338,7 +344,7 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, break; } - if (modrm_mod != 3 && rm_is(CFI_SP)) { + if (rm_is_mem(CFI_SP)) { /* mov reg, disp(%rsp) */ ADD_OP(op) { @@ -357,7 +363,7 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, if (!rex_w) break; - if ((modrm_mod == 1 || modrm_mod == 2) && modrm_rm == CFI_BP) { + if (rm_is_mem(CFI_BP)) { /* mov disp(%rbp), reg */ ADD_OP(op) { @@ -370,7 +376,7 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, break; } - if (modrm_mod != 3 && rm_is(CFI_SP)) { + if (rm_is_mem(CFI_SP)) { /* mov disp(%rsp), reg */ ADD_OP(op) { @@ -386,7 +392,7 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, break; case 0x8d: - if (modrm_mod == 3) { + if (mod_is_reg()) { WARN("invalid LEA encoding at %s:0x%lx", sec->name, offset); break; }
