diff --git a/tools/objtool/arch.h b/tools/objtool/arch.h index 467c2fe798a9..7a111a77b7aa 100644 --- a/tools/objtool/arch.h +++ b/tools/objtool/arch.h @@ -35,7 +35,9 @@ #define INSN_NOP 10 #define INSN_STAC 11 #define INSN_CLAC 12 -#define INSN_OTHER 13 +#define INSN_STD 13 +#define INSN_CLD 14 +#define INSN_OTHER 15 #define INSN_LAST INSN_OTHER enum op_dest_type { diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c index ab20a96fee50..472e991f6512 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -451,6 +451,14 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, *type = INSN_CALL; break; + case 0xfc: + *type = INSN_CLD; + break; + + case 0xfd: + *type = INSN_STD; + break; + case 0xff: if (modrm_reg == 2 || modrm_reg == 3) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 965e954e07f4..38b0517dc49e 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -1903,6 +1903,12 @@ static int validate_call(struct instruction *insn, struct insn_state *state) return 1; } + if (state->df) { + WARN_FUNC("call to %s() with DF set", + insn->sec, insn->offset, insn_dest_name(insn)); + return 1; + } + return 0; } @@ -2044,6 +2050,11 @@ static int validate_branch(struct objtool_file *file, struct instruction *first, return 1; } + if (state.df) { + WARN_FUNC("return with DF set", sec, insn->offset); + return 1; + } + if (func && has_modified_stack_frame(&state)) { WARN_FUNC("return with modified stack frame", sec, insn->offset); @@ -2172,6 +2183,20 @@ static int validate_branch(struct objtool_file *file, struct instruction *first, state.uaccess = false; break; + case INSN_STD: + if (state.df) + WARN_FUNC("recursive STD", sec, insn->offset); + + state.df = true; + break; + + case INSN_CLD: + if (!state.df && insn->func) + WARN_FUNC("redundant CLD", sec, insn->offset); + + state.df = false; + break; + default: break; } diff --git a/tools/objtool/check.h b/tools/objtool/check.h index 78a95d06c165..71e54f97dbcd 100644 --- a/tools/objtool/check.h +++ b/tools/objtool/check.h @@ -31,7 +31,7 @@ struct insn_state { int stack_size; unsigned char type; bool bp_scratch; - bool drap, end, uaccess; + bool drap, end, uaccess, df; unsigned int uaccess_stack; int drap_reg, drap_offset; struct cfi_reg vals[CFI_NUM_REGS];