diff options
| -rw-r--r-- | arch/x86/include/asm/processor.h | 2 | ||||
| -rw-r--r-- | tools/objtool/arch.h | 1 | ||||
| -rw-r--r-- | tools/objtool/arch/x86/decode.c | 14 | ||||
| -rw-r--r-- | tools/objtool/check.c | 29 |
4 files changed, 29 insertions, 17 deletions
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 3bcf27caf6c9..3eeaaeb75638 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -727,7 +727,6 @@ static inline void sync_core(void) unsigned int tmp; asm volatile ( - UNWIND_HINT_SAVE "mov %%ss, %0\n\t" "pushq %q0\n\t" "pushq %%rsp\n\t" @@ -737,7 +736,6 @@ static inline void sync_core(void) "pushq %q0\n\t" "pushq $1f\n\t" "iretq\n\t" - UNWIND_HINT_RESTORE "1:" : "=&r" (tmp), ASM_CALL_CONSTRAINT : : "cc", "memory"); #endif diff --git a/tools/objtool/arch.h b/tools/objtool/arch.h index f9883c431949..55396dfe0d07 100644 --- a/tools/objtool/arch.h +++ b/tools/objtool/arch.h @@ -19,6 +19,7 @@ enum insn_type { INSN_CALL, INSN_CALL_DYNAMIC, INSN_RETURN, + INSN_EXCEPTION_RETURN, INSN_CONTEXT_SWITCH, INSN_STACK, INSN_BUG, diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c index 199b4084a13c..32736383ead1 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -446,9 +446,19 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, *type = INSN_RETURN; break; + 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; + break; + case 0xca: /* retf */ case 0xcb: /* retf */ - case 0xcf: /* iret */ *type = INSN_CONTEXT_SWITCH; break; @@ -494,7 +504,7 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, *immediate = insn.immediate.nbytes ? insn.immediate.value : 0; - if (*type == INSN_STACK) + if (*type == INSN_STACK || *type == INSN_EXCEPTION_RETURN) list_add_tail(&op->list, ops_list); else free(op); diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 9e854fd128d4..781b3a3c2ba6 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -2065,15 +2065,14 @@ static int validate_return(struct symbol *func, struct instruction *insn, struct * tools/objtool/Documentation/stack-validation.txt. */ static int validate_branch(struct objtool_file *file, struct symbol *func, - struct instruction *first, struct insn_state state) + struct instruction *insn, struct insn_state state) { struct alternative *alt; - struct instruction *insn, *next_insn; + struct instruction *next_insn; struct section *sec; u8 visited; int ret; - insn = first; sec = insn->sec; if (insn->alt_group && list_empty(&insn->alts)) { @@ -2126,16 +2125,6 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, } if (!save_insn->visited) { - /* - * Oops, no state to copy yet. - * Hopefully we can reach this - * instruction from another branch - * after the save insn has been - * visited. - */ - if (insn == first) - return 0; - WARN_FUNC("objtool isn't smart enough to handle this CFI save/restore combo", sec, insn->offset); return 1; @@ -2228,6 +2217,20 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, break; + case INSN_EXCEPTION_RETURN: + if (handle_insn_ops(insn, &state)) + return 1; + + /* + * This handles x86's sync_core() case, where we use an + * IRET to self. All 'normal' IRET instructions are in + * STT_NOTYPE entry symbols. + */ + if (func) + break; + + return 0; + case INSN_CONTEXT_SWITCH: if (func && (!next_insn || !next_insn->hint)) { WARN_FUNC("unsupported instruction in callable function", |