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-rw-r--r--tools/objtool/arch.h1
-rw-r--r--tools/objtool/arch/x86/decode.c14
-rw-r--r--tools/objtool/check.c29
3 files changed, 29 insertions, 15 deletions
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",