diff mbox series

[v4,08/34] x86/objtool: teach objtool about ERETU and ERETS

Message ID 20230302052511.1918-9-xin3.li@intel.com
State New
Headers
Series x86: enable FRED for x86-64 |

Commit Message

Li, Xin3 March 2, 2023, 5:24 a.m. UTC 
  From: "H. Peter Anvin (Intel)" <hpa@zytor.com>

Update the objtool decoder to know about the ERETU and ERETS
instructions (type INSN_CONTEXT_SWITCH.)

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Tested-by: Shan Kang <shan.kang@intel.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
---
 tools/objtool/arch/x86/decode.c | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)
diff mbox series

Patch

diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index e7b030f7e2a5..735c909540b5 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -509,12 +509,22 @@  int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 	case 0x0f:
 
 		if (op2 == 0x01) {
-
-			if (modrm == 0xca)
-				*type = INSN_CLAC;
-			else if (modrm == 0xcb)
-				*type = INSN_STAC;
-
+			switch (insn_last_prefix_id(&insn)) {
+			case INAT_PFX_REPE:
+			case INAT_PFX_REPNE:
+				if (modrm == 0xca) {
+					/* eretu/erets */
+					*type = INSN_CONTEXT_SWITCH;
+				}
+				break;
+			default:
+				if (modrm == 0xca) {
+					*type = INSN_CLAC;
+				} else if (modrm == 0xcb) {
+					*type = INSN_STAC;
+				}
+				break;
+			}
 		} else if (op2 >= 0x80 && op2 <= 0x8f) {
 
 			*type = INSN_JUMP_CONDITIONAL;