[RFC PATCH v4 06/37] objtool: arm64: Decode jump and call related instructions

[Chen Zhongjin <chenzhongjin@huawei.com>]

From: Julien Thierry <jthierry@redhat.com>

Decode branch, branch and link (aarch64's call) and return instructions.

Signed-off-by: Julien Thierry <jthierry@redhat.com>
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
---
 tools/objtool/arch/arm64/decode.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/tools/objtool/arch/arm64/decode.c b/tools/objtool/arch/arm64/decode.c
index 84daec62006a..351f8b1bbd6d 100644
--- a/tools/objtool/arch/arm64/decode.c
+++ b/tools/objtool/arch/arm64/decode.c
@@ -219,6 +219,27 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 			}
 		}
 		break;
+	case AARCH64_INSN_CLS_BR_SYS:
+		if (aarch64_insn_is_ret(insn) &&
+		    aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RN, insn)
+			== AARCH64_INSN_REG_LR) {
+			*type = INSN_RETURN;
+		} else if (aarch64_insn_is_bl(insn)) {
+			*type = INSN_CALL;
+			*immediate = aarch64_get_branch_offset(insn);
+		} else if (aarch64_insn_is_blr(insn)) {
+			*type = INSN_CALL_DYNAMIC;
+		} else if (aarch64_insn_is_b(insn)) {
+			*type = INSN_JUMP_UNCONDITIONAL;
+			*immediate = aarch64_get_branch_offset(insn);
+		} else if (aarch64_insn_is_br(insn)) {
+			*type = INSN_JUMP_DYNAMIC;
+		} else if (aarch64_insn_is_branch_imm(insn)) {
+			/* Remaining branch opcodes are conditional */
+			*type = INSN_JUMP_CONDITIONAL;
+			*immediate = aarch64_get_branch_offset(insn);
+		}
+		break;
 	default:
 		break;
 	}
-- 
2.17.1