From eac51dc1b6eb89e00ed2294e39949ad056287d1e Mon Sep 17 00:00:00 2001
From: Wim Taymans <wtaymans@redhat.com>
Date: Fri, 19 Jul 2019 16:18:04 +0200
Subject: [PATCH] x86: add endbr32 and endbr64 instructions

Issue endbr instructions at the start of generated functions to
make IBT (indirect branch tracking) work.

Resolves #17
---
 orc/orcx86.c     | 4 ++++
 orc/orcx86insn.c | 2 ++
 orc/orcx86insn.h | 2 ++
 3 files changed, 8 insertions(+)

diff --git a/orc/orcx86.c b/orc/orcx86.c
index 02e6b34..d4cc086 100644
--- a/orc/orcx86.c
+++ b/orc/orcx86.c
@@ -452,6 +452,9 @@ orc_x86_emit_prologue (OrcCompiler *compiler)
   orc_compiler_append_code(compiler,"%s:\n", compiler->program->name);
   if (compiler->is_64bit) {
     int i;
+
+    orc_x86_emit_cpuinsn_none (compiler, ORC_X86_endbr64);
+
     for(i=0;i<16;i++){
       if (compiler->used_regs[ORC_GP_REG_BASE+i] &&
           compiler->save_regs[ORC_GP_REG_BASE+i]) {
@@ -459,6 +462,7 @@ orc_x86_emit_prologue (OrcCompiler *compiler)
       }
     }
   } else {
+    orc_x86_emit_cpuinsn_none (compiler, ORC_X86_endbr32);
     orc_x86_emit_push (compiler, 4, X86_EBP);
     if (compiler->use_frame_pointer) {
       orc_x86_emit_mov_reg_reg (compiler, 4, X86_ESP, X86_EBP);
diff --git a/orc/orcx86insn.c b/orc/orcx86insn.c
index 9d93197..a9bdd9f 100644
--- a/orc/orcx86insn.c
+++ b/orc/orcx86insn.c
@@ -254,6 +254,8 @@ static const OrcSysOpcode orc_x86_opcodes[] = {
   { "pshufw", ORC_X86_INSN_TYPE_IMM8_MMXM_MMX, 0, 0x00, 0x0f70 },
   { "movq", ORC_X86_INSN_TYPE_MMXM_MMX, 0, 0x00, 0x0f6f },
   { "movq", ORC_X86_INSN_TYPE_MMXM_MMX_REV, 0, 0x00, 0x0f7f },
+  { "endbr32", ORC_X86_INSN_TYPE_NONE, 0, 0xf3, 0x0f1efb },
+  { "endbr64", ORC_X86_INSN_TYPE_NONE, 0, 0xf3, 0x0f1efa },
 };
 
 static void
diff --git a/orc/orcx86insn.h b/orc/orcx86insn.h
index d109c95..864e5d6 100644
--- a/orc/orcx86insn.h
+++ b/orc/orcx86insn.h
@@ -277,6 +277,8 @@ typedef enum {
   ORC_X86_pshufw,
   ORC_X86_movq_mmx_load,
   ORC_X86_movq_mmx_store,
+  ORC_X86_endbr32,
+  ORC_X86_endbr64,
 } OrcX86Opcode;
 
 enum {
-- 
2.21.0