[ASan][windows] Recognize movzx r11d, BYTE PTR [rdx] in interception_win

[glandium]

The instruction is present in some library in the 24H2 update for Windows 11:

==8508==interception_win: unhandled instruction at 0x7ff83e193a40: 44 0f b6 1a 4c 8b d2 48

This could be generalized, but getting all the ModR/M byte combinations right is tricky. Many other classes of instructions handled in this file could use some generalization too.

[llvmbot]

@llvm/pr-subscribers-compiler-rt-sanitizer

Author: Mike Hommey (glandium)

Changes

The instruction is present in some library in the 24H2 update for Windows 11:

==8508==interception_win: unhandled instruction at 0x7ff83e193a40: 44 0f b6 1a 4c 8b d2 48

This could be generalized, but getting all the ModR/M byte combinations right is tricky. Many other classes of instructions handled in this file could use some generalization too.

---

Full diff: https://github.com/llvm/llvm-project/pull/111638.diff

1 Files Affected:

• (modified) compiler-rt/lib/interception/interception_win.cpp (+1)

diff --git a/compiler-rt/lib/interception/interception_win.cpp b/compiler-rt/lib/interception/interception_win.cpp
index 4a6ff6656edb1c..4f60d4251303d6 100644
--- a/compiler-rt/lib/interception/interception_win.cpp
+++ b/compiler-rt/lib/interception/interception_win.cpp
@@ -768,6 +768,7 @@ static size_t GetInstructionSize(uptr address, size_t* rel_offset = nullptr) {
   }
 
   switch (*(u32*)(address)) {
+    case 0x1ab60f44:  // 44 0f b6 1a : movzx r11d, BYTE PTR [rdx]
     case 0x24448b48:  // 48 8b 44 24 XX : mov rax, QWORD ptr [rsp + XX]
     case 0x246c8948:  // 48 89 6C 24 XX : mov QWORD ptr [rsp + XX], rbp
     case 0x245c8948:  // 48 89 5c 24 XX : mov QWORD PTR [rsp + XX], rbx

[glandium]

@rnk Could you take a look at this and merge it?

[serge-sans-paille]

@rnk approved it let's merge it then.

[bernhardu]

Hello, I am trying to prepare a patch to add more instructions to interception_win.
During this I wondered because this instruction "44 0f b6 1a" returns now 5,
but shouldn't it return 4?

[zmodem]

Hello, I am trying to prepare a patch to add more instructions to interception_win. During this I wondered because this instruction "44 0f b6 1a" returns now 5, but shouldn't it return 4?

You're right, it should be 4. I'll commit a fix.

Please CC me on your upcoming patch, I'd be happy to review it.