From df0778dc9eb9f15c9270ba1a09d475253018e824 Mon Sep 17 00:00:00 2001
From: Filip Navara <filip.navara@gmail.com>
Date: Sat, 3 Feb 2024 01:19:35 +0100
Subject: [PATCH] Initialize R12 pointer from context in StackFrameIterator
 (#97903)

---
 src/coreclr/nativeaot/Runtime/StackFrameIterator.cpp | 2 +-
 src/coreclr/nativeaot/Runtime/unix/UnixContext.cpp   | 2 ++
 src/coreclr/nativeaot/Runtime/unix/UnixContext.h     | 2 ++
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/coreclr/nativeaot/Runtime/StackFrameIterator.cpp b/src/coreclr/nativeaot/Runtime/StackFrameIterator.cpp
index 117c31fb99a99..bd83b0ac3dbf1 100644
--- a/src/coreclr/nativeaot/Runtime/StackFrameIterator.cpp
+++ b/src/coreclr/nativeaot/Runtime/StackFrameIterator.cpp
@@ -186,7 +186,6 @@ void StackFrameIterator::InternalInit(Thread * pThreadToWalk, PInvokeTransitionF
 
 #ifdef TARGET_ARM
     m_RegDisplay.pLR = (PTR_UIntNative)PTR_HOST_MEMBER(PInvokeTransitionFrame, pFrame, m_RIP);
-    m_RegDisplay.pR11 = (PTR_UIntNative)PTR_HOST_MEMBER(PInvokeTransitionFrame, pFrame, m_ChainPointer);
 
     if (pFrame->m_Flags & PTFF_SAVE_R4)  { m_RegDisplay.pR4 = pPreservedRegsCursor++; }
     if (pFrame->m_Flags & PTFF_SAVE_R5)  { m_RegDisplay.pR5 = pPreservedRegsCursor++; }
@@ -632,6 +631,7 @@ void StackFrameIterator::InternalInit(Thread * pThreadToWalk, NATIVE_CONTEXT* pC
     m_RegDisplay.pR9 = (PTR_UIntNative)PTR_TO_REG(pCtx, R9);
     m_RegDisplay.pR10 = (PTR_UIntNative)PTR_TO_REG(pCtx, R10);
     m_RegDisplay.pR11 = (PTR_UIntNative)PTR_TO_REG(pCtx, R11);
+    m_RegDisplay.pR12 = (PTR_UIntNative)PTR_TO_REG(pCtx, R12);
     m_RegDisplay.pLR = (PTR_UIntNative)PTR_TO_REG(pCtx, Lr);
 #else
     PORTABILITY_ASSERT("StackFrameIterator::InternalInit");
diff --git a/src/coreclr/nativeaot/Runtime/unix/UnixContext.cpp b/src/coreclr/nativeaot/Runtime/unix/UnixContext.cpp
index 4087e2ae6ac4f..8e587901f60a3 100644
--- a/src/coreclr/nativeaot/Runtime/unix/UnixContext.cpp
+++ b/src/coreclr/nativeaot/Runtime/unix/UnixContext.cpp
@@ -266,6 +266,7 @@
 #define MCREG_R9(mc)        ((mc).arm_r9)
 #define MCREG_R10(mc)       ((mc).arm_r10)
 #define MCREG_R11(mc)       ((mc).arm_fp)
+#define MCREG_R12(mc)       ((mc).arm_ip)
 
 #elif defined(HOST_X86)
 
@@ -526,6 +527,7 @@ uint64_t GetPC(void* context)
     uint64_t& UNIX_CONTEXT::R9(){ return (uint64_t&)MCREG_R9(ctx.uc_mcontext); }
     uint64_t& UNIX_CONTEXT::R10(){ return (uint64_t&)MCREG_R10(ctx.uc_mcontext); }
     uint64_t& UNIX_CONTEXT::R11(){ return (uint64_t&)MCREG_R11(ctx.uc_mcontext); }
+    uint64_t& UNIX_CONTEXT::R12(){ return (uint64_t&)MCREG_R12(ctx.uc_mcontext); }
 
 #else
     PORTABILITY_ASSERT("UNIX_CONTEXT");
diff --git a/src/coreclr/nativeaot/Runtime/unix/UnixContext.h b/src/coreclr/nativeaot/Runtime/unix/UnixContext.h
index 471f395bef1f5..caddff419d373 100644
--- a/src/coreclr/nativeaot/Runtime/unix/UnixContext.h
+++ b/src/coreclr/nativeaot/Runtime/unix/UnixContext.h
@@ -136,6 +136,7 @@ struct UNIX_CONTEXT
     uint64_t& R9();
     uint64_t& R10();
     uint64_t& R11();
+    uint64_t& R12();
 
     uintptr_t GetIp() { return (uintptr_t)Pc(); }
     uintptr_t GetSp() { return (uintptr_t)Sp(); }
@@ -155,6 +156,7 @@ struct UNIX_CONTEXT
         lambda((size_t*)&R9());
         lambda((size_t*)&R10());
         lambda((size_t*)&R11());
+        lambda((size_t*)&R12());
     }
 #else
     PORTABILITY_ASSERT("UNIX_CONTEXT");