ARM/THUMB PC Least Bit Set for Range Check

Fix #4859

Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

diff --git a/src/pal/src/thread/context.cpp b/src/pal/src/thread/context.cpp
index 384c7c8..d644e0d 100644 (file)
--- a/src/pal/src/thread/context.cpp
+++ b/src/pal/src/thread/context.cpp
@@ -488,6 +488,12 @@ void CONTEXTFromNativeContext(const native_context_t *native, LPCONTEXT lpContex
     if ((contextFlags & CONTEXT_CONTROL) == CONTEXT_CONTROL)
     {
         ASSIGN_CONTROL_REGS
+#ifdef _ARM_
+        // WinContext assumes that the least bit of Pc is always 1 (denoting thumb)
+        // although the pc value retrived from native context might not have set the least bit.
+        // This becomes especially problematic if the context is on the JIT_WRITEBARRIER.
+        lpContext->Pc |= 0x1;
+#endif
     }
 
     if ((contextFlags & CONTEXT_INTEGER) == CONTEXT_INTEGER)