Landing: Write protect executable pages in the VM.

runtime/vm/virtual_memory_win.cc

Index: runtime/vm/virtual_memory_win.cc
===================================================================
--- runtime/vm/virtual_memory_win.cc	(revision 31654)
+++ runtime/vm/virtual_memory_win.cc	(working copy)
@@ -63,7 +63,10 @@
 }
 
 
-bool VirtualMemory::Protect(Protection mode) {
+bool VirtualMemory::Protect(void* address, intptr_t size, Protection mode) {
+  uword start_address = reinterpret_cast<uword>(address);
+  uword end_address = start_address + size;
+  uword page_address = start_address & ~(PageSize() - 1);
   DWORD prot = 0;
   switch (mode) {
     case kNoAccess:
@@ -83,7 +86,10 @@
       break;
   }
   DWORD old_prot = 0;
-  return VirtualProtect(address(), size(), prot, &old_prot);
+  return VirtualProtect(reinterpret_cast<void*>(address),

[Florian Schneider, 2014/01/16 13:12:39]

s/address/page_address/

+                        end_address - page_address,

[Florian Schneider, 2014/01/16 13:12:39]

Or s/page_address/address/.

+                        prot,
+                        &old_prot);
 }
 
 }  // namespace dart