Split Mprotect into MmapNoAccess and MprotectNoAccess to be more portable

On Windows, we have to know if a memory to be protected is mapped or not.
On POSIX, Mprotect was semantically different from mprotect most people know.

llvm-svn: 234602

1 files changed, 7 insertions, 1 deletions

diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_win.cc b/compiler-rt/lib/sanitizer_common/sanitizer_win.cc
index c081daa4c60..e5e2f643eb8 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_win.cc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_win.cc
@@ -125,7 +125,7 @@ void *MmapNoReserveOrDie(uptr size, const char *mem_type) {
   return MmapOrDie(size, mem_type);
 }
 
-void *Mprotect(uptr fixed_addr, uptr size) {
+void *MmapNoAccess(uptr fixed_addr, uptr size) {
   void *res = VirtualAlloc((LPVOID)fixed_addr, size,
                            MEM_RESERVE | MEM_COMMIT, PAGE_NOACCESS);
   if (res == 0)
@@ -135,6 +135,12 @@ void *Mprotect(uptr fixed_addr, uptr size) {
   return res;
 }
 
+bool MprotectNoAccess(uptr addr, uptr size) {
+  DWORD old_protection;
+  return VirtualProtect((LPVOID)addr, size, PAGE_NOACCESS, &old_protection);
+}
+
+
 void FlushUnneededShadowMemory(uptr addr, uptr size) {
   // This is almost useless on 32-bits.
   // FIXME: add madvise-analog when we move to 64-bits.