From 78e70cee0d46bb14dcbedec993fbf855a4d13266 Mon Sep 17 00:00:00 2001
From: Vitaly Buka <vitalybuka@google.com>
Date: Wed, 30 Jun 2021 23:39:12 -0700
Subject: [PATCH] [scudo] Remove false DCHECK

MTE Cache.store passes MAP_NOACCESS here.

Reviewed By: pcc, cryptoad

Differential Revision: https://reviews.llvm.org/D105266
---
 compiler-rt/lib/scudo/standalone/linux.cpp                | 5 +----
 compiler-rt/lib/scudo/standalone/tests/secondary_test.cpp | 7 ++++++-
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/compiler-rt/lib/scudo/standalone/linux.cpp b/compiler-rt/lib/scudo/standalone/linux.cpp
index dedab61631bc..c77c1bb600d9 100644
--- a/compiler-rt/lib/scudo/standalone/linux.cpp
+++ b/compiler-rt/lib/scudo/standalone/linux.cpp
@@ -58,11 +58,8 @@ void *map(void *Addr, uptr Size, UNUSED const char *Name, uptr Flags,
   if (Flags & MAP_MEMTAG)
     MmapProt |= PROT_MTE;
 #endif
-  if (Addr) {
-    // Currently no scenario for a noaccess mapping with a fixed address.
-    DCHECK_EQ(Flags & MAP_NOACCESS, 0);
+  if (Addr)
     MmapFlags |= MAP_FIXED;
-  }
   void *P = mmap(Addr, Size, MmapProt, MmapFlags, -1, 0);
   if (P == MAP_FAILED) {
     if (!(Flags & MAP_ALLOWNOMEM) || errno != ENOMEM)
diff --git a/compiler-rt/lib/scudo/standalone/tests/secondary_test.cpp b/compiler-rt/lib/scudo/standalone/tests/secondary_test.cpp
index 6b8a60d386b8..d3b7c486f7c3 100644
--- a/compiler-rt/lib/scudo/standalone/tests/secondary_test.cpp
+++ b/compiler-rt/lib/scudo/standalone/tests/secondary_test.cpp
@@ -6,6 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "memtag.h"
 #include "tests/scudo_unit_test.h"
 
 #include "allocator_config.h"
@@ -20,7 +21,11 @@
 #include <vector>
 
 template <typename Config> static scudo::Options getOptionsForConfig() {
-  return {};
+  if (!Config::MaySupportMemoryTagging || !scudo::archSupportsMemoryTagging())
+    return {};
+  scudo::AtomicOptions AO;
+  AO.set(scudo::OptionBit::UseMemoryTagging);
+  return AO.load();
 }
 
 template <typename Config> static void testSecondaryBasic(void) {