[MTE] Fix tests after crrev.com/c/4495526

crrev.com/c/4495526 broke tests because it disabled MTE when tests were expecting sync MTE.

(cherry picked from commit a413841)

Bug: 1448009
Change-Id: Ifabb91c37a885920860b1116ed9dd5b7be699c75
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4570311
Reviewed-by: Bartek Nowierski <bartekn@chromium.org>
Commit-Queue: Keishi Hattori <keishi@chromium.org>
Cr-Original-Commit-Position: refs/heads/main@{#1151240}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4597036
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/branch-heads/5790@{#438}
Cr-Branched-From: 1d71a33-refs/heads/main@{#1148114}

base/allocator/partition_alloc_support.cc

@@ -1175,34 +1175,42 @@ void PartitionAllocSupport::ReconfigureAfterFeatureListInit(
                 .Get()
           : base::features::AlternateBucketDistributionMode::kDefault;
 
+  bool enable_memory_tagging = false;
 #if PA_CONFIG(HAS_MEMORY_TAGGING)
-  bool enable_memory_tagging = ShouldEnableMemoryTagging(process_type);
+  // If synchronous mode is enabled from startup it means this is a test and
+  // memory tagging should be enabled.
+  if (partition_alloc::internal::GetMemoryTaggingModeForCurrentThread() ==
+      partition_alloc::TagViolationReportingMode::kSynchronous) {
+    enable_memory_tagging = true;
+  } else {
+    enable_memory_tagging = ShouldEnableMemoryTagging(process_type);
 #if BUILDFLAG(IS_ANDROID)
-  if (enable_memory_tagging) {
-    partition_alloc::TagViolationReportingMode reporting_mode;
-    switch (base::features::kMemtagModeParam.Get()) {
-      case base::features::MemtagMode::kSync:
-        reporting_mode =
-            partition_alloc::TagViolationReportingMode::kSynchronous;
-        break;
-      case base::features::MemtagMode::kAsync:
-        reporting_mode =
-            partition_alloc::TagViolationReportingMode::kAsynchronous;
-        break;
+    if (enable_memory_tagging) {
+      partition_alloc::TagViolationReportingMode reporting_mode;
+      switch (base::features::kMemtagModeParam.Get()) {
+        case base::features::MemtagMode::kSync:
+          reporting_mode =
+              partition_alloc::TagViolationReportingMode::kSynchronous;
+          break;
+        case base::features::MemtagMode::kAsync:
+          reporting_mode =
+              partition_alloc::TagViolationReportingMode::kAsynchronous;
+          break;
+      }
+      partition_alloc::internal::ChangeMemoryTaggingModeForAllThreadsPerProcess(
+          reporting_mode);
+      CHECK_EQ(
+          partition_alloc::internal::GetMemoryTaggingModeForCurrentThread(),
+          reporting_mode);
+    } else if (base::CPU::GetInstanceNoAllocation().has_mte()) {
+      partition_alloc::internal::ChangeMemoryTaggingModeForAllThreadsPerProcess(
+          partition_alloc::TagViolationReportingMode::kDisabled);
+      CHECK_EQ(
+          partition_alloc::internal::GetMemoryTaggingModeForCurrentThread(),
+          partition_alloc::TagViolationReportingMode::kDisabled);
     }
-    partition_alloc::internal::ChangeMemoryTaggingModeForAllThreadsPerProcess(
-        reporting_mode);
-    CHECK_EQ(partition_alloc::internal::GetMemoryTaggingModeForCurrentThread(),
-             reporting_mode);
-  } else if (base::CPU::GetInstanceNoAllocation().has_mte()) {
-    partition_alloc::internal::ChangeMemoryTaggingModeForAllThreadsPerProcess(
-        partition_alloc::TagViolationReportingMode::kDisabled);
-    CHECK_EQ(partition_alloc::internal::GetMemoryTaggingModeForCurrentThread(),
-             partition_alloc::TagViolationReportingMode::kDisabled);
-  }
 #endif  // BUILDFLAG(IS_ANDROID)
-#else   // PA_CONFIG(HAS_MEMORY_TAGGING)
-  bool enable_memory_tagging = false;
+  }
 #endif  // PA_CONFIG(HAS_MEMORY_TAGGING)
 
   allocator_shim::ConfigurePartitions(

base/allocator/partition_allocator/pointers/raw_ptr_unittest.cc

@@ -1510,18 +1510,21 @@ void HandleOOM(size_t unused_size) {
   LOG(FATAL) << "Out of memory";
 }
 
-static constexpr partition_alloc::PartitionOptions kOpts = {
-    .cookie = partition_alloc::PartitionOptions::Cookie::kAllowed,
-    .backup_ref_ptr = partition_alloc::PartitionOptions::BackupRefPtr::kEnabled,
-};
-
 class BackupRefPtrTest : public testing::Test {
  protected:
   void SetUp() override {
     // TODO(bartekn): Avoid using PartitionAlloc API directly. Switch to
     // new/delete once PartitionAlloc Everywhere is fully enabled.
     partition_alloc::PartitionAllocGlobalInit(HandleOOM);
-    allocator_.init(kOpts);
+    allocator_.init(
+        {.cookie = partition_alloc::PartitionOptions::Cookie::kAllowed,
+         .backup_ref_ptr =
+             partition_alloc::PartitionOptions::BackupRefPtr::kEnabled,
+         .memory_tagging =
+             base::CPU::GetInstanceNoAllocation().has_mte()
+                 ? partition_alloc::PartitionOptions::MemoryTagging::kEnabled
+                 : partition_alloc::PartitionOptions::MemoryTagging::
+                       kDisabled});
   }
 
   partition_alloc::PartitionAllocator allocator_;

base/allocator/partition_allocator/starscan/pcscan_unittest.cc

@@ -59,7 +59,10 @@ class PartitionAllocPCScanTestBase : public testing::Test {
     allocator_.init(PartitionOptions{
         .aligned_alloc = PartitionOptions::AlignedAlloc::kAllowed,
         .quarantine = PartitionOptions::Quarantine::kAllowed,
-    });
+        .memory_tagging =
+            base::CPU::GetInstanceNoAllocation().has_mte()
+                ? partition_alloc::PartitionOptions::MemoryTagging::kEnabled
+                : partition_alloc::PartitionOptions::MemoryTagging::kDisabled});
     allocator_.root()->UncapEmptySlotSpanMemoryForTesting();
     allocator_.root()->SwitchToDenserBucketDistribution();