commit bf0756f3e40d51bf1193549f3b069f39d93551f7
author Mitch Phillips <31459023+hctim@users.noreply.github.com> Mon May 24 16:08:57 2021 -0700
committer Copybara-Service <copybara-worker@google.com> Tue May 25 19:11:40 2021 -0700
tree c736deee3845cc9e711a5778984690de8bbfed36
parent 8b4ce2e00e94c6ff5a71a385a7d86eb6528d5b68

[scudo] Add unmapTestOnly() to secondary.

When trying to track down a vaddr-poisoning bug, I found that that the
secondary cache isn't emptied on test teardown. We should probably do
that to make the tests hermetic. Otherwise, repeating the tests lots of
times using --gtest_repeat fails after the mmap vaddr space is
exhausted.

To repro:
$ ninja check-scudo_standalone # build
$ ./projects/compiler-rt/lib/scudo/standalone/tests/ScudoUnitTest-x86_64-Test \
--gtest_filter=ScudoSecondaryTest.*:-ScudoSecondaryTest.SecondaryCombinations \
--gtest_repeat=10000

Reviewed By: cryptoad

Differential Revision: https://reviews.llvm.org/D102874

GitOrigin-RevId: 1fb6a0307240b0c543ec5babb35e39db2c39052b

combined.h

diff --git a/combined.h b/combined.h
index 8080d67..f17c371 100644
--- a/combined.h
+++ b/combined.h
@@ -215,6 +215,7 @@
   void unmapTestOnly() {
     TSDRegistry.unmapTestOnly();
     Primary.unmapTestOnly();
+    Secondary.unmapTestOnly();
 #ifdef GWP_ASAN_HOOKS
     if (getFlags()->GWP_ASAN_InstallSignalHandlers)
       gwp_asan::segv_handler::uninstallSignalHandlers();

secondary.h

diff --git a/secondary.h b/secondary.h
index 77db873..3894b01 100644
--- a/secondary.h
+++ b/secondary.h
@@ -83,6 +83,7 @@
   void enable() {}
   void releaseToOS() {}
   void disableMemoryTagging() {}
+  void unmapTestOnly() {}
   bool setOption(Option O, UNUSED sptr Value) {
     if (O == Option::ReleaseInterval || O == Option::MaxCacheEntriesCount ||
         O == Option::MaxCacheEntrySize)
@@ -326,6 +327,8 @@
 
   void enable() { Mutex.unlock(); }
 
+  void unmapTestOnly() { empty(); }
+
 private:
   void empty() {
     struct {
@@ -456,6 +459,8 @@
 
   void disableMemoryTagging() { Cache.disableMemoryTagging(); }
 
+  void unmapTestOnly() { Cache.unmapTestOnly(); }
+
 private:
   typename Config::SecondaryCache Cache;
 

tests/secondary_test.cpp

diff --git a/tests/secondary_test.cpp b/tests/secondary_test.cpp
index c50101a..2320a4d 100644
--- a/tests/secondary_test.cpp
+++ b/tests/secondary_test.cpp
@@ -67,6 +67,7 @@
   scudo::ScopedString Str(1024);
   L->getStats(&Str);
   Str.output();
+  L->unmapTestOnly();
 }
 
 struct NoCacheConfig {
@@ -124,6 +125,7 @@
   scudo::ScopedString Str(1024);
   L->getStats(&Str);
   Str.output();
+  L->unmapTestOnly();
 }
 
 TEST(ScudoSecondaryTest, SecondaryIterate) {
@@ -147,6 +149,7 @@
   scudo::ScopedString Str(1024);
   L->getStats(&Str);
   Str.output();
+  L->unmapTestOnly();
 }
 
 TEST(ScudoSecondaryTest, SecondaryOptions) {
@@ -170,6 +173,7 @@
     EXPECT_TRUE(L->setOption(scudo::Option::MaxCacheEntrySize, 1UL << 20));
     EXPECT_TRUE(L->canCache(1UL << 16));
   }
+  L->unmapTestOnly();
 }
 
 static std::mutex Mutex;
@@ -216,4 +220,5 @@
   scudo::ScopedString Str(1024);
   L->getStats(&Str);
   Str.output();
+  L->unmapTestOnly();
 }