[llvm-branch-commits] [compiler-rt] e22d802 - scudo: Adjust test to use correct check for primary allocations.

[Peter Collingbourne via llvm-branch-commits]

Author: Peter Collingbourne
Date: 2020-12-17T10:42:17-08:00
New Revision: e22d802e587b8954748e2b2193195a946ba105e8

URL: https://github.com/llvm/llvm-project/commit/e22d802e587b8954748e2b2193195a946ba105e8
DIFF: https://github.com/llvm/llvm-project/commit/e22d802e587b8954748e2b2193195a946ba105e8.diff

LOG: scudo: Adjust test to use correct check for primary allocations.

canAllocate() does not take into account the header size so it does
not return the right answer in borderline cases. There was already
code handling this correctly in isTaggedAllocation() so split it out
into a separate function and call it from the test.

Furthermore the test was incorrect when MTE is enabled because MTE
does not pattern fill primary allocations. Fix it.

Differential Revision: https://reviews.llvm.org/D93437

Added: 
    

Modified: 
    compiler-rt/lib/scudo/standalone/tests/combined_test.cpp

Removed: 
    


################################################################################
diff  --git a/compiler-rt/lib/scudo/standalone/tests/combined_test.cpp b/compiler-rt/lib/scudo/standalone/tests/combined_test.cpp
index 7df4594246a6..b0ab0244e877 100644
--- a/compiler-rt/lib/scudo/standalone/tests/combined_test.cpp
+++ b/compiler-rt/lib/scudo/standalone/tests/combined_test.cpp
@@ -34,12 +34,7 @@ UNUSED static void disableDebuggerdMaybe() {
 }
 
 template <class AllocatorT>
-bool isTaggedAllocation(AllocatorT *Allocator, scudo::uptr Size,
-                        scudo::uptr Alignment) {
-  if (!Allocator->useMemoryTagging() ||
-      !scudo::systemDetectsMemoryTagFaultsTestOnly())
-    return false;
-
+bool isPrimaryAllocation(scudo::uptr Size, scudo::uptr Alignment) {
   const scudo::uptr MinAlignment = 1UL << SCUDO_MIN_ALIGNMENT_LOG;
   if (Alignment < MinAlignment)
     Alignment = MinAlignment;
@@ -49,6 +44,14 @@ bool isTaggedAllocation(AllocatorT *Allocator, scudo::uptr Size,
   return AllocatorT::PrimaryT::canAllocate(NeededSize);
 }
 
+template <class AllocatorT>
+bool isTaggedAllocation(AllocatorT *Allocator, scudo::uptr Size,
+                        scudo::uptr Alignment) {
+  return Allocator->useMemoryTagging() &&
+         scudo::systemDetectsMemoryTagFaultsTestOnly() &&
+         isPrimaryAllocation<AllocatorT>(Size, Alignment);
+}
+
 template <class AllocatorT>
 void checkMemoryTaggingMaybe(AllocatorT *Allocator, void *P, scudo::uptr Size,
                              scudo::uptr Alignment) {
@@ -147,9 +150,9 @@ template <class Config> static void testAllocator() {
   }
   Allocator->releaseToOS();
 
-  // Ensure that specifying PatternOrZeroFill returns a pattern-filled block in
-  // the primary allocator, and either pattern or zero filled block in the
-  // secondary.
+  // Ensure that specifying PatternOrZeroFill returns a pattern or zero filled
+  // block. The primary allocator only produces pattern filled blocks if MTE
+  // is disabled, so we only require pattern filled blocks in that case.
   Allocator->setFillContents(scudo::PatternOrZeroFill);
   for (scudo::uptr SizeLog = 0U; SizeLog <= 20U; SizeLog++) {
     for (scudo::uptr Delta = 0U; Delta <= 4U; Delta++) {
@@ -158,7 +161,8 @@ template <class Config> static void testAllocator() {
       EXPECT_NE(P, nullptr);
       for (scudo::uptr I = 0; I < Size; I++) {
         unsigned char V = (reinterpret_cast<unsigned char *>(P))[I];
-        if (AllocatorT::PrimaryT::canAllocate(Size))
+        if (isPrimaryAllocation<AllocatorT>(Size, 1U << MinAlignLog) &&
+            !Allocator->useMemoryTagging())
           ASSERT_EQ(V, scudo::PatternFillByte);
         else
           ASSERT_TRUE(V == scudo::PatternFillByte || V == 0);