commit 19dd965e49bc1119625765a09c757082846ec53f
author Peter Collingbourne <peter@pcc.me.uk> Wed Dec 16 11:24:30 2020 -0800
committer Copybara-Service <copybara-worker@google.com> Sun Jan 03 16:03:28 2021 -0800
tree 984fcc26e1709a4228b07e9a44a89dc025fe46ad
parent 6c45c6bdfc8bb0753cf80b232c4ace819ffce43e

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

GitOrigin-RevId: e22d802e587b8954748e2b2193195a946ba105e8

tests/combined_test.cpp

diff --git a/tests/combined_test.cpp b/tests/combined_test.cpp
index 7df4594..b0ab024 100644
--- a/tests/combined_test.cpp
+++ b/tests/combined_test.cpp
@@ -34,12 +34,7 @@
 }
 
 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;
@@ -50,6 +45,14 @@
 }
 
 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) {
   if (!isTaggedAllocation(Allocator, Size, Alignment))
@@ -147,9 +150,9 @@
   }
   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 @@
       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);