scudo: Support free_sized and free_aligned_sized from C23

Signed-off-by: Justin King <jcking@google.com>

Author: jcking

compiler-rt/lib/scudo/standalone/chunk.h

@@ -53,10 +53,11 @@ namespace Chunk {
 // but https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61414 prevents it from
 // happening, as it will error, complaining the number of bits is not enough.
 enum Origin : u8 {
-  Malloc = 0,
-  New = 1,
-  NewArray = 2,
-  Memalign = 3,
+  Malloc = 0,   // malloc, calloc, realloc, free, free_sized
+  New = 1,      // operator new, operator delete
+  NewArray = 2, // operator new [], operator delete []
+  Memalign = 3, // aligned_alloc, posix_memalign, memalign, pvalloc, valloc,
+                // free_aligned_sized
 };
 
 enum State : u8 { Available = 0, Allocated = 1, Quarantined = 2 };

compiler-rt/lib/scudo/standalone/combined.h

@@ -170,6 +170,12 @@ class Allocator {
       Primary.Options.set(OptionBit::DeallocTypeMismatch);
     if (getFlags()->delete_size_mismatch)
       Primary.Options.set(OptionBit::DeleteSizeMismatch);
+    if (getFlags()->free_size_mismatch)
+      Primary.Options.set(OptionBit::FreeSizeMismatch);
+    if (getFlags()->free_alignment_mismatch)
+      Primary.Options.set(OptionBit::FreeAlignmentMismatch);
+    if (getFlags()->delete_alignment_mismatch)
+      Primary.Options.set(OptionBit::DeleteAlignmentMismatch);
     if (allocatorSupportsMemoryTagging<AllocatorConfig>() &&
         systemSupportsMemoryTagging())
       Primary.Options.set(OptionBit::UseMemoryTagging);
@@ -433,7 +439,8 @@ class Allocator {
   }
 
   NOINLINE void deallocate(void *Ptr, Chunk::Origin Origin, uptr DeleteSize = 0,
-                           UNUSED uptr Alignment = MinAlignment) {
+                           bool HasDeleteSize = false, uptr DeleteAlignment = 0,
+                           bool HasDeleteAlignment = false) {
     if (UNLIKELY(!Ptr))
       return;
 
@@ -456,6 +463,9 @@ class Allocator {
     }
 #endif // GWP_ASAN_HOOKS
 
+    if (UNLIKELY(HasDeleteAlignment && !isPowerOfTwo(DeleteAlignment)))
+      reportAlignmentNotPowerOfTwo(DeleteAlignment);
+
     if (UNLIKELY(!isAligned(reinterpret_cast<uptr>(Ptr), MinAlignment)))
       reportMisalignedPointer(AllocatorAction::Deallocating, Ptr);
 
@@ -470,19 +480,41 @@ class Allocator {
 
     const Options Options = Primary.Options.load();
     if (Options.get(OptionBit::DeallocTypeMismatch)) {
-      if (UNLIKELY(Header.OriginOrWasZeroed != Origin)) {
-        // With the exception of memalign'd chunks, that can be still be free'd.
-        if (Header.OriginOrWasZeroed != Chunk::Origin::Memalign ||
-            Origin != Chunk::Origin::Malloc)
-          reportDeallocTypeMismatch(AllocatorAction::Deallocating, Ptr,
-                                    Header.OriginOrWasZeroed, Origin);
-      }
+      if (UNLIKELY(isOriginMismatch(
+              static_cast<Chunk::Origin>(Header.OriginOrWasZeroed), Origin,
+              HasDeleteSize)))
+        reportDeallocTypeMismatch(AllocatorAction::Deallocating, Ptr,
+                                  Header.OriginOrWasZeroed, Origin,
+                                  HasDeleteSize);
     }
 
     const uptr Size = getSize(Ptr, &Header);
-    if (DeleteSize && Options.get(OptionBit::DeleteSizeMismatch)) {
-      if (UNLIKELY(DeleteSize != Size))
-        reportDeleteSizeMismatch(Ptr, DeleteSize, Size);
+    switch (Origin) {
+    case Chunk::Origin::New:
+      FALLTHROUGH;
+    case Chunk::Origin::NewArray:
+      if (Options.get(OptionBit::DeleteSizeMismatch) && HasDeleteSize) {
+        if (UNLIKELY(DeleteSize != Size))
+          reportDeleteSizeMismatch(Ptr, DeleteSize, Size);
+      }
+      if (Options.get(OptionBit::DeleteAlignmentMismatch) &&
+          HasDeleteAlignment) {
+        if (UNLIKELY(!isAligned(reinterpret_cast<uptr>(Ptr), DeleteAlignment)))
+          reportDeleteAlignmentMismatch(Ptr, DeleteAlignment);
+      }
+      break;
+    case Chunk::Origin::Memalign:
+      if (Options.get(OptionBit::FreeAlignmentMismatch) && HasDeleteAlignment) {
+        if (UNLIKELY(!isAligned(reinterpret_cast<uptr>(Ptr), DeleteAlignment)))
+          reportFreeAlignmentMismatch(Ptr, DeleteAlignment);
+      }
+      FALLTHROUGH;
+    case Chunk::Origin::Malloc:
+      if (Options.get(OptionBit::FreeSizeMismatch) && HasDeleteSize) {
+        if (UNLIKELY(DeleteSize != Size))
+          reportFreeSizeMismatch(Ptr, DeleteSize, Size);
+      }
+      break;
     }
 
     quarantineOrDeallocateChunk(Options, TaggedPtr, &Header, Size);
@@ -529,14 +561,20 @@ class Allocator {
     if (UNLIKELY(Header.State != Chunk::State::Allocated))
       reportInvalidChunkState(AllocatorAction::Reallocating, OldPtr);
 
-    // Pointer has to be allocated with a malloc-type function. Some
-    // applications think that it is OK to realloc a memalign'ed pointer, which
-    // will trigger this check. It really isn't.
     if (Options.get(OptionBit::DeallocTypeMismatch)) {
-      if (UNLIKELY(Header.OriginOrWasZeroed != Chunk::Origin::Malloc))
-        reportDeallocTypeMismatch(AllocatorAction::Reallocating, OldPtr,
-                                  Header.OriginOrWasZeroed,
-                                  Chunk::Origin::Malloc);
+      // There is no language prohibiting the use of realloc with
+      // aligned_alloc/posix_memalign/memalign and etc. The outcome in
+      // practice is that the newly allocated memory will typically not
+      // have the same alignment but will have minimum alignment. With
+      // regards to operator new, there is no guarantee that the allocator
+      // being used with malloc is the same as operator new. There is also
+      // no guarantee that they share the same minimum alignment guarantees.
+      // So we reject these.
+      if (UNLIKELY(Header.OriginOrWasZeroed == Chunk::Origin::New ||
+                   Header.OriginOrWasZeroed == Chunk::Origin::NewArray))
+        reportDeallocTypeMismatch(
+            AllocatorAction::Reallocating, OldPtr, Header.OriginOrWasZeroed,
+            Chunk::Origin::Malloc, /*HasDeleteSize=*/false);
     }
 
     void *BlockBegin = getBlockBegin(OldTaggedPtr, &Header);
@@ -1746,6 +1784,19 @@ class Allocator {
     return (Bytes - sizeof(AllocationRingBuffer)) /
            sizeof(typename AllocationRingBuffer::Entry);
   }
+
+  static bool isOriginMismatch(Chunk::Origin Alloc, Chunk::Origin Dealloc,
+                               bool HasDeleteSize) {
+    if (Alloc == Dealloc) {
+      return false;
+    }
+    if (Alloc == Chunk::Origin::Memalign && Dealloc == Chunk::Origin::Malloc &&
+        !HasDeleteSize) {
+      // aligned_alloc with free is allowed, but not free_sized.
+      return false;
+    }
+    return true;
+  }
 };
 
 } // namespace scudo

compiler-rt/lib/scudo/standalone/flags.inc

@@ -49,3 +49,18 @@ SCUDO_FLAG(int, release_to_os_interval_ms, 5000,
 SCUDO_FLAG(int, allocation_ring_buffer_size, 32768,
            "Entries to keep in the allocation ring buffer for scudo. "
            "Values less or equal to zero disable the buffer.")
+
+SCUDO_FLAG(bool, delete_alignment_mismatch, true,
+           "Terminate on an alignment mismatch between a aligned-delete and "
+           "the actual "
+           "alignment of a chunk (as provided to new/new[]).")
+
+SCUDO_FLAG(bool, free_size_mismatch, true,
+           "Terminate on a size mismatch between a free_sized and the actual "
+           "size of a chunk (as provided to malloc/calloc/realloc).")
+
+SCUDO_FLAG(bool, free_alignment_mismatch, true,
+           "Terminate on an alignment mismatch between a free_aligned_sized "
+           "and the actual "
+           "alignment of a chunk (as provided to "
+           "aligned_alloc/posix_memalign/memalign).")

compiler-rt/lib/scudo/standalone/internal_defs.h

@@ -47,6 +47,15 @@
 #define UNUSED __attribute__((unused))
 #define USED __attribute__((used))
 #define NOEXCEPT noexcept
+#ifdef __has_attribute
+#if __has_attribute(fallthrough)
+#define FALLTHROUGH __attribute__((fallthrough))
+#else
+#define FALLTHROUGH
+#endif
+#else
+#define FALLTHROUGH
+#endif
 
 // This check is only available on Clang. This is essentially an alias of
 // C++20's 'constinit' specifier which will take care of this when (if?) we can

compiler-rt/lib/scudo/standalone/options.h

@@ -25,6 +25,9 @@ enum class OptionBit {
   UseOddEvenTags,
   UseMemoryTagging,
   AddLargeAllocationSlack,
+  DeleteAlignmentMismatch,
+  FreeSizeMismatch,
+  FreeAlignmentMismatch,
 };
 
 struct Options {

compiler-rt/lib/scudo/standalone/report.cpp

@@ -142,13 +142,48 @@ void NORETURN reportMisalignedPointer(AllocatorAction Action, const void *Ptr) {
                 stringifyAction(Action), Ptr);
 }
 
+static const char *stringifyAllocOrigin(Chunk::Origin AllocOrigin) {
+  switch (AllocOrigin) {
+  case Chunk::Origin::Malloc:
+    return "malloc";
+  case Chunk::Origin::New:
+    return "operator new";
+  case Chunk::Origin::NewArray:
+    return "operator new []";
+  case Chunk::Origin::Memalign:
+    return "aligned_alloc";
+  }
+  return "<invalid origin>";
+}
+
+static const char *stringifyDeallocOrigin(Chunk::Origin DeallocOrigin,
+                                          bool HasDeleteSize) {
+  switch (DeallocOrigin) {
+  case Chunk::Origin::Malloc:
+    if (HasDeleteSize)
+      return "free_sized";
+    return "free";
+  case Chunk::Origin::New:
+    return "operator delete";
+  case Chunk::Origin::NewArray:
+    return "operator delete []";
+  case Chunk::Origin::Memalign:
+    return "free_aligned_sized";
+  }
+  return "<invalid origin>";
+}
+
 // The deallocation function used is at odds with the one used to allocate the
 // chunk (eg: new[]/delete or malloc/delete, and so on).
 void NORETURN reportDeallocTypeMismatch(AllocatorAction Action, const void *Ptr,
-                                        u8 TypeA, u8 TypeB) {
+                                        u8 TypeA, u8 TypeB,
+                                        bool HasDeleteSize) {
   ScopedErrorReport Report;
-  Report.append("allocation type mismatch when %s address %p (%d vs %d)\n",
-                stringifyAction(Action), Ptr, TypeA, TypeB);
+  Report.append(
+      "allocation type mismatch when %s address %p (%s vs %s)\n",
+      stringifyAction(Action), Ptr,
+      stringifyAllocOrigin(static_cast<Chunk::Origin>(TypeA)),
+      stringifyDeallocOrigin(static_cast<Chunk::Origin>(TypeB), HasDeleteSize));
 }
 
 // The size specified to the delete operator does not match the one that was
@@ -161,6 +196,28 @@ void NORETURN reportDeleteSizeMismatch(const void *Ptr, uptr Size,
       Size, ExpectedSize);
 }
 
+void NORETURN reportDeleteAlignmentMismatch(const void *Ptr, uptr Alignment) {
+  ScopedErrorReport Report;
+  Report.append(
+      "invalid aligned delete when deallocating address %p (%zu vs %zu)\n", Ptr,
+      getLeastSignificantSetBitIndex(reinterpret_cast<uptr>(Ptr)), Alignment);
+}
+
+void NORETURN reportFreeSizeMismatch(const void *Ptr, uptr Size,
+                                     uptr ExpectedSize) {
+  ScopedErrorReport Report;
+  Report.append(
+      "invalid sized free when deallocating address %p (%zu vs %zu)\n", Ptr,
+      Size, ExpectedSize);
+}
+
+void NORETURN reportFreeAlignmentMismatch(const void *Ptr, uptr Alignment) {
+  ScopedErrorReport Report;
+  Report.append(
+      "invalid aligned free when deallocating address %p (%zu vs %zu)\n", Ptr,
+      getLeastSignificantSetBitIndex(reinterpret_cast<uptr>(Ptr)), Alignment);
+}
+
 void NORETURN reportAlignmentNotPowerOfTwo(uptr Alignment) {
   ScopedErrorReport Report;
   Report.append(

compiler-rt/lib/scudo/standalone/report.h

@@ -44,9 +44,13 @@ enum class AllocatorAction : u8 {
 void NORETURN reportInvalidChunkState(AllocatorAction Action, const void *Ptr);
 void NORETURN reportMisalignedPointer(AllocatorAction Action, const void *Ptr);
 void NORETURN reportDeallocTypeMismatch(AllocatorAction Action, const void *Ptr,
-                                        u8 TypeA, u8 TypeB);
+                                        u8 TypeA, u8 TypeB, bool HasDeleteSize);
 void NORETURN reportDeleteSizeMismatch(const void *Ptr, uptr Size,
                                        uptr ExpectedSize);
+void NORETURN reportDeleteAlignmentMismatch(const void *Ptr, uptr Alignment);
+void NORETURN reportFreeSizeMismatch(const void *Ptr, uptr Size,
+                                     uptr ExpectedSize);
+void NORETURN reportFreeAlignmentMismatch(const void *Ptr, uptr Alignment);
 
 // C wrappers errors.
 void NORETURN reportAlignmentNotPowerOfTwo(uptr Alignment);

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

@@ -327,7 +327,7 @@ void ScudoCombinedTest<Config>::BasicTest(scudo::uptr SizeLog) {
       EXPECT_LE(Size, Allocator->getUsableSize(P));
       memset(P, 0xaa, Size);
       checkMemoryTaggingMaybe(Allocator, P, Size, Align);
-      Allocator->deallocate(P, Origin, Size);
+      Allocator->deallocate(P, Origin, Size, true);
     }
   }
 
@@ -374,7 +374,7 @@ SCUDO_TYPED_TEST(ScudoCombinedTest, ZeroContents) {
       for (scudo::uptr I = 0; I < Size; I++)
         ASSERT_EQ((reinterpret_cast<char *>(P))[I], '\0');
       memset(P, 0xaa, Size);
-      Allocator->deallocate(P, Origin, Size);
+      Allocator->deallocate(P, Origin, Size, true);
     }
   }
 }
@@ -392,7 +392,7 @@ SCUDO_TYPED_TEST(ScudoCombinedTest, ZeroFill) {
       for (scudo::uptr I = 0; I < Size; I++)
         ASSERT_EQ((reinterpret_cast<char *>(P))[I], '\0');
       memset(P, 0xaa, Size);
-      Allocator->deallocate(P, Origin, Size);
+      Allocator->deallocate(P, Origin, Size, true);
     }
   }
 }
@@ -709,7 +709,7 @@ SCUDO_TYPED_TEST(ScudoCombinedTest, ThreadedCombined) {
 
       while (!V.empty()) {
         auto Pair = V.back();
-        Allocator->deallocate(Pair.first, Origin, Pair.second);
+        Allocator->deallocate(Pair.first, Origin, Pair.second, true);
         V.pop_back();
       }
     });
@@ -782,26 +782,26 @@ TEST(ScudoCombinedDeathTest, DeathCombined) {
   EXPECT_NE(P, nullptr);
 
   // Invalid sized deallocation.
-  EXPECT_DEATH(Allocator->deallocate(P, Origin, Size + 8U), "");
+  EXPECT_DEATH(Allocator->deallocate(P, Origin, Size + 8U, true), "");
 
   // Misaligned pointer. Potentially unused if EXPECT_DEATH isn't available.
   UNUSED void *MisalignedP =
       reinterpret_cast<void *>(reinterpret_cast<scudo::uptr>(P) | 1U);
-  EXPECT_DEATH(Allocator->deallocate(MisalignedP, Origin, Size), "");
-  EXPECT_DEATH(Allocator->reallocate(MisalignedP, Size * 2U), "");
+  EXPECT_DEATH(Allocator->deallocate(MisalignedP, Origin, Size, true), "");
+  EXPECT_DEATH(Allocator->reallocate(MisalignedP, Size * 2U, true), "");
 
   // Header corruption.
   scudo::u64 *H =
       reinterpret_cast<scudo::u64 *>(scudo::Chunk::getAtomicHeader(P));
   *H ^= 0x42U;
-  EXPECT_DEATH(Allocator->deallocate(P, Origin, Size), "");
+  EXPECT_DEATH(Allocator->deallocate(P, Origin, Size, true), "");
   *H ^= 0x420042U;
-  EXPECT_DEATH(Allocator->deallocate(P, Origin, Size), "");
+  EXPECT_DEATH(Allocator->deallocate(P, Origin, Size, true), "");
   *H ^= 0x420000U;
 
   // Invalid chunk state.
-  Allocator->deallocate(P, Origin, Size);
-  EXPECT_DEATH(Allocator->deallocate(P, Origin, Size), "");
+  Allocator->deallocate(P, Origin, Size, true);
+  EXPECT_DEATH(Allocator->deallocate(P, Origin, Size, true), "");
   EXPECT_DEATH(Allocator->reallocate(P, Size * 2U), "");
   EXPECT_DEATH(Allocator->getUsableSize(P), "");
 }
@@ -908,13 +908,13 @@ SCUDO_TYPED_TEST(ScudoCombinedTest, DisableMemInit) {
       memset(Ptrs[I], 0xaa, Size);
     }
     for (unsigned I = 0; I != Ptrs.size(); ++I)
-      Allocator->deallocate(Ptrs[I], Origin, Size);
+      Allocator->deallocate(Ptrs[I], Origin, Size, true);
     for (unsigned I = 0; I != Ptrs.size(); ++I) {
       Ptrs[I] = Allocator->allocate(Size - 8, Origin);
       memset(Ptrs[I], 0xbb, Size - 8);
     }
     for (unsigned I = 0; I != Ptrs.size(); ++I)
-      Allocator->deallocate(Ptrs[I], Origin, Size - 8);
+      Allocator->deallocate(Ptrs[I], Origin, Size - 8, true);
     for (unsigned I = 0; I != Ptrs.size(); ++I) {
       Ptrs[I] = Allocator->allocate(Size, Origin, 1U << MinAlignLog, true);
       for (scudo::uptr J = 0; J < Size; ++J)

compiler-rt/lib/scudo/standalone/tests/report_test.cpp

@@ -41,7 +41,7 @@ TEST(ScudoReportDeathTest, Generic) {
       scudo::reportMisalignedPointer(scudo::AllocatorAction::Deallocating, P),
       "Scudo ERROR.*deallocating.*42424242");
   EXPECT_DEATH(scudo::reportDeallocTypeMismatch(
-                   scudo::AllocatorAction::Reallocating, P, 0, 1),
+                   scudo::AllocatorAction::Reallocating, P, 0, 1, false),
                "Scudo ERROR.*reallocating.*42424242");
   EXPECT_DEATH(scudo::reportDeleteSizeMismatch(P, 123, 456),
                "Scudo ERROR.*42424242.*123.*456");