[Sanitizers] MSan allocator set errno on failure.

[alekseyshl]

Summary

Set proper errno code on allocation failures and change realloc, pvalloc,
aligned_alloc, memalign and posix_memalign implementation to satisfy
their man-specified requirements.

Modify allocator API implementation to bring it closer to other sanitizers allocators.

[cryptoad]

Instead of the ptr_check calls, couldn't errno be set to ENOMEM in ReturnNullOrDieOnFailure::OnOOM? Unless mistaken it should be the common function to the return nullptr scenario on OOM.
Also you are going to hate me, and I apologize in advance, but when starting Scudo I was asked to follow to LLVM casing scheme, which your additions to Scudo don't comply with :/

[vitalybuka]

Does this need to be a single patch?

[alekseyshl]

In D35275#805965, @cryptoad wrote:

Instead of the ptr_check calls, couldn't errno be set to ENOMEM in ReturnNullOrDieOnFailure::OnOOM? Unless mistaken it should be the common function to the return nullptr scenario on OOM.
Also you are going to hate me, and I apologize in advance, but when starting Scudo I was asked to follow to LLVM casing scheme, which your additions to Scudo don't comply with :/

Will change Scudo part to follow your scheme, no problem.

No, unfortunately, I cannot set errno in the policy, posix_memalign does not affect errno and errno is an API concept anyway, I'd like to keep allocator internals oblivious to it.

[alekseyshl]

In D35275#807144, @vitalybuka wrote:

Does this need to be a single patch?

No, it does not have to be a single patch, would you prefer to see per-sanitizer patches? My idea was that this way it is easier to see the similarities, but I'm fine splitting it into multiple patches.

[vitalybuka]

In D35275#807348, @alekseyshl wrote:

In D35275#807144, @vitalybuka wrote:

Does this need to be a single patch?

No, it does not have to be a single patch, would you prefer to see per-sanitizer patches? My idea was that this way it is easier to see the similarities, but I'm fine splitting it into multiple patches.

errno = errno_ENOMEM; and ptr_check changes seems trivial to be in one patch, but replacement MsanReallocate to msan_* probably deserve separate one.

[vitalybuka]

lib/asan/asan_allocator.cc

843

easier to read: size = size ? RoundUpTo(size, PageSize) : PageSize;

lib/scudo/scudo_allocator.cpp

676

same

[vitalybuka]

lib/msan/msan_allocator.cc

270

why not just (size % alignmet == 0) and ignore "power of two" check?

288

maybe just, pointer should be always power of two?
if (UNLIKELY((alignment % sizeof(void *)))) {

[morehouse]

lib/msan/msan_allocator.cc

288

From the posix_memalign man page:

The function posix_memalign() allocates size bytes and places the
address of the allocated memory in *memptr. The address of the allo‐
cated memory will be a multiple of alignment, which must be a power of
two and a multiple of sizeof(void *).

[morehouse]

lib/msan/msan_allocator.cc

270

From memalign and aligned_alloc man page:

The obsolete function memalign() allocates size bytes and returns a
pointer to the allocated memory. The memory address will be a multiple
of alignment, which must be a power of two.

The function aligned_alloc() is the same as memalign(), except for the
added restriction that size should be a multiple of alignment.

[vitalybuka]

lib/msan/msan_allocator.cc

270

power of two is posix specific requirement
http://en.cppreference.com/w/c/memory/aligned_alloc

Anyway (size & (alignment - 1)) != 0) can be replaced with simple (size % alignmet)

288

yes, but sizeof(void *) is already power of two

[morehouse]

Test cases for EINVAL in the various *memalign and *aligned_alloc functions might be a good idea.

[morehouse]

lib/msan/msan_allocator.cc

288

Suppose sizeof(void *) is 8 and alignment is 24. Then alignment % sizeof(void *) == 0 but alignment is not a power of 2.

[vitalybuka]

lib/msan/msan_allocator.cc

288

i've missed that, thanks for explaining

[alekseyshl]

In D35275#808959, @morehouse wrote:

Test cases for EINVAL in the various *memalign and *aligned_alloc functions might be a good idea.

Yes, I have them on my TODO list, but, with the exception of Scudo, not all platforms implement them and I did not want to revert the entire patch because of those failing tests. Will add them later.

lib/msan/msan_allocator.cc

270

My man memalign says exactly as quoted earlier, the power of two requirement affects both memalign and aligned_alloc.

[alekseyshl]

Ok, I'll split this patch by the sanitizer and send separate reviews.

[alekseyshl]

Merging with HEAD

[alekseyshl]

• Rename the check function and add a few UNLIKELY around.

[alekseyshl]

lib/msan/msan_allocator.cc

270

(size & (alignment - 1)) != 0) leads to appreciably more compact and faster assembly generated than (size % alignment), because div required for the latter touches a lot of registers, which forces compiler to push other vars around.

The difference is 0x41 vs 0x51 bytes of the function size.

[vitalybuka]

lib/msan/msan_allocator.cc

232

maybe move to some common header?

270

then why msan_posix_memalign uses % when you do the same?

270

your man is for posix

[alekseyshl]

lib/msan/msan_allocator.cc

232

Ok, let's try to common-ise some of the logc here.

270

Cause it % with compile time constant (which is a power of 2), the compiler was capable to optimize % part of the condition to one bitmask operation there.

270

Not sure how we can check for "valid alignment supported by the implementation" condition, but I can definitely relax it for non-POSIX platforms.

[alekseyshl]

• Move common functions to sanitizer_common.

[vitalybuka]

lgtm

[alekseyshl]

• Disable errno test on Windows until we figure out the problem.

lib/asan/asan_allocator.cc

 //===----------------------------------------------------------------------===//
 
 #include "asan_allocator.h"
 #include "asan_mapping.h"
 #include "asan_poisoning.h"
 #include "asan_report.h"
 #include "asan_stack.h"
 #include "asan_thread.h"
+#include "sanitizer_common/sanitizer_allocator_checks.h"
 #include "sanitizer_common/sanitizer_allocator_interface.h"
 #include "sanitizer_common/sanitizer_errno.h"
 #include "sanitizer_common/sanitizer_flags.h"
 #include "sanitizer_common/sanitizer_internal_defs.h"
 #include "sanitizer_common/sanitizer_list.h"
 #include "sanitizer_common/sanitizer_stackdepot.h"
 #include "sanitizer_common/sanitizer_quarantine.h"
 #include "lsan/lsan_common.h"
void asan_free(void *ptr, BufferedStackTrace *stack, AllocType alloc_type) {
   instance.Deallocate(ptr, 0, stack, alloc_type);
 }
 
 void asan_sized_free(void *ptr, uptr size, BufferedStackTrace *stack,
                      AllocType alloc_type) {
   instance.Deallocate(ptr, size, stack, alloc_type);
 }
 
-inline void *check_ptr(void *ptr) {
-  if (UNLIKELY(!ptr))
-    errno = errno_ENOMEM;
-  return ptr;
-}
-
 void *asan_malloc(uptr size, BufferedStackTrace *stack) {
-  return check_ptr(instance.Allocate(size, 8, stack, FROM_MALLOC, true));
+  return SetErrnoOnNull(instance.Allocate(size, 8, stack, FROM_MALLOC, true));
 }
 
 void *asan_calloc(uptr nmemb, uptr size, BufferedStackTrace *stack) {
-  return check_ptr(instance.Calloc(nmemb, size, stack));
+  return SetErrnoOnNull(instance.Calloc(nmemb, size, stack));
 }
 
 void *asan_realloc(void *p, uptr size, BufferedStackTrace *stack) {
   if (!p)
-    return check_ptr(instance.Allocate(size, 8, stack, FROM_MALLOC, true));
+    return SetErrnoOnNull(instance.Allocate(size, 8, stack, FROM_MALLOC, true));
   if (size == 0) {
     if (flags()->allocator_frees_and_returns_null_on_realloc_zero) {
       instance.Deallocate(p, 0, stack, FROM_MALLOC);
       return nullptr;
     }
     // Allocate a size of 1 if we shouldn't free() on Realloc to 0
     size = 1;
   }
-  return check_ptr(instance.Reallocate(p, size, stack));
+  return SetErrnoOnNull(instance.Reallocate(p, size, stack));
 }
 
 void *asan_valloc(uptr size, BufferedStackTrace *stack) {
-  return check_ptr(
+  return SetErrnoOnNull(
       instance.Allocate(size, GetPageSizeCached(), stack, FROM_MALLOC, true));
 }
 
 void *asan_pvalloc(uptr size, BufferedStackTrace *stack) {
   uptr PageSize = GetPageSizeCached();
   // pvalloc(0) should allocate one page.
   size = size ? RoundUpTo(size, PageSize) : PageSize;
-  return check_ptr(instance.Allocate(size, PageSize, stack, FROM_MALLOC, true));
+  return SetErrnoOnNull(
+      instance.Allocate(size, PageSize, stack, FROM_MALLOC, true));
 }
 
 void *asan_memalign(uptr alignment, uptr size, BufferedStackTrace *stack,
                     AllocType alloc_type) {
   if (UNLIKELY(!IsPowerOfTwo(alignment))) {
     errno = errno_EINVAL;
     return AsanAllocator::FailureHandler::OnBadRequest();
   }
-  return check_ptr(
+  return SetErrnoOnNull(
       instance.Allocate(size, alignment, stack, alloc_type, true));
 }
 
 int asan_posix_memalign(void **memptr, uptr alignment, uptr size,
                         BufferedStackTrace *stack) {
-  if (UNLIKELY(!IsPowerOfTwo(alignment) ||
-               (alignment % sizeof(void *)) != 0)) {  // NOLINT
+  if (UNLIKELY(!CheckPosixMemalignAlignment(alignment))) {
     AsanAllocator::FailureHandler::OnBadRequest();
     return errno_EINVAL;
   }
   void *ptr = instance.Allocate(size, alignment, stack, FROM_MALLOC, true);
-  if (!ptr)
+  if (UNLIKELY(!ptr))
     return errno_ENOMEM;
   CHECK(IsAligned((uptr)ptr, alignment));
   *memptr = ptr;
   return 0;
 }
 
 uptr asan_malloc_usable_size(const void *ptr, uptr pc, uptr bp) {
   if (!ptr) return 0;

lib/lsan/lsan_allocator.cc

 // This file is a part of LeakSanitizer.
 // See lsan_allocator.h for details.
 //
 //===----------------------------------------------------------------------===//
 
 #include "lsan_allocator.h"
 
 #include "sanitizer_common/sanitizer_allocator.h"
+#include "sanitizer_common/sanitizer_allocator_checks.h"
 #include "sanitizer_common/sanitizer_allocator_interface.h"
 #include "sanitizer_common/sanitizer_errno.h"
 #include "sanitizer_common/sanitizer_internal_defs.h"
 #include "sanitizer_common/sanitizer_stackdepot.h"
 #include "sanitizer_common/sanitizer_stacktrace.h"
 #include "lsan_common.h"
 
 extern "C" void *memset(void *ptr, int value, uptr num);

 }
 
 uptr GetMallocUsableSize(const void *p) {
   ChunkMetadata *m = Metadata(p);
   if (!m) return 0;
   return m->requested_size;
 }
 
-inline void *check_ptr(void *ptr) {
-  if (UNLIKELY(!ptr))
-    errno = errno_ENOMEM;
-  return ptr;
-}
-
 void *lsan_memalign(uptr alignment, uptr size, const StackTrace &stack) {
   if (UNLIKELY(!IsPowerOfTwo(alignment))) {
     errno = errno_EINVAL;
     return Allocator::FailureHandler::OnBadRequest();
   }
-  return check_ptr(Allocate(stack, size, alignment, kAlwaysClearMemory));
+  return SetErrnoOnNull(Allocate(stack, size, alignment, kAlwaysClearMemory));
 }
 
 void *lsan_malloc(uptr size, const StackTrace &stack) {
-  return check_ptr(Allocate(stack, size, 1, kAlwaysClearMemory));
+  return SetErrnoOnNull(Allocate(stack, size, 1, kAlwaysClearMemory));
 }
 
 void lsan_free(void *p) {
   Deallocate(p);
 }
 
 void *lsan_realloc(void *p, uptr size, const StackTrace &stack) {
-  return check_ptr(Reallocate(stack, p, size, 1));
+  return SetErrnoOnNull(Reallocate(stack, p, size, 1));
 }
 
 void *lsan_calloc(uptr nmemb, uptr size, const StackTrace &stack) {
-  return check_ptr(Calloc(nmemb, size, stack));
+  return SetErrnoOnNull(Calloc(nmemb, size, stack));
 }
 
 void *lsan_valloc(uptr size, const StackTrace &stack) {
-  return check_ptr(
+  return SetErrnoOnNull(
       Allocate(stack, size, GetPageSizeCached(), kAlwaysClearMemory));
 }
 
 uptr lsan_mz_size(const void *p) {
   return GetMallocUsableSize(p);
 }
 
 ///// Interface to the common LSan module. /////

lib/msan/msan.h

 
 bool ProtectRange(uptr beg, uptr end);
 bool InitShadow(bool init_origins);
 char *GetProcSelfMaps();
 void InitializeInterceptors();
 
 void MsanAllocatorInit();
 void MsanAllocatorThreadFinish();
-void *MsanCalloc(StackTrace *stack, uptr nmemb, uptr size);
-void *MsanReallocate(StackTrace *stack, void *oldp, uptr size,
-                     uptr alignment, bool zeroise);
 void MsanDeallocate(StackTrace *stack, void *ptr);
+
+void *msan_malloc(uptr size, StackTrace *stack);
+void *msan_calloc(uptr nmemb, uptr size, StackTrace *stack);
+void *msan_realloc(void *ptr, uptr size, StackTrace *stack);
+void *msan_valloc(uptr size, StackTrace *stack);
+void *msan_pvalloc(uptr size, StackTrace *stack);
+void *msan_aligned_alloc(uptr alignment, uptr size, StackTrace *stack);
+void *msan_memalign(uptr alignment, uptr size, StackTrace *stack);
+int msan_posix_memalign(void **memptr, uptr alignment, uptr size,
+                        StackTrace *stack);
+
 void InstallTrapHandler();
 void InstallAtExitHandler();
 
 const char *GetStackOriginDescr(u32 id, uptr *pc);
 
 void EnterSymbolizer();
 void ExitSymbolizer();
 bool IsInSymbolizer();

lib/msan/msan_allocator.cc

 //===-- msan_allocator.cc --------------------------- ---------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file is a part of MemorySanitizer.
 //
 // MemorySanitizer allocator.
 //===----------------------------------------------------------------------===//
 
 #include "sanitizer_common/sanitizer_allocator.h"
+#include "sanitizer_common/sanitizer_allocator_checks.h"
 #include "sanitizer_common/sanitizer_allocator_interface.h"
+#include "sanitizer_common/sanitizer_errno.h"
 #include "msan.h"
 #include "msan_allocator.h"
 #include "msan_origin.h"
 #include "msan_thread.h"
 #include "msan_poisoning.h"
 
 namespace __msan {
 
if (t) {
     allocator.Deallocate(cache, p);
   } else {
     SpinMutexLock l(&fallback_mutex);
     AllocatorCache *cache = &fallback_allocator_cache;
     allocator.Deallocate(cache, p);
   }
 }
 
-void *MsanCalloc(StackTrace *stack, uptr nmemb, uptr size) {
-  if (CheckForCallocOverflow(size, nmemb))
-    return Allocator::FailureHandler::OnBadRequest();
-  return MsanReallocate(stack, nullptr, nmemb * size, sizeof(u64), true);
-}
-
 void *MsanReallocate(StackTrace *stack, void *old_p, uptr new_size,
-                     uptr alignment, bool zeroise) {
-  if (!old_p)
-    return MsanAllocate(stack, new_size, alignment, zeroise);
-  if (!new_size) {
-    MsanDeallocate(stack, old_p);
-    return nullptr;
-  }
+                     uptr alignment) {
   Metadata *meta = reinterpret_cast<Metadata*>(allocator.GetMetaData(old_p));
   uptr old_size = meta->requested_size;
   uptr actually_allocated_size = allocator.GetActuallyAllocatedSize(old_p);
   if (new_size <= actually_allocated_size) {
     // We are not reallocating here.
     meta->requested_size = new_size;
     if (new_size > old_size) {
-      if (zeroise) {
-        __msan_clear_and_unpoison((char *)old_p + old_size,
-                                  new_size - old_size);
-      } else if (flags()->poison_in_malloc) {
+      if (flags()->poison_in_malloc) {
         stack->tag = StackTrace::TAG_ALLOC;
         PoisonMemory((char *)old_p + old_size, new_size - old_size, stack);
       }
     }
     return old_p;
   }
   uptr memcpy_size = Min(new_size, old_size);
-  void *new_p = MsanAllocate(stack, new_size, alignment, zeroise);
-  // Printf("realloc: old_size %zd new_size %zd\n", old_size, new_size);
+  void *new_p = MsanAllocate(stack, new_size, alignment, false /*zeroise*/);
   if (new_p) {
     CopyMemory(new_p, old_p, memcpy_size, stack);
     MsanDeallocate(stack, old_p);
   }
   return new_p;
 }
 
 static uptr AllocationSize(const void *p) {
   if (!p) return 0;
   const void *beg = allocator.GetBlockBegin(p);
   if (beg != p) return 0;
   Metadata *b = (Metadata *)allocator.GetMetaData(p);
   return b->requested_size;
 }
 
+void *msan_malloc(uptr size, StackTrace *stack) {
+  return SetErrnoOnNull(MsanAllocate(stack, size, sizeof(u64), false));
+}
+
+void *msan_calloc(uptr nmemb, uptr size, StackTrace *stack) {
+  if (UNLIKELY(CheckForCallocOverflow(size, nmemb)))
+    return SetErrnoOnNull(Allocator::FailureHandler::OnBadRequest());
+  return SetErrnoOnNull(MsanAllocate(stack, nmemb * size, sizeof(u64), true));
+}
+
+void *msan_realloc(void *ptr, uptr size, StackTrace *stack) {
+  if (!ptr)
+    return SetErrnoOnNull(MsanAllocate(stack, size, sizeof(u64), false));
+  if (size == 0) {
+    MsanDeallocate(stack, ptr);
+    return nullptr;
+  }
+  return SetErrnoOnNull(MsanReallocate(stack, ptr, size, sizeof(u64)));
+}
+
+void *msan_valloc(uptr size, StackTrace *stack) {
+  return SetErrnoOnNull(MsanAllocate(stack, size, GetPageSizeCached(), false));
+}
+
+void *msan_pvalloc(uptr size, StackTrace *stack) {
+  uptr PageSize = GetPageSizeCached();
+  // pvalloc(0) should allocate one page.
+  size = size == 0 ? PageSize : RoundUpTo(size, PageSize);
+  return SetErrnoOnNull(MsanAllocate(stack, size, PageSize, false));
+}
+
+void *msan_aligned_alloc(uptr alignment, uptr size, StackTrace *stack) {
+  if (UNLIKELY(!CheckAlignedAllocAlignmentAndSize(alignment, size))) {
+    errno = errno_EINVAL;
+    return Allocator::FailureHandler::OnBadRequest();
+  }
+  return SetErrnoOnNull(MsanAllocate(stack, size, alignment, false));
+}
+
+void *msan_memalign(uptr alignment, uptr size, StackTrace *stack) {
+  if (UNLIKELY(!IsPowerOfTwo(alignment))) {
+    errno = errno_EINVAL;
+    return Allocator::FailureHandler::OnBadRequest();
+  }
+  return SetErrnoOnNull(MsanAllocate(stack, size, alignment, false));
+}
+
+int msan_posix_memalign(void **memptr, uptr alignment, uptr size,
+                        StackTrace *stack) {
+  if (UNLIKELY(!CheckPosixMemalignAlignment(alignment))) {
+    Allocator::FailureHandler::OnBadRequest();
+    return errno_EINVAL;
+  }
+  void *ptr = MsanAllocate(stack, size, alignment, false);
+  if (UNLIKELY(!ptr))
+    return errno_ENOMEM;
+  CHECK(IsAligned((uptr)ptr, alignment));
+  *memptr = ptr;
+  return 0;
+}
+
 } // namespace __msan
 
 using namespace __msan;
 
 uptr __sanitizer_get_current_allocated_bytes() {
   uptr stats[AllocatorStatCount];
   allocator.GetStats(stats);
   return stats[AllocatorStatAllocated];

lib/msan/msan_interceptors.cc

 }
 
 INTERCEPTOR(void *, bcopy, const void *src, void *dest, SIZE_T n) {
   return __msan_memmove(dest, src, n);
 }
 
 INTERCEPTOR(int, posix_memalign, void **memptr, SIZE_T alignment, SIZE_T size) {
   GET_MALLOC_STACK_TRACE;
-  CHECK_EQ(alignment & (alignment - 1), 0);
   CHECK_NE(memptr, 0);
-  *memptr = MsanReallocate(&stack, nullptr, size, alignment, false);
-  CHECK_NE(*memptr, 0);
+  int res = msan_posix_memalign(memptr, alignment, size, &stack);
+  if (!res)
     __msan_unpoison(memptr, sizeof(*memptr));
-  return 0;
+  return res;
 }
 
 #if !SANITIZER_FREEBSD
-INTERCEPTOR(void *, memalign, SIZE_T boundary, SIZE_T size) {
+INTERCEPTOR(void *, memalign, SIZE_T alignment, SIZE_T size) {
   GET_MALLOC_STACK_TRACE;
-  CHECK_EQ(boundary & (boundary - 1), 0);
-  void *ptr = MsanReallocate(&stack, nullptr, size, boundary, false);
-  return ptr;
+  return msan_memalign(alignment, size, &stack);
 }
 #define MSAN_MAYBE_INTERCEPT_MEMALIGN INTERCEPT_FUNCTION(memalign)
 #else
 #define MSAN_MAYBE_INTERCEPT_MEMALIGN
 #endif
 
-INTERCEPTOR(void *, aligned_alloc, SIZE_T boundary, SIZE_T size) {
+INTERCEPTOR(void *, aligned_alloc, SIZE_T alignment, SIZE_T size) {
   GET_MALLOC_STACK_TRACE;
-  CHECK_EQ(boundary & (boundary - 1), 0);
-  void *ptr = MsanReallocate(&stack, nullptr, size, boundary, false);
-  return ptr;
+  return msan_aligned_alloc(alignment, size, &stack);
 }
 
-INTERCEPTOR(void *, __libc_memalign, SIZE_T boundary, SIZE_T size) {
+INTERCEPTOR(void *, __libc_memalign, SIZE_T alignment, SIZE_T size) {
   GET_MALLOC_STACK_TRACE;
-  CHECK_EQ(boundary & (boundary - 1), 0);
-  void *ptr = MsanReallocate(&stack, nullptr, size, boundary, false);
+  void *ptr = msan_memalign(alignment, size, &stack);
+  if (ptr)
     DTLS_on_libc_memalign(ptr, size);
   return ptr;
 }
 
 INTERCEPTOR(void *, valloc, SIZE_T size) {
   GET_MALLOC_STACK_TRACE;
-  void *ptr = MsanReallocate(&stack, nullptr, size, GetPageSizeCached(), false);
-  return ptr;
+  return msan_valloc(size, &stack);
 }
 
 #if !SANITIZER_FREEBSD
 INTERCEPTOR(void *, pvalloc, SIZE_T size) {
   GET_MALLOC_STACK_TRACE;
-  uptr PageSize = GetPageSizeCached();
-  size = RoundUpTo(size, PageSize);
-  if (size == 0) {
-    // pvalloc(0) should allocate one page.
-    size = PageSize;
-  }
-  void *ptr = MsanReallocate(&stack, nullptr, size, PageSize, false);
-  return ptr;
+  return msan_pvalloc(size, &stack);
 }
 #define MSAN_MAYBE_INTERCEPT_PVALLOC INTERCEPT_FUNCTION(pvalloc)
 #else
 #define MSAN_MAYBE_INTERCEPT_PVALLOC
 #endif
 
 INTERCEPTOR(void, free, void *ptr) {
   GET_MALLOC_STACK_TRACE;

 #define MSAN_MAYBE_INTERCEPT_EPOLL_PWAIT
 #endif
 
 INTERCEPTOR(void *, calloc, SIZE_T nmemb, SIZE_T size) {
   GET_MALLOC_STACK_TRACE;
   if (UNLIKELY(!msan_inited))
     // Hack: dlsym calls calloc before REAL(calloc) is retrieved from dlsym.
     return AllocateFromLocalPool(nmemb * size);
-  return MsanCalloc(&stack, nmemb, size);
+  return msan_calloc(nmemb, size, &stack);
 }
 
 INTERCEPTOR(void *, realloc, void *ptr, SIZE_T size) {
   GET_MALLOC_STACK_TRACE;
   if (UNLIKELY(IsInDlsymAllocPool(ptr))) {
     uptr offset = (uptr)ptr - (uptr)alloc_memory_for_dlsym;
     uptr copy_size = Min(size, kDlsymAllocPoolSize - offset);
     void *new_ptr;
     if (UNLIKELY(!msan_inited)) {
       new_ptr = AllocateFromLocalPool(copy_size);
     } else {
       copy_size = size;
-      new_ptr = MsanReallocate(&stack, nullptr, copy_size, sizeof(u64), false);
+      new_ptr = msan_malloc(copy_size, &stack);
     }
     internal_memcpy(new_ptr, ptr, copy_size);
     return new_ptr;
   }
-  return MsanReallocate(&stack, ptr, size, sizeof(u64), false);
+  return msan_realloc(ptr, size, &stack);
 }
 
 INTERCEPTOR(void *, malloc, SIZE_T size) {
   GET_MALLOC_STACK_TRACE;
   if (UNLIKELY(!msan_inited))
     // Hack: dlsym calls malloc before REAL(malloc) is retrieved from dlsym.
     return AllocateFromLocalPool(size);
-  return MsanReallocate(&stack, nullptr, size, sizeof(u64), false);
+  return msan_malloc(size, &stack);
 }
 
 void __msan_allocated_memory(const void *data, uptr size) {
   GET_MALLOC_STACK_TRACE;
   if (flags()->poison_in_malloc) {
     stack.tag = STACK_TRACE_TAG_POISON;
     PoisonMemory(data, size, &stack);
   }

lib/msan/msan_new_delete.cc

 namespace std {
   struct nothrow_t {};
 }  // namespace std
 
 
 // TODO(alekseys): throw std::bad_alloc instead of dying on OOM.
 #define OPERATOR_NEW_BODY(nothrow) \
   GET_MALLOC_STACK_TRACE; \
-  void *res = MsanReallocate(&stack, 0, size, sizeof(u64), false);\
+  void *res = msan_malloc(size, &stack);\
   if (!nothrow && UNLIKELY(!res)) DieOnFailure::OnOOM();\
   return res
 
 INTERCEPTOR_ATTRIBUTE
 void *operator new(size_t size) { OPERATOR_NEW_BODY(false /*nothrow*/); }
 INTERCEPTOR_ATTRIBUTE
 void *operator new[](size_t size) { OPERATOR_NEW_BODY(false /*nothrow*/); }
 INTERCEPTOR_ATTRIBUTE

lib/sanitizer_common/sanitizer_allocator.h

 struct NoOpMapUnmapCallback {
   void OnMap(uptr p, uptr size) const { }
   void OnUnmap(uptr p, uptr size) const { }
 };
 
 // Callback type for iterating over chunks.
 typedef void (*ForEachChunkCallback)(uptr chunk, void *arg);
 
-// Returns true if calloc(size, n) call overflows on size*n calculation.
-// The caller should "return POLICY::OnBadRequest();" where POLICY is the
-// current allocator failure handling policy.
-bool CheckForCallocOverflow(uptr size, uptr n);
-
 #include "sanitizer_allocator_size_class_map.h"
 #include "sanitizer_allocator_stats.h"
 #include "sanitizer_allocator_primary64.h"
 #include "sanitizer_allocator_bytemap.h"
 #include "sanitizer_allocator_primary32.h"
 #include "sanitizer_allocator_local_cache.h"
 #include "sanitizer_allocator_secondary.h"
 #include "sanitizer_allocator_combined.h"
 
 } // namespace __sanitizer
 
 #endif // SANITIZER_ALLOCATOR_H

lib/sanitizer_common/sanitizer_allocator.cc

 //===-- sanitizer_allocator.cc --------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file is shared between AddressSanitizer and ThreadSanitizer
 // run-time libraries.
 // This allocator is used inside run-times.
 //===----------------------------------------------------------------------===//
 
 #include "sanitizer_allocator.h"
 
+#include "sanitizer_allocator_checks.h"
 #include "sanitizer_allocator_internal.h"
 #include "sanitizer_atomic.h"
 #include "sanitizer_common.h"
 
 namespace __sanitizer {
 
 // ThreadSanitizer for Go uses libc malloc/free.
 #if SANITIZER_GO || defined(SANITIZER_USE_MALLOC)
void *InternalRealloc(void *addr, uptr size, InternalAllocatorCache *cache) {
   CHECK_EQ(kBlockMagic, ((u64*)addr)[0]);
   void *p = RawInternalRealloc(addr, size, cache);
   if (!p)
     return nullptr;
   return (char*)p + sizeof(u64);
 }
 
 void *InternalCalloc(uptr count, uptr size, InternalAllocatorCache *cache) {
-  if (CheckForCallocOverflow(count, size))
+  if (UNLIKELY(CheckForCallocOverflow(count, size)))
     return InternalAllocator::FailureHandler::OnBadRequest();
   void *p = InternalAlloc(count * size, cache);
   if (p) internal_memset(p, 0, count * size);
   return p;
 }
 
 void InternalFree(void *addr, InternalAllocatorCache *cache) {
   if (!addr)
void *LowLevelAllocator::Allocate(uptr size) {
   allocated_current_ += size;
   return res;
 }
 
 void SetLowLevelAllocateCallback(LowLevelAllocateCallback callback) {
   low_level_alloc_callback = callback;
 }
 
-bool CheckForCallocOverflow(uptr size, uptr n) {
-  if (!size) return false;
-  uptr max = (uptr)-1L;
-  return (max / size) < n;
-}
-
 static atomic_uint8_t allocator_out_of_memory = {0};
 static atomic_uint8_t allocator_may_return_null = {0};
 
 bool IsAllocatorOutOfMemory() {
   return atomic_load_relaxed(&allocator_out_of_memory);
 }
 
 // Prints error message and kills the program.

lib/sanitizer_common/sanitizer_allocator_checks.h

+//===-- sanitizer_allocator_checks.h ----------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Various checks shared between ThreadSanitizer, MemorySanitizer, etc. memory
+// allocators.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SANITIZER_ALLOCATOR_CHECKS_H
+#define SANITIZER_ALLOCATOR_CHECKS_H
+
+#include "sanitizer_errno.h"
+#include "sanitizer_internal_defs.h"
+#include "sanitizer_common.h"
+#include "sanitizer_platform.h"
+
+namespace __sanitizer {
+
+// A common errno setting logic shared by almost all sanitizer allocator APIs.
+INLINE void *SetErrnoOnNull(void *ptr) {
+  if (UNLIKELY(!ptr))
+    errno = errno_ENOMEM;
+  return ptr;
+}
+
+// In case of the check failure, the caller of the following Check... functions
+// should "return POLICY::OnBadRequest();" where POLICY is the current allocator
+// failure handling policy.
+
+// Checks aligned_alloc() parameters, verifies that the alignment is a power of
+// two and that the size is a multiple of alignment for POSIX implementation,
+// and a bit relaxed requirement for non-POSIX ones, that the size is a multiple
+// of alignment.
+INLINE bool CheckAlignedAllocAlignmentAndSize(uptr alignment, uptr size) {
+#if SANITIZER_POSIX
+  return IsPowerOfTwo(alignment) && (size & (alignment - 1)) == 0;
+#else
+  return size % alignment == 0;
+#endif
+}
+
+// Checks posix_memalign() parameters, verifies that alignment is a power of two
+// and a multiple of sizeof(void *).
+INLINE bool CheckPosixMemalignAlignment(uptr alignment) {
+  return IsPowerOfTwo(alignment) && (alignment % sizeof(void *)) == 0; // NOLINT
+}
+
+// Returns true if calloc(size, n) call overflows on size*n calculation.
+INLINE bool CheckForCallocOverflow(uptr size, uptr n) {
+  if (!size)
+    return false;
+  uptr max = (uptr)-1L;
+  return (max / size) < n;
+}
+
+} // namespace __sanitizer
+
+#endif  // SANITIZER_ALLOCATOR_CHECKS_H

lib/scudo/scudo_allocator.cpp

 ///
 //===----------------------------------------------------------------------===//
 
 #include "scudo_allocator.h"
 #include "scudo_crc32.h"
 #include "scudo_tls.h"
 #include "scudo_utils.h"
 
+#include "sanitizer_common/sanitizer_allocator_checks.h"
 #include "sanitizer_common/sanitizer_allocator_interface.h"
 #include "sanitizer_common/sanitizer_errno.h"
 #include "sanitizer_common/sanitizer_quarantine.h"
 
 #include <string.h>
 
 namespace __scudo {
 
void ScudoThreadContext::init() {
   Prng.init();
   memset(QuarantineCachePlaceHolder, 0, sizeof(QuarantineCachePlaceHolder));
 }
 
 void ScudoThreadContext::commitBack() {
   Instance.commitBack(this);
 }
 
-INLINE void *checkPtr(void *Ptr) {
-  if (UNLIKELY(!Ptr))
-    errno = errno_ENOMEM;
-  return Ptr;
-}
-
 void *scudoMalloc(uptr Size, AllocType Type) {
-  return checkPtr(Instance.allocate(Size, MinAlignment, Type));
+  return SetErrnoOnNull(Instance.allocate(Size, MinAlignment, Type));
 }
 
 void scudoFree(void *Ptr, AllocType Type) {
   Instance.deallocate(Ptr, 0, Type);
 }
 
 void scudoSizedFree(void *Ptr, uptr Size, AllocType Type) {
   Instance.deallocate(Ptr, Size, Type);
 }
 
 void *scudoRealloc(void *Ptr, uptr Size) {
   if (!Ptr)
-    return checkPtr(Instance.allocate(Size, MinAlignment, FromMalloc));
+    return SetErrnoOnNull(Instance.allocate(Size, MinAlignment, FromMalloc));
   if (Size == 0) {
     Instance.deallocate(Ptr, 0, FromMalloc);
     return nullptr;
   }
-  return checkPtr(Instance.reallocate(Ptr, Size));
+  return SetErrnoOnNull(Instance.reallocate(Ptr, Size));
 }
 
 void *scudoCalloc(uptr NMemB, uptr Size) {
-  return checkPtr(Instance.calloc(NMemB, Size));
+  return SetErrnoOnNull(Instance.calloc(NMemB, Size));
 }
 
 void *scudoValloc(uptr Size) {
-  return checkPtr(Instance.allocate(Size, GetPageSizeCached(), FromMemalign));
+  return SetErrnoOnNull(
+      Instance.allocate(Size, GetPageSizeCached(), FromMemalign));
 }
 
 void *scudoPvalloc(uptr Size) {
   uptr PageSize = GetPageSizeCached();
   // pvalloc(0) should allocate one page.
   Size = Size ? RoundUpTo(Size, PageSize) : PageSize;
-  return checkPtr(Instance.allocate(Size, PageSize, FromMemalign));
+  return SetErrnoOnNull(Instance.allocate(Size, PageSize, FromMemalign));
 }
 
 void *scudoMemalign(uptr Alignment, uptr Size) {
   if (UNLIKELY(!IsPowerOfTwo(Alignment))) {
     errno = errno_EINVAL;
     return ScudoAllocator::FailureHandler::OnBadRequest();
   }
-  return checkPtr(Instance.allocate(Size, Alignment, FromMemalign));
+  return SetErrnoOnNull(Instance.allocate(Size, Alignment, FromMemalign));
 }
 
 int scudoPosixMemalign(void **MemPtr, uptr Alignment, uptr Size) {
-  if (UNLIKELY(!IsPowerOfTwo(Alignment) || (Alignment % sizeof(void *)) != 0)) {
+  if (UNLIKELY(!CheckPosixMemalignAlignment(Alignment))) {
     ScudoAllocator::FailureHandler::OnBadRequest();
     return errno_EINVAL;
   }
   void *Ptr = Instance.allocate(Size, Alignment, FromMemalign);
-  if (!Ptr)
+  if (UNLIKELY(!Ptr))
     return errno_ENOMEM;
   *MemPtr = Ptr;
   return 0;
 }
 
 void *scudoAlignedAlloc(uptr Alignment, uptr Size) {
-  // Alignment must be a power of 2, Size must be a multiple of Alignment.
-  if (UNLIKELY(!IsPowerOfTwo(Alignment) || (Size & (Alignment - 1)) != 0)) {
+  if (UNLIKELY(!CheckAlignedAllocAlignmentAndSize(Alignment, Size))) {
     errno = errno_EINVAL;
     return ScudoAllocator::FailureHandler::OnBadRequest();
   }
-  return checkPtr(Instance.allocate(Size, Alignment, FromMalloc));
+  return SetErrnoOnNull(Instance.allocate(Size, Alignment, FromMalloc));
 }
 
 uptr scudoMallocUsableSize(void *Ptr) {
   return Instance.getUsableSize(Ptr);
 }
 
 }  // namespace __scudo
 

lib/tsan/rtl/tsan_mman.cc

 //===-- tsan_mman.cc ------------------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file is a part of ThreadSanitizer (TSan), a race detector.
 //
 //===----------------------------------------------------------------------===//
+#include "sanitizer_common/sanitizer_allocator_checks.h"
 #include "sanitizer_common/sanitizer_allocator_interface.h"
 #include "sanitizer_common/sanitizer_common.h"
 #include "sanitizer_common/sanitizer_placement_new.h"
 #include "tsan_mman.h"
 #include "tsan_rtl.h"
 #include "tsan_report.h"
 #include "tsan_flags.h"
 

test/msan/allocator_returns_null.cc

 // RUN:   | FileCheck %s --check-prefix=CHECK-nCRASH
 // RUN: MSAN_OPTIONS=allocator_may_return_null=0 not %run %t new-nothrow 2>&1 \
 // RUN:   | FileCheck %s --check-prefix=CHECK-nnCRASH
 // RUN: MSAN_OPTIONS=allocator_may_return_null=1     %run %t new-nothrow 2>&1 \
 // RUN:   | FileCheck %s --check-prefix=CHECK-nnNULL
 
 
 #include <assert.h>
-#include <string.h>
+#include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <limits>
 #include <new>
 
 int main(int argc, char **argv) {
   // Disable stderr buffering. Needed on Windows.
   setvbuf(stderr, NULL, _IONBF, 0);
 
   assert(argc == 2);
#endif
   } else if (!strcmp(action, "new")) {
     x = operator new(kMaxAllowedMallocSizePlusOne);
   } else if (!strcmp(action, "new-nothrow")) {
     x = operator new(kMaxAllowedMallocSizePlusOne, std::nothrow);
   } else {
     assert(0);
   }
 
+  fprintf(stderr, "errno: %d\n", errno);
+
   // The NULL pointer is printed differently on different systems, while (long)0
   // is always the same.
   fprintf(stderr, "x: %lx\n", (long)x);
   free(x);
 
   return x != 0;
 }
 
 // CHECK-mCRASH: malloc:
 // CHECK-mCRASH: MemorySanitizer's allocator is terminating the process
 // CHECK-cCRASH: calloc:
 // CHECK-cCRASH: MemorySanitizer's allocator is terminating the process
 // CHECK-coCRASH: calloc-overflow:
 // CHECK-coCRASH: MemorySanitizer's allocator is terminating the process
 // CHECK-rCRASH: realloc:
 // CHECK-rCRASH: MemorySanitizer's allocator is terminating the process
 // CHECK-mrCRASH: realloc-after-malloc:
 // CHECK-mrCRASH: MemorySanitizer's allocator is terminating the process
 // CHECK-nCRASH: new:
 // CHECK-nCRASH: MemorySanitizer's allocator is terminating the process
 // CHECK-nnCRASH: new-nothrow:
 // CHECK-nnCRASH: MemorySanitizer's allocator is terminating the process
 
 // CHECK-mNULL: malloc:
+// CHECK-mNULL: errno: 12
 // CHECK-mNULL: x: 0
 // CHECK-cNULL: calloc:
+// CHECK-cNULL: errno: 12
 // CHECK-cNULL: x: 0
 // CHECK-coNULL: calloc-overflow:
+// CHECK-coNULL: errno: 12
 // CHECK-coNULL: x: 0
 // CHECK-rNULL: realloc:
+// CHECK-rNULL: errno: 12
 // CHECK-rNULL: x: 0
 // CHECK-mrNULL: realloc-after-malloc:
+// CHECK-mrNULL: errno: 12
 // CHECK-mrNULL: x: 0
 // CHECK-nnNULL: new-nothrow:
 // CHECK-nnNULL: x: 0