[sanitizer] Implement reallocarray.

Summary:
It's a cross of calloc and realloc. Sanitizers implement calloc-like check for size
overflow.

Reviewers: vitalybuka, kcc

Subscribers: kubamracek, #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D61108

llvm-svn: 359708

3 files changed, 17 insertions, 0 deletions

diff --git a/compiler-rt/lib/msan/msan.h b/compiler-rt/lib/msan/msan.h
index 211256833bd..ac5f67e6ab3 100644
--- a/compiler-rt/lib/msan/msan.h
+++ b/compiler-rt/lib/msan/msan.h
@@ -288,6 +288,7 @@ 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_reallocarray(void *ptr, uptr nmemb, 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);
diff --git a/compiler-rt/lib/msan/msan_allocator.cc b/compiler-rt/lib/msan/msan_allocator.cc
index 48430b62133..8bf8fda061c 100644
--- a/compiler-rt/lib/msan/msan_allocator.cc
+++ b/compiler-rt/lib/msan/msan_allocator.cc
@@ -261,6 +261,16 @@ void *msan_realloc(void *ptr, uptr size, StackTrace *stack) {
   return SetErrnoOnNull(MsanReallocate(stack, ptr, size, sizeof(u64)));
 }
 
+void *msan_reallocarray(void *ptr, uptr nmemb, uptr size, StackTrace *stack) {
+  if (UNLIKELY(CheckForCallocOverflow(size, nmemb))) {
+    errno = errno_ENOMEM;
+    if (AllocatorMayReturnNull())
+      return nullptr;
+    ReportReallocArrayOverflow(nmemb, size, stack);
+  }
+  return msan_realloc(ptr, nmemb * size, stack);
+}
+
 void *msan_valloc(uptr size, StackTrace *stack) {
   return SetErrnoOnNull(MsanAllocate(stack, size, GetPageSizeCached(), false));
 }
diff --git a/compiler-rt/lib/msan/msan_interceptors.cc b/compiler-rt/lib/msan/msan_interceptors.cc
index f5120809ee3..f67cfe48916 100644
--- a/compiler-rt/lib/msan/msan_interceptors.cc
+++ b/compiler-rt/lib/msan/msan_interceptors.cc
@@ -907,6 +907,11 @@ INTERCEPTOR(void *, realloc, void *ptr, SIZE_T size) {
   return msan_realloc(ptr, size, &stack);
 }
 
+INTERCEPTOR(void *, reallocarray, void *ptr, SIZE_T nmemb, SIZE_T size) {
+  GET_MALLOC_STACK_TRACE;
+  return msan_reallocarray(ptr, nmemb, size, &stack);
+}
+
 INTERCEPTOR(void *, malloc, SIZE_T size) {
   GET_MALLOC_STACK_TRACE;
   if (UNLIKELY(!msan_inited))
@@ -1597,6 +1602,7 @@ void InitializeInterceptors() {
   INTERCEPT_FUNCTION(malloc);
   INTERCEPT_FUNCTION(calloc);
   INTERCEPT_FUNCTION(realloc);
+  INTERCEPT_FUNCTION(reallocarray);
   INTERCEPT_FUNCTION(free);
   MSAN_MAYBE_INTERCEPT_CFREE;
   MSAN_MAYBE_INTERCEPT_MALLOC_USABLE_SIZE;