[sanitizer] Support "alloc_dealloc_mismatch" suppressions

This adds a stack-based suppressions for alloc-dealloc-mismatch
violations, using the function name to match.

Author: andrewjcg

compiler-rt/lib/asan/asan_allocator.cpp

@@ -21,6 +21,7 @@
 #include "asan_poisoning.h"
 #include "asan_report.h"
 #include "asan_stack.h"
+#include "asan_suppressions.h"
 #include "asan_thread.h"
 #include "lsan/lsan_common.h"
 #include "sanitizer_common/sanitizer_allocator_checks.h"
@@ -732,7 +733,8 @@ struct Allocator {
     if (!AtomicallySetQuarantineFlagIfAllocated(m, ptr, stack)) return;
 
     if (m->alloc_type != alloc_type) {
-      if (atomic_load(&alloc_dealloc_mismatch, memory_order_acquire)) {
+      if (atomic_load(&alloc_dealloc_mismatch, memory_order_acquire) &&
+          !IsAllocDeallocMismatchSuppressed(stack)) {
         ReportAllocTypeMismatch((uptr)ptr, stack, (AllocType)m->alloc_type,
                                 (AllocType)alloc_type);
       }

compiler-rt/lib/asan/asan_suppressions.cpp

@@ -26,9 +26,10 @@ static const char kInterceptorName[] = "interceptor_name";
 static const char kInterceptorViaFunction[] = "interceptor_via_fun";
 static const char kInterceptorViaLibrary[] = "interceptor_via_lib";
 static const char kODRViolation[] = "odr_violation";
+static const char kAllocDeallocMismatch[] = "alloc_dealloc_mismatch";
 static const char *kSuppressionTypes[] = {
     kInterceptorName, kInterceptorViaFunction, kInterceptorViaLibrary,
-    kODRViolation};
+    kODRViolation, kAllocDeallocMismatch};
 
 SANITIZER_INTERFACE_WEAK_DEF(const char *, __asan_default_suppressions, void) {
   return "";
@@ -62,6 +63,44 @@ bool IsODRViolationSuppressed(const char *global_var_name) {
   return suppression_ctx->Match(global_var_name, kODRViolation, &s);
 }
 
+bool IsAddrSuppressed(const char *suppression, Symbolizer *symbolizer,
+                      uptr addr) {
+  CHECK(suppression_ctx);
+  CHECK(suppression_ctx->HasSuppressionType(suppression));
+  CHECK(symbolizer);
+  SymbolizedStackHolder symbolized_stack(symbolizer->SymbolizePC(addr));
+  const SymbolizedStack *frames = symbolized_stack.get();
+  CHECK(frames);
+  for (const SymbolizedStack *cur = frames; cur; cur = cur->next) {
+    const char *function_name = cur->info.function;
+    if (!function_name) {
+      continue;
+    }
+    // Match suppressions.
+    Suppression *s;
+    if (suppression_ctx->Match(function_name, suppression, &s)) {
+      return true;
+    }
+  }
+  return false;
+}
+
+bool IsAllocDeallocMismatchSuppressed(const StackTrace *stack) {
+  CHECK(suppression_ctx);
+  if (!suppression_ctx->HasSuppressionType(kAllocDeallocMismatch)) {
+    return false;
+  }
+  Symbolizer *symbolizer = Symbolizer::GetOrInit();
+  for (uptr i = 0; i < stack->size && stack->trace[i]; i++) {
+    uptr addr = stack->trace[i];
+    // Match "alloc_dealloc_mismatch" suppressions.
+    if (IsAddrSuppressed(kAllocDeallocMismatch, symbolizer, addr)) {
+      return true;
+    }
+  }
+  return false;
+}
+
 bool IsStackTraceSuppressed(const StackTrace *stack) {
   if (!HaveStackTraceBasedSuppressions())
     return false;
@@ -80,19 +119,9 @@ bool IsStackTraceSuppressed(const StackTrace *stack) {
     }
 
     if (suppression_ctx->HasSuppressionType(kInterceptorViaFunction)) {
-      SymbolizedStackHolder symbolized_stack(symbolizer->SymbolizePC(addr));
-      const SymbolizedStack *frames = symbolized_stack.get();
-      CHECK(frames);
-      for (const SymbolizedStack *cur = frames; cur; cur = cur->next) {
-        const char *function_name = cur->info.function;
-        if (!function_name) {
-          continue;
-        }
-        // Match "interceptor_via_fun" suppressions.
-        if (suppression_ctx->Match(function_name, kInterceptorViaFunction,
-                                   &s)) {
-          return true;
-        }
+      // Match "interceptor_via_func" suppressions.
+      if (IsAddrSuppressed(kInterceptorViaFunction, symbolizer, addr)) {
+        return true;
       }
     }
   }

compiler-rt/lib/asan/asan_suppressions.h

@@ -23,6 +23,7 @@ bool IsInterceptorSuppressed(const char *interceptor_name);
 bool HaveStackTraceBasedSuppressions();
 bool IsStackTraceSuppressed(const StackTrace *stack);
 bool IsODRViolationSuppressed(const char *global_var_name);
+bool IsAllocDeallocMismatchSuppressed(const StackTrace *stack);
 
 } // namespace __asan
 

compiler-rt/test/asan/TestCases/suppressions-alloc-dealloc-mismatch.cpp

@@ -0,0 +1,26 @@
+// Check that without suppressions, we catch the issue.
+// RUN: %clangxx_asan -O0 %s -o %t
+// RUN: not %run %t 2>&1 | FileCheck --check-prefix=CHECK-CRASH %s
+
+// RUN: echo "alloc_dealloc_mismatch:function" > %t.supp
+// RUN: %clangxx_asan -O0 %s -o %t && %env_asan_opts=suppressions='"%t.supp"' %run %t 2>&1 | FileCheck --check-prefix=CHECK-IGNORE %s
+// RUN: %clangxx_asan -O3 %s -o %t && %env_asan_opts=suppressions='"%t.supp"' %run %t 2>&1 | FileCheck --check-prefix=CHECK-IGNORE %s
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+void function() {
+  char *a = (char *)malloc(6);
+  a[0] = '\0';
+  size_t len = strlen(a);
+  delete a; // BOOM
+  fprintf(stderr, "strlen ignored, len = %zu\n", len);
+}
+
+int main() { function(); }
+
+// CHECK-CRASH: AddressSanitizer: alloc-dealloc-mismatch
+// CHECK-CRASH-NOT: strlen ignored
+// CHECK-IGNORE-NOT: AddressSanitizer: alloc-dealloc-mismatch
+// CHECK-IGNORE: strlen ignored