From b16672d91d47737e813b073b544c4139fda3fe72 Mon Sep 17 00:00:00 2001
From: Filipe Cabecinhas <me@filcab.net>
Date: Wed, 31 Aug 2016 07:38:09 +0000
Subject: [PATCH] Reify ErrorDoubleFree

Summary: Keep reifying other errors.

Reviewers: kcc, samsonov

Subscribers: llvm-commits, kubabrecka

Differential Revision: https://reviews.llvm.org/D23717

llvm-svn: 280201
---
 compiler-rt/lib/asan/asan_errors.cc | 18 ++++++++++++++++++
 compiler-rt/lib/asan/asan_errors.h  | 25 +++++++++++++++++++++++++
 compiler-rt/lib/asan/asan_report.cc | 17 ++---------------
 3 files changed, 45 insertions(+), 15 deletions(-)

diff --git a/compiler-rt/lib/asan/asan_errors.cc b/compiler-rt/lib/asan/asan_errors.cc
index ea30c1c..b1ab07e 100644
--- a/compiler-rt/lib/asan/asan_errors.cc
+++ b/compiler-rt/lib/asan/asan_errors.cc
@@ -13,6 +13,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "asan_errors.h"
+#include "asan_descriptions.h"
 #include "asan_stack.h"
 
 namespace __asan {
@@ -33,4 +34,21 @@ void ErrorStackOverflow::Print() {
   ReportErrorSummary("stack-overflow", &stack);
 }
 
+void ErrorDoubleFree::Print() {
+  Decorator d;
+  Printf("%s", d.Warning());
+  char tname[128];
+  Report(
+      "ERROR: AddressSanitizer: attempting double-free on %p in "
+      "thread T%d%s:\n",
+      addr_description.addr, tid,
+      ThreadNameWithParenthesis(tid, tname, sizeof(tname)));
+  Printf("%s", d.EndWarning());
+  GET_STACK_TRACE_FATAL(second_free_stack->trace[0],
+                        second_free_stack->top_frame_bp);
+  stack.Print();
+  addr_description.Print();
+  ReportErrorSummary("double-free", &stack);
+}
+
 }  // namespace __asan
diff --git a/compiler-rt/lib/asan/asan_errors.h b/compiler-rt/lib/asan/asan_errors.h
index 87bc869..637bb44 100644
--- a/compiler-rt/lib/asan/asan_errors.h
+++ b/compiler-rt/lib/asan/asan_errors.h
@@ -44,9 +44,27 @@ struct ErrorStackOverflow : ErrorBase {
   void Print();
 };
 
+struct ErrorDoubleFree : ErrorBase {
+  u32 tid;
+  HeapAddressDescription addr_description;
+  // ErrorDoubleFree doesn't own the stack trace.
+  BufferedStackTrace *second_free_stack;
+  // VS2013 doesn't implement unrestricted unions, so we need a trivial default
+  // constructor
+  ErrorDoubleFree() = default;
+  ErrorDoubleFree(uptr addr, u32 tid_, BufferedStackTrace *stack)
+      : tid(tid_), second_free_stack(stack) {
+    CHECK_GT(second_free_stack->size, 0);
+    GetHeapAddressInformation(addr, 1, &addr_description);
+    scariness.Scare(42, "double-free");
+  }
+  void Print();
+};
+
 enum ErrorKind {
   kErrorKindInvalid = 0,
   kErrorKindStackOverflow,
+  kErrorKindDoubleFree,
 };
 
 struct ErrorDescription {
@@ -58,11 +76,15 @@ struct ErrorDescription {
   // add a lot of code and the benefit wouldn't be that big.
   union {
     ErrorStackOverflow stack_overflow;
+    ErrorDoubleFree double_free;
   };
   ErrorDescription() { internal_memset(this, 0, sizeof(*this)); }
   ErrorDescription(const ErrorStackOverflow &e)  // NOLINT
       : kind(kErrorKindStackOverflow),
         stack_overflow(e) {}
+  ErrorDescription(const ErrorDoubleFree &e)  // NOLINT
+      : kind(kErrorKindDoubleFree),
+        double_free(e) {}
 
   bool IsValid() { return kind != kErrorKindInvalid; }
   void Print() {
@@ -70,6 +92,9 @@ struct ErrorDescription {
       case kErrorKindStackOverflow:
         stack_overflow.Print();
         return;
+      case kErrorKindDoubleFree:
+        double_free.Print();
+        return;
       case kErrorKindInvalid:
         CHECK(0);
     }
diff --git a/compiler-rt/lib/asan/asan_report.cc b/compiler-rt/lib/asan/asan_report.cc
index c8395a5..d4dfdc9 100644
--- a/compiler-rt/lib/asan/asan_report.cc
+++ b/compiler-rt/lib/asan/asan_report.cc
@@ -388,21 +388,8 @@ void ReportDeadlySignal(const char *description, const SignalContext &sig) {
 
 void ReportDoubleFree(uptr addr, BufferedStackTrace *free_stack) {
   ScopedInErrorReport in_report;
-  Decorator d;
-  Printf("%s", d.Warning());
-  char tname[128];
-  u32 curr_tid = GetCurrentTidOrInvalid();
-  Report("ERROR: AddressSanitizer: attempting double-free on %p in "
-         "thread T%d%s:\n",
-         addr, curr_tid,
-         ThreadNameWithParenthesis(curr_tid, tname, sizeof(tname)));
-  Printf("%s", d.EndWarning());
-  CHECK_GT(free_stack->size, 0);
-  ScarinessScore::PrintSimple(42, "double-free");
-  GET_STACK_TRACE_FATAL(free_stack->trace[0], free_stack->top_frame_bp);
-  stack.Print();
-  DescribeAddressIfHeap(addr);
-  ReportErrorSummary("double-free", &stack);
+  ErrorDoubleFree error{addr, GetCurrentTidOrInvalid(), free_stack};  // NOLINT
+  in_report.ReportError(error);
 }
 
 void ReportNewDeleteSizeMismatch(uptr addr, uptr alloc_size, uptr delete_size,
-- 
2.7.4