Fix use of uninitialized memory.
When creating an UnwindMapLocal fails in the Build() function call,
the destructor for UnwindMap is called. Unfortunately, the map_cursor_
member variable has not been initialized, so the call to destroy it
winds up operating on garbage data.
Part of this is a result of a bad class hierarchy, so this refactors
the classes slightly, and properly initializes the map_cursor_ member
variable in the base class.
Bug: 26931578
Change-Id: I885596bf65e4ef63559cee2c56cd41576d5ecc1b
diff --git a/libbacktrace/UnwindMap.h b/libbacktrace/UnwindMap.h
index e292016..111401f 100644
--- a/libbacktrace/UnwindMap.h
+++ b/libbacktrace/UnwindMap.h
@@ -29,29 +29,35 @@
class UnwindMap : public BacktraceMap {
public:
UnwindMap(pid_t pid);
- virtual ~UnwindMap();
-
- virtual bool Build();
unw_map_cursor_t* GetMapCursor() { return &map_cursor_; }
protected:
- virtual bool GenerateMap();
-
unw_map_cursor_t map_cursor_;
};
+class UnwindMapRemote : public UnwindMap {
+public:
+ UnwindMapRemote(pid_t pid);
+ virtual ~UnwindMapRemote();
+
+ bool Build() override;
+
+private:
+ bool GenerateMap();
+};
+
class UnwindMapLocal : public UnwindMap {
public:
UnwindMapLocal();
virtual ~UnwindMapLocal();
- virtual bool Build();
+ bool Build() override;
- virtual void FillIn(uintptr_t addr, backtrace_map_t* map);
+ void FillIn(uintptr_t addr, backtrace_map_t* map) override;
-protected:
- virtual bool GenerateMap();
+private:
+ bool GenerateMap();
bool map_created_;
};