[PATCH v3 0/1] MR10068: msvcrt: Create copy of C++ exception object in std::rethrow_exception()

[Piotr Pawłowski (＠DEATH)]

Fixes: https://bugs.winehq.org/show_bug.cgi?id=59329

Resolves whole lot of foobar2000 crashes after media indexing or playback errors (verified).

Passes various C++ exception torture tests I quickly wrote.

Notes about alloca() use-

Size of C++ object is used, one that already existed elsewhere on stack, so it should not be an issue.

MS runtime appears to do the same - copy the exception object on stack before rethrowing.

--
  v3: msvcrt: Create copy of C++ exception object in std::rethrow_exception().
 
https://gitlab.winehq.org/wine/wine/-/merge_requests/10068

[PATCH v3 1/1] msvcrt: Create copy of C++ exception object in std::rethrow_exception(). Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=59329

[Piotr Pawłowski]

From: Piotr Pawłowski <[e-mail]>

---
 dlls/msvcp90/exception.c | 28 ++++++++++++++++++++++++----
 1 file changed, 24 insertions(+), 4 deletions(-)

diff --git a/dlls/msvcp90/exception.c b/dlls/msvcp90/exception.c
index ab8de5de782..1df0c3caf95 100644
--- a/dlls/msvcp90/exception.c
+++ b/dlls/msvcp90/exception.c
@@ -18,6 +18,7 @@
 
 #include <errno.h>
 #include <stdarg.h>
+#include <malloc.h>
 
 #define COBJMACROS
 
@@ -1077,6 +1078,9 @@ typedef struct
     LONG *ref; /* not binary compatible with native */
 } exception_ptr;
 
+static inline void copy_exception( void *object, void **dest, UINT catch_flags,
+                                   const cxx_type_info *type, uintptr_t base );
+
 static void exception_ptr_rethrow(const exception_ptr *ep)
 {
     TRACE("(%p)\n", ep);
@@ -1090,6 +1094,20 @@ static void exception_ptr_rethrow(const exception_ptr *ep)
         _CxxThrowException(&e, &exception_exception_type);
         return;
     }
+    if (ep->rec->ExceptionCode == CXX_EXCEPTION) {
+        void *e;
+        void *obj = (void*)ep->rec->ExceptionInformation[1];
+        const cxx_exception_type *et = (void*)ep->rec->ExceptionInformation[2];
+        uintptr_t base = cxx_rva_base( et );
+        const cxx_type_info_table *table = cxx_rva( et->type_info_table, base );
+        const cxx_type_info *ti = cxx_rva( table->info[0], base );
+        
+        e = alloca(ti->size);
+
+        copy_exception(obj, (void**)e, 0, ti, base);
+        _CxxThrowException(e, et);
+        return;
+    }
 
     RaiseException(ep->rec->ExceptionCode, ep->rec->ExceptionFlags & ~EXCEPTION_UNWINDING,
             ep->rec->NumberParameters, ep->rec->ExceptionInformation);
@@ -1138,10 +1156,6 @@ void __cdecl _Throw_C_error(int code)
 
     _CxxThrowException(&se, &system_error_exception_type);
 }
-#endif
-
-#if _MSVCP_VER >= 140
-void** CDECL __current_exception(void);
 
 /* compute the this pointer for a base class of a given type */
 static inline void *get_this_pointer( const this_ptr_offsets *off, void *object )
@@ -1219,6 +1233,10 @@ static inline void copy_exception( void *object, void **dest, UINT catch_flags,
     }
 }
 
+#endif
+
+#if _MSVCP_VER >= 140
+
 int __cdecl __uncaught_exceptions(void)
 {
     return *__processing_throw();
@@ -1302,6 +1320,8 @@ void __cdecl __ExceptionPtrRethrow(const exception_ptr *ep)
     exception_ptr_rethrow(ep);
 }
 
+void** CDECL __current_exception(void);
+
 /*********************************************************************
  * ?__ExceptionPtrCurrentException@@YAXPAX@Z
  * ?__ExceptionPtrCurrentException@@YAXPEAX@Z
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/10068

[Piotr Pawłowski (＠DEATH)]

Done, thanks for looking into it.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/10068#note_129729