ntdll: Use wrapper function for consolidate callback on x86_64.

dlls/ntdll/signal_x86_64.c

@@ -3288,6 +3288,64 @@ static void call_teb_unwind_handler( EXCEPTION_RECORD *rec, DISPATCHER_CONTEXT *
 }
 
 
+/**********************************************************************
+ *           call_consolidate_callback
+ *
+ * Wrapper function to call a consolidate callback from a fake frame.
+ * If the callback executes RtlUnwindEx (like for example done in C++ handlers),
+ * we have to skip all frames which were already processed. To do that we
+ * trick the unwinding functions into thinking the call came from somewhere
+ * else. All CFI instructions are either DW_CFA_def_cfa_expression or
+ * DW_CFA_expression, and the expressions have the following format:
+ *
+ * DW_OP_breg6; sleb128 0x10            | Load %rbp + 0x10
+ * DW_OP_deref                          | Get *(%rbp + 0x10) == context
+ * DW_OP_plus_uconst; uleb128 <OFFSET>  | Add offset to get struct member
+ * [DW_OP_deref]                        | Dereference, only for CFA
+ */
+extern void * WINAPI call_consolidate_callback( CONTEXT *context,
+                                                void *(CALLBACK *callback)(EXCEPTION_RECORD *),
+                                                EXCEPTION_RECORD *rec );
+__ASM_GLOBAL_FUNC( call_consolidate_callback,
+                   "pushq %rbp\n\t"
+                   __ASM_CFI(".cfi_adjust_cfa_offset 8\n\t")
+                   __ASM_CFI(".cfi_rel_offset %rbp,0\n\t")
+                   "movq %rsp,%rbp\n\t"
+                   __ASM_CFI(".cfi_def_cfa_register %rbp\n\t")
+                   "subq $0x20,%rsp\n\t"
+                   "movq %rcx,0x10(%rbp)\n\t"
+                   __ASM_CFI(".cfi_remember_state\n\t")
+                   __ASM_CFI(".cfi_escape 0x0f,0x07,0x76,0x10,0x06,0x23,0x98,0x01,0x06\n\t") /* CFA    */
+                   __ASM_CFI(".cfi_escape 0x10,0x03,0x06,0x76,0x10,0x06,0x23,0x90,0x01\n\t") /* %rbx   */
+                   __ASM_CFI(".cfi_escape 0x10,0x04,0x06,0x76,0x10,0x06,0x23,0xa8,0x01\n\t") /* %rsi   */
+                   __ASM_CFI(".cfi_escape 0x10,0x05,0x06,0x76,0x10,0x06,0x23,0xb0,0x01\n\t") /* %rdi   */
+                   __ASM_CFI(".cfi_escape 0x10,0x06,0x06,0x76,0x10,0x06,0x23,0xa0,0x01\n\t") /* %rbp   */
+                   __ASM_CFI(".cfi_escape 0x10,0x0c,0x06,0x76,0x10,0x06,0x23,0xd8,0x01\n\t") /* %r12   */
+                   __ASM_CFI(".cfi_escape 0x10,0x0d,0x06,0x76,0x10,0x06,0x23,0xe0,0x01\n\t") /* %r13   */
+                   __ASM_CFI(".cfi_escape 0x10,0x0e,0x06,0x76,0x10,0x06,0x23,0xe8,0x01\n\t") /* %r14   */
+                   __ASM_CFI(".cfi_escape 0x10,0x0f,0x06,0x76,0x10,0x06,0x23,0xf0,0x01\n\t") /* %r15   */
+                   __ASM_CFI(".cfi_escape 0x10,0x10,0x06,0x76,0x10,0x06,0x23,0xf8,0x01\n\t") /* %rip   */
+                   __ASM_CFI(".cfi_escape 0x10,0x17,0x06,0x76,0x10,0x06,0x23,0x80,0x04\n\t") /* %xmm6  */
+                   __ASM_CFI(".cfi_escape 0x10,0x18,0x06,0x76,0x10,0x06,0x23,0x90,0x04\n\t") /* %xmm7  */
+                   __ASM_CFI(".cfi_escape 0x10,0x19,0x06,0x76,0x10,0x06,0x23,0xa0,0x04\n\t") /* %xmm8  */
+                   __ASM_CFI(".cfi_escape 0x10,0x1a,0x06,0x76,0x10,0x06,0x23,0xb0,0x04\n\t") /* %xmm9  */
+                   __ASM_CFI(".cfi_escape 0x10,0x1b,0x06,0x76,0x10,0x06,0x23,0xc0,0x04\n\t") /* %xmm10 */
+                   __ASM_CFI(".cfi_escape 0x10,0x1c,0x06,0x76,0x10,0x06,0x23,0xd0,0x04\n\t") /* %xmm11 */
+                   __ASM_CFI(".cfi_escape 0x10,0x1d,0x06,0x76,0x10,0x06,0x23,0xe0,0x04\n\t") /* %xmm12 */
+                   __ASM_CFI(".cfi_escape 0x10,0x1e,0x06,0x76,0x10,0x06,0x23,0xf0,0x04\n\t") /* %xmm13 */
+                   __ASM_CFI(".cfi_escape 0x10,0x1f,0x06,0x76,0x10,0x06,0x23,0x80,0x05\n\t") /* %xmm14 */
+                   __ASM_CFI(".cfi_escape 0x10,0x20,0x06,0x76,0x10,0x06,0x23,0x90,0x05\n\t") /* %xmm15 */
+                   "movq %r8,%rcx\n\t"
+                   "callq *%rdx\n\t"
+                   __ASM_CFI(".cfi_restore_state\n\t")
+                   "movq %rbp,%rsp\n\t"
+                   __ASM_CFI(".cfi_def_cfa_register %rsp\n\t")
+                   "popq %rbp\n\t"
+                   __ASM_CFI(".cfi_adjust_cfa_offset -8\n\t")
+                   __ASM_CFI(".cfi_same_value %rbp\n\t")
+                   "ret")
+
+
 /*******************************************************************
  *		RtlUnwindEx (NTDLL.@)
  */
@@ -3474,8 +3532,9 @@ void WINAPI RtlUnwindEx( PVOID end_frame, PVOID target_ip, EXCEPTION_RECORD *rec
     else if (rec->ExceptionCode == STATUS_UNWIND_CONSOLIDATE && rec->NumberParameters >= 1)
     {
         PVOID (CALLBACK *consolidate)(EXCEPTION_RECORD *) = (void *)rec->ExceptionInformation[0];
-        TRACE( "calling consolidate callback %p\n", consolidate );
-        target_ip = consolidate( rec );
+        TRACE( "calling consolidate callback %p (rec=%p)\n", consolidate, rec );
+        target_ip = call_consolidate_callback( context, consolidate, rec );
+        TRACE( "-> target=%p\n", target_ip );
     }
     context->Rax = (ULONG64)retval;
     context->Rip = (ULONG64)target_ip;