ntdll: Keep the previous iteration of NonVolatileRegisters in call_function_handlers.

Some language specific handlers, called by call_handler, can use the NonVolatileRegisters to restore the context before running code, and that assumes that NonVolatileRegisters contains the frame pointer as it was within the function (before unwinding). Signed-off-by: Martin Storsjo <martin@martin.st> Signed-off-by: Alexandre Julliard <julliard@winehq.org>

ntdll: Keep the previous iteration of NonVolatileRegisters in call_function_handlers.
a8a944c2 · Martin Storsjo · Alexandre Julliard · 6c11d1d7 · a8a944c2
Commit a8a944c2 authored May 28, 2020 by Martin Storsjo Committed by Alexandre Julliard May 28, 2020
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signal_arm64.c dlls/ntdll/signal_arm64.c +5 -2

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--- a/dlls/ntdll/signal_arm64.c
+++ b/dlls/ntdll/signal_arm64.c
@@ -849,14 +849,16 @@ static NTSTATUS call_function_handlers( EXCEPTION_RECORD *rec, CONTEXT *orig_con
    EXCEPTION_REGISTRATION_RECORD *teb_frame = NtCurrentTeb()->Tib.ExceptionList;
    UNWIND_HISTORY_TABLE table;
    DISPATCHER_CONTEXT dispatch;
-    CONTEXT context;
+    CONTEXT context, prev_context;
    NTSTATUS status;

    context = *orig_context;
    dispatch.TargetPc      = 0;
    dispatch.ContextRecord = &context;
    dispatch.HistoryTable  = &table;
-    dispatch.NonVolatileRegisters = (BYTE *)&context.u.s.X19;
+    prev_context = context;
+    dispatch.NonVolatileRegisters = (BYTE *)&prev_context.u.s.X19;
+
    for (;;)
    {
        status = virtual_unwind( UNW_FLAG_EHANDLER, &dispatch, &context );
@@ -933,6 +935,7 @@ static NTSTATUS call_function_handlers( EXCEPTION_RECORD *rec, CONTEXT *orig_con
        }

        if (context.Sp == (ULONG64)NtCurrentTeb()->Tib.StackBase) break;
+        prev_context = context;
    }
    return STATUS_UNHANDLED_EXCEPTION;
 }