Martin Storsjö : ntdll: Use ControlPcIsUnwound for the RtlVirtualUnwind pc parameter in virtual_unwind.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: d007c91d46bb9868ccde0c32865c616b1f255827
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=d007c91d46bb9868ccde0c32865c616b1f255827

Author: Martin Storsjö <martin at martin.st>
Date:   Tue Jun  7 14:10:07 2022 +0300

ntdll: Use ControlPcIsUnwound for the RtlVirtualUnwind pc parameter in virtual_unwind.

Don't just use ControlPcIsUnwound for picking which RUNTIME_FUNCTION
to use, but also use it for adjusting the pc value that is passed
to RtlVirtualUnwind.

This fixes one testcase (that I had missed to build and run before),
where the pc points at the start of an epilogue (which would mean
that no handler is returned from RtlVirtualUnwind). By taking
ControlPcIsUnwound and adjusting the pc pointer, the unwind handler
is returned and executed.

Signed-off-by: Martin Storsjö <martin at martin.st>

---

 dlls/ntdll/signal_arm.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/dlls/ntdll/signal_arm.c b/dlls/ntdll/signal_arm.c
index 01c911660de..c4cf557edaf 100644
--- a/dlls/ntdll/signal_arm.c
+++ b/dlls/ntdll/signal_arm.c
@@ -133,6 +133,7 @@ static NTSTATUS virtual_unwind( ULONG type, DISPATCHER_CONTEXT *dispatch, CONTEX
 {
     LDR_DATA_TABLE_ENTRY *module;
     NTSTATUS status;
+    DWORD pc;
 
     dispatch->ImageBase        = 0;
     dispatch->ScopeIndex       = 0;
@@ -143,14 +144,14 @@ static NTSTATUS virtual_unwind( ULONG type, DISPATCHER_CONTEXT *dispatch, CONTEX
      * signal frame.
      */
     dispatch->ControlPcIsUnwound = (context->ContextFlags & CONTEXT_UNWOUND_TO_CALL) != 0;
+    pc = context->Pc - (dispatch->ControlPcIsUnwound ? 2 : 0);
 
     /* first look for PE exception information */
 
-    if ((dispatch->FunctionEntry = lookup_function_info(
-             context->Pc - (dispatch->ControlPcIsUnwound ? 2 : 0),
+    if ((dispatch->FunctionEntry = lookup_function_info(pc,
              (ULONG_PTR*)&dispatch->ImageBase, &module )))
     {
-        dispatch->LanguageHandler = RtlVirtualUnwind( type, dispatch->ImageBase, context->Pc,
+        dispatch->LanguageHandler = RtlVirtualUnwind( type, dispatch->ImageBase, pc,
                                                       dispatch->FunctionEntry, context,
                                                       &dispatch->HandlerData, (ULONG_PTR *)&dispatch->EstablisherFrame,
                                                       NULL );