Martin Storsjo : ntdll: Fix unwinding functions that end with a branch instruction.
Alexandre Julliard
julliard at winehq.org
Thu May 28 17:11:10 CDT 2020
Module: wine
Branch: master
Commit: babbf352b651dac6458335e71a980317b3b42386
URL: https://source.winehq.org/git/wine.git/?a=commit;h=babbf352b651dac6458335e71a980317b3b42386
Author: Martin Storsjo <martin at martin.st>
Date: Thu May 28 11:14:42 2020 +0300
ntdll: Fix unwinding functions that end with a branch instruction.
This happens with functions that aren't intended to return e.g. like
_Unwind_Resume. In these cases, the return address is outside of the
function (the first instruction in the next function).
Set the flag CONTEXT_UNWOUND_TO_CALL after unwinding to a callsite,
and if this flag is set, look up a RUNTIME_FUNCTION based on
Control.Pc - 4.
This isn't a complete (nor probably entirely correct) implementation
of the flag CONTEXT_UNWOUND_TO_CALL, but it practically seems to
work fine and fixes a large number of unwinding cases.
Signed-off-by: Martin Storsjo <martin at martin.st>
Signed-off-by: Alexandre Julliard <julliard at winehq.org>
---
dlls/ntdll/signal_arm64.c | 13 ++++++++++++-
include/winnt.h | 2 ++
2 files changed, 14 insertions(+), 1 deletion(-)
diff --git a/dlls/ntdll/signal_arm64.c b/dlls/ntdll/signal_arm64.c
index 4c9017b9e2..cdffda7a12 100644
--- a/dlls/ntdll/signal_arm64.c
+++ b/dlls/ntdll/signal_arm64.c
@@ -527,6 +527,7 @@ static NTSTATUS libunwind_virtual_unwind( ULONG_PTR ip, ULONG_PTR *frame, CONTEX
*frame = context->Sp;
context->Pc = context->u.s.Lr;
context->Sp = context->Sp + sizeof(ULONG64);
+ context->ContextFlags |= CONTEXT_UNWOUND_TO_CALL;
return STATUS_SUCCESS;
}
@@ -577,6 +578,7 @@ static NTSTATUS libunwind_virtual_unwind( ULONG_PTR ip, ULONG_PTR *frame, CONTEX
unw_get_reg( &cursor, UNW_AARCH64_X30, (unw_word_t *)&context->u.s.Lr );
unw_get_reg( &cursor, UNW_AARCH64_SP, (unw_word_t *)&context->Sp );
context->Pc = context->u.s.Lr;
+ context->ContextFlags |= CONTEXT_UNWOUND_TO_CALL;
TRACE( "next function pc=%016lx%s\n", context->Pc, rc ? "" : " (last frame)" );
TRACE(" x0=%016lx x1=%016lx x2=%016lx x3=%016lx\n",
@@ -614,10 +616,17 @@ static NTSTATUS virtual_unwind( ULONG type, DISPATCHER_CONTEXT *dispatch, CONTEX
dispatch->ScopeIndex = 0;
dispatch->EstablisherFrame = 0;
dispatch->ControlPc = context->Pc;
+ /*
+ * TODO: CONTEXT_UNWOUND_TO_CALL should be cleared if unwound past a
+ * signal frame.
+ */
+ dispatch->ControlPcIsUnwound = (context->ContextFlags & CONTEXT_UNWOUND_TO_CALL) != 0;
/* first look for PE exception information */
- if ((dispatch->FunctionEntry = lookup_function_info( context->Pc, &dispatch->ImageBase, &module )))
+ if ((dispatch->FunctionEntry = lookup_function_info(
+ context->Pc - (dispatch->ControlPcIsUnwound ? 4 : 0),
+ &dispatch->ImageBase, &module )))
{
dispatch->LanguageHandler = RtlVirtualUnwind( type, dispatch->ImageBase, context->Pc,
dispatch->FunctionEntry, context,
@@ -654,6 +663,7 @@ static NTSTATUS virtual_unwind( ULONG type, DISPATCHER_CONTEXT *dispatch, CONTEX
dispatch->EstablisherFrame = context->u.s.Fp;
dispatch->LanguageHandler = NULL;
context->Pc = context->u.s.Lr;
+ context->ContextFlags |= CONTEXT_UNWOUND_TO_CALL;
return STATUS_SUCCESS;
}
@@ -1758,6 +1768,7 @@ PVOID WINAPI RtlVirtualUnwind( ULONG type, ULONG_PTR base, ULONG_PTR pc,
TRACE( "ret: lr=%lx sp=%lx handler=%p\n", context->u.s.Lr, context->Sp, handler );
context->Pc = context->u.s.Lr;
+ context->ContextFlags |= CONTEXT_UNWOUND_TO_CALL;
*frame_ret = context->Sp;
return handler;
}
diff --git a/include/winnt.h b/include/winnt.h
index 34951766dd..aa4daaa55f 100644
--- a/include/winnt.h
+++ b/include/winnt.h
@@ -1863,6 +1863,8 @@ NTSYSAPI PVOID WINAPI RtlVirtualUnwind(DWORD,DWORD,DWORD,RUNTIME_FUNCTION*,CONTE
#define CONTEXT_FLOATING_POINT (CONTEXT_ARM64 | 0x00000004)
#define CONTEXT_DEBUG_REGISTERS (CONTEXT_ARM64 | 0x00000008)
+#define CONTEXT_UNWOUND_TO_CALL 0x20000000
+
#define CONTEXT_FULL (CONTEXT_CONTROL | CONTEXT_INTEGER)
#define CONTEXT_ALL (CONTEXT_CONTROL | CONTEXT_INTEGER | CONTEXT_FLOATING_POINT | CONTEXT_DEBUG_REGISTERS)
More information about the wine-cvs
mailing list