From 8dc269c258e4554784f2fa13949e1a0f65d3d0c4 Mon Sep 17 00:00:00 2001
From: Timo Kreuzer <timo.kreuzer@reactos.org>
Date: Fri, 30 Apr 2010 22:47:44 +0000
Subject: [PATCH] [NTOSKRNL] - Fix RtlWalkFrameChain to do usermode back traces
 for threads that are not system threads. Also use _SEH2_YIELD when leaving
 the SEH block.

svn path=/trunk/; revision=47066
---
 reactos/ntoskrnl/rtl/libsupp.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/reactos/ntoskrnl/rtl/libsupp.c b/reactos/ntoskrnl/rtl/libsupp.c
index 27f78952c72..4a6c8bc55ea 100644
--- a/reactos/ntoskrnl/rtl/libsupp.c
+++ b/reactos/ntoskrnl/rtl/libsupp.c
@@ -317,7 +317,7 @@ RtlWalkFrameChain(OUT PVOID *Callers,
                                         &StackBegin,
                                         &StackEnd);
         if (!Result) return 0;
-    }
+        }
 
     /* Use a SEH block for maximum protection */
     _SEH2_TRY
@@ -331,12 +331,11 @@ RtlWalkFrameChain(OUT PVOID *Callers,
 
             /* Make sure we can trust the TEB and trap frame */
             if (!(Teb) ||
-                !(Thread->SystemThread) ||
                 (KeIsAttachedProcess()) ||
                 (KeGetCurrentIrql() >= DISPATCH_LEVEL))
             {
                 /* Invalid or unsafe attempt to get the stack */
-                return 0;
+                _SEH2_YIELD(return 0;)
             }
 
             /* Get the stack limits */
-- 
2.17.1