[PATCH v2 2/3] kernel32: Use RtlCreateUserStack().

[Zebediah Figura]

Planet Coaster allocates 128kB of stack (both reserve and commit) but expects
to be able to use at least one page more than that. Native Windows always
reserves at least 1MB of stack.

Signed-off-by: Zebediah Figura 
---
 dlls/kernel32/fiber.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/dlls/kernel32/fiber.c b/dlls/kernel32/fiber.c
index 151a6765a8bf..27abd78760c8 100644
--- a/dlls/kernel32/fiber.c
+++ b/dlls/kernel32/fiber.c
@@ -89,6 +89,8 @@ LPVOID WINAPI CreateFiberEx( SIZE_T stack_commit, SIZE_T stack_reserve, DWORD fl
                              LPFIBER_START_ROUTINE start, LPVOID param )
 {
     struct fiber_data *fiber;
+    INITIAL_TEB stack;
+    NTSTATUS status;

if (!(fiber = HeapAlloc( GetProcessHeap(), 0, sizeof(*fiber) )))
     {
@@ -96,15 +98,15 @@ LPVOID WINAPI CreateFiberEx( SIZE_T stack_commit, SIZE_T stack_reserve, DWORD fl
         return NULL;
     }

-    /* FIXME: should use the thread stack allocation routines here */
-    if (!stack_reserve) stack_reserve = 1024*1024;
-    if(!(fiber->stack_allocation = VirtualAlloc( 0, stack_reserve, MEM_COMMIT, PAGE_READWRITE )))
+    if ((status = RtlCreateUserStack( stack_commit, stack_reserve, 0, 1, 1, &stack )))
     {
-        HeapFree( GetProcessHeap(), 0, fiber );
+        SetLastError( RtlNtStatusToDosError(status) );
         return NULL;
     }
-    fiber->stack_base  = (char *)fiber->stack_allocation + stack_reserve;
-    fiber->stack_limit = fiber->stack_allocation;
+
+    fiber->stack_allocation = stack.DeallocationStack;
+    fiber->stack_base = stack.StackBase;
+    fiber->stack_limit = stack.StackLimit;
     fiber->param       = param;
     fiber->except      = (void *)-1;
     fiber->start       = start;
@@ -127,7 +129,7 @@ void WINAPI DeleteFiber( LPVOID fiber_ptr )
         HeapFree( GetProcessHeap(), 0, fiber );
         ExitThread(1);
     }
-    VirtualFree( fiber->stack_allocation, 0, MEM_RELEASE );
+    RtlFreeUserStack( fiber->stack_allocation );
     HeapFree( GetProcessHeap(), 0, fiber->fls_slots );
     HeapFree( GetProcessHeap(), 0, fiber );
 }