[PATCH 1/2] kernel32: Allocate at least 1MB of stack space in CreateFiberEx().

[Zebediah Figura]

Planet Coaster allocates 128KB of stack (both reserve and commit) but then
tries to use at least one page more. Testing shows that native Windows
always allocates at least 1MB of stack, for both 32-bit and 64-bit programs.

Signed-off-by: Zebediah Figura 
---
 dlls/kernel32/fiber.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/dlls/kernel32/fiber.c b/dlls/kernel32/fiber.c
index 151a6765a8bf..526ae57f2f42 100644
--- a/dlls/kernel32/fiber.c
+++ b/dlls/kernel32/fiber.c
@@ -97,7 +97,8 @@ LPVOID WINAPI CreateFiberEx( SIZE_T stack_commit, SIZE_T stack_reserve, DWORD fl
     }

/* FIXME: should use the thread stack allocation routines here */
-    if (!stack_reserve) stack_reserve = 1024*1024;
+    /* some applications try to use more stack than they allocate */
+    stack_reserve = max(stack_reserve, 1024 * 1024);
     if(!(fiber->stack_allocation = VirtualAlloc( 0, stack_reserve, MEM_COMMIT, PAGE_READWRITE )))
     {
         HeapFree( GetProcessHeap(), 0, fiber );

[PATCH 2/2] kernel32: Set up a guard page at the bottom of the fiber stack.

[Zebediah Figura]

Signed-off-by: Zebediah Figura 
---
 dlls/kernel32/fiber.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/dlls/kernel32/fiber.c b/dlls/kernel32/fiber.c
index 526ae57f2f42..8a3de81bb8ea 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;
+    SYSTEM_INFO si;
+    DWORD prev;

if (!(fiber = HeapAlloc( GetProcessHeap(), 0, sizeof(*fiber) )))
     {
@@ -96,16 +98,19 @@ LPVOID WINAPI CreateFiberEx( SIZE_T stack_commit, SIZE_T stack_reserve, DWORD fl
         return NULL;
     }

+    GetSystemInfo(&si);
+
     /* FIXME: should use the thread stack allocation routines here */
     /* some applications try to use more stack than they allocate */
-    stack_reserve = max(stack_reserve, 1024 * 1024);
-    if(!(fiber->stack_allocation = VirtualAlloc( 0, stack_reserve, MEM_COMMIT, PAGE_READWRITE )))
+    stack_reserve = max(stack_reserve, 1024 * 1024 - 3 * si.dwPageSize);
+    if(!(fiber->stack_allocation = VirtualAlloc( 0, stack_reserve + 3 * si.dwPageSize, MEM_COMMIT, PAGE_READWRITE )))
     {
         HeapFree( GetProcessHeap(), 0, fiber );
         return NULL;
     }
-    fiber->stack_base  = (char *)fiber->stack_allocation + stack_reserve;
-    fiber->stack_limit = fiber->stack_allocation;
+    VirtualProtect(fiber->stack_allocation, 3 * si.dwPageSize, PAGE_NOACCESS, &prev);
+    fiber->stack_base  = (char *)fiber->stack_allocation + 3 * si.dwPageSize + stack_reserve;
+    fiber->stack_limit = (char *)fiber->stack_allocation + 3 * si.dwPageSize;
     fiber->param       = param;
     fiber->except      = (void *)-1;
     fiber->start       = start;

[PATCH 2/2] kernel32: Set up a guard page at the bottom of the fiber stack.

[Alexandre Julliard]

Zebediah Figura  writes:
> @@ -96,16 +98,19 @@ LPVOID WINAPI CreateFiberEx( SIZE_T stack_commit, SIZE_T stack_reserve, DWORD fl
>          return NULL;
>      }
> - GetSystemInfo(&si);
> - /* FIXME: should use the thread stack allocation routines here */
>    /* some applications try to use more stack than they allocate */
> - stack_reserve = max(stack_reserve, 1024 * 1024);
> - if(!(fiber->stack_allocation = VirtualAlloc( 0, stack_reserve, MEM_COMMIT, PAGE_READWRITE )))
> - stack_reserve = max(stack_reserve, 1024 * 1024 - 3 * si.dwPageSize);
> - if(!(fiber->stack_allocation = VirtualAlloc( 0, stack_reserve + 3 * si.dwPageSize, MEM_COMMIT, PAGE_READWRITE )))
> {
>     HeapFree( GetProcessHeap(), 0, fiber );
>     return NULL;
> }
> - fiber->stack_base  = (char *)fiber->stack_allocation + stack_reserve;
> - fiber->stack_limit = fiber->stack_allocation;
> - VirtualProtect(fiber->stack_allocation, 3 * si.dwPageSize, PAGE_NOACCESS, &prev);
> - fiber->stack_base  = (char *)fiber->stack_allocation + 3 * si.dwPageSize + stack_reserve;
> - fiber->stack_limit = (char *)fiber->stack_allocation + 3 * si.dwPageSize;

Like the FIXME says, this should reuse the thread stack allocation
routines, instead of reinventing them.

Currently it's implemented in virtual_alloc_thread_stack(), but this
could be adapted and exported as RtlCreateUserStack().

[PATCH 2/2] kernel32: Set up a guard page at the bottom of the fiber stack.

[Zebediah Figura]

On 6/12/19 3:36 PM, Alexandre Julliard wrote:
> Zebediah Figura  writes:
> > @@ -96,16 +98,19 @@ LPVOID WINAPI CreateFiberEx( SIZE_T stack_commit, SIZE_T stack_reserve, DWORD fl
> >           return NULL;
> >       }
> > - GetSystemInfo(&si);
> > -
> > /* FIXME: should use the thread stack allocation routines here */
> > /* some applications try to use more stack than they allocate */
> > - stack_reserve = max(stack_reserve, 1024 * 1024);
> > - if(!(fiber->stack_allocation = VirtualAlloc( 0, stack_reserve, MEM_COMMIT, PAGE_READWRITE )))
> > - stack_reserve = max(stack_reserve, 1024 * 1024 - 3 * si.dwPageSize);
> > - if(!(fiber->stack_allocation = VirtualAlloc( 0, stack_reserve + 3 * si.dwPageSize, MEM_COMMIT, PAGE_READWRITE )))
> >  {
> >      HeapFree( GetProcessHeap(), 0, fiber );
> >      return NULL;
> >  }
> > - fiber->stack_base  = (char *)fiber->stack_allocation + stack_reserve;
> > - fiber->stack_limit = fiber->stack_allocation;
> > - VirtualProtect(fiber->stack_allocation, 3 * si.dwPageSize, PAGE_NOACCESS, &prev);
> > - fiber->stack_base  = (char *)fiber->stack_allocation + 3 * si.dwPageSize + stack_reserve;
> > - fiber->stack_limit = (char *)fiber->stack_allocation + 3 * si.dwPageSize;
>
> Like the FIXME says, this should reuse the thread stack allocation
> routines, instead of reinventing them.
>
> Currently it's implemented in virtual_alloc_thread_stack(), but this
> could be adapted and exported as RtlCreateUserStack().

Sure, I'll use that approach instead.