[PATCH v3 0/2] MR4699: wined3d: Store the resource heap memory pointer directly.

[Rémi Bernon (＠rbernon)]

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=55773

--
  v3: wined3d: Store the resource heap memory pointer separately.
      wined3d: Add more padding to resource memory allocations.

https://gitlab.winehq.org/wine/wine/-/merge_requests/4699

[PATCH v3 1/2] wined3d: Add more padding to resource memory allocations.

[Rémi Bernon]

From: Rémi Bernon

---
 dlls/wined3d/resource.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/dlls/wined3d/resource.c b/dlls/wined3d/resource.c
index 9d3fd0a426d..5351fbd3025 100644
--- a/dlls/wined3d/resource.c
+++ b/dlls/wined3d/resource.c
@@ -332,7 +332,11 @@ void CDECL wined3d_resource_preload(struct wined3d_resource *resource)
 static BOOL wined3d_resource_allocate_sysmem(struct wined3d_resource *resource)
 {
     void **p;
-    SIZE_T align = RESOURCE_ALIGNMENT - 1 + sizeof(*p);
+    /* Overallocate and add padding to the allocated pointer, to guard against
+     * games (for instance Railroad Tycoon 2) writing before the locked resource
+     * memory pointer.
+     */
+    SIZE_T align = RESOURCE_ALIGNMENT + sizeof(*p);
     void *mem;

if (!(mem = heap_alloc_zero(resource->size + align)))

[PATCH v3 2/2] wined3d: Store the resource heap memory pointer separately.

[Rémi Bernon]

From: Rémi Bernon

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=55773
---
 dlls/wined3d/resource.c        | 19 ++++++++-----------
 dlls/wined3d/wined3d_private.h |  1 +
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/dlls/wined3d/resource.c b/dlls/wined3d/resource.c
index 5351fbd3025..9f27a9100e6 100644
--- a/dlls/wined3d/resource.c
+++ b/dlls/wined3d/resource.c
@@ -208,6 +208,7 @@ HRESULT resource_init(struct wined3d_resource *resource, struct wined3d_device *
     resource->parent_ops = parent_ops;
     resource->resource_ops = resource_ops;
     resource->map_binding = WINED3D_LOCATION_SYSMEM;
+    resource->heap_pointer = NULL;
     resource->heap_memory = NULL;

/* Check that we have enough video ram left */
@@ -331,12 +332,11 @@ void CDECL wined3d_resource_preload(struct wined3d_resource *resource)

static BOOL wined3d_resource_allocate_sysmem(struct wined3d_resource *resource)
 {
-    void **p;
     /* Overallocate and add padding to the allocated pointer, to guard against
      * games (for instance Railroad Tycoon 2) writing before the locked resource
      * memory pointer.
      */
-    SIZE_T align = RESOURCE_ALIGNMENT + sizeof(*p);
+    static const SIZE_T align = RESOURCE_ALIGNMENT;
     void *mem;

if (!(mem = heap_alloc_zero(resource->size + align)))
@@ -345,10 +345,8 @@ static BOOL wined3d_resource_allocate_sysmem(struct wined3d_resource *resource)
         return FALSE;
     }

-    p = (void **)(((ULONG_PTR)mem + align) & ~(RESOURCE_ALIGNMENT - 1)) - 1;
-    *p = mem;
-
-    resource->heap_memory = ++p;
+    resource->heap_memory = (void *)(((ULONG_PTR)mem + align) & ~(RESOURCE_ALIGNMENT - 1));
+    resource->heap_pointer = mem;

return TRUE;
 }
@@ -363,13 +361,12 @@ BOOL wined3d_resource_prepare_sysmem(struct wined3d_resource *resource)

void wined3d_resource_free_sysmem(struct wined3d_resource *resource)
 {
-    void **p = resource->heap_memory;
-
-    if (!p)
+    if (!resource->heap_memory)
         return;
-
-    heap_free(*(--p));
     resource->heap_memory = NULL;
+
+    heap_free(resource->heap_pointer);
+    resource->heap_pointer = NULL;
 }

GLbitfield wined3d_resource_gl_storage_flags(const struct wined3d_resource *resource)
diff --git a/dlls/wined3d/wined3d_private.h b/dlls/wined3d/wined3d_private.h
index c17e29cddf2..238456e78d8 100644
--- a/dlls/wined3d/wined3d_private.h
+++ b/dlls/wined3d/wined3d_private.h
@@ -3199,6 +3199,7 @@ struct wined3d_resource
     UINT depth;
     UINT size;
     unsigned int priority;
+    void *heap_pointer;
     void *heap_memory;

uint32_t pin_sysmem : 1;

[Rémi Bernon (＠rbernon)]

I changed it to overallocate and store the pointer separately. Heap pointers are always aligned to 2 * sizeof(void *), so after the 16 byte alignment, this always ends up with either 8 or 16 bytes of padding on 32-bit (and always 16 bytes on 64-bit).