drm/vmwgfx: Protect from excessive execbuf kernel memory allocations v3

[linux.git] / drivers / gpu / drm / vmwgfx / vmwgfx_validation.c

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_validation.c b/drivers/gpu/drm/vmwgfx/vmwgfx_validation.c
index 184025fa938e78fd0372d255b1db552bdb95a88d..f116f092e00bcbf33a4c73a12f504a2580435e6c 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_validation.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_validation.c
@@ -104,11 +104,25 @@ void *vmw_validation_mem_alloc(struct vmw_validation_context *ctx,
                return NULL;
 
        if (ctx->mem_size_left < size) {
-               struct page *page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+               struct page *page;
 
+               if (ctx->vm && ctx->vm_size_left < PAGE_SIZE) {
+                       int ret = ctx->vm->reserve_mem(ctx->vm, ctx->vm->gran);
+
+                       if (ret)
+                               return NULL;
+
+                       ctx->vm_size_left += ctx->vm->gran;
+                       ctx->total_mem += ctx->vm->gran;
+               }
+
+               page = alloc_page(GFP_KERNEL | __GFP_ZERO);
                if (!page)
                        return NULL;
 
+               if (ctx->vm)
+                       ctx->vm_size_left -= PAGE_SIZE;
+
                list_add_tail(&page->lru, &ctx->page_list);
                ctx->page_address = page_address(page);
                ctx->mem_size_left = PAGE_SIZE;
@@ -138,6 +152,11 @@ static void vmw_validation_mem_free(struct vmw_validation_context *ctx)
        }
 
        ctx->mem_size_left = 0;
+       if (ctx->vm && ctx->total_mem) {
+               ctx->vm->unreserve_mem(ctx->vm, ctx->total_mem);
+               ctx->total_mem = 0;
+               ctx->vm_size_left = 0;
+       }
 }
 
 /**