[PATCH] staging: drm/omap: Add error handling

[PATCH] staging: drm/omap: Add error handling

[emilgoode]

From: Emil Goode <emilgoode@gmail.com>

This patch adds fail checks for kmalloc and kzalloc calls
and also adds a error path that frees allocated pages by
introducing a call to _drm_gem_put_pages.

Signed-off-by: Emil Goode <emilgoode@gmail.com>
---
 drivers/staging/omapdrm/omap_gem.c |   17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/omapdrm/omap_gem.c b/drivers/staging/omapdrm/omap_gem.c
index 74082aa..c828743 100644
--- a/drivers/staging/omapdrm/omap_gem.c
+++ b/drivers/staging/omapdrm/omap_gem.c
@@ -226,7 +226,8 @@ static int omap_gem_attach_pages(struct drm_gem_object *obj)
 	struct drm_device *dev = obj->dev;
 	struct omap_gem_object *omap_obj = to_omap_bo(obj);
 	struct page **pages;
-	int i, npages = obj->size >> PAGE_SHIFT;
+	int npages = obj->size >> PAGE_SHIFT;
+	int i, ret;
 	dma_addr_t *addrs;
 
 	WARN_ON(omap_obj->pages);
@@ -246,18 +247,32 @@ static int omap_gem_attach_pages(struct drm_gem_object *obj)
 	 */
 	if (omap_obj->flags & (OMAP_BO_WC|OMAP_BO_UNCACHED)) {
 		addrs = kmalloc(npages * sizeof(addrs), GFP_KERNEL);
+		if (!addrs) {
+			ret = -ENOMEM;
+			goto free_pages;
+		}
+
 		for (i = 0; i < npages; i++) {
 			addrs[i] = dma_map_page(dev->dev, pages[i],
 					0, PAGE_SIZE, DMA_BIDIRECTIONAL);
 		}
 	} else {
 		addrs = kzalloc(npages * sizeof(addrs), GFP_KERNEL);
+		if (!addrs) {
+			ret = -ENOMEM;
+			goto free_pages;
+		}
 	}
 
 	omap_obj->addrs = addrs;
 	omap_obj->pages = pages;
 
 	return 0;
+
+free_pages:
+	_drm_gem_put_pages(obj, pages, true, false);
+
+	return ret;
 }
 
 /** release backing pages */
-- 
1.7.10.4

Re: [PATCH] staging: drm/omap: Add error handling

[Clark, Rob]

On Fri, Aug 17, 2012 at 11:53 AM,  <emilgoode@gmail.com> wrote:
> From: Emil Goode <emilgoode@gmail.com>
>
> This patch adds fail checks for kmalloc and kzalloc calls
> and also adds a error path that frees allocated pages by
> introducing a call to _drm_gem_put_pages.
>
> Signed-off-by: Emil Goode <emilgoode@gmail.com>

Looks good, thanks

Signed-off-by: Rob Clark <rob@ti.com>

> ---
>  drivers/staging/omapdrm/omap_gem.c |   17 ++++++++++++++++-
>  1 file changed, 16 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/staging/omapdrm/omap_gem.c b/drivers/staging/omapdrm/omap_gem.c
> index 74082aa..c828743 100644
> --- a/drivers/staging/omapdrm/omap_gem.c
> +++ b/drivers/staging/omapdrm/omap_gem.c
> @@ -226,7 +226,8 @@ static int omap_gem_attach_pages(struct drm_gem_object *obj)
>         struct drm_device *dev = obj->dev;
>         struct omap_gem_object *omap_obj = to_omap_bo(obj);
>         struct page **pages;
> -       int i, npages = obj->size >> PAGE_SHIFT;
> +       int npages = obj->size >> PAGE_SHIFT;
> +       int i, ret;
>         dma_addr_t *addrs;
>
>         WARN_ON(omap_obj->pages);
> @@ -246,18 +247,32 @@ static int omap_gem_attach_pages(struct drm_gem_object *obj)
>          */
>         if (omap_obj->flags & (OMAP_BO_WC|OMAP_BO_UNCACHED)) {
>                 addrs = kmalloc(npages * sizeof(addrs), GFP_KERNEL);
> +               if (!addrs) {
> +                       ret = -ENOMEM;
> +                       goto free_pages;
> +               }
> +
>                 for (i = 0; i < npages; i++) {
>                         addrs[i] = dma_map_page(dev->dev, pages[i],
>                                         0, PAGE_SIZE, DMA_BIDIRECTIONAL);
>                 }
>         } else {
>                 addrs = kzalloc(npages * sizeof(addrs), GFP_KERNEL);
> +               if (!addrs) {
> +                       ret = -ENOMEM;
> +                       goto free_pages;
> +               }
>         }
>
>         omap_obj->addrs = addrs;
>         omap_obj->pages = pages;
>
>         return 0;
> +
> +free_pages:
> +       _drm_gem_put_pages(obj, pages, true, false);
> +
> +       return ret;
>  }
>
>  /** release backing pages */
> --
> 1.7.10.4
>