Dear Dan,
Your mail flashes back to my memory 5 years ago.
Back then, I had cleaned up the exynos driver.
And the replacement IS_ERR was one of items.
IMHO it is still better to modify those two functions,
drm_gem_cma_prime_get_sg_table and xen_drm_front_gem_get_sg_table.
Thank you.
Best regards YJ
On Thu, 14 Jun 2018, 23:42 Dan Carpenter, <dan.carpen...@oracle.com> wrote:
> Hello YoungJun Cho,
>
> The patch 7e3d88f9cce3: "drm/prime: replace NULL with error value in
> drm_prime_pages_to_sg" from Jun 24, 2013, leads to the following
> static checker warning:
>
> drivers/gpu/drm/drm_prime.c:317 drm_gem_map_dma_buf()
> warn: 'sgt' can also be NULL
>
> drivers/gpu/drm/drm_prime.c
> 307 /*
> 308 * two mappings with different directions for the same
> attachment are
> 309 * not allowed
> 310 */
> 311 if (WARN_ON(prime_attach->dir != DMA_NONE))
> 312 return ERR_PTR(-EBUSY);
> 313
> 314 sgt = obj->dev->driver->gem_prime_get_sg_table(obj);
>
> The problematic functions here are drm_gem_cma_prime_get_sg_table() and
> xen_drm_front_gem_get_sg_table(). My preference would be to update
> those functions to return error pointers, but I'm not familiar with the
> code or able to test it.
>
> But this static checker test seems pretty good so I'm likely to publish
> it soon and then this sort of bug will normally be caught quickly.
>
> 315
> 316 if (!IS_ERR(sgt)) {
> 317 if (!dma_map_sg_attrs(attach->dev, sgt->sgl,
> sgt->nents, dir,
> 318 DMA_ATTR_SKIP_CPU_SYNC)) {
> 319 sg_free_table(sgt);
> 320 kfree(sgt);
> 321 sgt = ERR_PTR(-ENOMEM);
> 322 } else {
> 323 prime_attach->sgt = sgt;
> 324 prime_attach->dir = dir;
> 325 }
> 326 }
> 327
> 328 return sgt;
>
> regards,
> dan carpenter
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
