linux-kernel - RE: [PATCH v4 1/3] drm/prime: use dma length macro when mapping sg

Open Source and information security mailing list archives

Message-ID: <14063C7AD467DE4B82DEDB5C278E8663FFFBD421@fmsmsx107.amr.corp.intel.com>
Date:   Wed, 25 Mar 2020 13:56:07 +0000
From:   "Ruhl, Michael J" <michael.j.ruhl@...el.com>
To:     Shane Francis <bigbeeshane@...il.com>,
        "dri-devel@...ts.freedesktop.org" <dri-devel@...ts.freedesktop.org>
CC:     "airlied@...ux.ie" <airlied@...ux.ie>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "amd-gfx-request@...ts.freedesktop.org" 
        <amd-gfx-request@...ts.freedesktop.org>,
        "alexander.deucher@....com" <alexander.deucher@....com>,
        "christian.koenig@....com" <christian.koenig@....com>
Subject: RE: [PATCH v4 1/3] drm/prime: use dma length macro when mapping sg

>-----Original Message-----
>From: dri-devel <dri-devel-bounces@...ts.freedesktop.org> On Behalf Of
>Shane Francis
>Sent: Wednesday, March 25, 2020 5:08 AM
>To: dri-devel@...ts.freedesktop.org
>Cc: airlied@...ux.ie; linux-kernel@...r.kernel.org; bigbeeshane@...il.com;
>amd-gfx-request@...ts.freedesktop.org; alexander.deucher@....com;
>christian.koenig@....com
>Subject: [PATCH v4 1/3] drm/prime: use dma length macro when mapping sg
>
>As dma_map_sg can reorganize scatter-gather lists in a
>way that can cause some later segments to be empty we should
>always use the sg_dma_len macro to fetch the actual length.
>
>This could now be 0 and not need to be mapped to a page or
>address array
>Signed-off-by: Shane Francis <bigbeeshane@...il.com>
>---
> drivers/gpu/drm/drm_prime.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
>diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
>index 86d9b0e45c8c..1de2cde2277c 100644
>--- a/drivers/gpu/drm/drm_prime.c
>+++ b/drivers/gpu/drm/drm_prime.c
>@@ -967,7 +967,7 @@ int drm_prime_sg_to_page_addr_arrays(struct
>sg_table *sgt, struct page **pages,
>
> 	index = 0;
> 	for_each_sg(sgt->sgl, sg, sgt->nents, count) {
>-		len = sg->length;
>+		len = sg_dma_len(sg);
> 		page = sg_page(sg);
> 		addr = sg_dma_address(sg);

This looks correct to me.

Reviewed-by: Michael J. Ruhl <michael.j.ruhl@...el.com>

M

>
>--
>2.26.0
>
>_______________________________________________
>dri-devel mailing list
>dri-devel@...ts.freedesktop.org
>https://lists.freedesktop.org/mailman/listinfo/dri-devel

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives