Vendor will define their own memory types on top of TTM_PL_PRIV, but call ttm_set_driver_manager directly without checking mem_type value when setting up memory manager. So add such check to aware the case when array bounds.
Signed-off-by: Leslie Shi Yuliang.Shi@amd.com Signed-off-by: Guchun Chen guchun.chen@amd.com --- include/drm/ttm/ttm_device.h | 1 + 1 file changed, 1 insertion(+)
diff --git a/include/drm/ttm/ttm_device.h b/include/drm/ttm/ttm_device.h index 7a0f561c57ee..24ad76ca8022 100644 --- a/include/drm/ttm/ttm_device.h +++ b/include/drm/ttm/ttm_device.h @@ -308,6 +308,7 @@ ttm_manager_type(struct ttm_device *bdev, int mem_type) static inline void ttm_set_driver_manager(struct ttm_device *bdev, int type, struct ttm_resource_manager *manager) { + BUG_ON(type >= TTM_NUM_MEM_TYPES); bdev->man_drv[type] = manager; }
[AMD Official Use Only]
looks good to me. But maybe build_bug_on works too and more reasonable to detect such wrong usage. ________________________________ From: Chen, Guchun Guchun.Chen@amd.com Sent: Friday, September 10, 2021 12:30:14 PM To: amd-gfx@lists.freedesktop.org amd-gfx@lists.freedesktop.org; dri-devel@lists.freedesktop.org dri-devel@lists.freedesktop.org; Koenig, Christian Christian.Koenig@amd.com; Pan, Xinhui Xinhui.Pan@amd.com; Deucher, Alexander Alexander.Deucher@amd.com Cc: Chen, Guchun Guchun.Chen@amd.com; Shi, Leslie Yuliang.Shi@amd.com Subject: [PATCH] drm/ttm: add a BUG_ON in ttm_set_driver_manager when array bounds
Vendor will define their own memory types on top of TTM_PL_PRIV, but call ttm_set_driver_manager directly without checking mem_type value when setting up memory manager. So add such check to aware the case when array bounds.
Signed-off-by: Leslie Shi Yuliang.Shi@amd.com Signed-off-by: Guchun Chen guchun.chen@amd.com --- include/drm/ttm/ttm_device.h | 1 + 1 file changed, 1 insertion(+)
diff --git a/include/drm/ttm/ttm_device.h b/include/drm/ttm/ttm_device.h index 7a0f561c57ee..24ad76ca8022 100644 --- a/include/drm/ttm/ttm_device.h +++ b/include/drm/ttm/ttm_device.h @@ -308,6 +308,7 @@ ttm_manager_type(struct ttm_device *bdev, int mem_type) static inline void ttm_set_driver_manager(struct ttm_device *bdev, int type, struct ttm_resource_manager *manager) { + BUG_ON(type >= TTM_NUM_MEM_TYPES); bdev->man_drv[type] = manager; }
-- 2.17.1
Yeah, that's a good point.
If build_bug_on() doesn't works for some reason then we at least need to lower this to a WARN_ON.
A BUG_ON() is only justified if we prevent strong data corruption with it or note a NULL pointer earlier on or similar.
Regards, Christian.
Am 10.09.21 um 06:36 schrieb Pan, Xinhui:
[AMD Official Use Only]
looks good to me. But maybe build_bug_on works too and more reasonable to detect such wrong usage.
*From:* Chen, Guchun Guchun.Chen@amd.com *Sent:* Friday, September 10, 2021 12:30:14 PM *To:* amd-gfx@lists.freedesktop.org amd-gfx@lists.freedesktop.org; dri-devel@lists.freedesktop.org dri-devel@lists.freedesktop.org; Koenig, Christian Christian.Koenig@amd.com; Pan, Xinhui Xinhui.Pan@amd.com; Deucher, Alexander Alexander.Deucher@amd.com *Cc:* Chen, Guchun Guchun.Chen@amd.com; Shi, Leslie Yuliang.Shi@amd.com *Subject:* [PATCH] drm/ttm: add a BUG_ON in ttm_set_driver_manager when array bounds Vendor will define their own memory types on top of TTM_PL_PRIV, but call ttm_set_driver_manager directly without checking mem_type value when setting up memory manager. So add such check to aware the case when array bounds.
Signed-off-by: Leslie Shi Yuliang.Shi@amd.com Signed-off-by: Guchun Chen guchun.chen@amd.com
include/drm/ttm/ttm_device.h | 1 + 1 file changed, 1 insertion(+)
diff --git a/include/drm/ttm/ttm_device.h b/include/drm/ttm/ttm_device.h index 7a0f561c57ee..24ad76ca8022 100644 --- a/include/drm/ttm/ttm_device.h +++ b/include/drm/ttm/ttm_device.h @@ -308,6 +308,7 @@ ttm_manager_type(struct ttm_device *bdev, int mem_type) static inline void ttm_set_driver_manager(struct ttm_device *bdev, int type, struct ttm_resource_manager *manager) { + BUG_ON(type >= TTM_NUM_MEM_TYPES); bdev->man_drv[type] = manager; }
-- 2.17.1
[Public]
Hi Christian and Xinhui,
Thanks for your suggestion. The cause is I saw data corruption in several proprietary use cases. BUILD_BUG_ON will have build variation per gcc difference?
Anyway, WARN_ON is fine to me, and I will send a new patch set soon to address this.
Regards, Guchun
From: Koenig, Christian Christian.Koenig@amd.com Sent: Friday, September 10, 2021 2:37 PM To: Pan, Xinhui Xinhui.Pan@amd.com; amd-gfx@lists.freedesktop.org; dri-devel@lists.freedesktop.org; Deucher, Alexander Alexander.Deucher@amd.com; Chen, Guchun Guchun.Chen@amd.com Cc: Shi, Leslie Yuliang.Shi@amd.com Subject: Re: [PATCH] drm/ttm: add a BUG_ON in ttm_set_driver_manager when array bounds
Yeah, that's a good point.
If build_bug_on() doesn't works for some reason then we at least need to lower this to a WARN_ON.
A BUG_ON() is only justified if we prevent strong data corruption with it or note a NULL pointer earlier on or similar.
Regards, Christian. Am 10.09.21 um 06:36 schrieb Pan, Xinhui:
[AMD Official Use Only]
looks good to me. But maybe build_bug_on works too and more reasonable to detect such wrong usage. ________________________________ From: Chen, Guchun Guchun.Chen@amd.commailto:Guchun.Chen@amd.com Sent: Friday, September 10, 2021 12:30:14 PM To: amd-gfx@lists.freedesktop.orgmailto:amd-gfx@lists.freedesktop.org amd-gfx@lists.freedesktop.orgmailto:amd-gfx@lists.freedesktop.org; dri-devel@lists.freedesktop.orgmailto:dri-devel@lists.freedesktop.org dri-devel@lists.freedesktop.orgmailto:dri-devel@lists.freedesktop.org; Koenig, Christian Christian.Koenig@amd.commailto:Christian.Koenig@amd.com; Pan, Xinhui Xinhui.Pan@amd.commailto:Xinhui.Pan@amd.com; Deucher, Alexander Alexander.Deucher@amd.commailto:Alexander.Deucher@amd.com Cc: Chen, Guchun Guchun.Chen@amd.commailto:Guchun.Chen@amd.com; Shi, Leslie Yuliang.Shi@amd.commailto:Yuliang.Shi@amd.com Subject: [PATCH] drm/ttm: add a BUG_ON in ttm_set_driver_manager when array bounds
Vendor will define their own memory types on top of TTM_PL_PRIV, but call ttm_set_driver_manager directly without checking mem_type value when setting up memory manager. So add such check to aware the case when array bounds.
Signed-off-by: Leslie Shi Yuliang.Shi@amd.commailto:Yuliang.Shi@amd.com Signed-off-by: Guchun Chen guchun.chen@amd.commailto:guchun.chen@amd.com --- include/drm/ttm/ttm_device.h | 1 + 1 file changed, 1 insertion(+)
diff --git a/include/drm/ttm/ttm_device.h b/include/drm/ttm/ttm_device.h index 7a0f561c57ee..24ad76ca8022 100644 --- a/include/drm/ttm/ttm_device.h +++ b/include/drm/ttm/ttm_device.h @@ -308,6 +308,7 @@ ttm_manager_type(struct ttm_device *bdev, int mem_type) static inline void ttm_set_driver_manager(struct ttm_device *bdev, int type, struct ttm_resource_manager *manager) { + BUG_ON(type >= TTM_NUM_MEM_TYPES); bdev->man_drv[type] = manager; }
-- 2.17.1
dri-devel@lists.freedesktop.org
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Chen, Guchun -
Christian König -
Guchun Chen
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Pan, Xinhui