[PATCH] drm/msm: Fix legacy relocs path

[PATCH] drm/msm: Fix legacy relocs path

[Rob Clark]

From: Rob Clark <robdclark@chromium.org>

In moving code around, we ended up using the same pointer to
copy_from_user() the relocs tables as we used for the cmd table
entry, which is clearly not right.  This went unnoticed because
modern mesa on non-ancent kernels does not actually use relocs.
But this broke ancient mesa on modern kernels.

Reported-by: Emil Velikov <emil.velikov@collabora.com>
Fixes: 20224d715a88 ("drm/msm/submit: Move copy_from_user ahead of locking bos")
Signed-off-by: Rob Clark <robdclark@chromium.org>
---
 drivers/gpu/drm/msm/msm_gem_submit.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
index d04c349d8112..5480852bdeda 100644
--- a/drivers/gpu/drm/msm/msm_gem_submit.c
+++ b/drivers/gpu/drm/msm/msm_gem_submit.c
@@ -198,6 +198,8 @@ static int submit_lookup_cmds(struct msm_gem_submit *submit,
 		submit->cmd[i].idx  = submit_cmd.submit_idx;
 		submit->cmd[i].nr_relocs = submit_cmd.nr_relocs;
 
+		userptr = u64_to_user_ptr(submit_cmd.relocs);
+
 		sz = array_size(submit_cmd.nr_relocs,
 				sizeof(struct drm_msm_gem_submit_reloc));
 		/* check for overflow: */
-- 
2.29.2

Re: [PATCH] drm/msm: Fix legacy relocs path

[Akhil P Oommen]

On 2/5/2021 4:26 AM, Rob Clark wrote:
> From: Rob Clark <robdclark@chromium.org>
> 
> In moving code around, we ended up using the same pointer to
> copy_from_user() the relocs tables as we used for the cmd table
> entry, which is clearly not right.  This went unnoticed because
> modern mesa on non-ancent kernels does not actually use relocs.
> But this broke ancient mesa on modern kernels.
> 
> Reported-by: Emil Velikov <emil.velikov@collabora.com>
> Fixes: 20224d715a88 ("drm/msm/submit: Move copy_from_user ahead of locking bos")
> Signed-off-by: Rob Clark <robdclark@chromium.org>
> ---
>   drivers/gpu/drm/msm/msm_gem_submit.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
> index d04c349d8112..5480852bdeda 100644
> --- a/drivers/gpu/drm/msm/msm_gem_submit.c
> +++ b/drivers/gpu/drm/msm/msm_gem_submit.c
> @@ -198,6 +198,8 @@ static int submit_lookup_cmds(struct msm_gem_submit *submit,
>   		submit->cmd[i].idx  = submit_cmd.submit_idx;
>   		submit->cmd[i].nr_relocs = submit_cmd.nr_relocs;
>   
> +		userptr = u64_to_user_ptr(submit_cmd.relocs);
> +
>   		sz = array_size(submit_cmd.nr_relocs,
>   				sizeof(struct drm_msm_gem_submit_reloc));
>   		/* check for overflow: */
> 

Reviewed-by: Akhil P Oommen <akhilpo@codeaurora.org>

-Akhil.

Re: [PATCH] drm/msm: Fix legacy relocs path

[patchwork-bot+linux-arm-msm]

Hello:

This patch was applied to qcom/linux.git (refs/heads/for-next):

On Thu,  4 Feb 2021 14:56:49 -0800 you wrote:
> From: Rob Clark <robdclark@chromium.org>
> 
> In moving code around, we ended up using the same pointer to
> copy_from_user() the relocs tables as we used for the cmd table
> entry, which is clearly not right.  This went unnoticed because
> modern mesa on non-ancent kernels does not actually use relocs.
> But this broke ancient mesa on modern kernels.
> 
> [...]

Here is the summary with links:
  - drm/msm: Fix legacy relocs path
    https://git.kernel.org/qcom/c/c8d99bb938d3

You are awesome, thank you!
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