Re: [PATCH v2 6/6] drm/tegra: Use u64_to_user_ptr helper

From: Dmitry Osipenko
Date: Tue Sep 05 2017 - 08:47:06 EST


On 05.09.2017 11:10, Mikko Perttunen wrote:
> Use the u64_to_user_ptr helper macro to cast IOCTL argument u64 values
> to user pointers instead of writing out the cast manually.
>
> Signed-off-by: Mikko Perttunen <mperttunen@xxxxxxxxxx>
> ---

This patch doesn't apply to linux-next, you should probably rebase this series.

> drivers/gpu/drm/tegra/drm.c | 18 ++++++++++--------
> 1 file changed, 10 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
> index e3331a2bc082..72d5c0021540 100644
> --- a/drivers/gpu/drm/tegra/drm.c
> +++ b/drivers/gpu/drm/tegra/drm.c
> @@ -388,18 +388,21 @@ int tegra_drm_submit(struct tegra_drm_context *context,
> unsigned int num_cmdbufs = args->num_cmdbufs;
> unsigned int num_relocs = args->num_relocs;
> unsigned int num_waitchks = args->num_waitchks;
> - struct drm_tegra_cmdbuf __user *cmdbufs =
> - (void __user *)(uintptr_t)args->cmdbufs;
> - struct drm_tegra_reloc __user *relocs =
> - (void __user *)(uintptr_t)args->relocs;
> - struct drm_tegra_waitchk __user *waitchks =
> - (void __user *)(uintptr_t)args->waitchks;
> + struct drm_tegra_cmdbuf __user *cmdbufs;
> + struct drm_tegra_reloc __user *relocs;
> + struct drm_tegra_waitchk __user *waitchks;
> + struct drm_tegra_syncpt __user *user_syncpt;
> struct drm_tegra_syncpt syncpt;
> struct host1x *host1x = dev_get_drvdata(drm->dev->parent);
> struct host1x_syncpt *sp;
> struct host1x_job *job;
> int err;
>
> + cmdbufs = u64_to_user_ptr(args->cmdbufs);
> + relocs = u64_to_user_ptr(args->relocs);
> + waitchks = u64_to_user_ptr(args->waitchks);

What about to prefix these variables with 'user_' for consistency?

> + user_syncpt = u64_to_user_ptr(args->syncpts);
> +
> /* We don't yet support other than one syncpt_incr struct per submit */
> if (args->num_syncpts != 1)
> return -EINVAL;
> @@ -520,8 +523,7 @@ int tegra_drm_submit(struct tegra_drm_context *context,
> }
> }
>
> - if (copy_from_user(&syncpt, (void __user *)(uintptr_t)args->syncpts,
> - sizeof(syncpt))) {
> + if (copy_from_user(&syncpt, user_syncpt, sizeof(syncpt))) {
> err = -EFAULT;
> goto fail;
> }
>


--
Dmitry