05.09.2020 13:34, Mikko Perttunen пишет:
> +static int submit_process_bufs(struct drm_device *drm, struct gather_bo *bo,
> + struct tegra_drm_job_data *job_data,
> + struct tegra_drm_channel_ctx *ctx,
> + struct drm_tegra_channel_submit *args,
> + struct ww_acquire_ctx *acquire_ctx)
> +{
> + struct drm_tegra_submit_buf __user *user_bufs_ptr =
> + u64_to_user_ptr(args->bufs_ptr);
If assignment makes line too long, then factor it out.
struct drm_tegra_submit_buf __user *user_bufs_ptr;
user_bufs_ptr = u64_to_user_ptr(args->bufs_ptr);
> + struct tegra_drm_mapping *mapping;
> + struct drm_tegra_submit_buf buf;
> + unsigned long copy_err;
> + int err;
> + u32 i;
> +
> + job_data->used_mappings =
> + kcalloc(args->num_bufs, sizeof(*job_data->used_mappings), GFP_KERNEL);
The checkpatch should disallow this coding style. I'd write it as:
size_t size;
size = sizeof(*job_data->used_mappings);
job_data->used_mappings = kcalloc(args->num_bufs, size..);
> + if (!job_data->used_mappings)
> + return -ENOMEM;
> +
> + for (i = 0; i < args->num_bufs; i++) {
> + copy_err = copy_from_user(&buf, user_bufs_ptr+i, sizeof(buf));
Whole array always should be copied at once. Please keep in mind that
each copy_from_user() has a cpu-time cost, there should maximum up to 2
copyings per job.
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