On Wed, 12 Jun 2019, Dmitry Safonov wrote:
>
> +#ifdef CONFIG_TIME_NS
> +int vdso_join_timens(struct task_struct *task)
> +{
> + struct mm_struct *mm = task->mm;
> + struct vm_area_struct *vma;
> +
> + if (down_write_killable(&mm->mmap_sem))
> + return -EINTR;
> +
> + for (vma = mm->mmap; vma; vma = vma->vm_next) {
> + unsigned long size = vma->vm_end - vma->vm_start;
> +
> + if (vma_is_special_mapping(vma, &vvar_mapping) ||
> + vma_is_special_mapping(vma, &vdso_mapping))
> + zap_page_range(vma, vma->vm_start, size);
> + }
> +
> + up_write(&mm->mmap_sem);
> + return 0;
> +}
> +#else /* CONFIG_TIME_NS */
> +int vdso_join_timens(struct task_struct *task)
> +{
> + return -ENXIO;
> +}
Is that else path really required? The callsite is only compiled when
CONFIG_TIME_NS is enabled, right?
Thanks,
tglx
