On 8/22/18 4:11 AM, Vlastimil Babka wrote:
On 08/15/2018 08:49 PM, Yang Shi wrote:+ start_vma = munmap_lookup_vma(mm, start, end); + if (!start_vma) + goto out; + if (IS_ERR(start_vma)) { + ret = PTR_ERR(start_vma); + goto out; + } + + prev = start_vma->vm_prev; + + if (unlikely(uf)) { + ret = userfaultfd_unmap_prep(start_vma, start, end, uf); + if (ret) + goto out; + } +You sure it's ok to redo this in case of goto regular path? The preparations have some side-effects... I would rather move this after the regular path check?
This preparation sets vma->vm_userfaultfd_ctx.ctx for each vmas. But, before doing this, it calls has_unmap_ctx() to check if the ctx has been set or not. If it has been set, it just skip the vma. It sounds ok, right?
