Messages in this thread | | | Subject | Re: [RFC v8 PATCH 3/5] mm: mmap: zap pages with read mmap_sem in munmap | From | Yang Shi <> | Date | Wed, 22 Aug 2018 12:20:37 -0700 |
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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?
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