On 2022/3/15 20:30, Miaohe Lin wrote: > On 2022/3/15 0:17, Matthew Wilcox wrote: >> On Mon, Mar 14, 2022 at 11:32:23PM +0800, Miaohe Lin wrote: >>> If find_vma returns a vma, it must satisfies that start < vma->vm_end. >>> Since vma list is sorted in the ascending order, so we will never see >>> start >= vma->vm_end here. Remove this unneeded check. >> >> faulty logic; vm_start + len might wrap. What do you mean is vm_start + len might wrap, so vm_end might be < vm_start ? If so, this could not happen as get_unmapped_area guarantees this. > > Many thanks for comment. I agree with you about "vm_start + len" might wrap. > But what I mean here is that we will never see "start" >= vma->vm_end here > as find_vma guarantees this. And I leave the "start + len <= vma->vm_start" > check untouched. So my cleanup should be right. Or am I miss something? So I think this "start >= vma->vm_end" check is unneeded and we can remove it. Or am I miss something? Many thanks! > > Thanks. > >> >> . >> >
