> On Feb 18, 2020, at 5:29 AM, Kirill A. Shutemov <kirill@xxxxxxxxxxxxx> wrote: > > I think I've got this: > > vm_area_dup() blindly copies all fields of orignal VMA to the new one. > This includes coping vm_area_struct::shared.rb which is normally protected > by i_mmap_lock. But this is fine because the read value will be > overwritten on the following __vma_link_file() under proper protectection. Right, multiple processes could share the same file-based address space where those vma have been linked into address_space::i_mmap via vm_area_struct::shared.rb. Thus, the reader could see its shared.rb linkage pointers got updated by other processes. > > So the fix is correct, but justificaiton is lacking. > > Also, I would like to more fine-grained annotation: marking with > data_race() 200 bytes copy may hide other issues. That is the harder part where I don’t think we have anything for that today. Macro, any suggestions? ASSERT_IGNORE_FIELD()?
