On Thu, Aug 20, 2020 at 02:18:21AM +0000, linmiaohe wrote: > Kees Cook <keescook@xxxxxxxxxxxx> wrote: > >On Mon, Aug 17, 2020 at 07:59:33AM -0400, Miaohe Lin wrote: > >> There is no need to check if this process has the right to modify the > >> specified process when they are same. > >> > >> Signed-off-by: Hongxiang Lou <louhongxiang@xxxxxxxxxx> > >> Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> > > > >NAK, please don't do this -- the ptrace and security hooks already do these kinds of self-introspection checks, and I'd like to keep a central place to perform these kinds of checks. > > > > Many thanks for your reply. > We also avoid get_task_struct/ put_task_struct pair of atomic ops, rcu_lock, task_lock and so on this way. > > >Is there a specific problem you've encountered that this fixes? > > > > I'am sorry but there's no specific problem. I do this mainly to skip the unnecessary ptrace and security hooks. Cool. Let's keep this as-is so we continue to have centralized instrumentation of these things in the LSM. :) Thanks for your attention to performance! -- Kees Cook
