On Tue, Apr 30, 2019 at 12:56:10PM +0200, Michal Koutný wrote: > On Tue, Apr 30, 2019 at 01:45:17PM +0300, Cyrill Gorcunov <gorcunov@xxxxxxxxx> wrote: > > It setups these parameters unconditionally. I need to revisit > > this moment. Technically (if only I'm not missing something > > obvious) we might have a race here with prctl setting up new > > params, but this should be harmless since most of them (except > > stack setup) are purely informative data. > > FTR, when I reviewed that usage, I noticed it was missing the > synchronization. My understanding was that the mm_struct isn't yet > shared at this moment. I can see some of the operations take place after > flush_old_exec (where current->mm = mm_struct), so potentially it is > shared since then. OTOH, I guess there aren't concurrent parties that > could access the field at this stage of exec. Just revisited this code -- we're either executing prctl, either execve. Since both operates with current task we're safe.
