On Wed, Oct 19, 2016 at 10:52:05AM +0200, Michal Hocko wrote: > yes this is the desirable and expected behavior. > > > wonder if this is desirable behaviour or whether this ought to be limited to > > ptrace system calls. Regardless, by making the flag more visible it makes it > > easier to see that this is happening. > > mem_open already enforces PTRACE_MODE_ATTACH Ah I missed this, that makes a lot of sense, thanks! I still wonder whether other invocations of access_remote_vm() in fs/proc/base.c (the principle caller of this function) need FOLL_FORCE, for example the various calls that simply read data from other processes, so I think the point stands about keeping this explicit.
