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.