On Tue, Aug 20, 2013 at 12:05 PM, Oleg Nesterov <[email protected]> wrote: > On 08/20, Andy Lutomirski wrote: >> >> On Tue, Aug 20, 2013 at 11:50 AM, Oleg Nesterov <[email protected]> wrote: >> > >> >> Currently (with or without your patch), vfork() followed by >> >> unshare(CLONE_NEWUSER) or unshare(CLONE_NEWPID) will unshare the VM. >> > >> > Could you spell please? >> > >> > We never unshare the VM. CLONE_VM in sys_unshare() paths just means >> > "fail unless ->mm is not shared". >> > >> >> Argh. In that case this is probably buggy, > > I don't think so. Just we can't really unshare ->mm or implement > unshare(CLONE_THREAD). We simply pretend it works if there is nothing > to unshare. > >> sys_unshare will see CLONE_NEWPID or CLONE_NEWUSER and set >> CLONE_THREAD. Then it will see CLONE_THREAD and set CLONE_VM. > > This matches copy_process() to some degree... but looks confusing, > I agree.
Huh? Doesn't this mean that unshare(CLONE_NEWPID); vfork() will work with your patches, but vfork(); unshare(CLONE_NEWPID) will fail? (I admit I haven't tested it.) --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
