On Thu, Aug 20, 2020 at 02:45:27PM -0700, Colin Cross wrote: > > > > Guys, could you please enlighen me, I don't understand -- we pass some > > random user-space pointer and save it in vm_area_struct then in procfs > > we treat it as "string" and print out? What prevents me to put some crap > > here then unmap this pointer the kernel will cause page fault in procfs > > output (in best scenario)? > > This is the same pattern used for /proc/pid/cmdline. > acccess_remote_vm handles addresses in unmapped pages, it will return > 0 if no bytes were readable. Yes, been in this part of code too long ago, managed to forget. You know I'm wondering do we really need a human readable names here? Maybe it would be more convenient to keep say u64 number instead? This would eliminate need to access VM at all. From user space point of view there should be no difference how to recognize such VMAs (by name or by some ID). Or there some need for string solely?
