On Fri, Sep 16, 2022 at 03:15:05PM +0100, Matthew Wilcox wrote: > Right, and Ulad is right about it beig callable from any context. I think > the longterm solution is to make the vmap_area_root tree walkable under > RCU protection. Agreed, I've updated my proposed patch. > For now, let's have a distinct return code (ERR_PTR(-EAGAIN), perhaps?) to > indicate that we've hit contention. It generally won't matter if we > hit it in process context because hardening doesn't have to be 100% > reliable to be useful. Right, as I note in the series[1], hardening shouldn't be getting called _at all_ in this path. :P -Kees [1] https://lore.kernel.org/linux-hardening/20220916135953.1320601-1-keescook@xxxxxxxxxxxx/ -- Kees Cook
