Well, if I reasd the patches right, uprobes will use "copy_to_user()" for
the self-probing case. So that would definitely just modify a shared
mapping.
Of course, arguably, who really cares? As long as it's not a security
issue (and it isn't - since the person could just have written to the
thing directly instead), I guess it doesn't much matter. But it's a bit
sad when a probing feature either
- changes a global mapping that may be executed by other non-related
processes that the prober isn't even _aware_ of.
- changes semantics by creating a non-coherent private page
so arguably it would be good to just make the rule be that you cannot
probe a shared mapping. Because whatever you do, it's always the wrong
thing.
Linus
--
