Re: Avoiding information leaks between users and between processes by default? [Was: : [PATCH 1/5] prctl: add PR_ISOLATE_BP process control]

[Alan Cox]

> Anyway, no need to add prctl(), if A can ptrace B and B can ptrace A,
> leaking info between them should not be a big deal. You can probably
> find existing macros doing neccessary checks.

Until one of them is security managed so it shouldn't be able to ptrace
the other, or (and this is the nasty one) when a process is executing
code it wants to protect from the rest of the same process (eg an
untrusted jvm, javascript or probably nastiest of all webassembly)

We don't need a prctl for trusted/untrusted IMHO but we do eventually
need to think about API's for "this lot is me but I don't trust
it" (flatpack, docker, etc) and for what JIT engines need to do.

Alan