On Mon, 26 Nov 2018 11:57:21 +0300 Alexey Budankov <alexey.budankov@xxxxxxxxxxxxxxx> wrote: > >> +For the purpose of performing security checks Linux implementation splits > >> +processes into two categories [6]_ : a) privileged processes (whose effective > >> +user ID is 0, referred to as superuser or root), and b) unprivileged processes > >> +(whose effective UID is nonzero). > > > > Is that really what's going on here? If I understand things correctly, > > it's looking for CAP_SYS_PTRACE rather than a specific UID; am I missing > > something here? > > You are right regarding CAP_SYS_PTRACE but this capability is not the only > one which is used by perf_events for security checks, so the capabilities > clarification is kept aside of these patches, because patches initial intention > is to clarify security specifics of sysctl_perf_even_paranoid settings. > > I agree that the document can be extended with details clarifying capabilities > used by perf_events for security checks. I don't really like the idea of adding a document that we know doesn't really describe how the security decision is made. Even a one-line parenthetical saying that things are more complicated and giving a pointer to a place to look for details would help, IMO. Either way, I can merge this, but I'd like to have an ack from the perf folks first. Thanks, jon
