Hello Jon, On 25.11.2018 22:47, Jonathan Corbet wrote: > On Wed, 21 Nov 2018 12:14:14 +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. > > (Also, you would want "*the* Linux implementation" in the first sentence > above). Accepted. > > One other thing: > >> +(whose effective UID is nonzero). Privileged processes bypass all kernel >> +security permission checks so perf_events performance monitoring is fully >> +available to privileged processes without *access*, *scope* and *resource* >> +restrictions. > > Could I ask for a slight toning down of the markup here? There's a lot of > *emphasis* here that isn't really needed and tends to get in the way. Accepted. Thanks, Alexey > > Thanks, > > jon >
