Re: [PATCH 2/3] perf: Use CAP_SYS_ADMIN with perf_event_paranoid checks

[Jiri Olsa]

On Tue, Jul 16, 2019 at 05:01:26PM +0000, Lubashev, Igor wrote:
> I could add another patch to the series for that.  Any suggestion for what capability to check for here?

it's:

	if (geteuid() != 0) {
		pr_err("ftrace only works for root!\n");
		return -1
	}

so I think check for CAP_SYS_ADMIN should be fine in here

jirka

> 
> (There is always an alternative to not check for anything and let the kernel refuse to perform actions that the user does not have permissions to perform.)
> 
> - Igor
> 
> -----Original Message-----
> From: Jiri Olsa <jolsa@xxxxxxxxxx> 
> Sent: Tuesday, July 16, 2019 4:48 AM
> Subject: Re: [PATCH 2/3] perf: Use CAP_SYS_ADMIN with perf_event_paranoid checks
> 
> On Tue, Jul 02, 2019 at 08:10:04PM -0400, Igor Lubashev wrote:
> > The kernel is using CAP_SYS_ADMIN instead of euid==0 to override
> > perf_event_paranoid check. Make perf do the same.
> 
> I see another geteuid check in __cmd_ftrace,
> perhaps we should cover this one as well
> 
> jirka