[Intel-gfx] [PATCH v8 04/12] perf tool: extend Perf tool with CAP_PERFMON capability support

[Alexey Budankov]

Hi Namhyung,

On 04.04.2020 5:18, Namhyung Kim wrote:
> Hello,
> 
> On Thu, Apr 2, 2020 at 5:47 PM Alexey Budankov
> <alexey.budankov at linux.intel.com> wrote:
>>
>>
>> Extend error messages to mention CAP_PERFMON capability as an option
>> to substitute CAP_SYS_ADMIN capability for secure system performance
>> monitoring and observability operations. Make perf_event_paranoid_check()
>> and __cmd_ftrace() to be aware of CAP_PERFMON capability.
>>
>> CAP_PERFMON implements the principal of least privilege for performance
>> monitoring and observability operations (POSIX IEEE 1003.1e 2.2.2.39
>> principle of least privilege: A security design principle that states
>> that a process or program be granted only those privileges (e.g.,
>> capabilities) necessary to accomplish its legitimate function, and only
>> for the time that such privileges are actually required)
>>
>> For backward compatibility reasons access to perf_events subsystem remains
>> open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage for
>> secure perf_events monitoring is discouraged with respect to CAP_PERFMON
>> capability.
>>
>> Signed-off-by: Alexey Budankov <alexey.budankov at linux.intel.com>
>> Reviewed-by: James Morris <jamorris at linux.microsoft.com>
> 
> Acked-by: Namhyung Kim <namhyung at kernel.org>

Thanks! I appreciate you involvement and effort.

~Alexey

> 
> Thanks
> Namhyung
>