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Date:   Wed, 19 Feb 2020 06:25:03 +1100 (AEDT)
From:   James Morris <jmorris@namei.org>
To:     Alexey Budankov <alexey.budankov@linux.intel.com>
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Subject: Re: [PATCH v7 05/12] drm/i915/perf: open access for CAP_PERFMON
 privileged process
In-Reply-To: <8b408c10-9bb0-4b08-8681-93c0f4a1132e@linux.intel.com>
Message-ID: <alpine.LRH.2.21.2002190624510.10165@namei.org>
References: <c8de937a-0b3a-7147-f5ef-69f467e87a13@linux.intel.com> <8b408c10-9bb0-4b08-8681-93c0f4a1132e@linux.intel.com>
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On Mon, 17 Feb 2020, Alexey Budankov wrote:

> 
> Open access to i915_perf monitoring for CAP_PERFMON privileged process.
> Providing the access under CAP_PERFMON capability singly, without the
> rest of CAP_SYS_ADMIN credentials, excludes chances to misuse the
> credentials and makes operation more secure.
> 
> 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 i915_events subsystem
> remains open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN
> usage for secure i915_events monitoring is discouraged with respect to
> CAP_PERFMON capability.
> 
> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>


Reviewed-by: James Morris <jamorris@linux.microsoft.com>


-- 
James Morris
<jmorris@namei.org>