[PATCH v7 12/12] doc/admin-guide: update kernel.rst with CAP_PERFMON information

Alexey Budankov <alexey.budankov-VuQAYsv1563Yd54FQh9/[email protected]> Mon, 17 Feb 2020 11:13:39 +0300
Newsgroups gmane.linux.man,gmane.linux.kernel,gmane.comp.freedesktop.xorg.drivers.intel,gmane.linux.kernel.lsm,gmane.linux.ports.arm.kernel,gmane.linux.ports.ppc64.devel,gmane.linux.ports.parisc,gmane.linux.oprofile,gmane.linux.documentation
Organization Intel Corp.
Message-ID <[email protected]>
Update kernel.rst documentation file with the information
related to usage of CAP_PERFMON capability to secure performance
monitoring and observability operations in system.

Signed-off-by: Alexey Budankov <alexey.budankov-VuQAYsv1563Yd54FQh9/[email protected]>
---
 Documentation/admin-guide/sysctl/kernel.rst | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
index def074807cee..b06ae9389809 100644
--- a/Documentation/admin-guide/sysctl/kernel.rst
+++ b/Documentation/admin-guide/sysctl/kernel.rst
@@ -720,20 +720,26 @@ perf_event_paranoid:
 ====================
 
 Controls use of the performance events system by unprivileged
-users (without CAP_SYS_ADMIN).  The default value is 2.
+users (without CAP_PERFMON). The default value is 2.
+
+For backward compatibility reasons access to system performance
+monitoring and observability remains open for CAP_SYS_ADMIN
+privileged processes but CAP_SYS_ADMIN usage for secure system
+performance monitoring and observability operations is discouraged
+with respect to CAP_PERFMON use cases.
 
 ===  ==================================================================
  -1  Allow use of (almost) all events by all users
 
      Ignore mlock limit after perf_event_mlock_kb without CAP_IPC_LOCK
 
->=0  Disallow ftrace function tracepoint by users without CAP_SYS_ADMIN
+>=0  Disallow ftrace function tracepoint by users without CAP_PERFMON
 
-     Disallow raw tracepoint access by users without CAP_SYS_ADMIN
+     Disallow raw tracepoint access by users without CAP_PERFMON
 
->=1  Disallow CPU event access by users without CAP_SYS_ADMIN
+>=1  Disallow CPU event access by users without CAP_PERFMON
 
->=2  Disallow kernel profiling by users without CAP_SYS_ADMIN
+>=2  Disallow kernel profiling by users without CAP_PERFMON
 ===  ==================================================================
 
 
-- 
2.20.1