[16/60] doc/admin-guide: update kernel.rst with CAP_PERFMON information

Commit Message

Arnaldo Carvalho de Melo April 20, 2020, 11:52 a.m. UTC

From: Alexey Budankov <[e-mail]>

Update the 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 <[e-mail]>
Cc: Alexei Starovoitov <[e-mail]>
Cc: Andi Kleen <[e-mail]>
Cc: Igor Lubashev <[e-mail]>
Cc: James Morris <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Serge Hallyn <[e-mail]>
Cc: Song Liu <[e-mail]>
Cc: Stephane Eranian <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Link: http://lore.kernel.org/lkml/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>
---
 Documentation/admin-guide/sysctl/kernel.rst | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

Patch

diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
index 39c95c0e13d3..7e4c28dfc9ca 100644
--- a/Documentation/admin-guide/sysctl/kernel.rst
+++ b/Documentation/admin-guide/sysctl/kernel.rst
@@ -730,7 +730,13 @@  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.
@@ -739,13 +745,13 @@  users (without CAP_SYS_ADMIN).  The default value is 2.
      ``CAP_IPC_LOCK``.
 
 >=0  Disallow ftrace function tracepoint by users without
-     ``CAP_SYS_ADMIN``.
+     ``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``.
 ===  ==================================================================