Merge tag 'perf-core-for-mingo-5.8-20200420' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core fixes and improvements from Arnaldo Carvalho de Melo:

kernel + tools/perf:

  Alexey Budankov:

  - Introduce CAP_PERFMON to kernel and user space.

callchains:

  Adrian Hunter:

  - Allow using Intel PT to synthesize callchains for regular events.

  Kan Liang:

  - Stitch LBR records from multiple samples to get deeper backtraces,
    there are caveats, see the csets for details.

perf script:

  Andreas Gerstmayr:

  - Add flamegraph.py script

BPF:

  Jiri Olsa:

  - Synthesize bpf_trampoline/dispatcher ksymbol events.

perf stat:

  Arnaldo Carvalho de Melo:

  - Honour --timeout for forked workloads.

  Stephane Eranian:

  - Force error in fallback on :k events, to avoid counting nothing when
    the user asks for kernel events but is not allowed to.

perf bench:

  Ian Rogers:

  - Add event synthesis benchmark.

tools api fs:

  Stephane Eranian:

 - Make xxx__mountpoint() more scalable

libtraceevent:

  He Zhe:

  - Handle return value of asprintf.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 11 insertions, 5 deletions

diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
index 0d427fd10941..8d25892a18f8 100644
--- a/Documentation/admin-guide/sysctl/kernel.rst
+++ b/Documentation/admin-guide/sysctl/kernel.rst
@@ -721,7 +721,13 @@ 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.
@@ -730,13 +736,13 @@ 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``.
 ===  ==================================================================