[GIT PULL] perf/core fixes and improvements

[GIT PULL] perf/core fixes and improvements

[Arnaldo Carvalho de Melo]

Hi Ingo/Thomas,

	Please consider pulling, the CAP_PERFMON got lots of reviewed-by
and acked-by from the relevant people, its just that it took more time
on my side to test everything, working less time than normal in the
current situation, delaying this lot more than I expected :-\

Best regards,

- Arnaldo

Test results at the end of this message, as usual.

The following changes since commit 7dc41b9b99cd0037a418ac47e342d56a438df649:

  Merge tag 'perf-urgent-for-mingo-5.7-20200403' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent (2020-04-04 10:35:15 +0200)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git tags/perf-core-for-mingo-5.7-20200413

for you to fetch changes up to 80af1ec0f23235271feda1436f1b5c74078a0453:

  perf script: Add flamegraph.py script (2020-04-13 11:03:08 -0300)

----------------------------------------------------------------
perf/core fixes and improvements:

kernel + tools/perf:

  Alexey Budankov:

  - Introduce CAP_PERFMON to kernel and user space.

perf stat:

  Jin Yao:

  - Fix no metric header if --per-socket and --metric-only set.

perf python:

  Arnaldo Carvalho de Melo:

  - Check if clang supports -fno-semantic-interposition, fixing the python
    binding when building with clang.

perf script:

  Andreas Gerstmayr:

  - Add flamegraph.py script

tools arch x86:

  Arnaldo Carvalho de Melo:

  - Sync the msr-index.h copy with the kernel sources.

perf bench:

  Ian Rogers:

  - Add event synthesis benchmark.

BPF:

  Jiri Olsa:

  - Synthesize bpf_trampoline/dispatcher ksymbol event.

tools api fs:

  Stephane Eranian:

 - Make xxx__mountpoint() more scalable

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

----------------------------------------------------------------
Adrian Hunter (1):
      perf script: Simplify auxiliary event printing functions

Alexey Budankov (12):
      capabilities: Introduce CAP_PERFMON to kernel and user space
      perf/core: Open access to the core for CAP_PERFMON privileged process
      perf/core: open access to probes for CAP_PERFMON privileged process
      perf tools: Support CAP_PERFMON capability
      drm/i915/perf: Open access for CAP_PERFMON privileged process
      trace/bpf_trace: Open access for CAP_PERFMON privileged process
      powerpc/perf: open access for CAP_PERFMON privileged process
      parisc/perf: open access for CAP_PERFMON privileged process
      drivers/perf: Open access for CAP_PERFMON privileged process
      drivers/oprofile: Open access for CAP_PERFMON privileged process
      doc/admin-guide: Update perf-security.rst with CAP_PERFMON information
      doc/admin-guide: update kernel.rst with CAP_PERFMON information

Andreas Gerstmayr (1):
      perf script: Add flamegraph.py script

Arnaldo Carvalho de Melo (2):
      tools arch x86: Sync the msr-index.h copy with the kernel sources
      perf python: Check if clang supports -fno-semantic-interposition

Ian Rogers (2):
      perf bench: Add event synthesis benchmark
      perf synthetic-events: save 4kb from 2 stack frames

Jin Yao (1):
      perf stat: Fix no metric header if --per-socket and --metric-only set

Jiri Olsa (5):
      perf tools: Synthesize bpf_trampoline/dispatcher ksymbol event
      perf machine: Set ksymbol dso as loaded on arrival
      perf annotate: Add basic support for bpf_image
      perf expr: Add expr_ prefix for parse_ctx and parse_id
      perf expr: Add expr_scanner_ctx object

Kajol Jain (1):
      perf metrictroup: Split the metricgroup__add_metric function

Stephane Eranian (1):
      tools api fs: Make xxx__mountpoint() more scalable

 Documentation/admin-guide/perf-security.rst     |  86 +++++--
 Documentation/admin-guide/sysctl/kernel.rst     |  16 +-
 arch/parisc/kernel/perf.c                       |   2 +-
 arch/powerpc/perf/imc-pmu.c                     |   4 +-
 drivers/gpu/drm/i915/i915_perf.c                |  13 +-
 drivers/oprofile/event_buffer.c                 |   2 +-
 drivers/perf/arm_spe_pmu.c                      |   4 +-
 include/linux/capability.h                      |   4 +
 include/linux/perf_event.h                      |   6 +-
 include/uapi/linux/capability.h                 |   8 +-
 kernel/events/core.c                            |   6 +-
 kernel/trace/bpf_trace.c                        |   2 +-
 security/selinux/include/classmap.h             |   4 +-
 tools/arch/x86/include/asm/msr-index.h          |   9 +
 tools/lib/api/fs/fs.c                           |  17 ++
 tools/lib/api/fs/fs.h                           |  12 +
 tools/perf/Documentation/perf-bench.txt         |   8 +
 tools/perf/bench/Build                          |   2 +-
 tools/perf/bench/bench.h                        |   2 +-
 tools/perf/bench/synthesize.c                   | 101 ++++++++
 tools/perf/builtin-bench.c                      |   6 +
 tools/perf/builtin-ftrace.c                     |   5 +-
 tools/perf/builtin-script.c                     | 304 +++++-------------------
 tools/perf/design.txt                           |   3 +-
 tools/perf/scripts/python/bin/flamegraph-record |   2 +
 tools/perf/scripts/python/bin/flamegraph-report |   3 +
 tools/perf/scripts/python/flamegraph.py         | 124 ++++++++++
 tools/perf/tests/expr.c                         |   4 +-
 tools/perf/util/annotate.c                      |  20 ++
 tools/perf/util/bpf-event.c                     |  93 ++++++++
 tools/perf/util/cap.h                           |   4 +
 tools/perf/util/dso.c                           |   1 +
 tools/perf/util/dso.h                           |   1 +
 tools/perf/util/evsel.c                         |  10 +-
 tools/perf/util/expr.c                          |  16 +-
 tools/perf/util/expr.h                          |  16 +-
 tools/perf/util/expr.l                          |  10 +-
 tools/perf/util/expr.y                          |   6 +-
 tools/perf/util/machine.c                       |  12 +
 tools/perf/util/metricgroup.c                   |  60 +++--
 tools/perf/util/setup.py                        |   2 +
 tools/perf/util/stat-shadow.c                   |   9 +-
 tools/perf/util/symbol.c                        |   1 +
 tools/perf/util/synthetic-events.c              |  22 +-
 tools/perf/util/util.c                          |   1 +
 45 files changed, 679 insertions(+), 364 deletions(-)
 create mode 100644 tools/perf/bench/synthesize.c
 create mode 100755 tools/perf/scripts/python/bin/flamegraph-record
 create mode 100755 tools/perf/scripts/python/bin/flamegraph-report
 create mode 100755 tools/perf/scripts/python/flamegraph.py

Test results:

The first ones are container based builds of tools/perf with and without libelf
support.  Where clang is available, it is also used to build perf with/without
libelf, and building with LIBCLANGLLVM=1 (built-in clang) with gcc and clang
when clang and its devel libraries are installed.

The objtool and samples/bpf/ builds are disabled now that I'm switching from
using the sources in a local volume to fetching them from a http server to
build it inside the container, to make it easier to build in a container cluster.
Those will come back later.

Several are cross builds, the ones with -x-ARCH and the android one, and those
may not have all the features built, due to lack of multi-arch devel packages,
available and being used so far on just a few, like
debian:experimental-x-{arm64,mipsel}.

The 'perf test' one will perform a variety of tests exercising
tools/perf/util/, tools/lib/{bpf,traceevent,etc}, as well as run perf commands
with a variety of command line event specifications to then intercept the
sys_perf_event syscall to check that the perf_event_attr fields are set up as
expected, among a variety of other unit tests.

Then there is the 'make -C tools/perf build-test' ones, that build tools/perf/
with a variety of feature sets, exercising the build with an incomplete set of
features as well as with a complete one. It is planned to have it run on each
of the containers mentioned above, using some container orchestration
infrastructure. Get in contact if interested in helping having this in place.

Ubuntu 19.10 is failing when linking against libllvm, which isn't the default,
needs to be investigated, haven't tested with CC=gcc, but should be the same
problem:

+ make ARCH= CROSS_COMPILE= EXTRA_CFLAGS= LIBCLANGLLVM=1 -C /git/linux/tools/perf O=/tmp/build/perf CC=clang

...
/usr/bin/ld: /usr/lib/llvm-9/lib/libclangAnalysis.a(ExprMutationAnalyzer.cpp.o): in function `clang::ast_matchers::internal::matcher_ignoringImpCasts0Matcher::matches(clang::Expr const&, clang::ast_matchers::internal::ASTMatchFinder*, clang::ast_matchers::internal::BoundNodesTreeBuilder*) const':
(.text._ZNK5clang12ast_matchers8internal32matcher_ignoringImpCasts0Matcher7matchesERKNS_4ExprEPNS1_14ASTMatchFinderEPNS1_21BoundNodesTreeBuilderE[_ZNK5clang12ast_matchers8internal32matcher_ignoringImpCasts0Matcher7matchesERKNS_4ExprEPNS1_14ASTMatchFinderEPNS1_21BoundNodesTreeBuilderE]+0x43): undefined reference to `clang::ast_matchers::internal::DynTypedMatcher::matches(clang::ast_type_traits::DynTypedNode const&, clang::ast_matchers::internal::ASTMatchFinder*, clang::ast_matchers::internal::BoundNodesTreeBuilder*) const'
/usr/bin/ld: /usr/lib/llvm-9/lib/libclangAnalysis.a(ExprMutationAnalyzer.cpp.o): in function `clang::ast_matchers::internal::matcher_hasLoopVariable0Matcher::matches(clang::CXXForRangeStmt const&, clang::ast_matchers::internal::ASTMatchFinder*, clang::ast_matchers::internal::BoundNodesTreeBuilder*) const':
(.text._ZNK5clang12ast_matchers8internal31matcher_hasLoopVariable0Matcher7matchesERKNS_15CXXForRangeStmtEPNS1_14ASTMatchFinderEPNS1_21BoundNodesTreeBuilderE[_ZNK5clang12ast_matchers8internal31matcher_hasLoopVariable0Matcher7matchesERKNS_15CXXForRangeStmtEPNS1_14ASTMatchFinderEPNS1_21BoundNodesTreeBuilderE]+0x48): undefined reference to `clang::ast_matchers::internal::DynTypedMatcher::matches(clang::ast_type_traits::DynTypedNode const&, clang::ast_matchers::internal::ASTMatchFinder*, clang::ast_matchers::internal::BoundNodesTreeBuilder*) const'
...

  It builds ok with the default set of options.

  $ export PERF_TARBALL=http://192.168.122.1/perf/perf-5.6.0.tar.xz
  $ dm 
   1 alpine:3.4                    : Ok   gcc (Alpine 5.3.0) 5.3.0, clang version 3.8.0 (tags/RELEASE_380/final)
   2 alpine:3.5                    : Ok   gcc (Alpine 6.2.1) 6.2.1 20160822, clang version 3.8.1 (tags/RELEASE_381/final)
   3 alpine:3.6                    : Ok   gcc (Alpine 6.3.0) 6.3.0, clang version 4.0.0 (tags/RELEASE_400/final)
   4 alpine:3.7                    : Ok   gcc (Alpine 6.4.0) 6.4.0, Alpine clang version 5.0.0 (tags/RELEASE_500/final) (based on LLVM 5.0.0)
   5 alpine:3.8                    : Ok   gcc (Alpine 6.4.0) 6.4.0, Alpine clang version 5.0.1 (tags/RELEASE_501/final) (based on LLVM 5.0.1)
   6 alpine:3.9                    : Ok   gcc (Alpine 8.3.0) 8.3.0, Alpine clang version 5.0.1 (tags/RELEASE_502/final) (based on LLVM 5.0.1)
   7 alpine:3.10                   : Ok   gcc (Alpine 8.3.0) 8.3.0, Alpine clang version 8.0.0 (tags/RELEASE_800/final) (based on LLVM 8.0.0)
   8 alpine:3.11                   : Ok   gcc (Alpine 9.2.0) 9.2.0, Alpine clang version 9.0.0 (https://git.alpinelinux.org/aports f7f0d2c2b8bcd6a5843401a9a702029556492689) (based on LLVM 9.0.0)
   9 alpine:edge                   : Ok   gcc (Alpine 9.2.0) 9.2.0, Alpine clang version 9.0.1 (git://git.alpinelinux.org/aports 6c34b9a10bcdcdac04a11569c50b61fb50c4ea6e) (based on LLVM 9.0.1)
  10 alt:p8                        : Ok   x86_64-alt-linux-gcc (GCC) 5.3.1 20151207 (ALT p8 5.3.1-alt3.M80P.1), clang version 3.8.0 (tags/RELEASE_380/final)
  11 alt:p9                        : Ok   x86_64-alt-linux-gcc (GCC) 8.3.1 20190507 (ALT p9 8.3.1-alt5), clang version 7.0.1 
  12 alt:sisyphus                  : Ok   x86_64-alt-linux-gcc (GCC) 9.2.1 20200123 (ALT Sisyphus 9.2.1-alt3), clang version 9.0.1 
  13 amazonlinux:1                 : Ok   gcc (GCC) 7.2.1 20170915 (Red Hat 7.2.1-2), clang version 3.6.2 (tags/RELEASE_362/final)
  14 amazonlinux:2                 : Ok   gcc (GCC) 7.3.1 20180712 (Red Hat 7.3.1-6), clang version 7.0.1 (Amazon Linux 2 7.0.1-1.amzn2.0.2)
  15 android-ndk:r12b-arm          : Ok   arm-linux-androideabi-gcc (GCC) 4.9.x 20150123 (prerelease)
  16 android-ndk:r15c-arm          : Ok   arm-linux-androideabi-gcc (GCC) 4.9.x 20150123 (prerelease)
  17 centos:5                      : Ok   gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-55)
  18 centos:6                      : Ok   gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-23)
  19 centos:7                      : Ok   gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-39)
  20 centos:8                      : Ok   gcc (GCC) 8.3.1 20190507 (Red Hat 8.3.1-4), clang version 8.0.1 (Red Hat 8.0.1-1.module_el8.1.0+215+a01033fb)
  21 clearlinux:latest             : Ok   gcc (Clear Linux OS for Intel Architecture) 9.3.1 20200325 releases/gcc-9.3.0-55-gdff885cdc0, clang version 9.0.1 
  22 debian:8                      : Ok   gcc (Debian 4.9.2-10+deb8u2) 4.9.2, Debian clang version 3.5.0-10 (tags/RELEASE_350/final) (based on LLVM 3.5.0)
  23 debian:9                      : Ok   gcc (Debian 6.3.0-18+deb9u1) 6.3.0 20170516, clang version 3.8.1-24 (tags/RELEASE_381/final)
  24 debian:10                     : Ok   gcc (Debian 8.3.0-6) 8.3.0, clang version 7.0.1-8 (tags/RELEASE_701/final)
  25 debian:experimental           : Ok   gcc (Debian 9.3.0-7) 9.3.0
  26 debian:experimental-x-mips    : Ok   mips-linux-gnu-gcc (Debian 9.2.1-24) 9.2.1 20200117
  27 fedora:20                     : Ok   gcc (GCC) 4.8.3 20140911 (Red Hat 4.8.3-7)
  28 fedora:22                     : Ok   gcc (GCC) 5.3.1 20160406 (Red Hat 5.3.1-6), clang version 3.5.0 (tags/RELEASE_350/final)
  29 fedora:23                     : Ok   gcc (GCC) 5.3.1 20160406 (Red Hat 5.3.1-6), clang version 3.7.0 (tags/RELEASE_370/final)
  30 fedora:24                     : Ok   gcc (GCC) 6.3.1 20161221 (Red Hat 6.3.1-1), clang version 3.8.1 (tags/RELEASE_381/final)
  31 fedora:24-x-ARC-uClibc        : Ok   arc-linux-gcc (ARCompact ISA Linux uClibc toolchain 2017.09-rc2) 7.1.1 20170710
  32 fedora:25                     : Ok   gcc (GCC) 6.4.1 20170727 (Red Hat 6.4.1-1), clang version 3.9.1 (tags/RELEASE_391/final)
  33 fedora:26                     : Ok   gcc (GCC) 7.3.1 20180130 (Red Hat 7.3.1-2), clang version 4.0.1 (tags/RELEASE_401/final)
  34 fedora:27                     : Ok   gcc (GCC) 7.3.1 20180712 (Red Hat 7.3.1-6), clang version 5.0.2 (tags/RELEASE_502/final)
  35 fedora:28                     : Ok   gcc (GCC) 8.3.1 20190223 (Red Hat 8.3.1-2), clang version 6.0.1 (tags/RELEASE_601/final)
  36 fedora:29                     : Ok   gcc (GCC) 8.3.1 20190223 (Red Hat 8.3.1-2), clang version 7.0.1 (Fedora 7.0.1-6.fc29)
  37 fedora:30                     : Ok   gcc (GCC) 9.2.1 20190827 (Red Hat 9.2.1-1), clang version 8.0.0 (Fedora 8.0.0-3.fc30)
  38 fedora:30-x-ARC-glibc         : Ok   arc-linux-gcc (ARC HS GNU/Linux glibc toolchain 2019.03-rc1) 8.3.1 20190225
  39 fedora:30-x-ARC-uClibc        : Ok   arc-linux-gcc (ARCv2 ISA Linux uClibc toolchain 2019.03-rc1) 8.3.1 20190225
  40 fedora:31                     : Ok   gcc (GCC) 9.2.1 20190827 (Red Hat 9.2.1-1), clang version 9.0.1 (Fedora 9.0.1-2.fc31)
  41 fedora:32                     : Ok   gcc (GCC) 10.0.1 20200216 (Red Hat 10.0.1-0.8), clang version 10.0.0 (Fedora 10.0.0-0.1.rc2.fc32)
  42 fedora:33                     : Ok   gcc (GCC) 10.0.1 20200311 (Red Hat 10.0.1-0.9), clang version 10.0.0 (Fedora 10.0.0-0.9.rc5.fc33)
  43 fedora:rawhide                : Ok   gcc (GCC) 10.0.1 20200216 (Red Hat 10.0.1-0.8), clang version 10.0.0 (Fedora 10.0.0-0.5.rc3.fc33)
  44 gentoo-stage3-amd64:latest    : Ok   gcc (Gentoo 9.2.0-r2 p3) 9.2.0
  45 mageia:5                      : Ok   gcc (GCC) 4.9.2, clang version 3.5.2 (tags/RELEASE_352/final)
  46 mageia:6                      : Ok   gcc (Mageia 5.5.0-1.mga6) 5.5.0, clang version 3.9.1 (tags/RELEASE_391/final)
  47 mageia:7                      : Ok   gcc (Mageia 8.4.0-1.mga7) 8.4.0, clang version 8.0.0 (Mageia 8.0.0-1.mga7)
  48 manjaro:latest                : Ok   gcc (Arch Linux 9.3.0-1) 9.3.0, clang version 9.0.1
  49 openmandriva:cooker           : Ok   gcc (GCC) 10.0.0 20200301 (OpenMandriva), clang version 10.0.0 
  50 opensuse:15.0                 : Ok   gcc (SUSE Linux) 7.4.1 20190905 [gcc-7-branch revision 275407], clang version 5.0.1 (tags/RELEASE_501/final 312548)
  51 opensuse:15.1                 : Ok   gcc (SUSE Linux) 7.5.0, clang version 7.0.1 (tags/RELEASE_701/final 349238)
  52 opensuse:42.3                 : Ok   gcc (SUSE Linux) 4.8.5, clang version 3.8.0 (tags/RELEASE_380/final 262553)
  53 opensuse:tumbleweed           : Ok   gcc (SUSE Linux) 9.2.1 20200128 [revision 83f65674e78d97d27537361de1a9d74067ff228d], clang version 9.0.1 
  54 oraclelinux:6                 : Ok   gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-23.0.1)
  55 oraclelinux:7                 : Ok   gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-39.0.3)
  56 oraclelinux:8                 : Ok   gcc (GCC) 8.3.1 20190507 (Red Hat 8.3.1-4.5.0.5), clang version 8.0.1 (Red Hat 8.0.1-1.0.1.module+el8.1.0+5428+345cee14)
  57 ubuntu:12.04                  : Ok   gcc (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3, Ubuntu clang version 3.0-6ubuntu3 (tags/RELEASE_30/final) (based on LLVM 3.0)
  58 ubuntu:14.04                  : Ok   gcc (Ubuntu 4.8.4-2ubuntu1~14.04.4) 4.8.4
  59 ubuntu:16.04                  : Ok   gcc (Ubuntu 5.4.0-6ubuntu1~16.04.12) 5.4.0 20160609, clang version 3.8.0-2ubuntu4 (tags/RELEASE_380/final)
  60 ubuntu:16.04-x-arm            : Ok   arm-linux-gnueabihf-gcc (Ubuntu/Linaro 5.4.0-6ubuntu1~16.04.9) 5.4.0 20160609
  61 ubuntu:16.04-x-arm64          : Ok   aarch64-linux-gnu-gcc (Ubuntu/Linaro 5.4.0-6ubuntu1~16.04.9) 5.4.0 20160609
  62 ubuntu:16.04-x-powerpc        : Ok   powerpc-linux-gnu-gcc (Ubuntu 5.4.0-6ubuntu1~16.04.9) 5.4.0 20160609
  63 ubuntu:16.04-x-powerpc64      : Ok   powerpc64-linux-gnu-gcc (Ubuntu/IBM 5.4.0-6ubuntu1~16.04.9) 5.4.0 20160609
  64 ubuntu:16.04-x-powerpc64el    : Ok   powerpc64le-linux-gnu-gcc (Ubuntu/IBM 5.4.0-6ubuntu1~16.04.9) 5.4.0 20160609
  65 ubuntu:16.04-x-s390           : Ok   s390x-linux-gnu-gcc (Ubuntu 5.4.0-6ubuntu1~16.04.9) 5.4.0 20160609
  66 ubuntu:18.04                  : Ok   gcc (Ubuntu 7.5.0-3ubuntu1~18.04) 7.5.0, clang version 6.0.0-1ubuntu2 (tags/RELEASE_600/final)
  67 ubuntu:18.04-x-arm            : Ok   arm-linux-gnueabihf-gcc (Ubuntu/Linaro 7.5.0-3ubuntu1~18.04) 7.5.0
  68 ubuntu:18.04-x-arm64          : Ok   aarch64-linux-gnu-gcc (Ubuntu/Linaro 7.5.0-3ubuntu1~18.04) 7.5.0
  69 ubuntu:18.04-x-m68k           : Ok   m68k-linux-gnu-gcc (Ubuntu 7.5.0-3ubuntu1~18.04) 7.5.0
  70 ubuntu:18.04-x-powerpc        : Ok   powerpc-linux-gnu-gcc (Ubuntu 7.5.0-3ubuntu1~18.04) 7.5.0
  71 ubuntu:18.04-x-powerpc64      : Ok   powerpc64-linux-gnu-gcc (Ubuntu 7.5.0-3ubuntu1~18.04) 7.5.0
  72 ubuntu:18.04-x-powerpc64el    : Ok   powerpc64le-linux-gnu-gcc (Ubuntu 7.5.0-3ubuntu1~18.04) 7.5.0
  73 ubuntu:18.04-x-riscv64        : Ok   riscv64-linux-gnu-gcc (Ubuntu 7.5.0-3ubuntu1~18.04) 7.5.0
  74 ubuntu:18.04-x-s390           : Ok   s390x-linux-gnu-gcc (Ubuntu 7.5.0-3ubuntu1~18.04) 7.5.0
  75 ubuntu:18.04-x-sh4            : Ok   sh4-linux-gnu-gcc (Ubuntu 7.5.0-3ubuntu1~18.04) 7.5.0
  76 ubuntu:18.04-x-sparc64        : Ok   sparc64-linux-gnu-gcc (Ubuntu 7.5.0-3ubuntu1~18.04) 7.5.0
  77 ubuntu:19.04                  : Ok   gcc (Ubuntu 8.3.0-6ubuntu1) 8.3.0, clang version 8.0.0-3 (tags/RELEASE_800/final)
  78 ubuntu:19.04-x-alpha          : Ok   alpha-linux-gnu-gcc (Ubuntu 8.3.0-6ubuntu1) 8.3.0
  79 ubuntu:19.04-x-arm64          : Ok   aarch64-linux-gnu-gcc (Ubuntu/Linaro 8.3.0-6ubuntu1) 8.3.0
  80 ubuntu:19.04-x-hppa           : Ok   hppa-linux-gnu-gcc (Ubuntu 8.3.0-6ubuntu1) 8.3.0
  81 ubuntu:19.10                  : FAIL gcc (Ubuntu 9.2.1-9ubuntu2) 9.2.1 20191008, clang version 9.0.0-2 (tags/RELEASE_900/final)
  82 ubuntu:20.04                  : Ok   gcc (Ubuntu 9.3.0-8ubuntu1) 9.3.0, clang version 10.0.0-1ubuntu1 
  $

  # uname -a
  Linux seventh 5.5.16-100.fc30.x86_64 #1 SMP Wed Apr 8 17:09:38 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
  # git log --oneline -1
  80af1ec0f232 perf script: Add flamegraph.py script
  # perf version --build-options
  perf version 5.6.g80af1ec0f232
                   dwarf: [ on  ]  # HAVE_DWARF_SUPPORT
      dwarf_getlocations: [ on  ]  # HAVE_DWARF_GETLOCATIONS_SUPPORT
                   glibc: [ on  ]  # HAVE_GLIBC_SUPPORT
                    gtk2: [ on  ]  # HAVE_GTK2_SUPPORT
           syscall_table: [ on  ]  # HAVE_SYSCALL_TABLE_SUPPORT
                  libbfd: [ on  ]  # HAVE_LIBBFD_SUPPORT
                  libelf: [ on  ]  # HAVE_LIBELF_SUPPORT
                 libnuma: [ on  ]  # HAVE_LIBNUMA_SUPPORT
  numa_num_possible_cpus: [ on  ]  # HAVE_LIBNUMA_SUPPORT
                 libperl: [ on  ]  # HAVE_LIBPERL_SUPPORT
               libpython: [ on  ]  # HAVE_LIBPYTHON_SUPPORT
                libslang: [ on  ]  # HAVE_SLANG_SUPPORT
               libcrypto: [ on  ]  # HAVE_LIBCRYPTO_SUPPORT
               libunwind: [ on  ]  # HAVE_LIBUNWIND_SUPPORT
      libdw-dwarf-unwind: [ on  ]  # HAVE_DWARF_SUPPORT
                    zlib: [ on  ]  # HAVE_ZLIB_SUPPORT
                    lzma: [ on  ]  # HAVE_LZMA_SUPPORT
               get_cpuid: [ on  ]  # HAVE_AUXTRACE_SUPPORT
                     bpf: [ on  ]  # HAVE_LIBBPF_SUPPORT
                     aio: [ on  ]  # HAVE_AIO_SUPPORT
                    zstd: [ on  ]  # HAVE_ZSTD_SUPPORT
  # perf test
   1: vmlinux symtab matches kallsyms                       : Ok
   2: Detect openat syscall event                           : Ok
   3: Detect openat syscall event on all cpus               : Ok
   4: Read samples using the mmap interface                 : Ok
   5: Test data source output                               : Ok
   6: Parse event definition strings                        : Ok
   7: Simple expression parser                              : Ok
   8: PERF_RECORD_* events & perf_sample fields             : Ok
   9: Parse perf pmu format                                 : Ok
  10: PMU events                                            : Ok
  11: DSO data read                                         : Ok
  12: DSO data cache                                        : Ok
  13: DSO data reopen                                       : Ok
  14: Roundtrip evsel->name                                 : Ok
  15: Parse sched tracepoints fields                        : Ok
  16: syscalls:sys_enter_openat event fields                : Ok
  17: Setup struct perf_event_attr                          : Ok
  18: Match and link multiple hists                         : Ok
  19: 'import perf' in python                               : Ok
  20: Breakpoint overflow signal handler                    : Ok
  21: Breakpoint overflow sampling                          : Ok
  22: Breakpoint accounting                                 : Ok
  23: Watchpoint                                            :
  23.1: Read Only Watchpoint                                : Skip
  23.2: Write Only Watchpoint                               : Ok
  23.3: Read / Write Watchpoint                             : Ok
  23.4: Modify Watchpoint                                   : Ok
  24: Number of exit events of a simple workload            : Ok
  25: Software clock events period values                   : Ok
  26: Object code reading                                   : Ok
  27: Sample parsing                                        : Ok
  28: Use a dummy software event to keep tracking           : Ok
  29: Parse with no sample_id_all bit set                   : Ok
  30: Filter hist entries                                   : Ok
  31: Lookup mmap thread                                    : Ok
  32: Share thread maps                                     : Ok
  33: Sort output of hist entries                           : Ok
  34: Cumulate child hist entries                           : Ok
  35: Track with sched_switch                               : Ok
  36: Filter fds with revents mask in a fdarray             : Ok
  37: Add fd to a fdarray, making it autogrow               : Ok
  38: kmod_path__parse                                      : Ok
  39: Thread map                                            : Ok
  40: LLVM search and compile                               :
  40.1: Basic BPF llvm compile                              : Ok
  40.2: kbuild searching                                    : Ok
  40.3: Compile source for BPF prologue generation          : Ok
  40.4: Compile source for BPF relocation                   : Ok
  41: Session topology                                      : Ok
  42: BPF filter                                            :
  42.1: Basic BPF filtering                                 : Ok
  42.2: BPF pinning                                         : Ok
  42.3: BPF prologue generation                             : Ok
  42.4: BPF relocation checker                              : Ok
  43: Synthesize thread map                                 : Ok
  44: Remove thread map                                     : Ok
  45: Synthesize cpu map                                    : Ok
  46: Synthesize stat config                                : Ok
  47: Synthesize stat                                       : Ok
  48: Synthesize stat round                                 : Ok
  49: Synthesize attr update                                : Ok
  50: Event times                                           : Ok
  51: Read backward ring buffer                             : Ok
  52: Print cpu map                                         : Ok
  53: Merge cpu map                                         : Ok
  54: Probe SDT events                                      : Ok
  55: is_printable_array                                    : Ok
  56: Print bitmap                                          : Ok
  57: perf hooks                                            : Ok
  58: builtin clang support                                 : Skip (not compiled in)
  59: unit_number__scnprintf                                : Ok
  60: mem2node                                              : Ok
  61: time utils                                            : Ok
  62: Test jit_write_elf                                    : Ok
  63: maps__merge_in                                        : Ok
  64: x86 rdpmc                                             : Ok
  65: Convert perf time to TSC                              : Ok
  66: DWARF unwind                                          : Ok
  67: x86 instruction decoder - new instructions            : Ok
  68: Intel PT packet decoder                               : Ok
  69: x86 bp modify                                         : Ok
  70: Use vfs_getname probe to get syscall args filenames   : Ok
  71: Check open filename arg using perf trace + vfs_getname: Ok
  72: Zstd perf.data compression/decompression              : Ok
  73: probe libc's inet_pton & backtrace it with ping       : Ok
  74: Add vfs_getname probe to get syscall args filenames   : Ok
  #

  $ git log --oneline -1 ; make -C tools/perf build-test
  80af1ec0f232 (HEAD -> perf/core, quaco/perf/core, five/perf/core) perf script: Add flamegraph.py script
  make: Entering directory '/home/acme/git/perf/tools/perf'
  - tarpkg: ./tests/perf-targz-src-pkg .
                   make_pure_O: make
                  make_debug_O: make DEBUG=1
           make_no_libpython_O: make NO_LIBPYTHON=1
             make_util_map_o_O: make util/map.o
              make_no_libbpf_O: make NO_LIBBPF=1
        make_with_babeltrace_O: make LIBBABELTRACE=1
             make_no_libperl_O: make NO_LIBPERL=1
                 make_static_O: make LDFLAGS=-static NO_PERF_READ_VDSO32=1 NO_PERF_READ_VDSOX32=1 NO_JVMTI=1
       make_util_pmu_bison_o_O: make util/pmu-bison.o
                 make_perf_o_O: make perf.o
            make_no_libaudit_O: make NO_LIBAUDIT=1
                make_install_O: make install
                 make_cscope_O: make cscope
           make_no_backtrace_O: make NO_BACKTRACE=1
   make_install_prefix_slash_O: make install prefix=/tmp/krava/
                make_minimal_O: make NO_LIBPERL=1 NO_LIBPYTHON=1 NO_NEWT=1 NO_GTK2=1 NO_DEMANGLE=1 NO_LIBELF=1 NO_LIBUNWIND=1 NO_BACKTRACE=1 NO_LIBNUMA=1 NO_LIBAUDIT=1 NO_LIBBIONIC=1 NO_LIBDW_DWARF_UNWIND=1 NO_AUXTRACE=1 NO_LIBBPF=1 NO_LIBCRYPTO=1 NO_SDT=1 NO_JVMTI=1 NO_LIBZSTD=1 NO_LIBCAP=1
                   make_help_O: make help
             make_no_libnuma_O: make NO_LIBNUMA=1
                    make_doc_O: make doc
              make_clean_all_O: make clean all
         make_install_prefix_O: make install prefix=/tmp/krava
             make_no_scripts_O: make NO_LIBPYTHON=1 NO_LIBPERL=1
            make_no_auxtrace_O: make NO_AUXTRACE=1
            make_no_demangle_O: make NO_DEMANGLE=1
              make_no_libelf_O: make NO_LIBELF=1
                   make_tags_O: make tags
               make_no_slang_O: make NO_SLANG=1
                  make_no_ui_O: make NO_NEWT=1 NO_SLANG=1 NO_GTK2=1
           make_no_libunwind_O: make NO_LIBUNWIND=1
            make_install_bin_O: make install-bin
                make_no_newt_O: make NO_NEWT=1
           make_no_libbionic_O: make NO_LIBBIONIC=1
         make_with_clangllvm_O: make LIBCLANGLLVM=1
  make_no_libdw_dwarf_unwind_O: make NO_LIBDW_DWARF_UNWIND=1
                make_no_gtk2_O: make NO_GTK2=1
  OK
  make: Leaving directory '/home/acme/git/perf/tools/perf'
  $

[PATCH 01/26] perf tools: Synthesize bpf_trampoline/dispatcher ksymbol event

[Arnaldo Carvalho de Melo]

From: Jiri Olsa <jolsa@kernel.org>

Synthesize bpf images (trampolines/dispatchers) on start, as ksymbol
events from /proc/kallsyms. Having this perf can recognize samples from
those images and perf report and top shows them correctly.

The rest of the ksymbol handling is already in place from for the bpf
programs monitoring, so only the initial state was needed.

perf report output:

  # Overhead  Command     Shared Object                  Symbol

    12.37%  test_progs  [kernel.vmlinux]                 [k] entry_SYSCALL_64
    11.80%  test_progs  [kernel.vmlinux]                 [k] syscall_return_via_sysret
     9.63%  test_progs  bpf_prog_bcf7977d3b93787c_prog2  [k] bpf_prog_bcf7977d3b93787c_prog2
     6.90%  test_progs  bpf_trampoline_24456             [k] bpf_trampoline_24456
     6.36%  test_progs  [kernel.vmlinux]                 [k] memcpy_erms

Committer notes:

Use scnprintf() instead of strncpy() to overcome this on fedora:32,
rawhide and OpenMandriva Cooker:

    CC       /tmp/build/perf/util/bpf-event.o
  In file included from /usr/include/string.h:495,
                   from /git/linux/tools/lib/bpf/libbpf_common.h:12,
                   from /git/linux/tools/lib/bpf/bpf.h:31,
                   from util/bpf-event.c:4:
  In function 'strncpy',
      inlined from 'process_bpf_image' at util/bpf-event.c:323:2,
      inlined from 'kallsyms_process_symbol' at util/bpf-event.c:358:9:
  /usr/include/bits/string_fortified.h:106:10: error: '__builtin_strncpy' specified bound 256 equals destination size [-Werror=stringop-truncation]
    106 |   return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
        |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  cc1: all warnings being treated as errors

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andriin@fb.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David S. Miller <davem@redhat.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jesper Dangaard Brouer <hawk@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200312195610.346362-14-jolsa@kernel.org/
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/bpf-event.c | 93 +++++++++++++++++++++++++++++++++++++
 1 file changed, 93 insertions(+)

diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
index a3207d900339..0cd41a862952 100644
--- a/tools/perf/util/bpf-event.c
+++ b/tools/perf/util/bpf-event.c
@@ -6,6 +6,9 @@
 #include <bpf/libbpf.h>
 #include <linux/btf.h>
 #include <linux/err.h>
+#include <linux/string.h>
+#include <internal/lib.h>
+#include <symbol/kallsyms.h>
 #include "bpf-event.h"
 #include "debug.h"
 #include "dso.h"
@@ -290,11 +293,82 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
 	return err ? -1 : 0;
 }
 
+struct kallsyms_parse {
+	union perf_event	*event;
+	perf_event__handler_t	 process;
+	struct machine		*machine;
+	struct perf_tool	*tool;
+};
+
+static int
+process_bpf_image(char *name, u64 addr, struct kallsyms_parse *data)
+{
+	struct machine *machine = data->machine;
+	union perf_event *event = data->event;
+	struct perf_record_ksymbol *ksymbol;
+	int len;
+
+	ksymbol = &event->ksymbol;
+
+	*ksymbol = (struct perf_record_ksymbol) {
+		.header = {
+			.type = PERF_RECORD_KSYMBOL,
+			.size = offsetof(struct perf_record_ksymbol, name),
+		},
+		.addr      = addr,
+		.len       = page_size,
+		.ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF,
+		.flags     = 0,
+	};
+
+	len = scnprintf(ksymbol->name, KSYM_NAME_LEN, "%s", name);
+	ksymbol->header.size += PERF_ALIGN(len + 1, sizeof(u64));
+	memset((void *) event + event->header.size, 0, machine->id_hdr_size);
+	event->header.size += machine->id_hdr_size;
+
+	return perf_tool__process_synth_event(data->tool, event, machine,
+					      data->process);
+}
+
+static int
+kallsyms_process_symbol(void *data, const char *_name,
+			char type __maybe_unused, u64 start)
+{
+	char disp[KSYM_NAME_LEN];
+	char *module, *name;
+	unsigned long id;
+	int err = 0;
+
+	module = strchr(_name, '\t');
+	if (!module)
+		return 0;
+
+	/* We are going after [bpf] module ... */
+	if (strcmp(module + 1, "[bpf]"))
+		return 0;
+
+	name = memdup(_name, (module - _name) + 1);
+	if (!name)
+		return -ENOMEM;
+
+	name[module - _name] = 0;
+
+	/* .. and only for trampolines and dispatchers */
+	if ((sscanf(name, "bpf_trampoline_%lu", &id) == 1) ||
+	    (sscanf(name, "bpf_dispatcher_%s", disp) == 1))
+		err = process_bpf_image(name, start, data);
+
+	free(name);
+	return err;
+}
+
 int perf_event__synthesize_bpf_events(struct perf_session *session,
 				      perf_event__handler_t process,
 				      struct machine *machine,
 				      struct record_opts *opts)
 {
+	const char *kallsyms_filename = "/proc/kallsyms";
+	struct kallsyms_parse arg;
 	union perf_event *event;
 	__u32 id = 0;
 	int err;
@@ -303,6 +377,8 @@ int perf_event__synthesize_bpf_events(struct perf_session *session,
 	event = malloc(sizeof(event->bpf) + KSYM_NAME_LEN + machine->id_hdr_size);
 	if (!event)
 		return -1;
+
+	/* Synthesize all the bpf programs in system. */
 	while (true) {
 		err = bpf_prog_get_next_id(id, &id);
 		if (err) {
@@ -335,6 +411,23 @@ int perf_event__synthesize_bpf_events(struct perf_session *session,
 			break;
 		}
 	}
+
+	/* Synthesize all the bpf images - trampolines/dispatchers. */
+	if (symbol_conf.kallsyms_name != NULL)
+		kallsyms_filename = symbol_conf.kallsyms_name;
+
+	arg = (struct kallsyms_parse) {
+		.event   = event,
+		.process = process,
+		.machine = machine,
+		.tool    = session->tool,
+	};
+
+	if (kallsyms__parse(kallsyms_filename, &arg, kallsyms_process_symbol)) {
+		pr_err("%s: failed to synthesize bpf images: %s\n",
+		       __func__, strerror(errno));
+	}
+
 	free(event);
 	return err;
 }
-- 
2.21.1

[PATCH 02/26] perf machine: Set ksymbol dso as loaded on arrival

[Arnaldo Carvalho de Melo]

From: Jiri Olsa <jolsa@kernel.org>

There's no special load action for ksymbol data on map__load/dso__load
action, where the kernel is getting loaded. It only gets confused with
kernel kallsyms/vmlinux load for bpf object, which fails and could mess
up with the map.

Disabling any further load of the map for ksymbol related dso/map.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andriin@fb.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David S. Miller <davem@redhat.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jesper Dangaard Brouer <hawk@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200312195610.346362-15-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/machine.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 97142e9671be..06aa4e4db63d 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -759,6 +759,7 @@ static int machine__process_ksymbol_register(struct machine *machine,
 		map->start = event->ksymbol.addr;
 		map->end = map->start + event->ksymbol.len;
 		maps__insert(&machine->kmaps, map);
+		dso__set_loaded(dso);
 	}
 
 	sym = symbol__new(map->map_ip(map, map->start),
-- 
2.21.1

[PATCH 03/26] perf annotate: Add basic support for bpf_image

[Arnaldo Carvalho de Melo]

From: Jiri Olsa <jolsa@kernel.org>

Add the DSO_BINARY_TYPE__BPF_IMAGE dso binary type to recognize BPF
images that carry trampoline or dispatcher.

Upcoming patches will add support to read the image data, store it
within the BPF feature in perf.data and display it for annotation
purposes.

Currently we only display following message:

  # ./perf annotate bpf_trampoline_24456 --stdio
   Percent |      Source code & Disassembly of . for cycles (504  ...
  --------------------------------------------------------------- ...
           :       to be implemented

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andriin@fb.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David S. Miller <davem@redhat.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jesper Dangaard Brouer <hawk@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200312195610.346362-16-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/annotate.c | 20 ++++++++++++++++++++
 tools/perf/util/dso.c      |  1 +
 tools/perf/util/dso.h      |  1 +
 tools/perf/util/machine.c  | 11 +++++++++++
 tools/perf/util/symbol.c   |  1 +
 5 files changed, 34 insertions(+)

diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index f1ea0d61eb5b..9760d58e979a 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -1821,6 +1821,24 @@ static int symbol__disassemble_bpf(struct symbol *sym __maybe_unused,
 }
 #endif // defined(HAVE_LIBBFD_SUPPORT) && defined(HAVE_LIBBPF_SUPPORT)
 
+static int
+symbol__disassemble_bpf_image(struct symbol *sym,
+			      struct annotate_args *args)
+{
+	struct annotation *notes = symbol__annotation(sym);
+	struct disasm_line *dl;
+
+	args->offset = -1;
+	args->line = strdup("to be implemented");
+	args->line_nr = 0;
+	dl = disasm_line__new(args);
+	if (dl)
+		annotation_line__add(&dl->al, &notes->src->source);
+
+	free(args->line);
+	return 0;
+}
+
 /*
  * Possibly create a new version of line with tabs expanded. Returns the
  * existing or new line, storage is updated if a new line is allocated. If
@@ -1920,6 +1938,8 @@ static int symbol__disassemble(struct symbol *sym, struct annotate_args *args)
 
 	if (dso->binary_type == DSO_BINARY_TYPE__BPF_PROG_INFO) {
 		return symbol__disassemble_bpf(sym, args);
+	} else if (dso->binary_type == DSO_BINARY_TYPE__BPF_IMAGE) {
+		return symbol__disassemble_bpf_image(sym, args);
 	} else if (dso__is_kcore(dso)) {
 		kce.kcore_filename = symfs_filename;
 		kce.addr = map__rip_2objdump(map, sym->start);
diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 91f21239608b..f338990e0fe6 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -191,6 +191,7 @@ int dso__read_binary_type_filename(const struct dso *dso,
 	case DSO_BINARY_TYPE__GUEST_KALLSYMS:
 	case DSO_BINARY_TYPE__JAVA_JIT:
 	case DSO_BINARY_TYPE__BPF_PROG_INFO:
+	case DSO_BINARY_TYPE__BPF_IMAGE:
 	case DSO_BINARY_TYPE__NOT_FOUND:
 		ret = -1;
 		break;
diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index 2db64b79617a..9553a1fd9e8a 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -40,6 +40,7 @@ enum dso_binary_type {
 	DSO_BINARY_TYPE__GUEST_KCORE,
 	DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
 	DSO_BINARY_TYPE__BPF_PROG_INFO,
+	DSO_BINARY_TYPE__BPF_IMAGE,
 	DSO_BINARY_TYPE__NOT_FOUND,
 };
 
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 06aa4e4db63d..09845eae9c03 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -736,6 +736,12 @@ int machine__process_switch_event(struct machine *machine __maybe_unused,
 	return 0;
 }
 
+static int is_bpf_image(const char *name)
+{
+	return strncmp(name, "bpf_trampoline_", sizeof("bpf_trampoline_") - 1) ||
+	       strncmp(name, "bpf_dispatcher_", sizeof("bpf_dispatcher_") - 1);
+}
+
 static int machine__process_ksymbol_register(struct machine *machine,
 					     union perf_event *event,
 					     struct perf_sample *sample __maybe_unused)
@@ -760,6 +766,11 @@ static int machine__process_ksymbol_register(struct machine *machine,
 		map->end = map->start + event->ksymbol.len;
 		maps__insert(&machine->kmaps, map);
 		dso__set_loaded(dso);
+
+		if (is_bpf_image(event->ksymbol.name)) {
+			dso->binary_type = DSO_BINARY_TYPE__BPF_IMAGE;
+			dso__set_long_name(dso, "", false);
+		}
 	}
 
 	sym = symbol__new(map->map_ip(map, map->start),
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 26bc6a0096ce..8f4300492dc7 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1544,6 +1544,7 @@ static bool dso__is_compatible_symtab_type(struct dso *dso, bool kmod,
 		return true;
 
 	case DSO_BINARY_TYPE__BPF_PROG_INFO:
+	case DSO_BINARY_TYPE__BPF_IMAGE:
 	case DSO_BINARY_TYPE__NOT_FOUND:
 	default:
 		return false;
-- 
2.21.1

[PATCH 04/26] tools arch x86: Sync the msr-index.h copy with the kernel sources

[Arnaldo Carvalho de Melo]

From: Arnaldo Carvalho de Melo <acme@redhat.com>

To pick up the changes in:

  6650cdd9a8cc ("x86/split_lock: Enable split lock detection by kernel")

  Warning: Kernel ABI header at 'tools/arch/x86/include/asm/msr-index.h' differs from latest version at 'arch/x86/include/asm/msr-index.h'
  diff -u tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.h

Which causes these changes in tooling:

  $ tools/perf/trace/beauty/tracepoints/x86_msr.sh > before
  $ cp arch/x86/include/asm/msr-index.h tools/arch/x86/include/asm/msr-index.h
  $ tools/perf/trace/beauty/tracepoints/x86_msr.sh > after
  $ diff -u before after
  --- before	2020-04-01 12:11:14.789344795 -0300
  +++ after	2020-04-01 12:11:56.907798879 -0300
  @@ -10,6 +10,7 @@
   	[0x00000029] = "KNC_EVNTSEL1",
   	[0x0000002a] = "IA32_EBL_CR_POWERON",
   	[0x0000002c] = "EBC_FREQUENCY_ID",
  +	[0x00000033] = "TEST_CTRL",
   	[0x00000034] = "SMI_COUNT",
   	[0x0000003a] = "IA32_FEAT_CTL",
   	[0x0000003b] = "IA32_TSC_ADJUST",
  @@ -27,6 +28,7 @@
   	[0x000000c2] = "IA32_PERFCTR1",
   	[0x000000cd] = "FSB_FREQ",
   	[0x000000ce] = "PLATFORM_INFO",
  +	[0x000000cf] = "IA32_CORE_CAPS",
   	[0x000000e2] = "PKG_CST_CONFIG_CONTROL",
   	[0x000000e7] = "IA32_MPERF",
   	[0x000000e8] = "IA32_APERF",
  $

  $ make -C tools/perf O=/tmp/build/perf install-bin
  <SNIP>
    CC       /tmp/build/perf/trace/beauty/tracepoints/x86_msr.o
    LD       /tmp/build/perf/trace/beauty/tracepoints/perf-in.o
    LD       /tmp/build/perf/trace/beauty/perf-in.o
    LD       /tmp/build/perf/perf-in.o
    LINK     /tmp/build/perf/perf
  <SNIP>

Now one can do:

	perf trace -e msr:* --filter=msr==IA32_CORE_CAPS

or:

	perf trace -e msr:* --filter='msr==IA32_CORE_CAPS || msr==TEST_CTRL'

And see only those MSRs being accessed via:

  # perf trace -v -e msr:* --filter='msr==IA32_CORE_CAPS || msr==TEST_CTRL'
  New filter for msr:read_msr: (msr==0xcf || msr==0x33) && (common_pid != 8263 && common_pid != 23250)
  New filter for msr:write_msr: (msr==0xcf || msr==0x33) && (common_pid != 8263 && common_pid != 23250)
  New filter for msr:rdpmc: (msr==0xcf || msr==0x33) && (common_pid != 8263 && common_pid != 23250)

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/lkml/20200401153325.GC12534@kernel.org/
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/arch/x86/include/asm/msr-index.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/tools/arch/x86/include/asm/msr-index.h b/tools/arch/x86/include/asm/msr-index.h
index d5e517d1c3dd..12c9684d59ba 100644
--- a/tools/arch/x86/include/asm/msr-index.h
+++ b/tools/arch/x86/include/asm/msr-index.h
@@ -41,6 +41,10 @@
 
 /* Intel MSRs. Some also available on other CPUs */
 
+#define MSR_TEST_CTRL				0x00000033
+#define MSR_TEST_CTRL_SPLIT_LOCK_DETECT_BIT	29
+#define MSR_TEST_CTRL_SPLIT_LOCK_DETECT		BIT(MSR_TEST_CTRL_SPLIT_LOCK_DETECT_BIT)
+
 #define MSR_IA32_SPEC_CTRL		0x00000048 /* Speculation Control */
 #define SPEC_CTRL_IBRS			BIT(0)	   /* Indirect Branch Restricted Speculation */
 #define SPEC_CTRL_STIBP_SHIFT		1	   /* Single Thread Indirect Branch Predictor (STIBP) bit */
@@ -70,6 +74,11 @@
  */
 #define MSR_IA32_UMWAIT_CONTROL_TIME_MASK	(~0x03U)
 
+/* Abbreviated from Intel SDM name IA32_CORE_CAPABILITIES */
+#define MSR_IA32_CORE_CAPS			  0x000000cf
+#define MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT_BIT  5
+#define MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT	  BIT(MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT_BIT)
+
 #define MSR_PKG_CST_CONFIG_CONTROL	0x000000e2
 #define NHM_C3_AUTO_DEMOTE		(1UL << 25)
 #define NHM_C1_AUTO_DEMOTE		(1UL << 26)
-- 
2.21.1

[PATCH 05/26] capabilities: Introduce CAP_PERFMON to kernel and user space

[Arnaldo Carvalho de Melo]

From: Alexey Budankov <alexey.budankov-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>

Introduce the CAP_PERFMON capability designed to secure system
performance monitoring and observability operations so that CAP_PERFMON
can assist CAP_SYS_ADMIN capability in its governing role for
performance monitoring and observability subsystems.

CAP_PERFMON hardens system security and integrity during performance
monitoring and observability operations by decreasing attack surface that
is available to a CAP_SYS_ADMIN privileged process [2]. Providing the access
to system performance monitoring and observability operations under CAP_PERFMON
capability singly, without the rest of CAP_SYS_ADMIN credentials, excludes
chances to misuse the credentials and makes the operation more secure.

Thus, CAP_PERFMON implements the principle 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)

CAP_PERFMON meets the demand to secure system performance monitoring and
observability operations for adoption in security sensitive, restricted,
multiuser production environments (e.g. HPC clusters, cloud and virtual compute
environments), where root or CAP_SYS_ADMIN credentials are not available to
mass users of a system, and securely unblocks applicability and scalability
of system performance monitoring and observability operations beyond root
and CAP_SYS_ADMIN use cases.

CAP_PERFMON takes over CAP_SYS_ADMIN credentials related to system performance
monitoring and observability operations and balances amount of CAP_SYS_ADMIN
credentials following the recommendations in the capabilities man page [1]
for CAP_SYS_ADMIN: "Note: this capability is overloaded; see Notes to kernel
developers, below." For backward compatibility reasons access to system
performance monitoring and observability subsystems of the kernel remains
open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN capability
usage for secure system performance monitoring and observability operations
is discouraged with respect to the designed CAP_PERFMON capability.

Although the software running under CAP_PERFMON can not ensure avoidance
of related hardware issues, the software can still mitigate these issues
following the official hardware issues mitigation procedure [2]. The bugs
in the software itself can be fixed following the standard kernel development
process [3] to maintain and harden security of system performance monitoring
and observability operations.

[1] http://man7.org/linux/man-pages/man7/capabilities.7.html
[2] https://www.kernel.org/doc/html/latest/process/embargoed-hardware-issues.html
[3] https://www.kernel.org/doc/html/latest/admin-guide/security-bugs.html

Signed-off-by: Alexey Budankov <alexey.budankov-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Acked-by: James Morris <jamorris-1pm0nblsJy7Jp67UH1NAhkEOCMrvLtNR@public.gmane.org>
Acked-by: Serge E. Hallyn <serge-A9i7LUbDfNHQT0dZR+AlfA@public.gmane.org>
Acked-by: Song Liu <songliubraving-b10kYP2dOMg@public.gmane.org>
Acked-by: Stephen Smalley <sds-+05T5uksL2qpZYMLLGbcSA@public.gmane.org>
Tested-by: Arnaldo Carvalho de Melo <acme-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: Alexei Starovoitov <ast-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: Andi Kleen <ak-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Cc: Igor Lubashev <ilubashe-JqFfY2XvxFXQT0dZR+AlfA@public.gmane.org>
Cc: Jiri Olsa <jolsa-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: Namhyung Kim <namhyung-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: Peter Zijlstra <peterz-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
Cc: Stephane Eranian <eranian-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
Cc: Thomas Gleixner <tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>
Cc: intel-gfx-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org
Cc: linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: linux-man-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: linux-security-module-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: selinux-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Link: http://lore.kernel.org/lkml/5590d543-82c6-490a-6544-08e6a5517db0-VuQAYsv1563Yd54FQh9/CA@public.gmane.org
Signed-off-by: Arnaldo Carvalho de Melo <acme-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
 include/linux/capability.h          | 4 ++++
 include/uapi/linux/capability.h     | 8 +++++++-
 security/selinux/include/classmap.h | 4 ++--
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/include/linux/capability.h b/include/linux/capability.h
index ecce0f43c73a..027d7e4a853b 100644
--- a/include/linux/capability.h
+++ b/include/linux/capability.h
@@ -251,6 +251,10 @@ extern bool privileged_wrt_inode_uidgid(struct user_namespace *ns, const struct
 extern bool capable_wrt_inode_uidgid(const struct inode *inode, int cap);
 extern bool file_ns_capable(const struct file *file, struct user_namespace *ns, int cap);
 extern bool ptracer_capable(struct task_struct *tsk, struct user_namespace *ns);
+static inline bool perfmon_capable(void)
+{
+	return capable(CAP_PERFMON) || capable(CAP_SYS_ADMIN);
+}
 
 /* audit system wants to get cap info from files as well */
 extern int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps);
diff --git a/include/uapi/linux/capability.h b/include/uapi/linux/capability.h
index 272dc69fa080..e58c9636741b 100644
--- a/include/uapi/linux/capability.h
+++ b/include/uapi/linux/capability.h
@@ -367,8 +367,14 @@ struct vfs_ns_cap_data {
 
 #define CAP_AUDIT_READ		37
 
+/*
+ * Allow system performance and observability privileged operations
+ * using perf_events, i915_perf and other kernel subsystems
+ */
+
+#define CAP_PERFMON		38
 
-#define CAP_LAST_CAP         CAP_AUDIT_READ
+#define CAP_LAST_CAP         CAP_PERFMON
 
 #define cap_valid(x) ((x) >= 0 && (x) <= CAP_LAST_CAP)
 
diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h
index 986f3ac14282..d233ab3f1533 100644
--- a/security/selinux/include/classmap.h
+++ b/security/selinux/include/classmap.h
@@ -27,9 +27,9 @@
 	    "audit_control", "setfcap"
 
 #define COMMON_CAP2_PERMS  "mac_override", "mac_admin", "syslog", \
-		"wake_alarm", "block_suspend", "audit_read"
+		"wake_alarm", "block_suspend", "audit_read", "perfmon"
 
-#if CAP_LAST_CAP > CAP_AUDIT_READ
+#if CAP_LAST_CAP > CAP_PERFMON
 #error New capability defined, please update COMMON_CAP2_PERMS.
 #endif
 
-- 
2.21.1

[PATCH 06/26] perf/core: Open access to the core for CAP_PERFMON privileged process

[Arnaldo Carvalho de Melo]

From: Alexey Budankov <alexey.budankov@linux.intel.com>

Open access to monitoring of kernel code, CPUs, tracepoints and
namespaces data for a 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 principle 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 the 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@linux.intel.com>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Igor Lubashev <ilubashe@akamai.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: linux-man@vger.kernel.org
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: intel-gfx@lists.freedesktop.org
Cc: linux-doc@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Cc: selinux@vger.kernel.org
Link: http://lore.kernel.org/lkml/471acaef-bb8a-5ce2-923f-90606b78eef9@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 include/linux/perf_event.h | 6 +++---
 kernel/events/core.c       | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 9c3e7619c929..87e21681759c 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -1305,7 +1305,7 @@ static inline int perf_is_paranoid(void)
 
 static inline int perf_allow_kernel(struct perf_event_attr *attr)
 {
-	if (sysctl_perf_event_paranoid > 1 && !capable(CAP_SYS_ADMIN))
+	if (sysctl_perf_event_paranoid > 1 && !perfmon_capable())
 		return -EACCES;
 
 	return security_perf_event_open(attr, PERF_SECURITY_KERNEL);
@@ -1313,7 +1313,7 @@ static inline int perf_allow_kernel(struct perf_event_attr *attr)
 
 static inline int perf_allow_cpu(struct perf_event_attr *attr)
 {
-	if (sysctl_perf_event_paranoid > 0 && !capable(CAP_SYS_ADMIN))
+	if (sysctl_perf_event_paranoid > 0 && !perfmon_capable())
 		return -EACCES;
 
 	return security_perf_event_open(attr, PERF_SECURITY_CPU);
@@ -1321,7 +1321,7 @@ static inline int perf_allow_cpu(struct perf_event_attr *attr)
 
 static inline int perf_allow_tracepoint(struct perf_event_attr *attr)
 {
-	if (sysctl_perf_event_paranoid > -1 && !capable(CAP_SYS_ADMIN))
+	if (sysctl_perf_event_paranoid > -1 && !perfmon_capable())
 		return -EPERM;
 
 	return security_perf_event_open(attr, PERF_SECURITY_TRACEPOINT);
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 1569979c8912..f9d564127e2e 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -11486,7 +11486,7 @@ SYSCALL_DEFINE5(perf_event_open,
 	}
 
 	if (attr.namespaces) {
-		if (!capable(CAP_SYS_ADMIN))
+		if (!perfmon_capable())
 			return -EACCES;
 	}
 
-- 
2.21.1

[PATCH 07/26] perf/core: open access to probes for CAP_PERFMON privileged process

[Arnaldo Carvalho de Melo]

From: Alexey Budankov <alexey.budankov@linux.intel.com>

Open access to monitoring via kprobes and uprobes and eBPF tracing 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.

perf kprobes and uprobes are used by ftrace and eBPF. perf probe uses
ftrace to define new kprobe events, and those events are treated as
tracepoint events. eBPF defines new probes via perf_event_open interface
and then the probes are used in eBPF tracing.

CAP_PERFMON implements the principle 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@linux.intel.com>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Igor Lubashev <ilubashe@akamai.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: intel-gfx@lists.freedesktop.org
Cc: linux-doc@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Cc: selinux@vger.kernel.org
Cc: linux-man@vger.kernel.org
Link: http://lore.kernel.org/lkml/3c129d9a-ba8a-3483-ecc5-ad6c8e7c203f@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 kernel/events/core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index f9d564127e2e..d6e021612b2c 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -9377,7 +9377,7 @@ static int perf_kprobe_event_init(struct perf_event *event)
 	if (event->attr.type != perf_kprobe.type)
 		return -ENOENT;
 
-	if (!capable(CAP_SYS_ADMIN))
+	if (!perfmon_capable())
 		return -EACCES;
 
 	/*
@@ -9437,7 +9437,7 @@ static int perf_uprobe_event_init(struct perf_event *event)
 	if (event->attr.type != perf_uprobe.type)
 		return -ENOENT;
 
-	if (!capable(CAP_SYS_ADMIN))
+	if (!perfmon_capable())
 		return -EACCES;
 
 	/*
-- 
2.21.1

[PATCH 08/26] perf tools: Support CAP_PERFMON capability

[Arnaldo Carvalho de Melo]

From: Alexey Budankov <alexey.budankov@linux.intel.com>

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 principle 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.

Committer testing:

Using a libcap with this patch:

  diff --git a/libcap/include/uapi/linux/capability.h b/libcap/include/uapi/linux/capability.h
  index 78b2fd4c8a95..89b5b0279b60 100644
  --- a/libcap/include/uapi/linux/capability.h
  +++ b/libcap/include/uapi/linux/capability.h
  @@ -366,8 +366,9 @@ struct vfs_ns_cap_data {

   #define CAP_AUDIT_READ       37

  +#define CAP_PERFMON	     38

  -#define CAP_LAST_CAP         CAP_AUDIT_READ
  +#define CAP_LAST_CAP         CAP_PERFMON

   #define cap_valid(x) ((x) >= 0 && (x) <= CAP_LAST_CAP)

Note that using '38' in place of 'cap_perfmon' works to some degree with
an old libcap, its only when cap_get_flag() is called that libcap
performs an error check based on the maximum value known for
capabilities that it will fail.

This makes determining the default of perf_event_attr.exclude_kernel to
fail, as it can't determine if CAP_PERFMON is in place.

Using 'perf top -e cycles' avoids the default check and sets
perf_event_attr.exclude_kernel to 1.

As root, with a libcap supporting CAP_PERFMON:

  # groupadd perf_users
  # adduser perf -g perf_users
  # mkdir ~perf/bin
  # cp ~acme/bin/perf ~perf/bin/
  # chgrp perf_users ~perf/bin/perf
  # setcap "cap_perfmon,cap_sys_ptrace,cap_syslog=ep" ~perf/bin/perf
  # getcap ~perf/bin/perf
  /home/perf/bin/perf = cap_sys_ptrace,cap_syslog,cap_perfmon+ep
  # ls -la ~perf/bin/perf
  -rwxr-xr-x. 1 root perf_users 16968552 Apr  9 13:10 /home/perf/bin/perf

As the 'perf' user in the 'perf_users' group:

  $ perf top -a --stdio
  Error:
  Failed to mmap with 1 (Operation not permitted)
  $

Either add the cap_ipc_lock capability to the perf binary or reduce the
ring buffer size to some smaller value:

  $ perf top -m10 -a --stdio
  rounding mmap pages size to 64K (16 pages)
  Error:
  Failed to mmap with 1 (Operation not permitted)
  $ perf top -m4 -a --stdio
  Error:
  Failed to mmap with 1 (Operation not permitted)
  $ perf top -m2 -a --stdio
   PerfTop: 762 irqs/sec  kernel:49.7%  exact: 100.0% lost: 0/0 drop: 0/0 [4000Hz cycles], (all, 4 CPUs)
  ------------------------------------------------------------------------------------------------------

     9.83%  perf                [.] __symbols__insert
     8.58%  perf                [.] rb_next
     5.91%  [kernel]            [k] module_get_kallsym
     5.66%  [kernel]            [k] kallsyms_expand_symbol.constprop.0
     3.98%  libc-2.29.so        [.] __GI_____strtoull_l_internal
     3.66%  perf                [.] rb_insert_color
     2.34%  [kernel]            [k] vsnprintf
     2.30%  [kernel]            [k] string_nocheck
     2.16%  libc-2.29.so        [.] _IO_getdelim
     2.15%  [kernel]            [k] number
     2.13%  [kernel]            [k] format_decode
     1.58%  libc-2.29.so        [.] _IO_feof
     1.52%  libc-2.29.so        [.] __strcmp_avx2
     1.50%  perf                [.] rb_set_parent_color
     1.47%  libc-2.29.so        [.] __libc_calloc
     1.24%  [kernel]            [k] do_syscall_64
     1.17%  [kernel]            [k] __x86_indirect_thunk_rax

  $ perf record -a sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.552 MB perf.data (74 samples) ]
  $ perf evlist
  cycles
  $ perf evlist -v
  cycles: size: 120, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|CPU|PERIOD, read_format: ID, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, task: 1, precise_ip: 3, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1
  $ perf report | head -20
  # To display the perf.data header info, please use --header/--header-only options.
  #
  #
  # Total Lost Samples: 0
  #
  # Samples: 74  of event 'cycles'
  # Event count (approx.): 15694834
  #
  # Overhead  Command          Shared Object               Symbol
  # ........  ...............  ..........................  ......................................
  #
      19.62%  perf             [kernel.vmlinux]            [k] strnlen_user
      13.88%  swapper          [kernel.vmlinux]            [k] intel_idle
      13.83%  ksoftirqd/0      [kernel.vmlinux]            [k] pfifo_fast_dequeue
      13.51%  swapper          [kernel.vmlinux]            [k] kmem_cache_free
       6.31%  gnome-shell      [kernel.vmlinux]            [k] kmem_cache_free
       5.66%  kworker/u8:3+ix  [kernel.vmlinux]            [k] delay_tsc
       4.42%  perf             [kernel.vmlinux]            [k] __set_cpus_allowed_ptr
       3.45%  kworker/2:1-eve  [kernel.vmlinux]            [k] shmem_truncate_range
       2.29%  gnome-shell      libgobject-2.0.so.0.6000.7  [.] g_closure_ref
  $

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Igor Lubashev <ilubashe@akamai.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: intel-gfx@lists.freedesktop.org
Cc: linux-doc@vger.kernel.org
Cc: linux-man@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Cc: selinux@vger.kernel.org
Link: http://lore.kernel.org/lkml/a66d5648-2b8e-577e-e1f2-1d56c017ab5e@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/builtin-ftrace.c |  5 +++--
 tools/perf/design.txt       |  3 ++-
 tools/perf/util/cap.h       |  4 ++++
 tools/perf/util/evsel.c     | 10 +++++-----
 tools/perf/util/util.c      |  1 +
 5 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index d5adc417a4ca..55eda54240fb 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -284,10 +284,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 		.events = POLLIN,
 	};
 
-	if (!perf_cap__capable(CAP_SYS_ADMIN)) {
+	if (!(perf_cap__capable(CAP_PERFMON) ||
+	      perf_cap__capable(CAP_SYS_ADMIN))) {
 		pr_err("ftrace only works for %s!\n",
 #ifdef HAVE_LIBCAP_SUPPORT
-		"users with the SYS_ADMIN capability"
+		"users with the CAP_PERFMON or CAP_SYS_ADMIN capability"
 #else
 		"root"
 #endif
diff --git a/tools/perf/design.txt b/tools/perf/design.txt
index 0453ba26cdbd..a42fab308ff6 100644
--- a/tools/perf/design.txt
+++ b/tools/perf/design.txt
@@ -258,7 +258,8 @@ gets schedule to. Per task counters can be created by any user, for
 their own tasks.
 
 A 'pid == -1' and 'cpu == x' counter is a per CPU counter that counts
-all events on CPU-x. Per CPU counters need CAP_SYS_ADMIN privilege.
+all events on CPU-x. Per CPU counters need CAP_PERFMON or CAP_SYS_ADMIN
+privilege.
 
 The 'flags' parameter is currently unused and must be zero.
 
diff --git a/tools/perf/util/cap.h b/tools/perf/util/cap.h
index 051dc590ceee..ae52878c0b2e 100644
--- a/tools/perf/util/cap.h
+++ b/tools/perf/util/cap.h
@@ -29,4 +29,8 @@ static inline bool perf_cap__capable(int cap __maybe_unused)
 #define CAP_SYSLOG	34
 #endif
 
+#ifndef CAP_PERFMON
+#define CAP_PERFMON	38
+#endif
+
 #endif /* __PERF_CAP_H */
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index eb880efbce16..d23db6755f51 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2523,14 +2523,14 @@ int perf_evsel__open_strerror(struct evsel *evsel, struct target *target,
 		 "You may not have permission to collect %sstats.\n\n"
 		 "Consider tweaking /proc/sys/kernel/perf_event_paranoid,\n"
 		 "which controls use of the performance events system by\n"
-		 "unprivileged users (without CAP_SYS_ADMIN).\n\n"
+		 "unprivileged users (without CAP_PERFMON or CAP_SYS_ADMIN).\n\n"
 		 "The current value is %d:\n\n"
 		 "  -1: Allow use of (almost) all events by all users\n"
 		 "      Ignore mlock limit after perf_event_mlock_kb without CAP_IPC_LOCK\n"
-		 ">= 0: Disallow ftrace function tracepoint by users without CAP_SYS_ADMIN\n"
-		 "      Disallow raw tracepoint access by users without CAP_SYS_ADMIN\n"
-		 ">= 1: Disallow CPU event access by users without CAP_SYS_ADMIN\n"
-		 ">= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN\n\n"
+		 ">= 0: Disallow ftrace function tracepoint by users without CAP_PERFMON or CAP_SYS_ADMIN\n"
+		 "      Disallow raw tracepoint access by users without CAP_SYS_PERFMON or CAP_SYS_ADMIN\n"
+		 ">= 1: Disallow CPU event access by users without CAP_PERFMON or CAP_SYS_ADMIN\n"
+		 ">= 2: Disallow kernel profiling by users without CAP_PERFMON or CAP_SYS_ADMIN\n\n"
 		 "To make this setting permanent, edit /etc/sysctl.conf too, e.g.:\n\n"
 		 "	kernel.perf_event_paranoid = -1\n" ,
 				 target->system_wide ? "system-wide " : "",
diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index d707c9624dd9..37a9492edb3e 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -290,6 +290,7 @@ int perf_event_paranoid(void)
 bool perf_event_paranoid_check(int max_level)
 {
 	return perf_cap__capable(CAP_SYS_ADMIN) ||
+			perf_cap__capable(CAP_PERFMON) ||
 			perf_event_paranoid() <= max_level;
 }
 
-- 
2.21.1

[PATCH 09/26] drm/i915/perf: Open access for CAP_PERFMON privileged process

[Arnaldo Carvalho de Melo]

From: Alexey Budankov <alexey.budankov@linux.intel.com>

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 principle 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>
Acked-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Igor Lubashev <ilubashe@akamai.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: intel-gfx@lists.freedesktop.org
Cc: linux-doc@vger.kernel.org
Cc: linux-man@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Cc: selinux@vger.kernel.org
Link: http://lore.kernel.org/lkml/e3e3292f-f765-ea98-e59c-fbe2db93fd34@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 drivers/gpu/drm/i915/i915_perf.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
index 3b6b913bd27a..f59265cebe1e 100644
--- a/drivers/gpu/drm/i915/i915_perf.c
+++ b/drivers/gpu/drm/i915/i915_perf.c
@@ -3402,10 +3402,10 @@ i915_perf_open_ioctl_locked(struct i915_perf *perf,
 	/* Similar to perf's kernel.perf_paranoid_cpu sysctl option
 	 * we check a dev.i915.perf_stream_paranoid sysctl option
 	 * to determine if it's ok to access system wide OA counters
-	 * without CAP_SYS_ADMIN privileges.
+	 * without CAP_PERFMON or CAP_SYS_ADMIN privileges.
 	 */
 	if (privileged_op &&
-	    i915_perf_stream_paranoid && !capable(CAP_SYS_ADMIN)) {
+	    i915_perf_stream_paranoid && !perfmon_capable()) {
 		DRM_DEBUG("Insufficient privileges to open i915 perf stream\n");
 		ret = -EACCES;
 		goto err_ctx;
@@ -3598,9 +3598,8 @@ static int read_properties_unlocked(struct i915_perf *perf,
 			} else
 				oa_freq_hz = 0;
 
-			if (oa_freq_hz > i915_oa_max_sample_rate &&
-			    !capable(CAP_SYS_ADMIN)) {
-				DRM_DEBUG("OA exponent would exceed the max sampling frequency (sysctl dev.i915.oa_max_sample_rate) %uHz without root privileges\n",
+			if (oa_freq_hz > i915_oa_max_sample_rate && !perfmon_capable()) {
+				DRM_DEBUG("OA exponent would exceed the max sampling frequency (sysctl dev.i915.oa_max_sample_rate) %uHz without CAP_PERFMON or CAP_SYS_ADMIN privileges\n",
 					  i915_oa_max_sample_rate);
 				return -EACCES;
 			}
@@ -4021,7 +4020,7 @@ int i915_perf_add_config_ioctl(struct drm_device *dev, void *data,
 		return -EINVAL;
 	}
 
-	if (i915_perf_stream_paranoid && !capable(CAP_SYS_ADMIN)) {
+	if (i915_perf_stream_paranoid && !perfmon_capable()) {
 		DRM_DEBUG("Insufficient privileges to add i915 OA config\n");
 		return -EACCES;
 	}
@@ -4168,7 +4167,7 @@ int i915_perf_remove_config_ioctl(struct drm_device *dev, void *data,
 		return -ENOTSUPP;
 	}
 
-	if (i915_perf_stream_paranoid && !capable(CAP_SYS_ADMIN)) {
+	if (i915_perf_stream_paranoid && !perfmon_capable()) {
 		DRM_DEBUG("Insufficient privileges to remove i915 OA config\n");
 		return -EACCES;
 	}
-- 
2.21.1

[PATCH 10/26] trace/bpf_trace: Open access for CAP_PERFMON privileged process

[Arnaldo Carvalho de Melo]

From: Alexey Budankov <alexey.budankov@linux.intel.com>

Open access to bpf_trace 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 principle 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 bpf_trace monitoring
remains open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN
usage for secure bpf_trace 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>
Acked-by: Song Liu <songliubraving@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Igor Lubashev <ilubashe@akamai.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: intel-gfx@lists.freedesktop.org
Cc: linux-doc@vger.kernel.org
Cc: linux-man@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Cc: selinux@vger.kernel.org
Link: http://lore.kernel.org/lkml/c0a0ae47-8b6e-ff3e-416b-3cd1faaf71c0@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 kernel/trace/bpf_trace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 68250d433bd7..770b742fc922 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1416,7 +1416,7 @@ int perf_event_query_prog_array(struct perf_event *event, void __user *info)
 	u32 *ids, prog_cnt, ids_len;
 	int ret;
 
-	if (!capable(CAP_SYS_ADMIN))
+	if (!perfmon_capable())
 		return -EPERM;
 	if (event->attr.type != PERF_TYPE_TRACEPOINT)
 		return -EINVAL;
-- 
2.21.1

[PATCH 11/26] powerpc/perf: open access for CAP_PERFMON privileged process

[Arnaldo Carvalho de Melo]

From: Alexey Budankov <alexey.budankov@linux.intel.com>

Open access to 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 principle 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 the monitoring remains open
for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage for
secure 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>
Acked-by: Anju T Sudhakar <anju@linux.vnet.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Igor Lubashev <ilubashe@akamai.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: intel-gfx@lists.freedesktop.org
Cc: linux-doc@vger.kernel.org
Cc: linux-man@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Cc: selinux@vger.kernel.org
Link: http://lore.kernel.org/lkml/ac98cd9f-b59e-673c-c70d-180b3e7695d2@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 arch/powerpc/perf/imc-pmu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/perf/imc-pmu.c b/arch/powerpc/perf/imc-pmu.c
index cb50a9e1fd2d..e837717492e4 100644
--- a/arch/powerpc/perf/imc-pmu.c
+++ b/arch/powerpc/perf/imc-pmu.c
@@ -898,7 +898,7 @@ static int thread_imc_event_init(struct perf_event *event)
 	if (event->attr.type != event->pmu->type)
 		return -ENOENT;
 
-	if (!capable(CAP_SYS_ADMIN))
+	if (!perfmon_capable())
 		return -EACCES;
 
 	/* Sampling not supported */
@@ -1307,7 +1307,7 @@ static int trace_imc_event_init(struct perf_event *event)
 	if (event->attr.type != event->pmu->type)
 		return -ENOENT;
 
-	if (!capable(CAP_SYS_ADMIN))
+	if (!perfmon_capable())
 		return -EACCES;
 
 	/* Return if this is a couting event */
-- 
2.21.1

[PATCH 12/26] parisc/perf: open access for CAP_PERFMON privileged process

[Arnaldo Carvalho de Melo]

From: Alexey Budankov <alexey.budankov@linux.intel.com>

Open access to 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 principle 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 the monitoring remains open
for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage for
secure 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>
Acked-by: Helge Deller <deller@gmx.de>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Igor Lubashev <ilubashe@akamai.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: intel-gfx@lists.freedesktop.org
Cc: linux-doc@vger.kernel.org
Cc: linux-man@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Cc: selinux@vger.kernel.org
Link: http://lore.kernel.org/lkml/8cc98809-d35b-de0f-de02-4cf554f3cf62@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 arch/parisc/kernel/perf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/parisc/kernel/perf.c b/arch/parisc/kernel/perf.c
index e1a8fee3ad49..d46b6709ec56 100644
--- a/arch/parisc/kernel/perf.c
+++ b/arch/parisc/kernel/perf.c
@@ -300,7 +300,7 @@ static ssize_t perf_write(struct file *file, const char __user *buf,
 	else
 		return -EFAULT;
 
-	if (!capable(CAP_SYS_ADMIN))
+	if (!perfmon_capable())
 		return -EACCES;
 
 	if (count != sizeof(uint32_t))
-- 
2.21.1

[PATCH 13/26] drivers/perf: Open access for CAP_PERFMON privileged process

[Arnaldo Carvalho de Melo]

From: Alexey Budankov <alexey.budankov@linux.intel.com>

Open access to 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 principle 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 the monitoring remains open
for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage for
secure 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>
Acked-by: Will Deacon <will@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Igor Lubashev <ilubashe@akamai.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: intel-gfx@lists.freedesktop.org
Cc: linux-doc@vger.kernel.org
Cc: linux-man@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Cc: selinux@vger.kernel.org
Link: http://lore.kernel.org/lkml/4ec1d6f7-548c-8d1c-f84a-cebeb9674e4e@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 drivers/perf/arm_spe_pmu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/perf/arm_spe_pmu.c b/drivers/perf/arm_spe_pmu.c
index b72c04852599..0e0961a2b405 100644
--- a/drivers/perf/arm_spe_pmu.c
+++ b/drivers/perf/arm_spe_pmu.c
@@ -274,7 +274,7 @@ static u64 arm_spe_event_to_pmscr(struct perf_event *event)
 	if (!attr->exclude_kernel)
 		reg |= BIT(SYS_PMSCR_EL1_E1SPE_SHIFT);
 
-	if (IS_ENABLED(CONFIG_PID_IN_CONTEXTIDR) && capable(CAP_SYS_ADMIN))
+	if (IS_ENABLED(CONFIG_PID_IN_CONTEXTIDR) && perfmon_capable())
 		reg |= BIT(SYS_PMSCR_EL1_CX_SHIFT);
 
 	return reg;
@@ -700,7 +700,7 @@ static int arm_spe_pmu_event_init(struct perf_event *event)
 		return -EOPNOTSUPP;
 
 	reg = arm_spe_event_to_pmscr(event);
-	if (!capable(CAP_SYS_ADMIN) &&
+	if (!perfmon_capable() &&
 	    (reg & (BIT(SYS_PMSCR_EL1_PA_SHIFT) |
 		    BIT(SYS_PMSCR_EL1_CX_SHIFT) |
 		    BIT(SYS_PMSCR_EL1_PCT_SHIFT))))
-- 
2.21.1

[PATCH 14/26] drivers/oprofile: Open access for CAP_PERFMON privileged process

[Arnaldo Carvalho de Melo]

From: Alexey Budankov <alexey.budankov@linux.intel.com>

Open access to 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 principle 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 the monitoring remains open
for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage for
secure monitoring is discouraged with respect to CAP_PERFMON capability.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Acked-by: James Morris <jamorris@linux.microsoft.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Igor Lubashev <ilubashe@akamai.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: intel-gfx@lists.freedesktop.org
Cc: linux-doc@vger.kernel.org
Cc: linux-man@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Cc: selinux@vger.kernel.org
Link: http://lore.kernel.org/lkml/691f1096-b15f-9b12-50a0-c2b93918149e@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 drivers/oprofile/event_buffer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/oprofile/event_buffer.c b/drivers/oprofile/event_buffer.c
index 12ea4a4ad607..6c9edc8bbc95 100644
--- a/drivers/oprofile/event_buffer.c
+++ b/drivers/oprofile/event_buffer.c
@@ -113,7 +113,7 @@ static int event_buffer_open(struct inode *inode, struct file *file)
 {
 	int err = -EPERM;
 
-	if (!capable(CAP_SYS_ADMIN))
+	if (!perfmon_capable())
 		return -EPERM;
 
 	if (test_and_set_bit_lock(0, &buffer_opened))
-- 
2.21.1

[PATCH 15/26] doc/admin-guide: Update perf-security.rst with CAP_PERFMON information

[Arnaldo Carvalho de Melo]

From: Alexey Budankov <alexey.budankov@linux.intel.com>

Update perf-security.rst documentation file with the information
related to usage of CAP_PERFMON capability to secure performance
monitoring and observability operations in system.

Committer notes:

While testing 'perf top' under cap_perfmon I noticed that it needs
some more capability and Alexey pointed out cap_ipc_lock, as needed by
this kernel chunk:

  kernel/events/core.c: 6101
       if ((locked > lock_limit) && perf_is_paranoid() &&
               !capable(CAP_IPC_LOCK)) {
               ret = -EPERM;
               goto unlock;
       }

So I added it to the documentation, and also mentioned that if the
libcap version doesn't yet supports 'cap_perfmon', its numeric value can
be used instead, i.e. if:

	# setcap "cap_perfmon,cap_ipc_lock,cap_sys_ptrace,cap_syslog=ep" perf

Fails, try:

	# setcap "38,cap_ipc_lock,cap_sys_ptrace,cap_syslog=ep" perf

I also added a paragraph stating that using an unpatched libcap will
fail the check for CAP_PERFMON, as it checks the cap number against a
maximum to see if it is valid, which makes it use as the default the
'cycles:u' event, even tho a cap_perfmon capable perf binary can get
kernel samples, to workaround that just use, e.g.:

  # perf top -e cycles
  # perf record -e cycles

And it will sample kernel and user modes.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Igor Lubashev <ilubashe@akamai.com>
Cc: James Morris <jmorris@namei.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: intel-gfx@lists.freedesktop.org
Cc: linux-doc@vger.kernel.org
Cc: linux-man@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Cc: selinux@vger.kernel.org
Link: http://lore.kernel.org/lkml/17278551-9399-9ebe-d665-8827016a217d@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 Documentation/admin-guide/perf-security.rst | 86 +++++++++++++++------
 1 file changed, 61 insertions(+), 25 deletions(-)

diff --git a/Documentation/admin-guide/perf-security.rst b/Documentation/admin-guide/perf-security.rst
index 72effa7c23b9..1307b5274a0f 100644
--- a/Documentation/admin-guide/perf-security.rst
+++ b/Documentation/admin-guide/perf-security.rst
@@ -1,6 +1,6 @@
 .. _perf_security:
 
-Perf Events and tool security
+Perf events and tool security
 =============================
 
 Overview
@@ -42,11 +42,11 @@ categories:
 Data that belong to the fourth category can potentially contain
 sensitive process data. If PMUs in some monitoring modes capture values
 of execution context registers or data from process memory then access
-to such monitoring capabilities requires to be ordered and secured
-properly. So, perf_events/Perf performance monitoring is the subject for
-security access control management [5]_ .
+to such monitoring modes requires to be ordered and secured properly.
+So, perf_events performance monitoring and observability operations are
+the subject for security access control management [5]_ .
 
-perf_events/Perf access control
+perf_events access control
 -------------------------------
 
 To perform security checks, the Linux implementation splits processes
@@ -66,11 +66,25 @@ into distinct units, known as capabilities [6]_ , which can be
 independently enabled and disabled on per-thread basis for processes and
 files of unprivileged users.
 
-Unprivileged processes with enabled CAP_SYS_ADMIN capability are treated
+Unprivileged processes with enabled CAP_PERFMON capability are treated
 as privileged processes with respect to perf_events performance
-monitoring and bypass *scope* permissions checks in the kernel.
-
-Unprivileged processes using perf_events system call API is also subject
+monitoring and observability operations, thus, bypass *scope* permissions
+checks in the kernel. CAP_PERFMON implements the principle of least
+privilege [13]_ (POSIX 1003.1e: 2.2.2.39) for performance monitoring and
+observability operations in the kernel and provides a secure approach to
+perfomance monitoring and observability in the system.
+
+For backward compatibility reasons the access to perf_events monitoring and
+observability operations is also open for CAP_SYS_ADMIN privileged
+processes but CAP_SYS_ADMIN usage for secure monitoring and observability
+use cases is discouraged with respect to the CAP_PERFMON capability.
+If system audit records [14]_ for a process using perf_events system call
+API contain denial records of acquiring both CAP_PERFMON and CAP_SYS_ADMIN
+capabilities then providing the process with CAP_PERFMON capability singly
+is recommended as the preferred secure approach to resolve double access
+denial logging related to usage of performance monitoring and observability.
+
+Unprivileged processes using perf_events system call are also subject
 for PTRACE_MODE_READ_REALCREDS ptrace access mode check [7]_ , whose
 outcome determines whether monitoring is permitted. So unprivileged
 processes provided with CAP_SYS_PTRACE capability are effectively
@@ -82,14 +96,14 @@ performance analysis of monitored processes or a system. For example,
 CAP_SYSLOG capability permits reading kernel space memory addresses from
 /proc/kallsyms file.
 
-perf_events/Perf privileged users
+Privileged Perf users groups
 ---------------------------------
 
 Mechanisms of capabilities, privileged capability-dumb files [6]_ and
-file system ACLs [10]_ can be used to create a dedicated group of
-perf_events/Perf privileged users who are permitted to execute
-performance monitoring without scope limits. The following steps can be
-taken to create such a group of privileged Perf users.
+file system ACLs [10]_ can be used to create dedicated groups of
+privileged Perf users who are permitted to execute performance monitoring
+and observability without scope limits. The following steps can be
+taken to create such groups of privileged Perf users.
 
 1. Create perf_users group of privileged Perf users, assign perf_users
    group to Perf tool executable and limit access to the executable for
@@ -108,30 +122,51 @@ taken to create such a group of privileged Perf users.
    -rwxr-x---  2 root perf_users  11M Oct 19 15:12 perf
 
 2. Assign the required capabilities to the Perf tool executable file and
-   enable members of perf_users group with performance monitoring
+   enable members of perf_users group with monitoring and observability
    privileges [6]_ :
 
 ::
 
-   # setcap "cap_sys_admin,cap_sys_ptrace,cap_syslog=ep" perf
-   # setcap -v "cap_sys_admin,cap_sys_ptrace,cap_syslog=ep" perf
+   # setcap "cap_perfmon,cap_sys_ptrace,cap_syslog=ep" perf
+   # setcap -v "cap_perfmon,cap_sys_ptrace,cap_syslog=ep" perf
    perf: OK
    # getcap perf
-   perf = cap_sys_ptrace,cap_sys_admin,cap_syslog+ep
+   perf = cap_sys_ptrace,cap_syslog,cap_perfmon+ep
+
+If the libcap installed doesn't yet support "cap_perfmon", use "38" instead,
+i.e.:
+
+::
+
+   # setcap "38,cap_ipc_lock,cap_sys_ptrace,cap_syslog=ep" perf
+
+Note that you may need to have 'cap_ipc_lock' in the mix for tools such as
+'perf top', alternatively use 'perf top -m N', to reduce the memory that
+it uses for the perf ring buffer, see the memory allocation section below.
+
+Using a libcap without support for CAP_PERFMON will make cap_get_flag(caps, 38,
+CAP_EFFECTIVE, &val) fail, which will lead the default event to be 'cycles:u',
+so as a workaround explicitly ask for the 'cycles' event, i.e.:
+
+::
+
+  # perf top -e cycles
+
+To get kernel and user samples with a perf binary with just CAP_PERFMON.
 
 As a result, members of perf_users group are capable of conducting
-performance monitoring by using functionality of the configured Perf
-tool executable that, when executes, passes perf_events subsystem scope
-checks.
+performance monitoring and observability by using functionality of the
+configured Perf tool executable that, when executes, passes perf_events
+subsystem scope checks.
 
 This specific access control management is only available to superuser
 or root running processes with CAP_SETPCAP, CAP_SETFCAP [6]_
 capabilities.
 
-perf_events/Perf unprivileged users
+Unprivileged users
 -----------------------------------
 
-perf_events/Perf *scope* and *access* control for unprivileged processes
+perf_events *scope* and *access* control for unprivileged processes
 is governed by perf_event_paranoid [2]_ setting:
 
 -1:
@@ -166,7 +201,7 @@ is governed by perf_event_paranoid [2]_ setting:
      perf_event_mlock_kb locking limit is imposed but ignored for
      unprivileged processes with CAP_IPC_LOCK capability.
 
-perf_events/Perf resource control
+Resource control
 ---------------------------------
 
 Open file descriptors
@@ -227,4 +262,5 @@ Bibliography
 .. [10] `<http://man7.org/linux/man-pages/man5/acl.5.html>`_
 .. [11] `<http://man7.org/linux/man-pages/man2/getrlimit.2.html>`_
 .. [12] `<http://man7.org/linux/man-pages/man5/limits.conf.5.html>`_
-
+.. [13] `<https://sites.google.com/site/fullycapable>`_
+.. [14] `<http://man7.org/linux/man-pages/man8/auditd.8.html>`_
-- 
2.21.1

[PATCH 16/26] doc/admin-guide: update kernel.rst with CAP_PERFMON information

[Arnaldo Carvalho de Melo]

From: Alexey Budankov <alexey.budankov@linux.intel.com>

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 <alexey.budankov@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Igor Lubashev <ilubashe@akamai.com>
Cc: James Morris <jmorris@namei.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: intel-gfx@lists.freedesktop.org
Cc: linux-doc@vger.kernel.org
Cc: linux-man@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Cc: selinux@vger.kernel.org
Link: http://lore.kernel.org/lkml/84c32383-14a2-fa35-16b6-f9e59bd37240@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 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 335696d3360d..aaa5bbcd1e33 100644
--- a/Documentation/admin-guide/sysctl/kernel.rst
+++ b/Documentation/admin-guide/sysctl/kernel.rst
@@ -709,7 +709,13 @@ 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.
@@ -718,13 +724,13 @@ 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``.
 ===  ==================================================================
 
 
-- 
2.21.1

[PATCH 17/26] perf python: Check if clang supports -fno-semantic-interposition

[Arnaldo Carvalho de Melo]

From: Arnaldo Carvalho de Melo <acme@redhat.com>

The set of C compiler options used by distros to build python bindings
may include options that are unknown to clang, we check for a variety of
such options, add -fno-semantic-interposition to that mix:

This fixes the build on, among others, Manjaro Linux:

    GEN      /tmp/build/perf/python/perf.so
  clang-9: error: unknown argument: '-fno-semantic-interposition'
  error: command 'clang' failed with exit status 1
  make: Leaving directory '/git/perf/tools/perf'

  [perfbuilder@602aed1c266d ~]$ gcc -v
  Using built-in specs.
  COLLECT_GCC=gcc
  COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/9.3.0/lto-wrapper
  Target: x86_64-pc-linux-gnu
  Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info --with-pkgversion='Arch Linux 9.3.0-1' --with-bugurl=https://bugs.archlinux.org/ --enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++,d --enable-shared --enable-threads=posix --with-system-zlib --with-isl --enable-__cxa_atexit --disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch --disable-libssp --enable-gnu-unique-object --enable-linker-build-id --enable-lto --enable-plugin --enable-install-libiberty --with-linker-hash-style=gnu --enable-gnu-indirect-function --enable-multilib --disable-werror --enable-checking=release --enable-default-pie --enable-default-ssp --enable-cet=auto gdc_include_dir=/usr/include/dlang/
 gdc
  Thread model: posix
  gcc version 9.3.0 (Arch Linux 9.3.0-1)
  [perfbuilder@602aed1c266d ~]$

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/setup.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/perf/util/setup.py b/tools/perf/util/setup.py
index 347b2c0789e4..c5e3e9a68162 100644
--- a/tools/perf/util/setup.py
+++ b/tools/perf/util/setup.py
@@ -21,6 +21,8 @@ if cc_is_clang:
             vars[var] = sub("-fstack-clash-protection", "", vars[var])
         if not clang_has_option("-fstack-protector-strong"):
             vars[var] = sub("-fstack-protector-strong", "", vars[var])
+        if not clang_has_option("-fno-semantic-interposition"):
+            vars[var] = sub("-fno-semantic-interposition", "", vars[var])
 
 from distutils.core import setup, Extension
 
-- 
2.21.1

[PATCH 18/26] perf script: Simplify auxiliary event printing functions

[Arnaldo Carvalho de Melo]

From: Adrian Hunter <adrian.hunter@intel.com>

This simplifies the print functions for the following perf script
options:

	--show-task-events
	--show-namespace-events
	--show-cgroup-events
	--show-mmap-events
	--show-switch-events
	--show-lost-events
	--show-bpf-events

Example:
	# perf record --switch-events -a -e cycles -c 10000 sleep 1
 Before:
	# perf script --show-task-events --show-namespace-events --show-cgroup-events --show-mmap-events --show-switch-events --show-lost-events --show-bpf-events > out-before.txt
 After:
	# perf script --show-task-events --show-namespace-events --show-cgroup-events --show-mmap-events --show-switch-events --show-lost-events --show-bpf-events > out-after.txt
	# diff -s out-before.txt out-after.txt
	Files out-before.txt and out-after.tx are identical

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200402141548.21283-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/builtin-script.c | 304 ++++++++----------------------------
 1 file changed, 66 insertions(+), 238 deletions(-)

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 1f57a7ecdf3d..8bf3ba280312 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -2040,7 +2040,7 @@ static int cleanup_scripting(void)
 
 static bool filter_cpu(struct perf_sample *sample)
 {
-	if (cpu_list)
+	if (cpu_list && sample->cpu != (u32)-1)
 		return !test_bit(sample->cpu, cpu_bitmap);
 	return false;
 }
@@ -2138,41 +2138,59 @@ static int process_attr(struct perf_tool *tool, union perf_event *event,
 	return err;
 }
 
-static int process_comm_event(struct perf_tool *tool,
-			      union perf_event *event,
-			      struct perf_sample *sample,
-			      struct machine *machine)
+static int print_event_with_time(struct perf_tool *tool,
+				 union perf_event *event,
+				 struct perf_sample *sample,
+				 struct machine *machine,
+				 pid_t pid, pid_t tid, u64 timestamp)
 {
-	struct thread *thread;
 	struct perf_script *script = container_of(tool, struct perf_script, tool);
 	struct perf_session *session = script->session;
 	struct evsel *evsel = perf_evlist__id2evsel(session->evlist, sample->id);
-	int ret = -1;
+	struct thread *thread = NULL;
 
-	thread = machine__findnew_thread(machine, event->comm.pid, event->comm.tid);
-	if (thread == NULL) {
-		pr_debug("problem processing COMM event, skipping it.\n");
-		return -1;
+	if (evsel && !evsel->core.attr.sample_id_all) {
+		sample->cpu = 0;
+		sample->time = timestamp;
+		sample->pid = pid;
+		sample->tid = tid;
 	}
 
-	if (perf_event__process_comm(tool, event, sample, machine) < 0)
-		goto out;
+	if (filter_cpu(sample))
+		return 0;
 
-	if (!evsel->core.attr.sample_id_all) {
-		sample->cpu = 0;
-		sample->time = 0;
-		sample->tid = event->comm.tid;
-		sample->pid = event->comm.pid;
-	}
-	if (!filter_cpu(sample)) {
+	if (tid != -1)
+		thread = machine__findnew_thread(machine, pid, tid);
+
+	if (thread && evsel) {
 		perf_sample__fprintf_start(sample, thread, evsel,
-				   PERF_RECORD_COMM, stdout);
-		perf_event__fprintf(event, stdout);
+					   event->header.type, stdout);
 	}
-	ret = 0;
-out:
+
+	perf_event__fprintf(event, stdout);
+
 	thread__put(thread);
-	return ret;
+
+	return 0;
+}
+
+static int print_event(struct perf_tool *tool, union perf_event *event,
+		       struct perf_sample *sample, struct machine *machine,
+		       pid_t pid, pid_t tid)
+{
+	return print_event_with_time(tool, event, sample, machine, pid, tid, 0);
+}
+
+static int process_comm_event(struct perf_tool *tool,
+			      union perf_event *event,
+			      struct perf_sample *sample,
+			      struct machine *machine)
+{
+	if (perf_event__process_comm(tool, event, sample, machine) < 0)
+		return -1;
+
+	return print_event(tool, event, sample, machine, event->comm.pid,
+			   event->comm.tid);
 }
 
 static int process_namespaces_event(struct perf_tool *tool,
@@ -2180,37 +2198,11 @@ static int process_namespaces_event(struct perf_tool *tool,
 				    struct perf_sample *sample,
 				    struct machine *machine)
 {
-	struct thread *thread;
-	struct perf_script *script = container_of(tool, struct perf_script, tool);
-	struct perf_session *session = script->session;
-	struct evsel *evsel = perf_evlist__id2evsel(session->evlist, sample->id);
-	int ret = -1;
-
-	thread = machine__findnew_thread(machine, event->namespaces.pid,
-					 event->namespaces.tid);
-	if (thread == NULL) {
-		pr_debug("problem processing NAMESPACES event, skipping it.\n");
-		return -1;
-	}
-
 	if (perf_event__process_namespaces(tool, event, sample, machine) < 0)
-		goto out;
+		return -1;
 
-	if (!evsel->core.attr.sample_id_all) {
-		sample->cpu = 0;
-		sample->time = 0;
-		sample->tid = event->namespaces.tid;
-		sample->pid = event->namespaces.pid;
-	}
-	if (!filter_cpu(sample)) {
-		perf_sample__fprintf_start(sample, thread, evsel,
-					   PERF_RECORD_NAMESPACES, stdout);
-		perf_event__fprintf(event, stdout);
-	}
-	ret = 0;
-out:
-	thread__put(thread);
-	return ret;
+	return print_event(tool, event, sample, machine, event->namespaces.pid,
+			   event->namespaces.tid);
 }
 
 static int process_cgroup_event(struct perf_tool *tool,
@@ -2218,34 +2210,11 @@ static int process_cgroup_event(struct perf_tool *tool,
 				struct perf_sample *sample,
 				struct machine *machine)
 {
-	struct thread *thread;
-	struct perf_script *script = container_of(tool, struct perf_script, tool);
-	struct perf_session *session = script->session;
-	struct evsel *evsel = perf_evlist__id2evsel(session->evlist, sample->id);
-	int ret = -1;
-
-	thread = machine__findnew_thread(machine, sample->pid, sample->tid);
-	if (thread == NULL) {
-		pr_debug("problem processing CGROUP event, skipping it.\n");
-		return -1;
-	}
-
 	if (perf_event__process_cgroup(tool, event, sample, machine) < 0)
-		goto out;
+		return -1;
 
-	if (!evsel->core.attr.sample_id_all) {
-		sample->cpu = 0;
-		sample->time = 0;
-	}
-	if (!filter_cpu(sample)) {
-		perf_sample__fprintf_start(sample, thread, evsel,
-					   PERF_RECORD_CGROUP, stdout);
-		perf_event__fprintf(event, stdout);
-	}
-	ret = 0;
-out:
-	thread__put(thread);
-	return ret;
+	return print_event(tool, event, sample, machine, sample->pid,
+			    sample->tid);
 }
 
 static int process_fork_event(struct perf_tool *tool,
@@ -2253,69 +2222,24 @@ static int process_fork_event(struct perf_tool *tool,
 			      struct perf_sample *sample,
 			      struct machine *machine)
 {
-	struct thread *thread;
-	struct perf_script *script = container_of(tool, struct perf_script, tool);
-	struct perf_session *session = script->session;
-	struct evsel *evsel = perf_evlist__id2evsel(session->evlist, sample->id);
-
 	if (perf_event__process_fork(tool, event, sample, machine) < 0)
 		return -1;
 
-	thread = machine__findnew_thread(machine, event->fork.pid, event->fork.tid);
-	if (thread == NULL) {
-		pr_debug("problem processing FORK event, skipping it.\n");
-		return -1;
-	}
-
-	if (!evsel->core.attr.sample_id_all) {
-		sample->cpu = 0;
-		sample->time = event->fork.time;
-		sample->tid = event->fork.tid;
-		sample->pid = event->fork.pid;
-	}
-	if (!filter_cpu(sample)) {
-		perf_sample__fprintf_start(sample, thread, evsel,
-					   PERF_RECORD_FORK, stdout);
-		perf_event__fprintf(event, stdout);
-	}
-	thread__put(thread);
-
-	return 0;
+	return print_event_with_time(tool, event, sample, machine,
+				     event->fork.pid, event->fork.tid,
+				     event->fork.time);
 }
 static int process_exit_event(struct perf_tool *tool,
 			      union perf_event *event,
 			      struct perf_sample *sample,
 			      struct machine *machine)
 {
-	int err = 0;
-	struct thread *thread;
-	struct perf_script *script = container_of(tool, struct perf_script, tool);
-	struct perf_session *session = script->session;
-	struct evsel *evsel = perf_evlist__id2evsel(session->evlist, sample->id);
-
-	thread = machine__findnew_thread(machine, event->fork.pid, event->fork.tid);
-	if (thread == NULL) {
-		pr_debug("problem processing EXIT event, skipping it.\n");
+	/* Print before 'exit' deletes anything */
+	if (print_event_with_time(tool, event, sample, machine, event->fork.pid,
+				  event->fork.tid, event->fork.time))
 		return -1;
-	}
-
-	if (!evsel->core.attr.sample_id_all) {
-		sample->cpu = 0;
-		sample->time = 0;
-		sample->tid = event->fork.tid;
-		sample->pid = event->fork.pid;
-	}
-	if (!filter_cpu(sample)) {
-		perf_sample__fprintf_start(sample, thread, evsel,
-					   PERF_RECORD_EXIT, stdout);
-		perf_event__fprintf(event, stdout);
-	}
 
-	if (perf_event__process_exit(tool, event, sample, machine) < 0)
-		err = -1;
-
-	thread__put(thread);
-	return err;
+	return perf_event__process_exit(tool, event, sample, machine);
 }
 
 static int process_mmap_event(struct perf_tool *tool,
@@ -2323,33 +2247,11 @@ static int process_mmap_event(struct perf_tool *tool,
 			      struct perf_sample *sample,
 			      struct machine *machine)
 {
-	struct thread *thread;
-	struct perf_script *script = container_of(tool, struct perf_script, tool);
-	struct perf_session *session = script->session;
-	struct evsel *evsel = perf_evlist__id2evsel(session->evlist, sample->id);
-
 	if (perf_event__process_mmap(tool, event, sample, machine) < 0)
 		return -1;
 
-	thread = machine__findnew_thread(machine, event->mmap.pid, event->mmap.tid);
-	if (thread == NULL) {
-		pr_debug("problem processing MMAP event, skipping it.\n");
-		return -1;
-	}
-
-	if (!evsel->core.attr.sample_id_all) {
-		sample->cpu = 0;
-		sample->time = 0;
-		sample->tid = event->mmap.tid;
-		sample->pid = event->mmap.pid;
-	}
-	if (!filter_cpu(sample)) {
-		perf_sample__fprintf_start(sample, thread, evsel,
-					   PERF_RECORD_MMAP, stdout);
-		perf_event__fprintf(event, stdout);
-	}
-	thread__put(thread);
-	return 0;
+	return print_event(tool, event, sample, machine, event->mmap.pid,
+			   event->mmap.tid);
 }
 
 static int process_mmap2_event(struct perf_tool *tool,
@@ -2357,33 +2259,11 @@ static int process_mmap2_event(struct perf_tool *tool,
 			      struct perf_sample *sample,
 			      struct machine *machine)
 {
-	struct thread *thread;
-	struct perf_script *script = container_of(tool, struct perf_script, tool);
-	struct perf_session *session = script->session;
-	struct evsel *evsel = perf_evlist__id2evsel(session->evlist, sample->id);
-
 	if (perf_event__process_mmap2(tool, event, sample, machine) < 0)
 		return -1;
 
-	thread = machine__findnew_thread(machine, event->mmap2.pid, event->mmap2.tid);
-	if (thread == NULL) {
-		pr_debug("problem processing MMAP2 event, skipping it.\n");
-		return -1;
-	}
-
-	if (!evsel->core.attr.sample_id_all) {
-		sample->cpu = 0;
-		sample->time = 0;
-		sample->tid = event->mmap2.tid;
-		sample->pid = event->mmap2.pid;
-	}
-	if (!filter_cpu(sample)) {
-		perf_sample__fprintf_start(sample, thread, evsel,
-					   PERF_RECORD_MMAP2, stdout);
-		perf_event__fprintf(event, stdout);
-	}
-	thread__put(thread);
-	return 0;
+	return print_event(tool, event, sample, machine, event->mmap2.pid,
+			   event->mmap2.tid);
 }
 
 static int process_switch_event(struct perf_tool *tool,
@@ -2391,10 +2271,7 @@ static int process_switch_event(struct perf_tool *tool,
 				struct perf_sample *sample,
 				struct machine *machine)
 {
-	struct thread *thread;
 	struct perf_script *script = container_of(tool, struct perf_script, tool);
-	struct perf_session *session = script->session;
-	struct evsel *evsel = perf_evlist__id2evsel(session->evlist, sample->id);
 
 	if (perf_event__process_switch(tool, event, sample, machine) < 0)
 		return -1;
@@ -2405,20 +2282,8 @@ static int process_switch_event(struct perf_tool *tool,
 	if (!script->show_switch_events)
 		return 0;
 
-	thread = machine__findnew_thread(machine, sample->pid,
-					 sample->tid);
-	if (thread == NULL) {
-		pr_debug("problem processing SWITCH event, skipping it.\n");
-		return -1;
-	}
-
-	if (!filter_cpu(sample)) {
-		perf_sample__fprintf_start(sample, thread, evsel,
-					   PERF_RECORD_SWITCH, stdout);
-		perf_event__fprintf(event, stdout);
-	}
-	thread__put(thread);
-	return 0;
+	return print_event(tool, event, sample, machine, sample->pid,
+			   sample->tid);
 }
 
 static int
@@ -2427,23 +2292,8 @@ process_lost_event(struct perf_tool *tool,
 		   struct perf_sample *sample,
 		   struct machine *machine)
 {
-	struct perf_script *script = container_of(tool, struct perf_script, tool);
-	struct perf_session *session = script->session;
-	struct evsel *evsel = perf_evlist__id2evsel(session->evlist, sample->id);
-	struct thread *thread;
-
-	thread = machine__findnew_thread(machine, sample->pid,
-					 sample->tid);
-	if (thread == NULL)
-		return -1;
-
-	if (!filter_cpu(sample)) {
-		perf_sample__fprintf_start(sample, thread, evsel,
-					   PERF_RECORD_LOST, stdout);
-		perf_event__fprintf(event, stdout);
-	}
-	thread__put(thread);
-	return 0;
+	return print_event(tool, event, sample, machine, sample->pid,
+			   sample->tid);
 }
 
 static int
@@ -2462,33 +2312,11 @@ process_bpf_events(struct perf_tool *tool __maybe_unused,
 		   struct perf_sample *sample,
 		   struct machine *machine)
 {
-	struct thread *thread;
-	struct perf_script *script = container_of(tool, struct perf_script, tool);
-	struct perf_session *session = script->session;
-	struct evsel *evsel = perf_evlist__id2evsel(session->evlist, sample->id);
-
 	if (machine__process_ksymbol(machine, event, sample) < 0)
 		return -1;
 
-	if (!evsel->core.attr.sample_id_all) {
-		perf_event__fprintf(event, stdout);
-		return 0;
-	}
-
-	thread = machine__findnew_thread(machine, sample->pid, sample->tid);
-	if (thread == NULL) {
-		pr_debug("problem processing MMAP event, skipping it.\n");
-		return -1;
-	}
-
-	if (!filter_cpu(sample)) {
-		perf_sample__fprintf_start(sample, thread, evsel,
-					   event->header.type, stdout);
-		perf_event__fprintf(event, stdout);
-	}
-
-	thread__put(thread);
-	return 0;
+	return print_event(tool, event, sample, machine, sample->pid,
+			   sample->tid);
 }
 
 static void sig_handler(int sig __maybe_unused)
-- 
2.21.1

[PATCH 19/26] perf bench: Add event synthesis benchmark

[Arnaldo Carvalho de Melo]

From: Ian Rogers <irogers@google.com>

Event synthesis may occur at the start or end (tail) of a perf command.
In system-wide mode it can scan every process in /proc, which may add
seconds of latency before event recording. Add a new benchmark that
times how long event synthesis takes with and without data synthesis.

An example execution looks like:

 $ perf bench internals synthesize
 # Running 'internals/synthesize' benchmark:
 Average synthesis took: 168.253800 usec
 Average data synthesis took: 208.104700 usec

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrey Zhizhikin <andrey.z@gmail.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lore.kernel.org/lkml/20200402154357.107873-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/Documentation/perf-bench.txt |   8 ++
 tools/perf/bench/Build                  |   2 +-
 tools/perf/bench/bench.h                |   2 +-
 tools/perf/bench/synthesize.c           | 101 ++++++++++++++++++++++++
 tools/perf/builtin-bench.c              |   6 ++
 5 files changed, 117 insertions(+), 2 deletions(-)
 create mode 100644 tools/perf/bench/synthesize.c

diff --git a/tools/perf/Documentation/perf-bench.txt b/tools/perf/Documentation/perf-bench.txt
index 0921a3c67381..bad16512c48d 100644
--- a/tools/perf/Documentation/perf-bench.txt
+++ b/tools/perf/Documentation/perf-bench.txt
@@ -61,6 +61,9 @@ SUBSYSTEM
 'epoll'::
 	Eventpoll (epoll) stressing benchmarks.
 
+'internals'::
+	Benchmark internal perf functionality.
+
 'all'::
 	All benchmark subsystems.
 
@@ -214,6 +217,11 @@ Suite for evaluating concurrent epoll_wait calls.
 *ctl*::
 Suite for evaluating multiple epoll_ctl calls.
 
+SUITES FOR 'internals'
+~~~~~~~~~~~~~~~~~~~~~~
+*synthesize*::
+Suite for evaluating perf's event synthesis performance.
+
 SEE ALSO
 --------
 linkperf:perf[1]
diff --git a/tools/perf/bench/Build b/tools/perf/bench/Build
index e4e321b6f883..042827385c87 100644
--- a/tools/perf/bench/Build
+++ b/tools/perf/bench/Build
@@ -6,9 +6,9 @@ perf-y += futex-wake.o
 perf-y += futex-wake-parallel.o
 perf-y += futex-requeue.o
 perf-y += futex-lock-pi.o
-
 perf-y += epoll-wait.o
 perf-y += epoll-ctl.o
+perf-y += synthesize.o
 
 perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-lib.o
 perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-asm.o
diff --git a/tools/perf/bench/bench.h b/tools/perf/bench/bench.h
index 4aa6de1aa67d..4d669c803237 100644
--- a/tools/perf/bench/bench.h
+++ b/tools/perf/bench/bench.h
@@ -41,9 +41,9 @@ int bench_futex_wake_parallel(int argc, const char **argv);
 int bench_futex_requeue(int argc, const char **argv);
 /* pi futexes */
 int bench_futex_lock_pi(int argc, const char **argv);
-
 int bench_epoll_wait(int argc, const char **argv);
 int bench_epoll_ctl(int argc, const char **argv);
+int bench_synthesize(int argc, const char **argv);
 
 #define BENCH_FORMAT_DEFAULT_STR	"default"
 #define BENCH_FORMAT_DEFAULT		0
diff --git a/tools/perf/bench/synthesize.c b/tools/perf/bench/synthesize.c
new file mode 100644
index 000000000000..6291257bc9c9
--- /dev/null
+++ b/tools/perf/bench/synthesize.c
@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Benchmark synthesis of perf events such as at the start of a 'perf
+ * record'. Synthesis is done on the current process and the 'dummy' event
+ * handlers are invoked that support dump_trace but otherwise do nothing.
+ *
+ * Copyright 2019 Google LLC.
+ */
+#include <stdio.h>
+#include "bench.h"
+#include "../util/debug.h"
+#include "../util/session.h"
+#include "../util/synthetic-events.h"
+#include "../util/target.h"
+#include "../util/thread_map.h"
+#include "../util/tool.h"
+#include <linux/err.h>
+#include <linux/time64.h>
+#include <subcmd/parse-options.h>
+
+static unsigned int iterations = 10000;
+
+static const struct option options[] = {
+	OPT_UINTEGER('i', "iterations", &iterations,
+		"Number of iterations used to compute average"),
+	OPT_END()
+};
+
+static const char *const usage[] = {
+	"perf bench internals synthesize <options>",
+	NULL
+};
+
+
+static int do_synthesize(struct perf_session *session,
+			struct perf_thread_map *threads,
+			struct target *target, bool data_mmap)
+{
+	const unsigned int nr_threads_synthesize = 1;
+	struct timeval start, end, diff;
+	u64 runtime_us;
+	unsigned int i;
+	double average;
+	int err;
+
+	gettimeofday(&start, NULL);
+	for (i = 0; i < iterations; i++) {
+		err = machine__synthesize_threads(&session->machines.host,
+						target, threads, data_mmap,
+						nr_threads_synthesize);
+		if (err)
+			return err;
+	}
+
+	gettimeofday(&end, NULL);
+	timersub(&end, &start, &diff);
+	runtime_us = diff.tv_sec * USEC_PER_SEC + diff.tv_usec;
+	average = (double)runtime_us/(double)iterations;
+	printf("Average %ssynthesis took: %f usec\n",
+		data_mmap ? "data " : "", average);
+	return 0;
+}
+
+int bench_synthesize(int argc, const char **argv)
+{
+	struct perf_tool tool;
+	struct perf_session *session;
+	struct target target = {
+		.pid = "self",
+	};
+	struct perf_thread_map *threads;
+	int err;
+
+	argc = parse_options(argc, argv, options, usage, 0);
+
+	session = perf_session__new(NULL, false, NULL);
+	if (IS_ERR(session)) {
+		pr_err("Session creation failed.\n");
+		return PTR_ERR(session);
+	}
+	threads = thread_map__new_by_pid(getpid());
+	if (!threads) {
+		pr_err("Thread map creation failed.\n");
+		err = -ENOMEM;
+		goto err_out;
+	}
+	perf_tool__fill_defaults(&tool);
+
+	err = do_synthesize(session, threads, &target, false);
+	if (err)
+		goto err_out;
+
+	err = do_synthesize(session, threads, &target, true);
+
+err_out:
+	if (threads)
+		perf_thread_map__put(threads);
+
+	perf_session__delete(session);
+	return err;
+}
diff --git a/tools/perf/builtin-bench.c b/tools/perf/builtin-bench.c
index c06fe21c8613..11c79a8d85d6 100644
--- a/tools/perf/builtin-bench.c
+++ b/tools/perf/builtin-bench.c
@@ -76,6 +76,11 @@ static struct bench epoll_benchmarks[] = {
 };
 #endif // HAVE_EVENTFD
 
+static struct bench internals_benchmarks[] = {
+	{ "synthesize", "Benchmark perf event synthesis",	bench_synthesize	},
+	{ NULL,		NULL,					NULL			}
+};
+
 struct collection {
 	const char	*name;
 	const char	*summary;
@@ -92,6 +97,7 @@ static struct collection collections[] = {
 #ifdef HAVE_EVENTFD
 	{"epoll",       "Epoll stressing benchmarks",                   epoll_benchmarks        },
 #endif
+	{ "internals",	"Perf-internals benchmarks",			internals_benchmarks	},
 	{ "all",	"All benchmarks",				NULL			},
 	{ NULL,		NULL,						NULL			}
 };
-- 
2.21.1

[PATCH 20/26] tools api fs: Make xxx__mountpoint() more scalable

[Arnaldo Carvalho de Melo]

From: Stephane Eranian <eranian@google.com>

The xxx_mountpoint() interface provided by fs.c finds mount points for
common pseudo filesystems. The first time xxx_mountpoint() is invoked,
it scans the mount table (/proc/mounts) looking for a match. If found,
it is cached. The price to scan /proc/mounts is paid once if the mount
is found.

When the mount point is not found, subsequent calls to xxx_mountpoint()
scan /proc/mounts over and over again.  There is no caching.

This causes a scaling issue in perf record with hugeltbfs__mountpoint().
The function is called for each process found in
synthesize__mmap_events().  If the machine has thousands of processes
and if the /proc/mounts has many entries this could cause major overhead
in perf record. We have observed multi-second slowdowns on some
configurations.

As an example on a laptop:

Before:

  $ sudo umount /dev/hugepages
  $ strace -e trace=openat -o /tmp/tt perf record -a ls
  $ fgrep mounts /tmp/tt
  285

After:

  $ sudo umount /dev/hugepages
  $ strace -e trace=openat -o /tmp/tt perf record -a ls
  $ fgrep mounts /tmp/tt
  1

One could argue that the non-caching in case the moint point is not
found is intentional. That way subsequent calls may discover a moint
point if the sysadmin mounts the filesystem. But the same argument could
be made against caching the mount point. It could be unmounted causing
errors.  It all depends on the intent of the interface. This patch
assumes it is expected to scan /proc/mounts once. The patch documents
the caching behavior in the fs.h header file.

An alternative would be to just fix perf record. But it would solve the
problem with hugetlbs__mountpoint() but there could be similar issues
(possibly down the line) with other xxx_mountpoint() calls in perf or
other tools.

Signed-off-by: Stephane Eranian <eranian@google.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrey Zhizhikin <andrey.z@gmail.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lore.kernel.org/lkml/20200402154357.107873-3-irogers@google.com
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/lib/api/fs/fs.c | 17 +++++++++++++++++
 tools/lib/api/fs/fs.h | 12 ++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/tools/lib/api/fs/fs.c b/tools/lib/api/fs/fs.c
index 027b18f7ed8c..82f53d81a7a7 100644
--- a/tools/lib/api/fs/fs.c
+++ b/tools/lib/api/fs/fs.c
@@ -90,6 +90,7 @@ struct fs {
 	const char * const	*mounts;
 	char			 path[PATH_MAX];
 	bool			 found;
+	bool			 checked;
 	long			 magic;
 };
 
@@ -111,31 +112,37 @@ static struct fs fs__entries[] = {
 		.name	= "sysfs",
 		.mounts	= sysfs__fs_known_mountpoints,
 		.magic	= SYSFS_MAGIC,
+		.checked = false,
 	},
 	[FS__PROCFS] = {
 		.name	= "proc",
 		.mounts	= procfs__known_mountpoints,
 		.magic	= PROC_SUPER_MAGIC,
+		.checked = false,
 	},
 	[FS__DEBUGFS] = {
 		.name	= "debugfs",
 		.mounts	= debugfs__known_mountpoints,
 		.magic	= DEBUGFS_MAGIC,
+		.checked = false,
 	},
 	[FS__TRACEFS] = {
 		.name	= "tracefs",
 		.mounts	= tracefs__known_mountpoints,
 		.magic	= TRACEFS_MAGIC,
+		.checked = false,
 	},
 	[FS__HUGETLBFS] = {
 		.name	= "hugetlbfs",
 		.mounts = hugetlbfs__known_mountpoints,
 		.magic	= HUGETLBFS_MAGIC,
+		.checked = false,
 	},
 	[FS__BPF_FS] = {
 		.name	= "bpf",
 		.mounts = bpf_fs__known_mountpoints,
 		.magic	= BPF_FS_MAGIC,
+		.checked = false,
 	},
 };
 
@@ -158,6 +165,7 @@ static bool fs__read_mounts(struct fs *fs)
 	}
 
 	fclose(fp);
+	fs->checked = true;
 	return fs->found = found;
 }
 
@@ -220,6 +228,7 @@ static bool fs__env_override(struct fs *fs)
 		return false;
 
 	fs->found = true;
+	fs->checked = true;
 	strncpy(fs->path, override_path, sizeof(fs->path) - 1);
 	fs->path[sizeof(fs->path) - 1] = '\0';
 	return true;
@@ -246,6 +255,14 @@ static const char *fs__mountpoint(int idx)
 	if (fs->found)
 		return (const char *)fs->path;
 
+	/* the mount point was already checked for the mount point
+	 * but and did not exist, so return NULL to avoid scanning again.
+	 * This makes the found and not found paths cost equivalent
+	 * in case of multiple calls.
+	 */
+	if (fs->checked)
+		return NULL;
+
 	return fs__get_mountpoint(fs);
 }
 
diff --git a/tools/lib/api/fs/fs.h b/tools/lib/api/fs/fs.h
index 936edb95e1f3..aa222ca30311 100644
--- a/tools/lib/api/fs/fs.h
+++ b/tools/lib/api/fs/fs.h
@@ -18,6 +18,18 @@
 	const char *name##__mount(void);	\
 	bool name##__configured(void);		\
 
+/*
+ * The xxxx__mountpoint() entry points find the first match mount point for each
+ * filesystems listed below, where xxxx is the filesystem type.
+ *
+ * The interface is as follows:
+ *
+ * - If a mount point is found on first call, it is cached and used for all
+ *   subsequent calls.
+ *
+ * - If a mount point is not found, NULL is returned on first call and all
+ *   subsequent calls.
+ */
 FS(sysfs)
 FS(procfs)
 FS(debugfs)
-- 
2.21.1

[PATCH 21/26] perf synthetic-events: save 4kb from 2 stack frames

[Arnaldo Carvalho de Melo]

From: Ian Rogers <irogers@google.com>

Reuse an existing char buffer to avoid two PATH_MAX sized char buffers.

Reduces stack frame sizes by 4kb.

perf_event__synthesize_mmap_events before 'sub $0x45b8,%rsp' after
'sub $0x35b8,%rsp'.

perf_event__get_comm_ids before 'sub $0x2028,%rsp' after
'sub $0x1028,%rsp'.

The performance impact of this change is negligible.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrey Zhizhikin <andrey.z@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lore.kernel.org/lkml/20200402154357.107873-4-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/synthetic-events.c | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c
index a661b122d9d8..9d4aa951eaa6 100644
--- a/tools/perf/util/synthetic-events.c
+++ b/tools/perf/util/synthetic-events.c
@@ -71,7 +71,6 @@ int perf_tool__process_synth_event(struct perf_tool *tool,
 static int perf_event__get_comm_ids(pid_t pid, char *comm, size_t len,
 				    pid_t *tgid, pid_t *ppid)
 {
-	char filename[PATH_MAX];
 	char bf[4096];
 	int fd;
 	size_t size = 0;
@@ -81,11 +80,11 @@ static int perf_event__get_comm_ids(pid_t pid, char *comm, size_t len,
 	*tgid = -1;
 	*ppid = -1;
 
-	snprintf(filename, sizeof(filename), "/proc/%d/status", pid);
+	snprintf(bf, sizeof(bf), "/proc/%d/status", pid);
 
-	fd = open(filename, O_RDONLY);
+	fd = open(bf, O_RDONLY);
 	if (fd < 0) {
-		pr_debug("couldn't open %s\n", filename);
+		pr_debug("couldn't open %s\n", bf);
 		return -1;
 	}
 
@@ -281,9 +280,9 @@ int perf_event__synthesize_mmap_events(struct perf_tool *tool,
 				       struct machine *machine,
 				       bool mmap_data)
 {
-	char filename[PATH_MAX];
 	FILE *fp;
 	unsigned long long t;
+	char bf[BUFSIZ];
 	bool truncation = false;
 	unsigned long long timeout = proc_map_timeout * 1000000ULL;
 	int rc = 0;
@@ -293,15 +292,15 @@ int perf_event__synthesize_mmap_events(struct perf_tool *tool,
 	if (machine__is_default_guest(machine))
 		return 0;
 
-	snprintf(filename, sizeof(filename), "%s/proc/%d/task/%d/maps",
-		 machine->root_dir, pid, pid);
+	snprintf(bf, sizeof(bf), "%s/proc/%d/task/%d/maps",
+		machine->root_dir, pid, pid);
 
-	fp = fopen(filename, "r");
+	fp = fopen(bf, "r");
 	if (fp == NULL) {
 		/*
 		 * We raced with a task exiting - just return:
 		 */
-		pr_debug("couldn't open %s\n", filename);
+		pr_debug("couldn't open %s\n", bf);
 		return -1;
 	}
 
@@ -309,7 +308,6 @@ int perf_event__synthesize_mmap_events(struct perf_tool *tool,
 	t = rdclock();
 
 	while (1) {
-		char bf[BUFSIZ];
 		char prot[5];
 		char execname[PATH_MAX];
 		char anonstr[] = "//anon";
@@ -321,10 +319,10 @@ int perf_event__synthesize_mmap_events(struct perf_tool *tool,
 			break;
 
 		if ((rdclock() - t) > timeout) {
-			pr_warning("Reading %s time out. "
+			pr_warning("Reading %s/proc/%d/task/%d/maps time out. "
 				   "You may want to increase "
 				   "the time limit by --proc-map-timeout\n",
-				   filename);
+				   machine->root_dir, pid, pid);
 			truncation = true;
 			goto out;
 		}
-- 
2.21.1

[PATCH 22/26] perf stat: Fix no metric header if --per-socket and --metric-only set

[Arnaldo Carvalho de Melo]

From: Jin Yao <yao.jin@linux.intel.com>

We received a report that was no metric header displayed if --per-socket
and --metric-only were both set.

It's hard for script to parse the perf-stat output. This patch fixes this
issue.

Before:

  root@kbl-ppc:~# perf stat -a -M CPI --metric-only --per-socket
  ^C
   Performance counter stats for 'system wide':

  S0        8                  2.6

         2.215270071 seconds time elapsed

  root@kbl-ppc:~# perf stat -a -M CPI --metric-only --per-socket -I1000
  #           time socket cpus
       1.000411692 S0        8                  2.2
       2.001547952 S0        8                  3.4
       3.002446511 S0        8                  3.4
       4.003346157 S0        8                  4.0
       5.004245736 S0        8                  0.3

After:

  root@kbl-ppc:~# perf stat -a -M CPI --metric-only --per-socket
  ^C
   Performance counter stats for 'system wide':

                               CPI
  S0        8                  2.1

         1.813579830 seconds time elapsed

  root@kbl-ppc:~# perf stat -a -M CPI --metric-only --per-socket -I1000
  #           time socket cpus                  CPI
       1.000415122 S0        8                  3.2
       2.001630051 S0        8                  2.9
       3.002612278 S0        8                  4.3
       4.003523594 S0        8                  3.0
       5.004504256 S0        8                  3.7

Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20200331180226.25915-1-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/stat-shadow.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/stat-shadow.c b/tools/perf/util/stat-shadow.c
index 0fd713d3674f..03ecb8cd0eec 100644
--- a/tools/perf/util/stat-shadow.c
+++ b/tools/perf/util/stat-shadow.c
@@ -803,8 +803,11 @@ static void generic_metric(struct perf_stat_config *config,
 				     out->force_header ?
 				     (metric_name ? metric_name : name) : "", 0);
 		}
-	} else
-		print_metric(config, ctxp, NULL, NULL, "", 0);
+	} else {
+		print_metric(config, ctxp, NULL, NULL,
+			     out->force_header ?
+			     (metric_name ? metric_name : name) : "", 0);
+	}
 
 	for (i = 1; i < pctx.num_ids; i++)
 		zfree(&pctx.ids[i].name);
-- 
2.21.1

[PATCH 23/26] perf expr: Add expr_ prefix for parse_ctx and parse_id

[Arnaldo Carvalho de Melo]

From: Jiri Olsa <jolsa@kernel.org>

Adding expr_ prefix for parse_ctx and parse_id, to straighten out the
expr* namespace.

There's no functional change.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Anju T Sudhakar <anju@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Mamatha Inamdar <mamatha4@linux.vnet.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lore.kernel.org/lkml/20200401203340.31402-2-kjain@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/tests/expr.c       |  4 ++--
 tools/perf/util/expr.c        | 10 +++++-----
 tools/perf/util/expr.h        | 12 ++++++------
 tools/perf/util/expr.y        |  6 +++---
 tools/perf/util/stat-shadow.c |  2 +-
 5 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/tools/perf/tests/expr.c b/tools/perf/tests/expr.c
index 28313e59d6f6..ea10fc4412c4 100644
--- a/tools/perf/tests/expr.c
+++ b/tools/perf/tests/expr.c
@@ -6,7 +6,7 @@
 #include <string.h>
 #include <linux/zalloc.h>
 
-static int test(struct parse_ctx *ctx, const char *e, double val2)
+static int test(struct expr_parse_ctx *ctx, const char *e, double val2)
 {
 	double val;
 
@@ -22,7 +22,7 @@ int test__expr(struct test *t __maybe_unused, int subtest __maybe_unused)
 	const char **other;
 	double val;
 	int i, ret;
-	struct parse_ctx ctx;
+	struct expr_parse_ctx ctx;
 	int num_other;
 
 	expr__ctx_init(&ctx);
diff --git a/tools/perf/util/expr.c b/tools/perf/util/expr.c
index fd192ddf93c1..c8ccc548a585 100644
--- a/tools/perf/util/expr.c
+++ b/tools/perf/util/expr.c
@@ -11,7 +11,7 @@ extern int expr_debug;
 #endif
 
 /* Caller must make sure id is allocated */
-void expr__add_id(struct parse_ctx *ctx, const char *name, double val)
+void expr__add_id(struct expr_parse_ctx *ctx, const char *name, double val)
 {
 	int idx;
 
@@ -21,13 +21,13 @@ void expr__add_id(struct parse_ctx *ctx, const char *name, double val)
 	ctx->ids[idx].val = val;
 }
 
-void expr__ctx_init(struct parse_ctx *ctx)
+void expr__ctx_init(struct expr_parse_ctx *ctx)
 {
 	ctx->num_ids = 0;
 }
 
 static int
-__expr__parse(double *val, struct parse_ctx *ctx, const char *expr,
+__expr__parse(double *val, struct expr_parse_ctx *ctx, const char *expr,
 	      int start)
 {
 	YY_BUFFER_STATE buffer;
@@ -52,7 +52,7 @@ __expr__parse(double *val, struct parse_ctx *ctx, const char *expr,
 	return ret;
 }
 
-int expr__parse(double *final_val, struct parse_ctx *ctx, const char *expr)
+int expr__parse(double *final_val, struct expr_parse_ctx *ctx, const char *expr)
 {
 	return __expr__parse(final_val, ctx, expr, EXPR_PARSE) ? -1 : 0;
 }
@@ -75,7 +75,7 @@ int expr__find_other(const char *expr, const char *one, const char ***other,
 		     int *num_other)
 {
 	int err, i = 0, j = 0;
-	struct parse_ctx ctx;
+	struct expr_parse_ctx ctx;
 
 	expr__ctx_init(&ctx);
 	err = __expr__parse(NULL, &ctx, expr, EXPR_OTHER);
diff --git a/tools/perf/util/expr.h b/tools/perf/util/expr.h
index 9377538f4097..b9e53f2b5844 100644
--- a/tools/perf/util/expr.h
+++ b/tools/perf/util/expr.h
@@ -5,19 +5,19 @@
 #define EXPR_MAX_OTHER 20
 #define MAX_PARSE_ID EXPR_MAX_OTHER
 
-struct parse_id {
+struct expr_parse_id {
 	const char *name;
 	double val;
 };
 
-struct parse_ctx {
+struct expr_parse_ctx {
 	int num_ids;
-	struct parse_id ids[MAX_PARSE_ID];
+	struct expr_parse_id ids[MAX_PARSE_ID];
 };
 
-void expr__ctx_init(struct parse_ctx *ctx);
-void expr__add_id(struct parse_ctx *ctx, const char *id, double val);
-int expr__parse(double *final_val, struct parse_ctx *ctx, const char *expr);
+void expr__ctx_init(struct expr_parse_ctx *ctx);
+void expr__add_id(struct expr_parse_ctx *ctx, const char *id, double val);
+int expr__parse(double *final_val, struct expr_parse_ctx *ctx, const char *expr);
 int expr__find_other(const char *expr, const char *one, const char ***other,
 		int *num_other);
 
diff --git a/tools/perf/util/expr.y b/tools/perf/util/expr.y
index 4720cbe79357..cd17486c1c5d 100644
--- a/tools/perf/util/expr.y
+++ b/tools/perf/util/expr.y
@@ -15,7 +15,7 @@
 %define api.pure full
 
 %parse-param { double *final_val }
-%parse-param { struct parse_ctx *ctx }
+%parse-param { struct expr_parse_ctx *ctx }
 %parse-param {void *scanner}
 %lex-param {void* scanner}
 
@@ -39,14 +39,14 @@
 
 %{
 static void expr_error(double *final_val __maybe_unused,
-		       struct parse_ctx *ctx __maybe_unused,
+		       struct expr_parse_ctx *ctx __maybe_unused,
 		       void *scanner,
 		       const char *s)
 {
 	pr_debug("%s\n", s);
 }
 
-static int lookup_id(struct parse_ctx *ctx, char *id, double *val)
+static int lookup_id(struct expr_parse_ctx *ctx, char *id, double *val)
 {
 	int i;
 
diff --git a/tools/perf/util/stat-shadow.c b/tools/perf/util/stat-shadow.c
index 03ecb8cd0eec..1ad5c5be7e97 100644
--- a/tools/perf/util/stat-shadow.c
+++ b/tools/perf/util/stat-shadow.c
@@ -729,7 +729,7 @@ static void generic_metric(struct perf_stat_config *config,
 			   struct runtime_stat *st)
 {
 	print_metric_t print_metric = out->print_metric;
-	struct parse_ctx pctx;
+	struct expr_parse_ctx pctx;
 	double ratio, scale;
 	int i;
 	void *ctxp = out->ctx;
-- 
2.21.1

[PATCH 24/26] perf expr: Add expr_scanner_ctx object

[Arnaldo Carvalho de Melo]

From: Jiri Olsa <jolsa@kernel.org>

Add the expr_scanner_ctx object to hold user data for the expr scanner.
Currently it holds only start_token, Kajol Jain will use it to hold 24x7
runtime param.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Anju T Sudhakar <anju@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Mamatha Inamdar <mamatha4@linux.vnet.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lore.kernel.org/lkml/20200401203340.31402-3-kjain@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/expr.c |  6 ++++--
 tools/perf/util/expr.h |  4 ++++
 tools/perf/util/expr.l | 10 +++++-----
 3 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/tools/perf/util/expr.c b/tools/perf/util/expr.c
index c8ccc548a585..c3382d58cf40 100644
--- a/tools/perf/util/expr.c
+++ b/tools/perf/util/expr.c
@@ -3,7 +3,6 @@
 #include <assert.h>
 #include "expr.h"
 #include "expr-bison.h"
-#define YY_EXTRA_TYPE int
 #include "expr-flex.h"
 
 #ifdef PARSER_DEBUG
@@ -30,11 +29,14 @@ static int
 __expr__parse(double *val, struct expr_parse_ctx *ctx, const char *expr,
 	      int start)
 {
+	struct expr_scanner_ctx scanner_ctx = {
+		.start_token = start,
+	};
 	YY_BUFFER_STATE buffer;
 	void *scanner;
 	int ret;
 
-	ret = expr_lex_init_extra(start, &scanner);
+	ret = expr_lex_init_extra(&scanner_ctx, &scanner);
 	if (ret)
 		return ret;
 
diff --git a/tools/perf/util/expr.h b/tools/perf/util/expr.h
index b9e53f2b5844..0938ad166ece 100644
--- a/tools/perf/util/expr.h
+++ b/tools/perf/util/expr.h
@@ -15,6 +15,10 @@ struct expr_parse_ctx {
 	struct expr_parse_id ids[MAX_PARSE_ID];
 };
 
+struct expr_scanner_ctx {
+	int start_token;
+};
+
 void expr__ctx_init(struct expr_parse_ctx *ctx);
 void expr__add_id(struct expr_parse_ctx *ctx, const char *id, double val);
 int expr__parse(double *final_val, struct expr_parse_ctx *ctx, const char *expr);
diff --git a/tools/perf/util/expr.l b/tools/perf/util/expr.l
index eaad29243c23..2582c2464938 100644
--- a/tools/perf/util/expr.l
+++ b/tools/perf/util/expr.l
@@ -76,13 +76,13 @@ sym		[0-9a-zA-Z_\.:@]+
 symbol		{spec}*{sym}*{spec}*{sym}*
 
 %%
-	{
-		int start_token;
+	struct expr_scanner_ctx *sctx = expr_get_extra(yyscanner);
 
-		start_token = expr_get_extra(yyscanner);
+	{
+		int start_token = sctx->start_token;
 
-		if (start_token) {
-			expr_set_extra(NULL, yyscanner);
+		if (sctx->start_token) {
+			sctx->start_token = 0;
 			return start_token;
 		}
 	}
-- 
2.21.1

[PATCH 25/26] perf metrictroup: Split the metricgroup__add_metric function

[Arnaldo Carvalho de Melo]

From: Kajol Jain <kjain@linux.ibm.com>

This patch refactors metricgroup__add_metric function where some part of
it move to function metricgroup__add_metric_param.  No logic change.

Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Anju T Sudhakar <anju@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Mamatha Inamdar <mamatha4@linux.vnet.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lore.kernel.org/lkml/20200401203340.31402-4-kjain@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/metricgroup.c | 60 ++++++++++++++++++++---------------
 1 file changed, 35 insertions(+), 25 deletions(-)

diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index 926449a7cdbf..7ad81c8177ea 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -485,6 +485,39 @@ static bool metricgroup__has_constraint(struct pmu_event *pe)
 	return false;
 }
 
+static int __metricgroup__add_metric(struct strbuf *events,
+			struct list_head *group_list, struct pmu_event *pe)
+{
+
+	const char **ids;
+	int idnum;
+	struct egroup *eg;
+
+	if (expr__find_other(pe->metric_expr, NULL, &ids, &idnum) < 0)
+		return -EINVAL;
+
+	if (events->len > 0)
+		strbuf_addf(events, ",");
+
+	if (metricgroup__has_constraint(pe))
+		metricgroup__add_metric_non_group(events, ids, idnum);
+	else
+		metricgroup__add_metric_weak_group(events, ids, idnum);
+
+	eg = malloc(sizeof(*eg));
+	if (!eg)
+		return -ENOMEM;
+
+	eg->ids = ids;
+	eg->idnum = idnum;
+	eg->metric_name = pe->metric_name;
+	eg->metric_expr = pe->metric_expr;
+	eg->metric_unit = pe->unit;
+	list_add_tail(&eg->nd, group_list);
+
+	return 0;
+}
+
 static int metricgroup__add_metric(const char *metric, struct strbuf *events,
 				   struct list_head *group_list)
 {
@@ -504,35 +537,12 @@ static int metricgroup__add_metric(const char *metric, struct strbuf *events,
 			continue;
 		if (match_metric(pe->metric_group, metric) ||
 		    match_metric(pe->metric_name, metric)) {
-			const char **ids;
-			int idnum;
-			struct egroup *eg;
 
 			pr_debug("metric expr %s for %s\n", pe->metric_expr, pe->metric_name);
 
-			if (expr__find_other(pe->metric_expr,
-					     NULL, &ids, &idnum) < 0)
-				continue;
-			if (events->len > 0)
-				strbuf_addf(events, ",");
-
-			if (metricgroup__has_constraint(pe))
-				metricgroup__add_metric_non_group(events, ids, idnum);
-			else
-				metricgroup__add_metric_weak_group(events, ids, idnum);
-
-			eg = malloc(sizeof(struct egroup));
-			if (!eg) {
-				ret = -ENOMEM;
+			ret = __metricgroup__add_metric(events,	group_list, pe);
+			if (ret == -ENOMEM)
 				break;
-			}
-			eg->ids = ids;
-			eg->idnum = idnum;
-			eg->metric_name = pe->metric_name;
-			eg->metric_expr = pe->metric_expr;
-			eg->metric_unit = pe->unit;
-			list_add_tail(&eg->nd, group_list);
-			ret = 0;
 		}
 	}
 	return ret;
-- 
2.21.1

[PATCH 26/26] perf script: Add flamegraph.py script

[Arnaldo Carvalho de Melo]

From: Andreas Gerstmayr <agerstmayr@redhat.com>

This script works in tandem with d3-flame-graph to generate flame graphs
from perf. It supports two output formats: JSON and HTML (the default).
The HTML format will look for a standalone d3-flame-graph template file
in /usr/share/d3-flame-graph/d3-flamegraph-base.html and fill in the
collected stacks.

Usage:

    perf record -a -g -F 99 sleep 60
    perf script report flamegraph

Combined:

    perf script flamegraph -a -F 99 sleep 60

Committer testing:

Tested both with "PYTHON=python3" and with the default, that uses
python2-devel:

Complete set of instructions:

  $ mkdir /tmp/build/perf
  $ make PYTHON=python3 -C tools/perf O=/tmp/build/perf install-bin
  $ export PATH=~/bin:$PATH
  $ perf record -a -g -F 99 sleep 60
  $ perf script report flamegraph

Now go and open the generated flamegraph.html file in a browser.

At first this required building with PYTHON=python3, but after I
reported this Andreas was kind enough to send a patch making it work
with both python and python3.

Signed-off-by: Andreas Gerstmayr <agerstmayr@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Brendan Gregg <bgregg@netflix.com>
Cc: Martin Spier <mspier@netflix.com>
Link: http://lore.kernel.org/lkml/20200320151355.66302-1-agerstmayr@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 .../perf/scripts/python/bin/flamegraph-record |   2 +
 .../perf/scripts/python/bin/flamegraph-report |   3 +
 tools/perf/scripts/python/flamegraph.py       | 124 ++++++++++++++++++
 3 files changed, 129 insertions(+)
 create mode 100755 tools/perf/scripts/python/bin/flamegraph-record
 create mode 100755 tools/perf/scripts/python/bin/flamegraph-report
 create mode 100755 tools/perf/scripts/python/flamegraph.py

diff --git a/tools/perf/scripts/python/bin/flamegraph-record b/tools/perf/scripts/python/bin/flamegraph-record
new file mode 100755
index 000000000000..725d66e71570
--- /dev/null
+++ b/tools/perf/scripts/python/bin/flamegraph-record
@@ -0,0 +1,2 @@
+#!/usr/bin/sh
+perf record -g "$@"
diff --git a/tools/perf/scripts/python/bin/flamegraph-report b/tools/perf/scripts/python/bin/flamegraph-report
new file mode 100755
index 000000000000..b1a79afd903b
--- /dev/null
+++ b/tools/perf/scripts/python/bin/flamegraph-report
@@ -0,0 +1,3 @@
+#!/usr/bin/sh
+# description: create flame graphs
+perf script -s "$PERF_EXEC_PATH"/scripts/python/flamegraph.py -- "$@"
diff --git a/tools/perf/scripts/python/flamegraph.py b/tools/perf/scripts/python/flamegraph.py
new file mode 100755
index 000000000000..61f3be9add6b
--- /dev/null
+++ b/tools/perf/scripts/python/flamegraph.py
@@ -0,0 +1,124 @@
+# flamegraph.py - create flame graphs from perf samples
+# SPDX-License-Identifier: GPL-2.0
+#
+# Usage:
+#
+#     perf record -a -g -F 99 sleep 60
+#     perf script report flamegraph
+#
+# Combined:
+#
+#     perf script flamegraph -a -F 99 sleep 60
+#
+# Written by Andreas Gerstmayr <agerstmayr@redhat.com>
+# Flame Graphs invented by Brendan Gregg <bgregg@netflix.com>
+# Works in tandem with d3-flame-graph by Martin Spier <mspier@netflix.com>
+
+from __future__ import print_function
+import sys
+import os
+import argparse
+import json
+
+
+class Node:
+    def __init__(self, name, libtype=""):
+        self.name = name
+        self.libtype = libtype
+        self.value = 0
+        self.children = []
+
+    def toJSON(self):
+        return {
+            "n": self.name,
+            "l": self.libtype,
+            "v": self.value,
+            "c": self.children
+        }
+
+
+class FlameGraphCLI:
+    def __init__(self, args):
+        self.args = args
+        self.stack = Node("root")
+
+        if self.args.format == "html" and \
+                not os.path.isfile(self.args.template):
+            print("Flame Graph template {} does not exist. Please install "
+                  "the js-d3-flame-graph (RPM) or libjs-d3-flame-graph (deb) "
+                  "package, specify an existing flame graph template "
+                  "(--template PATH) or another output format "
+                  "(--format FORMAT).".format(self.args.template),
+                  file=sys.stderr)
+            sys.exit(1)
+
+    def find_or_create_node(self, node, name, dso):
+        libtype = "kernel" if dso == "[kernel.kallsyms]" else ""
+        if name is None:
+            name = "[unknown]"
+
+        for child in node.children:
+            if child.name == name and child.libtype == libtype:
+                return child
+
+        child = Node(name, libtype)
+        node.children.append(child)
+        return child
+
+    def process_event(self, event):
+        node = self.find_or_create_node(self.stack, event["comm"], None)
+        if "callchain" in event:
+            for entry in reversed(event['callchain']):
+                node = self.find_or_create_node(
+                    node, entry.get("sym", {}).get("name"), event.get("dso"))
+        else:
+            node = self.find_or_create_node(
+                node, entry.get("symbol"), event.get("dso"))
+        node.value += 1
+
+    def trace_end(self):
+        json_str = json.dumps(self.stack, default=lambda x: x.toJSON())
+
+        if self.args.format == "html":
+            try:
+                with open(self.args.template) as f:
+                    output_str = f.read().replace("/** @flamegraph_json **/",
+                                                  json_str)
+            except IOError as e:
+                print("Error reading template file: {}".format(e), file=sys.stderr)
+                sys.exit(1)
+            output_fn = self.args.output or "flamegraph.html"
+        else:
+            output_str = json_str
+            output_fn = self.args.output or "stacks.json"
+
+        if output_fn == "-":
+            sys.stdout.write(output_str)
+        else:
+            print("dumping data to {}".format(output_fn))
+            try:
+                with open(output_fn, "w") as out:
+                    out.write(output_str)
+            except IOError as e:
+                print("Error writing output file: {}".format(e), file=sys.stderr)
+                sys.exit(1)
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(description="Create flame graphs.")
+    parser.add_argument("-f", "--format",
+                        default="html", choices=["json", "html"],
+                        help="output file format")
+    parser.add_argument("-o", "--output",
+                        help="output file name")
+    parser.add_argument("--template",
+                        default="/usr/share/d3-flame-graph/d3-flamegraph-base.html",
+                        help="path to flamegraph HTML template")
+    parser.add_argument("-i", "--input",
+                        help=argparse.SUPPRESS)
+
+    args = parser.parse_args()
+    cli = FlameGraphCLI(args)
+
+    process_event = cli.process_event
+    trace_end = cli.trace_end
-- 
2.21.1