Add missing 'const' qualifiers so following commits are able to create
tracepoints using const strings.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1468406646-21642-4-git-send-email-wangnan0@huawei.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Now libbpf support tracepoint program type. Report meaningful error when kernel
version is less than 4.7.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1468406646-21642-3-git-send-email-wangnan0@huawei.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Add 4 new APIs to adjust and query the type of a BPF program.
Load program according to type set by caller. Default is set to
BPF_PROG_TYPE_KPROBE.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1468406646-21642-2-git-send-email-wangnan0@huawei.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

That doesn't have -I to match lines.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-1zqv1h6okt70e2huokkdtf1u@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Not all libelf implementations have this "Please, ELF_C_READ, but use
mmap if possible" elf_begin() cmd, so provide a fallback to plain old
ELF_C_READ.

Case in point: Alpine Linux 3.4.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-1fctuknrawgoi5xqon4mu9dv@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

It was set based on CONFIG_64BIT, that is available only when using
Kconfig, which we're working towards but not to the point of having this
CONFIG variable set, so synthesize it from available compiler defined
defines, __SIZEOF_LONG__ or, lacking that, __WORDSIZE.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-og5fmkr17856lhupacihwxvb@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The objtool build fails with the recent changes to the bits-per-long
headers:

  tools/include/linux/bitops.h:12:0: error: "BITS_PER_LONG" redefined [-Werror]

Which got introduced by:

  bb970707 tools: Copy the bitsperlong.h files from the kernel

Work it around for the time being.

Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'perf-core-for-mingo-20160712' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

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

User visible changes:

- Add demangling of symbols in programs written in the Rust language (David Tolnay)

- Add support for tracepoints in the python binding, including an example, that
  sets up and parses sched:sched_switch events, tools/perf/python/tracepoint.py
  (Jiri Olsa)

- Introduce --stdio-color to set up the color output mode selection in
  'annotate' and 'report', allowing emit color escape sequences when
  redirecting the output of these tools (Arnaldo Carvalho de Melo)

Infrastructure changes:

- Various tweaks to allow the 'perf trace' beautifiers to build without using
  kernel headers and in a wider range of Linux distributions/releases
  (Arnaldo Carvalho de Melo)

- Stop using kernel source files, instead copy what is needed and
  check when the original kernel source file gets modified, warning
  the developers about it. This helps in building the tool in older
  systems and even in recent ones, for just added kernel features
  for which ABI details (struct changes, defines, etc) still are not
  available on system headers (Arnaldo Carvalho de Melo)

- Be consistent in how to use strerror_r, adding a wrapper that makes sure that
  it returns a pointer to passed buffer, and using the XSI variant, that is
  available in more libc implementations (Arnaldo Carvalho de Melo)

- Avoid checking code drift on busibox's diff perf intel-pt-decoder, as it
  doesn't have the '-I' command line switch to check for regexps
  (Arnaldo Carvalho de Melo)

- Add missing headers in various places (Arnaldo Carvalho de Melo)

- Remove unneeded headers from various other places (Arnaldo Carvalho de Melo)

- Add feature detection for gelf_getnote(), disabling SDT support if not
  present (Arnaldo Carvalho de Melo)

- Fix oddities with GCC 5.3.0 by initializing some variables
  (Arnaldo Carvalho de Melo)

- With those changes in place perf now builds on Alpine Linux 3.4, in addition to
  on centos (5, 6, 7), debian (7, 8, experimental), fedora (21, 22, 23, 24, rawhide),
  mageia 5, opensuse (13.2, 42.1) and ubuntu (12.04.5, 14.04.4, 15.10, 16.04) and
  will be test build on those systems prior to future pull requests.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Add a 'CPU' special field to allow the filter in trace-cmd report to
filter on the task's CPU.

By adding a special field 'CPU' (all caps) the user can now filter out
tasks based on which CPU they are on. This is useful when filtering out
(or in) a bunch of threads.

  -F 'CPU == 0'
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/20160712093306.5b058103@gandalf.local.homeSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To show how to enable a tracepoint and access its fields.

Committer note:

Testing it:

  # ls -l /tmp/build/perf/python/perf.so
  -rwxrwxr-x. 1 acme acme 1563256 Jul 12 16:19 /tmp/build/perf/python/perf.so
  # export PYTHONPATH=/tmp/build/perf/python/
  # tools/perf/python/tracepoint.py 2> /dev/null | head -200 | tail -10
  time 76345337296548 prev_comm=swapper/0 prev_pid=0 prev_prio=120 prev_state=0x0 ==> next_comm=tracepoint.py- next_pid=18479 next_prio=120
  time 76345338520479 prev_comm=gnome-shelln-b prev_pid=2186 prev_prio=120 prev_state=0x1 ==> next_comm=swapper/1 next_pid=0 next_prio=120
  time 76345337309942 prev_comm=tracepoint.py- prev_pid=18479 prev_prio=120 prev_state=0x1 ==> next_comm=swapper/0 next_pid=0 next_prio=120
  time 76345337312302 prev_comm=swapper/0 prev_pid=0 prev_prio=120 prev_state=0x0 ==> next_comm=tracepoint.py- next_pid=18479 next_prio=120
  time 76345337324927 prev_comm=tracepoint.py- prev_pid=18479 prev_prio=120 prev_state=0x1 ==> next_comm=swapper/0 next_pid=0 next_prio=120
  time 76345337327115 prev_comm=swapper/0 prev_pid=0 prev_prio=120 prev_state=0x0 ==> next_comm=tracepoint.py- next_pid=18479 next_prio=120
  time 76345338621750 prev_comm=swapper/2 prev_pid=0 prev_prio=120 prev_state=0x0 ==> next_comm=rcuos/2 next_pid=29 next_prio=120
  time 76345338607922 prev_comm=swapper/3 prev_pid=0 prev_prio=120 prev_state=0x0 ==> next_comm=rcu_sched next_pid=7 next_prio=120
  time 76345337338817 prev_comm=tracepoint.py- prev_pid=18479 prev_prio=120 prev_state=0x1 ==> next_comm=swapper/0 next_pid=0 next_prio=120
  time 76345338627156 prev_comm=swapper/1 prev_pid=0 prev_prio=120 prev_state=0x0 ==> next_comm=head-terminal- next_pid=18480 next_prio=120
  #
  # strip /tmp/build/perf/python/perf.so
  # ls -l /tmp/build/perf/python/perf.so
  -rwxrwxr-x. 1 acme acme 319616 Jul 12 16:25 /tmp/build/perf/python/perf.so
Reported-and-Tested-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1468148882-10362-10-git-send-email-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Adding tp_getattro callback for sample event. It resolves tracepoint
fields in runtime.

It's now possible to access tracepoint fields in normal fashion like
hardcoded ones (see the example in the next patch).
Reported-and-Tested-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1468148882-10362-9-git-send-email-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To be able to find out event configuration info during sample parsing.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1468148882-10362-8-git-send-email-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To get id of the tracepoint from subsystem and name strings. The
interface is:

  id = perf.tracepoint(sys, name)

In case of error -1 is returned.

It will be used to get python tracepoint event's config value for
tracepoint event.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1468148882-10362-7-git-send-email-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Make perf.event object parts of the perf module dictionary so we can
address them by name.

The following objects/names are added:

  mmap_event
  lost_event
  comm_event
  task_event
  throttle_event
  task_event
  read_event
  sample_event
  switch_event

We can now use it in python script like:
  ...
  event = evlist.read_on_cpu(cpu)
  ...
  if not isinstance(event, perf.sample_event):
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1468148882-10362-6-git-send-email-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

We can't consume the event before parsing it. Under heavy load we could
get caught by kernel writer overwriting the event we're trying to parse.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1468148882-10362-5-git-send-email-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Currently 0 is passed as perf_event_attr::size, which could block usage
of new features.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1468148882-10362-4-git-send-email-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To get struct event_format object from tracepoint ID.  It will be used
in following patches.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1468148882-10362-3-git-send-email-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

It will be used outside of evlist.c object in folowing patches.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1468148882-10362-2-git-send-email-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Rust demangling is another step after bfd demangling. Add a diagnosis to
identify mangled Rust symbols based on the hash that the Rust mangler appends
as the last path component, as well as other characteristics.  Add a demangler
to reconstruct the original symbol.

Committer notes:

How I tested it:

Enabled COPR on Fedora 24 and then installed the 'rust-binary' package,
with it:

  $ cat src/main.rs
  fn main() {
      println!("Hello, world!");
  }
  $ cat Cargo.toml
  [package]

  name = "hello_world"
  version = "0.0.1"
  authors = [ "Arnaldo Carvalho de Melo <acme@kernel.org>" ]

  $ perf record cargo bench
   Compiling hello_world v0.0.1 (file:///home/acme/projects/hello_world)
     Running target/release/hello_world-d4b9dab4b2a47d75

  running 0 tests

  test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured

  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.096 MB perf.data (1457 samples) ]
  $

Before this patch:

  $ perf report --stdio --dsos librbml-e8edd0fd.so
  # dso: librbml-e8edd0fd.so
  #
  # Total Lost Samples: 0
  #
  # Samples: 1K of event 'cycles:u'
  # Event count (approx.): 979599126
  #
  # Overhead  Command  Symbol
  # ........  .......  .............................................................................................................
  #
       1.78%  rustc    [.] rbml::reader::maybe_get_doc::hb9d387df6024b15b
       1.50%  rustc    [.] _$LT$reader..DocsIterator$LT$$u27$a$GT$$u20$as$u20$std..iter..Iterator$GT$::next::hd9af9e60d79a35c8
       1.20%  rustc    [.] rbml::reader::doc_at::hc88107fba445af31
       0.46%  rustc    [.] _$LT$reader..TaggedDocsIterator$LT$$u27$a$GT$$u20$as$u20$std..iter..Iterator$GT$::next::h0cb40e696e4bb489
       0.35%  rustc    [.] rbml::reader::Decoder::_next_int::h66eef7825a398bc3
       0.29%  rustc    [.] rbml::reader::Decoder::_next_sub::h8e5266005580b836
       0.15%  rustc    [.] rbml::reader::get_doc::h094521c645459139
       0.14%  rustc    [.] _$LT$reader..Decoder$LT$$u27$doc$GT$$u20$as$u20$serialize..Decoder$GT$::read_u32::h0acea2fff9669327
       0.07%  rustc    [.] rbml::reader::Decoder::next_doc::h6714d469c9dfaf91
       0.07%  rustc    [.] _ZN4rbml6reader10doc_as_u6417h930b740aa94f1d3aE@plt
       0.06%  rustc    [.] _fini
  $

After:

  $ perf report --stdio --dsos librbml-e8edd0fd.so
  # dso: librbml-e8edd0fd.so
  #
  # Total Lost Samples: 0
  #
  # Samples: 1K of event 'cycles:u'
  # Event count (approx.): 979599126
  #
  # Overhead  Command  Symbol
  # ........  .......  .................................................................
  #
     1.78%  rustc    [.] rbml::reader::maybe_get_doc
     1.50%  rustc    [.] <reader::DocsIterator<'a> as std::iter::Iterator>::next
     1.20%  rustc    [.] rbml::reader::doc_at
     0.46%  rustc    [.] <reader::TaggedDocsIterator<'a> as std::iter::Iterator>::next
     0.35%  rustc    [.] rbml::reader::Decoder::_next_int
     0.29%  rustc    [.] rbml::reader::Decoder::_next_sub
     0.15%  rustc    [.] rbml::reader::get_doc
     0.14%  rustc    [.] <reader::Decoder<'doc> as serialize::Decoder>::read_u32
     0.07%  rustc    [.] rbml::reader::Decoder::next_doc
     0.07%  rustc    [.] _ZN4rbml6reader10doc_as_u6417h930b740aa94f1d3aE@plt
     0.06%  rustc    [.] _fini
  $
Signed-off-by: David Tolnay <dtolnay@gmail.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/5780B7FA.3030602@gmail.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

That is not present on some libelf implementations, such as the one used
in Alpine Linux: libelf-0.8.13.

This ends up disabling the SDT code, that relies on this function.

One alternative would be to provide an weak fallback implementation or
the open coded variant used by the buildid sysfs notes reading code.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-82lh22ybedy9b9lych8xj12g@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

That doesn't have -I to match lines.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-7nz9hnbk7a9p91ou927ye5yh@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

We've decided not to access kernel source files because changes there
could break the tooling side, this is one more step in that direction.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ar0hupkxl45h5hk09l2rprj3@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

So that we don't end up using the kernel one when building out of tree,
via a detached tarball.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 737ef7d3 ("tools include: Copy linux/stringify.h from the kernel")
Link: http://lkml.kernel.org/n/tip-t8yn1d7y0magk889ymc8jlai@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

We use it in bitops/__ffs.h and bitops/atomic.h, that we also got from
the kernel, but were getting it from either newer systems that carry it
in /usr/include, or from the kernel sources, that we decided not to
touch from tools/ code. Fix it.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-lwqvgbuitjmrdpjmjp6zqnyx@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Sounds like a compiler bug, but to silence it, initialize those
variables to NULL.

Noticed on:

Target: x86_64-alpine-linux-musl
Configured with: /home/buildozer/aports/main/gcc/src/gcc-5.3.0/configure
--prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info
--build=x86_64-alpine-linux-musl --host=x86_64-alpine-linux-musl
--target=x86_64-alpine-linux-musl --with-pkgversion='Alpine 5.3.0'
--enable-checking=release --disable-fixed-point --disable-libstdcxx-pch
--disable-multilib --disable-nls --disable-werror --disable-symvers
--enable-__cxa_atexit --enable-esp --enable-cloog-backend
--enable-languages=c,c++,objc,java,fortran,ada --disable-libssp
--disable-libmudflap --disable-libsanitizer --enable-shared
--enable-threads --enable-tls --with-system-zlib
Thread model: posix
gcc version 5.3.0 (Alpine 5.3.0)

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-zyvsjvbl45o7hzcuz78wu2xi@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

This one can be safely defined to be Elf64_Nhdr, as it is in elfutils's
libelf, but not on musl libc, as both Elf64_Nhdr and  Elf32_Nhdr have
the same layout.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-w8z8614l03lc8bip4ijbywbt@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

All we need from it is already conditionally defined, and this header
file is not present in older systems, so ditch it.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-3jxpz9gwahk4e7ltqtnr1rjg@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-6qkuhv2mrcxmpy5sasc3c9tf@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

On systems where sysconf(_SC_LEVEL1_DCACHE_LINESIZE) is not available,
such as musl LIBC and Android's bionic libc.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Chris Phlipot <cphlipot0@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-772obxzby758g7m2wmzcejxz@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Those kernel files were being directly accessed, which we're not
allowing anymore to avoid that changes in the kernel side break tooling.

Warn if these copies drift from the original files.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Eric Auger <eric.auger@linaro.org>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Yunlong Song <yunlong.song@huawei.com>
Link: http://lkml.kernel.org/n/tip-mnopguymhnwzjhw3mowllvsy@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Noticed while making a copy of these files to tools/ where those kernel
files were being directly accessed, which we're not allowing anymore to
avoid that changes in the kernel side break tooling.

Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Eric Auger <eric.auger@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-82thftcdhj2j5wt6ir4vuyhk@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ogtjqc0hxm961djgiwboe2q7@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Not used anymore, IIRC it was for useless PROC_FS_MAGIC procfs checks,
but those are long gone.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-v027did3kvj0vz7bofgzkw29@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Which is just a wrapper for sys_getcpu and is not present in at least
musl libc.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-kblef7svmhr0g93kkx78envg@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To allow the build to complete on older systems, where those files are
either not uptodate, lacking some recent additions or not present at
all.

And check if the copy drifts from the kernel.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-3jz31pz4nw526uko5da9e7o3@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The prototype for epoll_wait() is available in older distros, so use it
instead of epoll_pwait() (removing the last NULL arg, the sigmask,
makes it the same thing anyway) to avoid breaking the build.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-pwiwizloxt0jujy8em80qut3@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To allow the build to complete on older systems, where those files are
either not uptodate, lacking some recent additions or not present at
all.

And check if the copy drifts from the kernel.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-sxf7rpow2blsno5f7t6n0sqz@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To allow the build to complete on older systems, where those files are
either not uptodate, lacking some recent additions or not present at
all.

And check if the copy drifts from the kernel, as in this synthetic test:

    BUILD:   Doing 'make -j4' parallel build
  Warning: tools/include/linux/bpf.h differs from kernel
  Warning: tools/include/linux/bpf_common.h differs from kernel

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-5plvi2gq4x469dcyybiu226q@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

We can't access kernel files directly from tools/, so copy the required
bits, and make sure that we detect when the original files, in the
kernel, gets modified.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-z7e76274ch5j4nugv048qacb@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

We shouldn't use headers from the kernel sources directly, instead we
should use the system's headers or in cases where that isn't possible,
like with perf_event.h, where the introduction of kernel features such
as perf_event_attr.{write_backwards,sample_max_stack} and
PERF_EVENT_IOC_PAUSE_OUTPUT take some time to become available in
/usr/include/linux/perf_event.h we need a copy.

Do it and check for source code drift, emitting a warning when changes
are detected.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-v6aks5un3s5pehory6f42nrl@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>