u32 is not defined for libbpf when compiled outside of kernel sources (e.g.,
in Github projection). Use __u32 instead.

Fixes: b8c54ea4

 ("libbpf: Add support to attach to fentry/fexit tracing progs")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191125212948.1163343-1-andriin@fb.com

For BPF_PROG_TYPE_TRACING, the bpf_prog's ctx is an array of u64.
This patch borrows the idea from BPF_CALL_x in filter.h to
convert a u64 to the arg type of the traced function.

The new BPF_TRACE_x has an arg to specify the return type of a bpf_prog.
It will be used in the future TCP-ops bpf_prog that may return "void".

The new macros are defined in the new header file "bpf_trace_helpers.h".
It is under selftests/bpf/ for now.  It could be moved to libbpf later
after seeing more upcoming non-tracing use cases.

The tests are changed to use these new macros also.  Hence,
the k[s]u8/16/32/64 are no longer needed and they are removed
from the bpf_helpers.h.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191123202504.1502696-1-kafai@fb.com

Add several BPF kselftest cases for tail calls which test the various
patch directions, and that multiple locations are patched in same and
different programs.

  # ./test_progs -n 45
   #45/1 tailcall_1:OK
   #45/2 tailcall_2:OK
   #45/3 tailcall_3:OK
   #45/4 tailcall_4:OK
   #45/5 tailcall_5:OK
   #45 tailcalls:OK
  Summary: 1/5 PASSED, 0 SKIPPED, 0 FAILED

I've also verified the JITed dump after each of the rewrite cases that
it matches expectations.

Also regular test_verifier suite passes fine which contains further tail
call tests:

  # ./test_verifier
  [...]
  Summary: 1563 PASSED, 0 SKIPPED, 0 FAILED

Checked under JIT, interpreter and JIT + hardening.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/3d6cbecbeb171117dccfe153306e479798fb608d.1574452833.git.daniel@iogearbox.net

Add a test that benchmarks different ways of attaching BPF program to a kernel function.
Here are the results for 2.4Ghz x86 cpu on a kernel without mitigations:
$ ./test_progs -n 49 -v|grep events
task_rename base	2743K events per sec
task_rename kprobe	2419K events per sec
task_rename kretprobe	1876K events per sec
task_rename raw_tp	2578K events per sec
task_rename fentry	2710K events per sec
task_rename fexit	2685K events per sec

On a kernel with retpoline:
$ ./test_progs -n 49 -v|grep events
task_rename base	2401K events per sec
task_rename kprobe	1930K events per sec
task_rename kretprobe	1485K events per sec
task_rename raw_tp	2053K events per sec
task_rename fentry	2351K events per sec
task_rename fexit	2185K events per sec

All 5 approaches:
- kprobe/kretprobe in __set_task_comm()
- raw tracepoint in trace_task_rename()
- fentry/fexit in __set_task_comm()
are roughly equivalent.

__set_task_comm() by itself is quite fast, so any extra instructions add up.
Until BPF trampoline was introduced the fastest mechanism was raw tracepoint.
kprobe via ftrace was second best. kretprobe is slow due to trap. New
fentry/fexit methods via BPF trampoline are clearly the fastest and the
difference is more pronounced with retpoline on, since BPF trampoline doesn't
use indirect jumps.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20191122011515.255371-1-ast@kernel.org

test_core_reloc_kernel.c selftest is the only CO-RE test that reads and
returns for validation calling thread's information (pid, tgid, comm). Thus it
has to make sure that only test_prog's invocations are honored.

Fixes: df36e621

 ("selftests/bpf: add CO-RE relocs testing setup")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20191121175900.3486133-1-andriin@fb.com

Three test cases are added.
Test 1: jmp32 'reg op imm'.
Test 2: jmp32 'reg op reg' where dst 'reg' has unknown constant
        and src 'reg' has known constant
Test 3: jmp32 'reg op reg' where dst 'reg' has known constant
        and src 'reg' has unknown constant

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191121170651.449096-1-yhs@fb.com

If bpf_object__open_file() gets path like "some/dir/obj.o", it should derive
BPF object's name as "obj" (unless overriden through opts->object_name).
Instead, due to using `path` as a fallback value for opts->obj_name, path is
used as is for object name, so for above example BPF object's name will be
verbatim "some/dir/obj", which leads to all sorts of troubles, especially when
internal maps are concern (they are using up to 8 characters of object name).
Fix that by ensuring object_name stays NULL, unless overriden.

Fixes: 291ee02b

 ("libbpf: Refactor bpf_object__open APIs to use common opts")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191122003527.551556-1-andriin@fb.com

Add exra level of verboseness, activated by -vvv argument. When -vv is
specified, verbose libbpf and verifier log (level 1) is output, even for
successful tests. With -vvv, verifier log goes to level 2.

This is extremely useful to debug verifier failures, as well as just see the
state and flow of verification. Before this, you'd have to go and modify
load_program()'s source code inside libbpf to specify extra log_level flags,
which is suboptimal to say the least.

Currently -vv and -vvv triggering verifier output is integrated into
test_stub's bpf_prog_load as well as bpf_verif_scale.c tests.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191120003548.4159797-1-andriin@fb.com

Initialized global variables are no different in ELF from static variables,
and don't require any extra support from libbpf. But they are matching
semantics of global data (backed by BPF maps) more closely, preventing
LLVM/Clang from aggressively inlining constant values and not requiring
volatile incantations to prevent those. This patch enables global variables.
It still disables uninitialized variables, which will be put into special COM
(common) ELF section, because BPF doesn't allow uninitialized data to be
accessed.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191121070743.1309473-5-andriin@fb.com

If selftests are copied over to another machine/location
for execution the build test of bpftool will obviously
not work, since the sources are not copied.
Skip it if we can't find bpftool's Makefile.

Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191119105010.19189-3-quentin.monnet@netronome.com

Fix a bunch of warnings and errors reported by checkpatch.pl, to make it
easier to spot new problems.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191121070743.1309473-4-andriin@fb.com

The trap on EXIT is used to clean up any temporary directory left by the
build attempts. It is not needed when the user simply calls the script
with its --help option, and may not be needed either if we add checks
(e.g. on the availability of bpftool files) before the build attempts.

Let's move this trap and related variables lower down in the code, so
that we don't accidentally change the value returned from the script
on early exits at pre-checks.

Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Link: https://lore.kernel.org/bpf/20191119105010.19189-2-quentin.monnet@netronome.com

Relocation handling code is convoluted and unnecessarily deeply nested. Split
out per-relocation logic into separate function. Also refactor the logic to be
more a sequence of per-relocation type checks and processing steps, making it
simpler to follow control flow. This makes it easier to further extends it to
new kinds of relocations (e.g., support for extern variables).

This patch also makes relocation's section verification more robust.
Previously relocations against not yet supported externs were silently ignored
because of obj->efile.text_shndx was zero, when all BPF programs had custom
section names and there was no .text section. Also, invalid LDIMM64 relocations
against non-map sections were passed through, if they were pointing to a .text
section (or 0, which is invalid section). All these bugs are fixed within this
refactoring and checks are made more appropriate for each type of relocation.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191121070743.1309473-3-andriin@fb.com

Building selftests with 'make TARGETS=bpf kselftest' was fixed in commit
55d554f5 ("tools: bpf: Use !building_out_of_srctree to determine
srctree"). However, by updating $(srctree) in tools/bpf/Makefile for
in-tree builds only, we leave out the case where we pass an output
directory to build BPF tools, but $(srctree) is not set. This
typically happens for:

    $ make -s tools/bpf O=/tmp/foo
    Makefile:40: /tools/build/Makefile.feature: No such file or directory

Fix it by updating $(srctree) in the Makefile not only for out-of-tree
builds, but also if $(srctree) is empty.

Detected with test_bpftool_build.sh.

Fixes: 55d554f5

 ("tools: bpf: Use !building_out_of_srctree to determine srctree")
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Link: https://lore.kernel.org/bpf/20191119105626.21453-1-quentin.monnet@netronome.com

Add -mattr=dwarfris attribute to llc to avoid having relocations against DWARF
data. These relocations make it impossible to inspect DWARF contents: all
strings are invalid.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191121070743.1309473-2-andriin@fb.com

When building bpftool, a warning was introduced by commit a9436460


("bpftool: Allow to read btf as raw data"), because the return value
from a call to 'read()' is ignored. Let's address it.

Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191119111706.22440-1-quentin.monnet@netronome.com

An error may be in place when tracepoint_error is called, use
parse_events__handle_error to avoid a memory leak and to capture the
first and last error. Error detected by LLVM's libFuzzer using the
following event:

$ perf stat -e 'msr/event/,f:e'
event syntax error: 'msr/event/,f:e'
                     \___ can't access trace events

Error:  No permissions to read /sys/kernel/debug/tracing/events/f/e
Hint:   Try 'sudo mount -o remount,mode=755 /sys/kernel/debug/tracing/'

Initial error:
event syntax error: 'msr/event/,f:e'
                                \___ no value assigned for term
Run 'perf list' for a list of valid events

 Usage: perf stat [<options>] [<command>]

    -e, --event <event>   event selector. use 'perf list' to list available events

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@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: Stephane Eranian <eranian@google.com>
Cc: clang-built-linux@googlegroups.com
Link: http://lore.kernel.org/lkml/20191120180925.21787-1-irogers@google.com


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

There is a spelling mistake in a pr_warning message. Fix it.

Signed-off-by: Colin King <colin.king@canonical.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
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: kernel-janitors@vger.kernel.org
Link: http://lore.kernel.org/lkml/20191121092623.374896-1-colin.king@canonical.com


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

It is necessary to free the memory that we have allocated when error occurs.

Fixes: ef3072cd

 ("tools lib traceevent: Get rid of die in add_filter_type()")
Signed-off-by: Hewenliang <hewenliang4@huawei.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Tzvetomir Stoyanov <tstoyanov@vmware.com>
Link: http://lore.kernel.org/lkml/20191119014415.57210-1-hewenliang4@huawei.com


Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

When we passed some location in DESTDIR, install_headers called
do_install with DESTDIR as part of the second argument.

But do_install is again using '$(DESTDIR_SQ)$2', so as a result the
headers were installed in a location $DESTDIR/$DESTDIR.

In my testing I passed DESTDIR=/home/sudip/test and the headers were
installed in: /home/sudip/test/home/sudip/test/usr/include/traceevent.

Lets remove DESTDIR from the second argument of do_install so that the
headers are installed in the correct location.

Signed-off-by: Sudipm Mukherjee <sudipm.mukherjee@gmail.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Sudipm Mukherjee <sudipm.mukherjee@gmail.com>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20191114133719.309-1-sudipm.mukherjee@gmail.com


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

Add an error message because Intel BTS does not support AUX area
sampling.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20191115124225.5247-16-adrian.hunter@intel.com


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

Add support for dumping, queuing and decoding AUX area samples. Decoding
samples is the same as regular decoding, except in the case where there
are no timestamps, in which case buffers are decoded immediately before
the sample event.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20191115124225.5247-15-adrian.hunter@intel.com


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

Set up the default number of mmap pages, default sample size and default
psb_period for AUX area sampling. Add documentation also.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20191115124225.5247-14-adrian.hunter@intel.com


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

Default config for a PMU is defined before selected events are parsed.
That allows the user-entered config to override the default config.

However that does not allow for changing the default config based on
other options.

For example, if the user chooses AUX area sampling mode, in the case of
Intel PT, the psb_period needs to be small for sampling, so there is a
need to set the default psb_period to 0 (2 KiB) in that case. However
that should not override a value set by the user. To allow for that,
when using default config, record which bits of config were changed by
the user.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20191115124225.5247-13-adrian.hunter@intel.com


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

Add functions to queue AUX area samples in advance
(auxtrace_queue_data()) or individually (auxtrace_queues__add_sample())
or find out what queue a sample belongs on
(auxtrace_queues__sample_queue()).

auxtrace_queue_data() can also queue snapshot data which keeps snapshots
and samples ordered with respect to each other in case support for that
is desired.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20191115124225.5247-12-adrian.hunter@intel.com


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

AUX area samples are not limited in how far back in time the sample
could start. Consequently samples must be queued in advance to allow for
time-ordered processing. To achieve that, add
perf_session__peek_events() that walks and peeks at all the events.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20191115124225.5247-11-adrian.hunter@intel.com


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

Add support for dumping AUX area samples i.e. via the perf script/report
 -D (--dump-raw-trace) option.

Committer notes:

Add __maybe_unused to the two args for auxtrace__dump_auxtrace_sample()
for when we don't HAVE_AUXTRACE_SUPPORT.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20191115124225.5247-10-adrian.hunter@intel.com


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

After decoding AUX area samples, the AUX area data is no longer needed
(having been replaced by synthesized events) so cut it out.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20191115124225.5247-9-adrian.hunter@intel.com


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

To allow individual events to be selected for AUX area sampling, add
aux-sample-size config term. attr.aux_sample_size is updated by
auxtrace_parse_sample_options() so that the existing validation will see
the value. Any event that has a non-zero aux_sample_size will cause AUX
area sampling to be configured, irrespective of the --aux-sample option.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20191115124225.5247-8-adrian.hunter@intel.com


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

Add a 'perf record' option '--aux-sample' to request AUX area sampling.
AUX area sampling uses an overwriting buffer much like snapshot mode, so
adjust the AUX buffer mmapping accordingly. To make it easy to queue
samples for decoding, synthesize an ID index.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20191115124225.5247-7-adrian.hunter@intel.com


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

Add support for parsing and validating AUX area sample options. At
present, the only option is the sample size, but it is also necessary to
ensure that events are in a group with an AUX area event as the leader.

Committer note:

Add missing 'static inline' in front of auxtrace_parse_sample_options()
for when we don't HAVE_AUXTRACE_SUPPORT.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20191115124225.5247-6-adrian.hunter@intel.com


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

Move perf_evsel__find_pmu() so it can be used without forward
declaration.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20191115124225.5247-5-adrian.hunter@intel.com


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

Architectures are expected to know if AUX area sampling is supported by
the hardware. Add a function perf_can_aux_sample() which will determine
whether the kernel supports it.

Committer notes:

I reported that this message was taking place on a kernel without the
required bits:

  # perf record --aux-sample -e '{intel_pt//u,branch-misses:u}'
  Error:
  The sys_perf_event_open() syscall returned with 7 (Argument list too long) for event (branch-misses:u).
  /bin/dmesg | grep -i perf may provide additional information.

Adrian sent a patch addressing it, with this explanation:

 ----
  perf_can_aux_sample_size() always returned true because it did not pass
  the attribute size to sys_perf_event_open, nor correctly check the
  return value and errno.
 ----

After applying it I get, later in the series, when --aux-sample is
added:

  # perf record --aux-sample -e '{intel_pt//u,branch-misses:u}'
  AUX area sampling is not supported by kernel

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20191115124225.5247-4-adrian.hunter@intel.com


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

This is a userspace tool to drive the testing. Currently it supports
introducing user specified delay in the host to guest communication
path on a per-channel basis.

Signed-off-by: Branden Bonaby <brandonbonaby94@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

If the kernel accidentally uses DS or ES while the user values are
loaded, it will work fine for sane userspace.  In the interest of
simulating maximally insane userspace, make sigreturn_32 zero out DS
and ES for the nasty parts so that inadvertent use of these segments
will crash.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@kernel.org

For reasons that I haven't quite fully diagnosed, running
mov_ss_trap_32 on a 32-bit kernel results in an infinite loop in
userspace.  This appears to be because the hacky SYSENTER test
doesn't segfault as desired; instead it corrupts the program state
such that it infinite loops.

Fix it by explicitly clearing EBP before doing SYSENTER.  This will
give a more reliable segfault.

Fixes: 59c2a722

 ("x86/selftests: Add mov_to_ss test")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@kernel.org

Add kernel AUX area sampling definitions, which brings perf_event.h into
line with the kernel version.

New sample type PERF_SAMPLE_AUX requests a sample of the AUX area
buffer.  New perf_event_attr member 'aux_sample_size' specifies the
desired size of the sample.

Also add support for parsing samples containing AUX area data i.e.
PERF_SAMPLE_AUX.

Committer notes:

I squashed the first two patches in this series to avoid breaking
automatic bisection, i.e. after applying only the original first patch
in this series we would have:

  # perf test -v parsing
  26: Sample parsing                                        :
  --- start ---
  test child forked, pid 17018
  sample format has changed, some new PERF_SAMPLE_ bit was introduced - test needs updating
  test child finished with -1
  ---- end ----
  Sample parsing: FAILED!
  #

With the two paches combined:

  # perf test parsing
  26: Sample parsing                                        : Ok
  #

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20191115124225.5247-3-adrian.hunter@intel.com


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

When only base config level is present, this tool is displaying TRL
(Turbo-ratio-limits) by reading legacy MSR. In this case, also present
core count for TRL by reading MSR 0x1AE.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

It is possible that certain config levels are not available, even
if the max level includes the level. There can be missing levels in
some platforms. So ignore the level when called for information dump
for all levels and fail if specifically ask for the missing level.

Here the changes is to continue reading information about other levels
even if we fail to get information for the current level. But use the
"processed" flag to indicate the failure. When the "processed" flag is
not set, don't dump information about that level.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

The spectre_v2 test must be built 64-bit, it includes hand-written asm
that is 64-bit only, and segfaults if built 32-bit.

Fixes: c790c3d2

 ("selftests/powerpc: Add a test of spectre_v2 mitigations")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191120023924.13130-1-mpe@ellerman.id.au