Add the API function tep_load_plugins_hook() to the traceevent API to
allow tools a common method to load in the plugins that are part of the
lib traceevent library.

Link: http://lore.kernel.org/linux-trace-devel/20190802110101.14759-4-tz.stoyanov@gmail.com
Link: http://lore.kernel.org/linux-trace-devel/20200625100516.365338-4-tz.stoyanov@gmail.comSigned-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200702185703.946652691@goodmis.orgSigned-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Rather than disable all warnings with -w, disable specific warnings.

Predicate enabling the warnings on a recent version of bison.

Tested with GCC 9.3.0 and clang 9.0.1.

Committer testing:

The full set of compilers, gcc and clang that this will be tested on
will be on the signed tag when this change goes upstream.

Had to add -Wno-switch-enum to build on opensuse tumbleweed:

  /tmp/build/perf/util/parse-events-bison.c: In function 'yydestruct':
  /tmp/build/perf/util/parse-events-bison.c:1200:3: error: enumeration value 'YYSYMBOL_YYEMPTY' not handled in switch [-Werror=switch-enum]
   1200 |   switch (yykind)
        |   ^~~~~~
  /tmp/build/perf/util/parse-events-bison.c:1200:3: error: enumeration value 'YYSYMBOL_YYEOF' not handled in switch [-Werror=switch-enum]

Also replace -Wno-error=implicit-function-declaration with -Wno-implicit-function-declaration.

Also needed to check just the first two levels of the bison version, as
the patch was assuming that all versions were of the form x.y.z, and
there are several cases where it is just x.y, breaking the build.
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.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: John Garry <john.garry@huawei.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>
Link: http://lore.kernel.org/lkml/20200619043356.90024-11-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Rather than disable all warnings with -w, disable specific warnings.

Predicate enabling the warnings on more recent flex versions.

Tested with GCC 9.3.0 and clang 9.0.1.

Committer notes:

The full set of compilers, gcc and clang that this will be tested on
will be on the signed tag when this change goes upstream.

Added -Wno-misleading-indentation to the flex_flags to overcome this on
opensuse tumbleweed when building with clang:

    CC       /tmp/build/perf/util/parse-events-flex.o
    CC       /tmp/build/perf/util/pmu.o
  /tmp/build/perf/util/parse-events-flex.c:5038:13: error: misleading indentation; statement is not part of the previous 'if' [-Werror,-Wmisleading-indentation]
              if ( ! yyg->yy_state_buf )
              ^
  /tmp/build/perf/util/parse-events-flex.c:5036:9: note: previous statement is here
          if ( ! yyg->yy_state_buf )
          ^

And we need to use this to redirect stderr to stdin and then grep in a
way that is acceptable for BusyBox shell:

  2>&1 |

Previously I was using:

  |&

Which seems to be bash specific.

Added -Wno-sign-compare to overcome this on systems such as centos:7:

    CC       /tmp/build/perf/util/parse-events-flex.o
    CC       /tmp/build/perf/util/pmu.o
    CC       /tmp/build/perf/util/pmu-flex.o
  util/parse-events.l: In function 'parse_events_lex':
  /tmp/build/perf/util/parse-events-flex.c:193:36: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
                   for ( yyl = n; yyl < yyleng; ++yyl )\
                                      ^
  /tmp/build/perf/util/parse-events-flex.c:204:9: note: in expansion of macro 'YY_LESS_LINENO'

Added -Wno-unused-parameter to overcome this in systems such as
centos:7:

    CC       /tmp/build/perf/util/parse-events-flex.o
    CC       /tmp/build/perf/util/pmu.o
  /tmp/build/perf/util/parse-events-flex.c: In function 'yy_fatal_error':
  /tmp/build/perf/util/parse-events-flex.c:6265:58: error: unused parameter 'yyscanner' [-Werror=unused-parameter]
   static void yy_fatal_error (yyconst char* msg , yyscan_t yyscanner)
                                                            ^
Added -Wno-missing-declarations to build in systems such as centos:6:

  /tmp/build/perf/util/parse-events-flex.c:6313: error: no previous prototype for 'parse_events_get_column'
  /tmp/build/perf/util/parse-events-flex.c:6389: error: no previous prototype for 'parse_events_set_column'

And -Wno-missing-prototypes to cover older compilers:

  -Wmissing-prototypes (C only)
  Warn if a global function is defined without a previous prototype declaration. This warning is issued even if the definition itself provides a prototype. The aim is to detect global functions that fail to be declared in header files.
  -Wmissing-declarations (C only)
  Warn if a global function is defined without a previous declaration. Do so even if the definition itself provides a prototype. Use this option to detect global functions that are not declared in header files.

Older C compilers lack -Wno-misleading-indentation, check if it is
available before using it.

Also needed to check just the first two levels of the flex version, as
the patch was assuming that all versions were of the form x.y.z, and
there are several cases where it is just x.y, breaking the build.
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.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: John Garry <john.garry@huawei.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>
Link: http://lore.kernel.org/lkml/20200619043356.90024-8-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Declare bison header file output so that C files can depend upon them.

As there are multiple output targets $@ is replaced by the target name.
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.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: John Garry <john.garry@huawei.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>
Link: http://lore.kernel.org/lkml/20200619043356.90024-7-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

These will break the build as soon as we stop disabling all warnings
when building flex and bison generated files, so add them before we do
that to keep the tree bisectable.

Noticed when building on centos:7 with NO_LIBBPF=1:

  util/expr.c: In function 'key_equal':
  util/expr.c:29:2: error: implicit declaration of function 'strcmp' [-Werror=implicit-function-declaration]
    return !strcmp((const char *)key1, (const char *)key2);
    ^
  util/expr.c: In function 'expr__add_id':
  util/expr.c:40:3: error: implicit declaration of function 'malloc' [-Werror=implicit-function-declaration]
     val_ptr = malloc(sizeof(double));
     ^
  util/expr.c:40:13: error: incompatible implicit declaration of built-in function 'malloc' [-Werror]
     val_ptr = malloc(sizeof(double));
               ^
  util/expr.c:42:12: error: 'ENOMEM' undeclared (first use in this function)
      return -ENOMEM;
              ^
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.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: John Garry <john.garry@huawei.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>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Declare flex header file output so that bison C files can depend upon
them. As there are multiple output targets $@ is replaced by the target
name.
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.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: John Garry <john.garry@huawei.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>
Link: http://lore.kernel.org/lkml/20200619043356.90024-6-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Allow pmu parser's flex to be debugged as the parse-events and expr
currently are. Enabling this requires the C code to call
perf_pmu__flex_debug.
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.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: John Garry <john.garry@huawei.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>
Link: http://lore.kernel.org/lkml/20200619043356.90024-5-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Allow pmu parser to be debugged as the parse-events and expr currently
are.  Enabling this requires the C code to set perf_pmu_debug.
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.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: John Garry <john.garry@huawei.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>
Link: http://lore.kernel.org/lkml/20200619043356.90024-4-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

This reduces the command line size slightly.
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.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: John Garry <john.garry@huawei.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>
Link: http://lore.kernel.org/lkml/20200619043356.90024-3-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

This reduces the command line size slightly.
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.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: John Garry <john.garry@huawei.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>
Link: http://lore.kernel.org/lkml/20200619043356.90024-2-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To differentiate from libperf's 'struct perf_evlist' methods.

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>

To differentiate from libperf's 'struct perf_evlist' methods.

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>

To differentiate from libperf's 'struct perf_evlist' methods.

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>

To differentiate from libperf's 'struct perf_evlist' methods.

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>

To differentiate from libperf's 'struct perf_evlist' methods.

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>

For perf list, the CPU core PMU HW event ordering is such that not all
events may will be listed adjacent - consider this example:

  $ tools/perf/perf list

  List of pre-defined events (to be used in -e):

    duration_time                                      [Tool event]

    branch-instructions OR cpu/branch-instructions/    [Kernel PMU event]
    branch-misses OR cpu/branch-misses/                [Kernel PMU event]
    bus-cycles OR cpu/bus-cycles/                      [Kernel PMU event]
    cache-misses OR cpu/cache-misses/                  [Kernel PMU event]
    cache-references OR cpu/cache-references/          [Kernel PMU event]
    cpu-cycles OR cpu/cpu-cycles/                      [Kernel PMU event]
    cstate_core/c3-residency/                          [Kernel PMU event]
    cstate_core/c6-residency/                          [Kernel PMU event]
    cstate_core/c7-residency/                          [Kernel PMU event]
    cstate_pkg/c2-residency/                           [Kernel PMU event]
    cstate_pkg/c3-residency/                           [Kernel PMU event]
    cstate_pkg/c6-residency/                           [Kernel PMU event]
    cstate_pkg/c7-residency/                           [Kernel PMU event]
    cycles-ct OR cpu/cycles-ct/                        [Kernel PMU event]
    cycles-t OR cpu/cycles-t/                          [Kernel PMU event]
    el-abort OR cpu/el-abort/                          [Kernel PMU event]
    el-capacity OR cpu/el-capacity/                    [Kernel PMU event]

Notice in the above example how the cstate_core PMU events are mixed in
the middle of the CPU core events.

For my arm64 platform, all the uncore events get mixed in, making the list
very disorganised:

    page-faults OR faults                              [Software event]
    task-clock                                         [Software event]
    duration_time                                      [Tool event]
    L1-dcache-load-misses                              [Hardware cache event]
    L1-dcache-loads                                    [Hardware cache event]
    L1-icache-load-misses                              [Hardware cache event]
    L1-icache-loads                                    [Hardware cache event]
    branch-load-misses                                 [Hardware cache event]
    branch-loads                                       [Hardware cache event]
    dTLB-load-misses                                   [Hardware cache event]
    dTLB-loads                                         [Hardware cache event]
    iTLB-load-misses                                   [Hardware cache event]
    iTLB-loads                                         [Hardware cache event]
    br_mis_pred OR armv8_pmuv3_0/br_mis_pred/          [Kernel PMU event]
    br_mis_pred_retired OR armv8_pmuv3_0/br_mis_pred_retired/ [Kernel PMU event]
    br_pred OR armv8_pmuv3_0/br_pred/                  [Kernel PMU event]
    br_retired OR armv8_pmuv3_0/br_retired/            [Kernel PMU event]
    br_return_retired OR armv8_pmuv3_0/br_return_retired/ [Kernel PMU event]
    bus_access OR armv8_pmuv3_0/bus_access/            [Kernel PMU event]
    bus_cycles OR armv8_pmuv3_0/bus_cycles/            [Kernel PMU event]
    cid_write_retired OR armv8_pmuv3_0/cid_write_retired/ [Kernel PMU event]
    cpu_cycles OR armv8_pmuv3_0/cpu_cycles/            [Kernel PMU event]
    dtlb_walk OR armv8_pmuv3_0/dtlb_walk/              [Kernel PMU event]
    exc_return OR armv8_pmuv3_0/exc_return/            [Kernel PMU event]
    exc_taken OR armv8_pmuv3_0/exc_taken/              [Kernel PMU event]
    hisi_sccl1_ddrc0/act_cmd/                          [Kernel PMU event]
    hisi_sccl1_ddrc0/flux_rcmd/                        [Kernel PMU event]
    hisi_sccl1_ddrc0/flux_rd/                          [Kernel PMU event]
    hisi_sccl1_ddrc0/flux_wcmd/                        [Kernel PMU event]
    hisi_sccl1_ddrc0/flux_wr/                          [Kernel PMU event]
    hisi_sccl1_ddrc0/pre_cmd/                          [Kernel PMU event]
    hisi_sccl1_ddrc0/rnk_chg/                          [Kernel PMU event]

...

    hisi_sccl7_l3c21/wr_hit_cpipe/                     [Kernel PMU event]
    hisi_sccl7_l3c21/wr_hit_spipe/                     [Kernel PMU event]
    hisi_sccl7_l3c21/wr_spipe/                         [Kernel PMU event]
    inst_retired OR armv8_pmuv3_0/inst_retired/        [Kernel PMU event]
    inst_spec OR armv8_pmuv3_0/inst_spec/              [Kernel PMU event]
    itlb_walk OR armv8_pmuv3_0/itlb_walk/              [Kernel PMU event]
    l1d_cache OR armv8_pmuv3_0/l1d_cache/              [Kernel PMU event]
    l1d_cache_refill OR armv8_pmuv3_0/l1d_cache_refill/ [Kernel PMU event]
    l1d_cache_wb OR armv8_pmuv3_0/l1d_cache_wb/        [Kernel PMU event]
    l1d_tlb OR armv8_pmuv3_0/l1d_tlb/                  [Kernel PMU event]
    l1d_tlb_refill OR armv8_pmuv3_0/l1d_tlb_refill/    [Kernel PMU event]

So the events are list alphabetically. However, CPU core event listing is
special from commit dc098b35 ("perf list: List kernel supplied event
aliases"), in that the alias and full event is shown (in that order).
As such, the core events may become sparse.

Improve this by grouping the CPU core events and ensure that they are
listed first for kernel PMU events. For the first example, above, this
now looks like:

    duration_time                                      [Tool event]
    branch-instructions OR cpu/branch-instructions/    [Kernel PMU event]
    branch-misses OR cpu/branch-misses/                [Kernel PMU event]
    bus-cycles OR cpu/bus-cycles/                      [Kernel PMU event]
    cache-misses OR cpu/cache-misses/                  [Kernel PMU event]
    cache-references OR cpu/cache-references/          [Kernel PMU event]
    cpu-cycles OR cpu/cpu-cycles/                      [Kernel PMU event]
    cycles-ct OR cpu/cycles-ct/                        [Kernel PMU event]
    cycles-t OR cpu/cycles-t/                          [Kernel PMU event]
    el-abort OR cpu/el-abort/                          [Kernel PMU event]
    el-capacity OR cpu/el-capacity/                    [Kernel PMU event]
    el-commit OR cpu/el-commit/                        [Kernel PMU event]
    el-conflict OR cpu/el-conflict/                    [Kernel PMU event]
    el-start OR cpu/el-start/                          [Kernel PMU event]
    instructions OR cpu/instructions/                  [Kernel PMU event]
    mem-loads OR cpu/mem-loads/                        [Kernel PMU event]
    mem-stores OR cpu/mem-stores/                      [Kernel PMU event]
    ref-cycles OR cpu/ref-cycles/                      [Kernel PMU event]
    topdown-fetch-bubbles OR cpu/topdown-fetch-bubbles/ [Kernel PMU event]
    topdown-recovery-bubbles OR cpu/topdown-recovery-bubbles/ [Kernel PMU event]
    topdown-slots-issued OR cpu/topdown-slots-issued/  [Kernel PMU event]
    topdown-slots-retired OR cpu/topdown-slots-retired/ [Kernel PMU event]
    topdown-total-slots OR cpu/topdown-total-slots/    [Kernel PMU event]
    tx-abort OR cpu/tx-abort/                          [Kernel PMU event]
    tx-capacity OR cpu/tx-capacity/                    [Kernel PMU event]
    tx-commit OR cpu/tx-commit/                        [Kernel PMU event]
    tx-conflict OR cpu/tx-conflict/                    [Kernel PMU event]
    tx-start OR cpu/tx-start/                          [Kernel PMU event]
    cstate_core/c3-residency/                          [Kernel PMU event]
    cstate_core/c6-residency/                          [Kernel PMU event]
    cstate_core/c7-residency/                          [Kernel PMU event]
    cstate_pkg/c2-residency/                           [Kernel PMU event]
    cstate_pkg/c3-residency/                           [Kernel PMU event]
    cstate_pkg/c6-residency/                           [Kernel PMU event]
    cstate_pkg/c7-residency/                           [Kernel PMU event]
Signed-off-by: John Garry <john.garry@huawei.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: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxarm@huawei.com
Link: http://lore.kernel.org/lkml/1592384514-119954-3-git-send-email-john.garry@huawei.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

In commit dc098b35 ("perf list: List kernel supplied event aliases"),
the aliases for events are supplied in addition to CPU event in perf list.

This relies on the name of the core PMU being "cpu", which is not the case
for arm64, so arm64 has always missed this. Use generic is_pmu_core()
helper which takes account of arm64 to make this feature work for arm64
(and possibly other archs).

Sample, before:

  armv8_pmuv3_0/br_mis_pred/          [Kernel PMU event]

after:

  br_mis_pred OR armv8_pmuv3_0/br_mis_pred/          [Kernel PMU event]
Signed-off-by: John Garry <john.garry@huawei.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxarm@huawei.com
Link: http://lore.kernel.org/lkml/1592384514-119954-2-git-send-email-john.garry@huawei.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Adjust the handling of the session sink selection to allow no sink to be
selected on the command line. This then forwards the sink selection to
the CoreSight infrastructure which will attempt to select a sink based
on the default sink select priorities.
Signed-off-by: Mike Leach <mike.leach@linaro.org>
Tested-by: Leo Yan <leo.yan@linaro.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

These are broadly useful but required to handle TMA metrics. For example
encoding Ports_Utilization from:

  https://download.01.org/perfmon/TMA_Metrics.csv

requires '<'.

  {
    "BriefDescription": "This metric estimates fraction of cycles the CPU performance was potentially limited due to Core computation issues (non divider-related).  Two distinct categories can be attributed into this metric: (1) heavy data-dependency among contiguous instructions would manifest in this metric - such cases are often referred to as low Instruction Level Parallelism (ILP). (2) Contention on some hardware execution unit other than Divider. For example; when there are too many multiply operations.",
    "MetricExpr": "( ( cpu@EXE_ACTIVITY.EXE_BOUND_0_PORTS@ + cpu@EXE_ACTIVITY.1_PORTS_UTIL@ + ( cpu@EXE_ACTIVITY.2_PORTS_UTIL@ * ( ( ( cpu@UOPS_RETIRED.RETIRE_SLOTS@ ) / ( cpu@CPU_CLK_UNHALTED.THREAD@ ) ) / ( ( 4.000000 ) + 1.000000 ) ) ) ) / ( cpu@CPU_CLK_UNHALTED.THREAD@ ) if ( cpu@ARITH.DIVIDER_ACTIVE\\,cmask\\=1@ < cpu@EXE_ACTIVITY.EXE_BOUND_0_PORTS@ ) else ( ( cpu@EXE_ACTIVITY.EXE_BOUND_0_PORTS@ + cpu@EXE_ACTIVITY.1_PORTS_UTIL@ + ( cpu@EXE_ACTIVITY.2_PORTS_UTIL@ * ( ( ( cpu@UOPS_RETIRED.RETIRE_SLOTS@ ) / ( cpu@CPU_CLK_UNHALTED.THREAD@ ) ) / ( ( 4.000000 ) + 1.000000 ) ) ) ) - cpu@EXE_ACTIVITY.EXE_BOUND_0_PORTS@ ) / ( cpu@CPU_CLK_UNHALTED.THREAD@ ) )",
    "MetricGroup": "Topdown_Group_Ports_Utilization",
    "MetricName": "Topdown_Metric_Ports_Utilization"
  },
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Jiri Olsa <jolsa@redhat.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: John Garry <john.garry@huawei.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200610235823.52557-2-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

d_ratio avoids division by 0 yielding infinity, such as when a counter
doesn't get scheduled. An example usage is:

  {
      "BriefDescription": "DCache L1 misses",
      "MetricExpr": "d_ratio(MEM_LOAD_RETIRED.L1_MISS, MEM_LOAD_RETIRED.L1_HIT + MEM_LOAD_RETIRED.L1_MISS + MEM_LOAD_RETIRED.FB_HIT)",
      "MetricGroup": "DCache;DCache_L1",
      "MetricName": "DCache_L1_Miss",
      "ScaleUnit": "100%",
  }
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Jiri Olsa <jolsa@redhat.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: John Garry <john.garry@huawei.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200610235823.52557-1-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Fixups related to the introduction of libperf, where the
perf_{evsel,evlist}__ prefix is reserved for functions operating on
struct perf_{evsel,evlist}.

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>

Adding new metric test for frontend metric. It's stolen from x86 pmu
events.

Committer testing:

  # perf test "Parse and process metrics"
  67: Parse and process metrics                             : Ok
  # perf test -v "Parse and process metrics"
  #
  67: Parse and process metrics                             :
  --- start ---
  test child forked, pid 104881
  metric expr inst_retired.any / cpu_clk_unhalted.thread for IPC
  found event inst_retired.any
  found event cpu_clk_unhalted.thread
  adding {inst_retired.any,cpu_clk_unhalted.thread}:W
  metric expr idq_uops_not_delivered.core / (4 * (( ( cpu_clk_unhalted.thread / 2 ) * ( 1 + cpu_clk_unhalted.one_thread_active / cpu_clk_unhalted.ref_xclk ) ))) for Frontend_Bound_SMT
  found event cpu_clk_unhalted.one_thread_active
  found event cpu_clk_unhalted.ref_xclk
  found event idq_uops_not_delivered.core
  found event cpu_clk_unhalted.thread
  adding {cpu_clk_unhalted.one_thread_active,cpu_clk_unhalted.ref_xclk,idq_uops_not_delivered.core,cpu_clk_unhalted.thread}:W
  test child finished with 0
  ---- end ----
  Parse and process metrics: Ok
  #

Had to fix it to initialize that 'struct value' array sentinel with a
named initializer to fix the build with some versions of clang:

  tests/parse-metric.c:154:7: error: missing field 'val' initializer [-Werror,-Wmissing-field-initializers]
                { 0 },
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200602214741.1218986-14-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Adding new test that process metrics code and checks the expected
results. Starting with easy ipc metric.

Committer testing:

  # perf test "Parse and process metrics"
  67: Parse and process metrics                             : Ok
  #
  # perf test -v "Parse and process metrics"
  67: Parse and process metrics                             :
  --- start ---
  test child forked, pid 103402
  metric expr inst_retired.any / cpu_clk_unhalted.thread for IPC
  found event inst_retired.any
  found event cpu_clk_unhalted.thread
  adding {inst_retired.any,cpu_clk_unhalted.thread}:W
  test child finished with 0
  ---- end ----
  Parse and process metrics: Ok
  #

Had to fix it to initialize that 'struct value' array sentinel with a
named initializer to fix the build with some versions of clang:

  tests/parse-metric.c:135:7: error: missing field 'val' initializer [-Werror,-Wmissing-field-initializers]
                { 0 },
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200602214741.1218986-13-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Adding test_generic_metric that prepares and runs given metric over the
data from struct runtime_stat object.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200602214741.1218986-12-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

We don't release metric_events rblist, add the missing delete hook and
call the release before leaving cmd_stat.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200602214741.1218986-11-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Factoring out prepare_metric function so it can be used in test
interface coming in following changes.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200602214741.1218986-10-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Add the metricgroup__parse_groups_test function. It will be used as
test's interface to metric parsing in following changes.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200602214741.1218986-9-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

For testing purposes we need to pass our own map of events from
parse_groups() through metricgroup__add_metric.
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200602214741.1218986-8-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Allow to pass fake_pmu in parse_groups function so it can be used in
parse_events call.

It's will be passed by the upcoming metricgroup__parse_groups_test
function.

Committer notes:

Made it a 'struct perf_pmu' pointer, in line with the changes at the
start of this patchkit to avoid statics deep down in library code.
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200602214741.1218986-6-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Factor out the parse_groups function, it will be used for new test
interface coming in following changes.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200602214741.1218986-6-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The test goes through all metrics compiled for arch within pmu events
and try to parse them.

This test is different from 'test_parsing' in that we go through all the
events in the current arch, not just one defined for current CPU model.
Using 'fake_pmu' to parse events which do not have PMUs defined in the
system.

Say there's bad change in ivybridge metrics file, like:

  - a/tools/perf/pmu-events/arch/x86/ivybridge/ivb-metrics.json
  + b/tools/perf/pmu-events/arch/x86/ivybridge/ivb-metrics.json
  @@ -8,7 +8,7 @@
  -        "MetricExpr": "IDQ_UOPS_NOT_DELIVERED.CORE / (4 * ((
  +        "MetricExpr": "IDQ_UOPS_NOT_DELIVERED.CORE / / (4 *

the test fails with (on my kabylake laptop):

  $ perf test 'Parsing of PMU event table metrics with fake PMUs' -v
  parsing 'idq_uops_not_delivered.core / / (4 * (( ( cpu_clk_unh...
  syntax error, line 1
  expr__parse failed
  test child finished with -1
  ...

The test also defines its own list of metrics and tries to parse them.
It's handy for developing.

Committer notes:

Testing it:

  $ perf test fake
  10: PMU events                                            :
  10.4: Parsing of PMU event table metrics with fake PMUs   : FAILED!
  $ perf test -v fake |& tail
  parsing '(unc_p_freq_trans_cycles / unc_p_clockticks) * 100.'
  parsing '(unc_m_power_channel_ppd / unc_m_clockticks) * 100.'
  parsing '(unc_m_power_critical_throttle_cycles / unc_m_clockticks) * 100.'
  parsing '(unc_m_power_self_refresh / unc_m_clockticks) * 100.'
  parsing 'idq_uops_not_delivered.core / * (4 * cycles)'
  syntax error
  expr__parse failed
  test child finished with -1
  ---- end ----
  PMU events subtest 4: FAILED!
  $

And fix this error:

  tests/pmu-events.c:437:40: error: missing field 'idx' initializer [-Werror,-Wmissing-field-initializers]
        struct parse_events_error error = { 0 };
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200602214741.1218986-5-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

When wanting to use the support in __parse_events() for fake pmus, just
pass it.

Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

This is an alternative patch to what Jiri sent that instead of changing
all callers to parse_events() for allowing to pass a fake_pmu, provide
another function specifically for that.

From Jiri's patch:

This way it's possible to parse events from PMUs which are not present
in the system. It's available only for testing purposes coming in
following changes, so all the current users set fake_pmu argument as
false.
Based-on-a-patch-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lore.kernel.org/lkml/20200602214741.1218986-3-jolsa@kernel.orgAcked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Separating the generic part of check_parse_id function,
so it can be used in following changes for the new test.

Committer notes:

Fix this error:

  tests/pmu-events.c:413:40: error: missing field 'idx' initializer [-Werror,-Wmissing-field-initializers]
        struct parse_events_error error = { 0 };
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200602214741.1218986-4-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Add a way to create a pmu event without the actual PMU being in place.

This way we can test metrics defined for any processor.

The interface is to define fake_pmu in struct parse_events_state data.
It will be used only in tests via special interface function added in
following changes.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200602214741.1218986-2-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The '>' expression itself is bool, no need to convert it to bool again.
This fixes the following coccicheck warning:

  tools/perf/ui/browsers/annotate.c:212:30-35: WARNING: conversion to bool
  not needed here
Signed-off-by: Jason Yan <yanaijie@huawei.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>
Link: http://lore.kernel.org/lkml/20200420123528.11655-1-yanaijie@huawei.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

On some platforms the default encoding is not utf-8, which causes an
UnicodeDecodeError when reading the flamegraph template and writing the
flamegraph
Signed-off-by: Andreas Gerstmayr <agerstmayr@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20200619153232.203537-1-agerstmayr@redhat.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

This reverts commit 8ece3b3e.

This commit broke userspace. Bash uses ESPIPE to determine whether or
not the file should be read using "unbuffered I/O", which means reading
1 byte at a time instead of 128 bytes at a time. I used to use bash to
read through kmsg in a really quite nasty way:

    while read -t 0.1 -r line 2>/dev/null || [[ $? -ne 142 ]]; do
       echo "SARU $line"
    done < /dev/kmsg

This will show all lines that can fit into the 128 byte buffer, and skip
lines that don't. That's pretty awful, but at least it worked.

With this change, bash now tries to do 1-byte reads, which means it
skips all the lines, which is worse than before.

Now, I don't really care very much about this, and I'm already look for
a workaround. But I did just spend an hour trying to figure out why my
scripts were broken. Either way, it makes no difference to me personally
whether this is reverted, but it might be something to consider. If you
declare that "trying to read /dev/kmsg with bash is terminally stupid
anyway," I might be inclined to agree with you. But do note that bash
uses lseek(fd, 0, SEEK_CUR)==>ESPIPE to determine whether or not it's
reading from a pipe.

Cc: Bruno Meneguele <bmeneg@redhat.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull SELinux fixes from Paul Moore:
 "Three small patches to fix problems in the SELinux code, all found via
  clang.

  Two patches fix potential double-free conditions and one fixes an
  undefined return value"

* tag 'selinux-pr-20200621' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: fix undefined return of cond_evaluate_expr
  selinux: fix a double free in cond_read_node()/cond_read_list()
  selinux: fix double free