In places where the equivalent was already being done, i.e.:

   free(a);
   a = NULL;

And in placs where struct members are being freed so that if we have
some erroneous reference to its struct, then accesses to freed members
will result in segfaults, which we can detect faster than use after free
to areas that may still have something seemingly valid.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-jatyoofo5boc1bsvoig6bb6i@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Eroding a bit more the tools/perf/util/util.h hodpodge header.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-natazosyn9rwjka25tvcnyi0@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

And in a separate header, so that we erode util.h a bit more.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-xpzvuu9d0gei9jl9bkzgobln@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Out of util.h, to reduce its scope, and since we have a namespaces.h
header, much better to have it there, where it is related to.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-zlu81bbtccuzygh7m8nmgybc@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Part of the erosion of util/util.h, that will lose its include stdlib.h,
we need to add it to places where it is needed but was getting it
indirectly.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-1imnqezw99ahc07fjeb51qby@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

It'll return "unknown", no need to open code it.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-4okvjmm18arjrcyfhuahgfxm@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Based on the following report from Smatch, fix the potential
NULL pointer dereference check.

  tools/perf/util/session.c:1252
  dump_read() error: we previously assumed 'evsel' could be null
  (see line 1249)

  tools/perf/util/session.c
  1240 static void dump_read(struct perf_evsel *evsel, union perf_event *event)
  1241 {
  1242         struct read_event *read_event = &event->read;
  1243         u64 read_format;
  1244
  1245         if (!dump_trace)
  1246                 return;
  1247
  1248         printf(": %d %d %s %" PRIu64 "\n", event->read.pid, event->read.tid,
  1249                evsel ? perf_evsel__name(evsel) : "FAIL",
  1250                event->read.value);
  1251
  1252         read_format = evsel->attr.read_format;
                             ^^^^^^^

'evsel' could be NULL pointer, for this case this patch directly bails
out without dumping read_event.
Signed-off-by: NLeo Yan <leo.yan@linaro.org>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Alexios Zavras <alexios.zavras@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Changbin Du <changbin.du@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Eric Saint-Etienne <eric.saint.etienne@oracle.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Song Liu <songliubraving@fb.com>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20190702103420.27540-9-leo.yan@linaro.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Check first, as machines__deliver_event() may have
perf_evlist__id2evsel() returning NULL.

This was found while checking a report from Leo Yan that used the smatch
tool to find places where a pointer is checked before use and then,
later in the same function gets used without checking.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-muvb8xqyh0gysgfjfq35w642@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Based on the following report from Smatch, fix the potential NULL
pointer dereference check.

  tools/perf/util/map.c:479
  map__fprintf_srccode() error: we previously assumed 'state' could be
  null (see line 466)

  tools/perf/util/map.c
  465         /* Avoid redundant printing */
  466         if (state &&
  467             state->srcfile &&
  468             !strcmp(state->srcfile, srcfile) &&
  469             state->line == line) {
  470                 free(srcfile);
  471                 return 0;
  472         }
  473
  474         srccode = find_sourceline(srcfile, line, &len);
  475         if (!srccode)
  476                 goto out_free_line;
  477
  478         ret = fprintf(fp, "|%-8d %.*s", line, len, srccode);
  479         state->srcfile = srcfile;
              ^^^^^^^
  480         state->line = line;
              ^^^^^^^

This patch validates 'state' pointer before access its elements.
Signed-off-by: NLeo Yan <leo.yan@linaro.org>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Alexios Zavras <alexios.zavras@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Changbin Du <changbin.du@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Eric Saint-Etienne <eric.saint.etienne@oracle.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Song Liu <songliubraving@fb.com>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: linux-arm-kernel@lists.infradead.org
Fixes: dd2e18e9 ("perf tools: Support 'srccode' output")
Link: http://lkml.kernel.org/r/20190702103420.27540-8-leo.yan@linaro.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Based on the following report from Smatch, fix the potential NULL
pointer dereference check.

  tools/perf/builtin-trace.c:1044
  thread_trace__new() error: we previously assumed 'ttrace' could be
  null (see line 1041).

  tools/perf/builtin-trace.c
  1037 static struct thread_trace *thread_trace__new(void)
  1038 {
  1039         struct thread_trace *ttrace =  zalloc(sizeof(struct thread_trace));
  1040
  1041         if (ttrace)
  1042                 ttrace->files.max = -1;
  1043
  1044         ttrace->syscall_stats = intlist__new(NULL);
               ^^^^^^^^
  1045
  1046         return ttrace;
  1047 }
Signed-off-by: NLeo Yan <leo.yan@linaro.org>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Alexios Zavras <alexios.zavras@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Changbin Du <changbin.du@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Eric Saint-Etienne <eric.saint.etienne@oracle.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Song Liu <songliubraving@fb.com>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20190702103420.27540-6-leo.yan@linaro.org
[ Just made it look like other tools/perf constructors, same end result ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Based on the following report from Smatch, fix the potential
dereferencing freed memory check.

  tools/perf/util/annotate.c:1125
  disasm_line__parse() error: dereferencing freed memory 'namep'

  tools/perf/util/annotate.c
  1100 static int disasm_line__parse(char *line, const char **namep, char **rawp)
  1101 {
  1102         char tmp, *name = ltrim(line);

  [...]

  1114         *namep = strdup(name);
  1115
  1116         if (*namep == NULL)
  1117                 goto out_free_name;

  [...]

  1124 out_free_name:
  1125         free((void *)namep);
                            ^^^^^
  1126         *namep = NULL;
               ^^^^^^
  1127         return -1;
  1128 }

If strdup() fails to allocate memory space for *namep, we don't need to
free memory with pointer 'namep', which is resident in data structure
disasm_line::ins::name; and *namep is NULL pointer for this failure, so
it's pointless to assign NULL to *namep again.

Committer note:

Freeing namep, which is the address of the first entry of the 'struct
ins' that is the first member of struct disasm_line would in fact free
that disasm_line instance, if it was allocated via malloc/calloc, which,
later, would a dereference of freed memory.
Signed-off-by: NLeo Yan <leo.yan@linaro.org>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Alexios Zavras <alexios.zavras@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Changbin Du <changbin.du@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Eric Saint-Etienne <eric.saint.etienne@oracle.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Song Liu <songliubraving@fb.com>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20190702103420.27540-5-leo.yan@linaro.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Based on the following report from Smatch, fix the potential NULL
pointer dereference check.

  tools/perf/builtin-top.c:109
  perf_top__parse_source() warn: variable dereferenced before check 'he'
  (see line 103)

  tools/perf/builtin-top.c:233
  perf_top__show_details() warn: variable dereferenced before check 'he'
  (see line 228)

  tools/perf/builtin-top.c
  101 static int perf_top__parse_source(struct perf_top *top, struct hist_entry *he)
  102 {
  103         struct perf_evsel *evsel = hists_to_evsel(he->hists);
                                                        ^^^^
  104         struct symbol *sym;
  105         struct annotation *notes;
  106         struct map *map;
  107         int err = -1;
  108
  109         if (!he || !he->ms.sym)
  110                 return -1;

This patch moves the values assignment after validating pointer 'he'.
Signed-off-by: NLeo Yan <leo.yan@linaro.org>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Alexios Zavras <alexios.zavras@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Changbin Du <changbin.du@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Eric Saint-Etienne <eric.saint.etienne@oracle.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Song Liu <songliubraving@fb.com>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20190702103420.27540-4-leo.yan@linaro.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Based on the following report from Smatch, fix the use-after-freed
pointer.

  tools/perf/builtin-stat.c:1353
  add_default_attributes() warn: passing freed memory 'str'.

The pointer 'str' has been freed but later it is still passed into the
function parse_events_print_error().  This patch fixes this
use-after-freed issue.
Signed-off-by: NLeo Yan <leo.yan@linaro.org>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Alexios Zavras <alexios.zavras@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Changbin Du <changbin.du@intel.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Saint-Etienne <eric.saint.etienne@oracle.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Song Liu <songliubraving@fb.com>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Link: http://lkml.kernel.org/r/20190702103420.27540-3-leo.yan@linaro.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Running the 'perf test' command after building perf with a memory
sanitizer causes a warning that says:

  WARNING: MemorySanitizer: use-of-uninitialized-value... in mmap-thread-lookup.c

Initializing the go variable to 0 silences this harmless warning.

Committer warning:

This was harmless, just a simple test writing whatever was at that
sizeof(int) memory area just to signal another thread blocked reading
that file created with pipe(). Initialize it tho so that we don't get
this warning.
Signed-off-by: NNumfor Mbiziwo-Tiapo <nums@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Drayton <mbd@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/20190702173716.181223-1-nums@google.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To pick up the changes in:

  6dbbf5ec ("x86/cpufeatures: Enumerate user wait instructions")
  b302e4b1 ("x86/cpufeatures: Enumerate the new AVX512 BFLOAT16 instructions")
  acec0ce0 ("x86/cpufeatures: Combine word 11 and 12 into a new scattered features word")
  cbb99c0f ("x86/cpufeatures: Add FDP_EXCPTN_ONLY and ZERO_FCS_FDS")

That don't affect anything in tools/.

This silences this perf build warning:

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

Cc: Aaron Lewis <aaronlewis@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/n/tip-y60wnyg2fuxi0hx7icruo9po@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Laura reported that the perf build failed in fedora when we got a glibc
that provides gettid(), which I reproduced using fedora rawhide with the
glibc-devel-2.29.9000-26.fc31.x86_64 package.

Add a feature check to avoid providing a gettid() helper in such
systems.

On a fedora rawhide system with this patch applied we now get:

  [root@7a5f55352234 perf]# grep gettid /tmp/build/perf/FEATURE-DUMP
  feature-gettid=1
  [root@7a5f55352234 perf]# cat /tmp/build/perf/feature/test-gettid.make.output
  [root@7a5f55352234 perf]# ldd /tmp/build/perf/feature/test-gettid.bin
          linux-vdso.so.1 (0x00007ffc6b1f6000)
          libc.so.6 => /lib64/libc.so.6 (0x00007f04e0a74000)
          /lib64/ld-linux-x86-64.so.2 (0x00007f04e0c47000)
  [root@7a5f55352234 perf]# nm /tmp/build/perf/feature/test-gettid.bin | grep -w gettid
                   U gettid@@GLIBC_2.30
  [root@7a5f55352234 perf]#

While on a fedora:29 system:

  [acme@quaco perf]$ grep gettid /tmp/build/perf/FEATURE-DUMP
  feature-gettid=0
  [acme@quaco perf]$ cat /tmp/build/perf/feature/test-gettid.make.output
  test-gettid.c: In function ‘main’:
  test-gettid.c:8:9: error: implicit declaration of function ‘gettid’; did you mean ‘getgid’? [-Werror=implicit-function-declaration]
    return gettid();
           ^~~~~~
           getgid
  cc1: all warnings being treated as errors
  [acme@quaco perf]$
Reported-by: NLaura Abbott <labbott@redhat.com>
Tested-by: NLaura Abbott <labbott@redhat.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lkml.kernel.org/n/tip-yfy3ch53agmklwu9o7rlgf9c@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

We are getting false positive gcc warning when we compile with gcc9 (9.1.1):

     CC       jvmti/libjvmti.o
   In file included from /usr/include/string.h:494,
                    from jvmti/libjvmti.c:5:
   In function ‘strncpy’,
       inlined from ‘copy_class_filename.constprop’ at jvmti/libjvmti.c:166:3:
   /usr/include/bits/string_fortified.h:106:10: error: ‘__builtin_strncpy’ specified bound depends on the length of the source argument [-Werror=stringop-overflow=]
     106 |   return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
         |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   jvmti/libjvmti.c: In function ‘copy_class_filename.constprop’:
   jvmti/libjvmti.c:165:26: note: length computed here
     165 |   size_t file_name_len = strlen(file_name);
         |                          ^~~~~~~~~~~~~~~~~
   cc1: all warnings being treated as errors

As per Arnaldo's suggestion use strlcpy(), which does the same thing and keeps
gcc silent.
Suggested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ben Gainey <ben.gainey@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/20190531131321.GB1281@kravaSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Some distros put -fstack-protector-strong in the compiler flags to be
used to build python extensions, but then, the clang version in that
distro doesn't know about that, only gcc does.

Check if that is the case and remove it from the set of options used to
build the python binding with clang.

Case at hand:

oraclelinux:7

  $ head -2 /etc/os-release
  NAME="Oracle Linux Server"
  VERSION="7.6"
  $ grep stack-protector /usr/lib64/python2.7/_sysconfigdata.py | head -1 | cut -c-120
 'CFLAGS': '-fno-strict-aliasing -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --para
  $
  gcc version 4.8.5 20150623 (Red Hat 4.8.5-36.0.1) (GCC)
  clang version 3.4.2 (tags/RELEASE_34/dot2-final)

  clang: error: unknown argument: '-fstack-protector-strong'
  clang: error: unknown argument: '-fstack-protector-strong'
  error: command 'clang' failed with exit status 1
  cp: cannot stat '/tmp/build/perf/python_ext_build/lib/perf*.so': No such file or directory
  make[2]: *** [/tmp/build/perf/python/perf.so] Error 1

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-brmp2415zxpbhz45etkgjoma@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Some compilers will complain when using a member of a struct to
initialize another member, in the same struct initialization.

For instance:

  debian:8      Debian clang version 3.5.0-10 (tags/RELEASE_350/final) (based on LLVM 3.5.0)
  oraclelinux:7 clang version 3.4.2 (tags/RELEASE_34/dot2-final)

Produce:

  ui/browsers/annotate.c:104:12: error: variable 'ops' is uninitialized when used within its own initialization [-Werror,-Wuninitialized]
                                              (!ops.current_entry ||
                                                ^~~
  1 error generated.

So use an extra variable, initialized just before that struct, to have
the value used in the expressions used to init two of the struct
members.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Fixes: c298304b ("perf annotate: Use a ops table for annotation_line__write()")
Link: https://lkml.kernel.org/n/tip-f9nexro58q62l3o9hez8hr0i@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

'probe libc's inet_pton & backtrace it with ping' testcase sometimes
fails on powerpc because distro ping binary does not have symbol
information and thus it prints "[unknown]" function name in the
backtrace.

Accept "[unknown]" as valid function name for powerpc as well.

 # perf test -v "probe libc's inet_pton & backtrace it with ping"

Before:

  59: probe libc's inet_pton & backtrace it with ping       :
  --- start ---
  test child forked, pid 79695
  ping 79718 [077] 96483.787025: probe_libc:inet_pton: (7fff83a754c8)
  7fff83a754c8 __GI___inet_pton+0x8 (/usr/lib64/power9/libc-2.28.so)
  7fff83a2b7a0 gaih_inet.constprop.7+0x1020
  (/usr/lib64/power9/libc-2.28.so)
  7fff83a2c170 getaddrinfo+0x160 (/usr/lib64/power9/libc-2.28.so)
  1171830f4 [unknown] (/usr/bin/ping)
  FAIL: expected backtrace entry
  ".*\+0x[[:xdigit:]]+[[:space:]]\(.*/bin/ping.*\)$"
  got "1171830f4 [unknown] (/usr/bin/ping)"
  test child finished with -1
  ---- end ----
  probe libc's inet_pton & backtrace it with ping: FAILED!

After:

  59: probe libc's inet_pton & backtrace it with ping       :
  --- start ---
  test child forked, pid 79085
  ping 79108 [045] 96400.214177: probe_libc:inet_pton: (7fffbb9654c8)
  7fffbb9654c8 __GI___inet_pton+0x8 (/usr/lib64/power9/libc-2.28.so)
  7fffbb91b7a0 gaih_inet.constprop.7+0x1020
  (/usr/lib64/power9/libc-2.28.so)
  7fffbb91c170 getaddrinfo+0x160 (/usr/lib64/power9/libc-2.28.so)
  132e830f4 [unknown] (/usr/bin/ping)
  test child finished with 0
  ---- end ----
  probe libc's inet_pton & backtrace it with ping: Ok
Signed-off-by: NSeeteena Thoufeek <s1seetee@linux.vnet.ibm.com>
Reviewed-by: NKim Phillips <kim.phillips@amd.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Hendrik Brueckner <brueckner@linux.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sandipan Das <sandipan@linux.ibm.com>
Fixes: 16329364 ("perf tests: Fix record+probe_libc_inet_pton.sh without ping's debuginfo")
Link: http://lkml.kernel.org/r/1561630614-3216-1-git-send-email-s1seetee@linux.vnet.ibm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Konstantin reported problem with default perf record command, which
fails on some AMD servers, because of the default maximum precise
config.

The current fallback mechanism counts on getting ENOTSUP errno for
precise_ip fails, but that's not the case on some AMD servers.

We can fix this by removing the errno check completely, because the
precise_ip fallback is separated. We can just try  (if requested by
evsel->precise_max) all possible precise_ip, and if one succeeds we win,
if not, we continue with standard fallback.
Reported-by: NKonstantin Kharlamov <Hi-Angel@yandex.ru>
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Monnet <quentin.monnet@netronome.com>
Cc: Kim Phillips <kim.phillips@amd.com>
Link: http://lkml.kernel.org/r/20190703080949.10356-1-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Threads are created when we either synthesize PERF_RECORD_FORK events
for pre-existing threads or when we receive PERF_RECORD_FORK events from
the kernel as new threads get created.

We then keep them in machine->threads[].entries rb trees till when we
receive a PERF_RECORD_EXIT, i.e. that thread terminated.

The thread object has a reference count that is grabbed when, for
instance, we keep that thread referenced in struct hist_entry, in 'perf
report' and 'perf top'.

When we receive a PERF_RECORD_EXIT we remove the thread object from the
rb tree and move it to the corresponding machine->threads[].dead list,
then we do a thread__put(), dropping the reference we had for keeping it
in the rb tree.

In thread__put() we were assuming that when the reference count hit zero
we should remove it from the dead list by simply doing a
list_del_init(&thread->node).

That works well when all the thread lifetime is during the machine that
has the list heads lifetime, since we know that we can do the
list_del_init() and it will update the 'dead' list_head.

But in 'perf sched lat' we were doing:

    machine__new() (via perf_session__new)

    process events, grabbing refcounts to keep those thread objects
    in 'perf sched' local data structures.

    machine__exit() (via perf_session__delete) which would delete the
    'dead' list heads.

    And then doing the final thread__put() for the refcounts 'perf sched'
    rightfully obtained for keeping those thread object references.

    b00m, since thread__put() would do the list_del_init() touching
    a dead dead list head.

Fix it by removing all the dead threads from machine->threads[].dead at
machine__exit(), since whatever is there should have refcounts taken by
things like 'perf sched lat', and make thread__put() check if the thread
is in a linked list before removing it from that list.
Reported-by: NWei Li <liwei391@huawei.com>
Link: https://lkml.kernel.org/r/20190508143648.8153-1-liwei391@huawei.com
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Zhipeng Xie <xiezhipeng1@huawei.com>
Link: https://lkml.kernel.org/r/20190704194355.GI10740@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

bpf/btf write_* functions need ff->ph->env.

With this missing, pipe-mode (perf record -o -)  would crash like:

Program terminated with signal SIGSEGV, Segmentation fault.

This patch assign proper ph value to ff.

Committer testing:

  (gdb) run record -o -
  Starting program: /root/bin/perf record -o -
  PERFILE2
  <SNIP start of perf.data headers>
  Thread 1 "perf" received signal SIGSEGV, Segmentation fault.
  __do_write_buf (size=4, buf=0x160, ff=0x7fffffff8f80) at util/header.c:126
  126		memcpy(ff->buf + ff->offset, buf, size);
  (gdb) bt
  #0  __do_write_buf (size=4, buf=0x160, ff=0x7fffffff8f80) at util/header.c:126
  #1  do_write (ff=ff@entry=0x7fffffff8f80, buf=buf@entry=0x160, size=4) at util/header.c:137
  #2  0x00000000004eddba in write_bpf_prog_info (ff=0x7fffffff8f80, evlist=<optimized out>) at util/header.c:912
  #3  0x00000000004f69d7 in perf_event__synthesize_features (tool=tool@entry=0x97cc00 <record>, session=session@entry=0x7fffe9c6d010,
      evlist=0x7fffe9cae010, process=process@entry=0x4435d0 <process_synthesized_event>) at util/header.c:3695
  #4  0x0000000000443c79 in record__synthesize (tail=tail@entry=false, rec=0x97cc00 <record>) at builtin-record.c:1214
  #5  0x0000000000444ec9 in __cmd_record (rec=0x97cc00 <record>, argv=<optimized out>, argc=0) at builtin-record.c:1435
  #6  cmd_record (argc=0, argv=<optimized out>) at builtin-record.c:2450
  #7  0x00000000004ae3e9 in run_builtin (p=p@entry=0x98e058 <commands+216>, argc=argc@entry=3, argv=0x7fffffffd670) at perf.c:304
  #8  0x000000000042eded in handle_internal_command (argv=<optimized out>, argc=<optimized out>) at perf.c:356
  #9  run_argv (argcp=<optimized out>, argv=<optimized out>) at perf.c:400
  #10 main (argc=3, argv=<optimized out>) at perf.c:522
  (gdb)

After the patch the SEGSEGV is gone.
Reported-by: NDavid Carrillo Cisneros <davidca@fb.com>
Signed-off-by: NSong Liu <songliubraving@fb.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: kernel-team@fb.com
Cc: stable@vger.kernel.org # v5.1+
Fixes: 606f972b ("perf bpf: Save bpf_prog_info information as headers to perf.data")
Link: http://lkml.kernel.org/r/20190620010453.4118689-1-songliubraving@fb.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To pick up the changes from:

  41040cf7 ("arm64/sve: Fix missing SVE/FPSIMD endianness conversions")
  6ca00dfa ("KVM: x86: Modify struct kvm_nested_state to have explicit fields for data")

None entail changes in tooling.

This silences these tools/perf build warnings:

  Warning: Kernel ABI header at 'tools/arch/x86/include/uapi/asm/kvm.h' differs from latest version at 'arch/x86/include/uapi/asm/kvm.h'
  diff -u tools/arch/x86/include/uapi/asm/kvm.h arch/x86/include/uapi/asm/kvm.h
  Warning: Kernel ABI header at 'tools/arch/arm64/include/uapi/asm/kvm.h' differs from latest version at 'arch/arm64/include/uapi/asm/kvm.h'
  diff -u tools/arch/arm64/include/uapi/asm/kvm.h arch/arm64/include/uapi/asm/kvm.h

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Liran Alon <liran.alon@oracle.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Link: https://lkml.kernel.org/n/tip-1cdbq5ulr4d6cx3iv2ye5wdv@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

This refactors do_unexpected_base() to clean up some code.  It also
fixes the following bugs in test_ptrace_write_gsbase():

 - Incorrect printf() format string caused crashes.

 - Hardcoded 0x7 for the gs selector was not reliably correct.

It also documents the fact that the test is expected to fail on old
kernels.

Fixes: a87730cc ("selftests/x86/fsgsbase: Test ptracer-induced GSBASE write with FSGSBASE")
Fixes: 1b6858d5 ("selftests/x86/fsgsbase: Test ptracer-induced GSBASE write")
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc:  "BaeChang Seok" <chang.seok.bae@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: "BaeChang Seok" <chang.seok.bae@intel.com>
Link: https://lkml.kernel.org/r/bab29c84f2475e2c30ddb00f1b877fcd7f4f96a8.1562125333.git.luto@kernel.org

The 'perf kvm' command set up things so that we can record, report, top,
etc, but not 'script', so make 'perf script' be able to process samples
by allowing to pass guest kallsyms, vmlinux, modules, etc, and if at
least one of those is provided, set perf_guest to true so that guest
samples get properly resolved.

Testing it:

  # perf kvm --guest --guestkallsyms /wb/rhel6.kallsyms --guestmodules /wb/rhel6.modules record -e cycles:Gk
^C[ perf record: Woken up 7 times to write data ]
  [ perf record: Captured and wrote 3.602 MB perf.data.guest (10492 samples) ]

  #
  # perf evlist -i perf.data.guest
cycles:Gk
  # perf evlist -v -i perf.data.guest
cycles:Gk: size: 112, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|CPU|PERIOD, read_format: ID, disabled: 1, inherit: 1, exclude_user: 1, exclude_hv: 1, mmap: 1, comm: 1, freq: 1, task: 1, sample_id_all: 1, exclude_host: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1
  #
  # perf kvm --guestkallsyms /wb/rhel6.kallsyms --guestmodules /wb/rhel6.modules report --stdio -s sym | head -30
  # To display the perf.data header info, please use --header/--header-only options.
  #
  #
  # Total Lost Samples: 0
  #
  # Samples: 10K of event 'cycles:Gk'
  # Event count (approx.): 2434201408
  #
  # Overhead  Symbol
  # ........  ..............................................
  #
      11.93%  [g] avtab_search_node
       3.95%  [g] sidtab_context_to_sid
       2.41%  [g] n_tty_write
       2.20%  [g] _spin_unlock_irqrestore
       1.37%  [g] _aesni_dec4
       1.33%  [g] kmem_cache_alloc
       1.07%  [g] native_write_cr0
       0.99%  [g] kfree
       0.95%  [g] _spin_lock
       0.91%  [g] __memset
       0.87%  [g] schedule
       0.83%  [g] _spin_lock_irqsave
       0.76%  [g] __kmalloc
       0.67%  [g] avc_has_perm_noaudit
       0.66%  [g] kmem_cache_free
       0.65%  [g] glue_xts_crypt_128bit
       0.59%  [g] __d_lookup
       0.59%  [g] __audit_syscall_exit
       0.56%  [g] __memcpy
  #

Then, when trying to use perf script to generate a python script and
then process the events after adding a python hook for non-tracepoint
events:

  # perf script -i perf.data.guest -g python
  generated Python script: perf-script.py
  # vim perf-script.py
  # tail -2 perf-script.py
  def process_event(param_dict):
        print(param_dict["symbol"])
  #
  # perf script -i perf.data.guest -s perf-script.py  | head
  in trace_begin
  vmx_vmexit
  vmx_vmexit
  vmx_vmexit
  vmx_vmexit
  vmx_vmexit
  vmx_vmexit
  vmx_vmexit
  vmx_vmexit
  vmx_vmexit
  231
  #

We'd see just the vmx_vmexit, i.e. the samples from the guest don't show
up.

After this patch:

  # perf script --guestkallsyms /wb/rhel6.kallsyms --guestmodules /wb/rhel6.modules -i perf.data.guest -s perf-script.py 2> /dev/null | head -30
  in trace_begin
  apic_timer_interrupt
  apic_timer_interrupt
  apic_timer_interrupt
  apic_timer_interrupt
  apic_timer_interrupt
  save_args
  do_timer
  drain_array
  inode_permission
  avc_has_perm_noaudit
  run_timer_softirq
  apic_timer_interrupt
  apic_timer_interrupt
  apic_timer_interrupt
  apic_timer_interrupt
  apic_timer_interrupt
  kvm_guest_apic_eoi_write
  run_posix_cpu_timers
  _spin_lock
  handle_pte_fault
  rcu_irq_enter
  delay_tsc
  delay_tsc
  native_read_tsc
  apic_timer_interrupt
  sys_open
  internal_add_timer
  list_del
  rcu_exit_nohz
  #

Jiri Olsa noticed we need to set 'perf_guest' to true if we want to
process guest samples and I made it be set if one of the guest files
settings get set via the command line options added in this patch, that
match those present in the 'perf kvm' command.

We probably want to have 'perf record', 'perf report' etc to notice that
there are guest samples and do the right thing, which is to look for
files with some suffix that make it be associated with the guest used to
collect the samples, i.e. if a vmlinux file is passed, we can get the
build-id from it, if not some other identifier or simply looking for
"kallsyms.guest", for instance, in the current directory.
Reported-by: NMariano Pache <npache@redhat.com>
Tested-by: NMariano Pache <npache@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
Cc: Ali Raza <alirazabhutta.10@gmail.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Joe Mario <jmario@redhat.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Orran Krieger <okrieger@redhat.com>
Cc: Ramkumar Ramachandra <artagnon@gmail.com>
Cc: Yunlong Song <yunlong.song@huawei.com>
Link: https://lkml.kernel.org/n/tip-d54gj64rerlxcqsrod05biwn@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The Memory_BW metric generates groups including duration_time, which
maps to a software event.

For some reason this makes the group always not count.

Always put duration_time outside a group when generating metrics.  It's
always the same time, so no need to group it.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20190628220737.13259-3-andi@firstfloor.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

When printing the metrics raw, don't print : after the metricgroups.
This helps the command line completion to complete those too.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20190628220737.13259-2-andi@firstfloor.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

- Add a missing filter for the DRAM_Latency / DRAM_Parallel_Reads metrics
- Remove the useless PMM_* metrics from Skylake
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20190628220737.13259-1-andi@firstfloor.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

- Fix a typo in the man page
- Fix a tip that doesn't make any sense.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20190628220900.13741-1-andi@firstfloor.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Add support for Hisi hip08 L3C PMU aliasing.

The kernel driver is in drivers/perf/hisilicon/hisi_uncore_l3c_pmu.c
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Hendrik Brueckner <brueckner@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shaokun Zhang <zhangshaokun@hisilicon.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxarm@huawei.com
Link: http://lkml.kernel.org/r/1561732552-143038-5-git-send-email-john.garry@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Add support for Hisi hip08 HHA PMU aliasing.

The kernel driver is in drivers/perf/hisilicon/hisi_uncore_hha_pmu.c
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Hendrik Brueckner <brueckner@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shaokun Zhang <zhangshaokun@hisilicon.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxarm@huawei.com
Link: http://lkml.kernel.org/r/1561732552-143038-4-git-send-email-john.garry@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Add support for Hisi hip08 DDRC PMU aliasing. We can now do something like
this:

$perf list

[snip]

uncore ddrc:
  uncore_hisi_ddrc.act_cmd
       [DDRC active commands. Unit: hisi_sccl,ddrc]
  uncore_hisi_ddrc.flux_rcmd
       [DDRC read commands. Unit: hisi_sccl,ddrc]
  uncore_hisi_ddrc.flux_wcmd
       [DDRC write commands. Unit: hisi_sccl,ddrc]
  uncore_hisi_ddrc.flux_wr
       [DDRC precharge commands. Unit: hisi_sccl,ddrc]
  uncore_hisi_ddrc.rnk_chg
       [DDRC rank commands. Unit: hisi_sccl,ddrc]
  uncore_hisi_ddrc.rw_chg
       [DDRC read and write changes. Unit: hisi_sccl,ddrc]

Performance counter stats for 'system wide':

                 0      uncore_hisi_ddrc.flux_rcmd [hisi_sccl1_ddrc0]
                 0      uncore_hisi_ddrc.flux_rcmd [hisi_sccl3_ddrc1]
                 0      uncore_hisi_ddrc.flux_rcmd [hisi_sccl5_ddrc2]
                 0      uncore_hisi_ddrc.flux_rcmd [hisi_sccl7_ddrc3]
                 0      uncore_hisi_ddrc.flux_rcmd [hisi_sccl5_ddrc0]
                 0      uncore_hisi_ddrc.flux_rcmd [hisi_sccl7_ddrc1]
                 0      uncore_hisi_ddrc.flux_rcmd [hisi_sccl1_ddrc3]
                 0      uncore_hisi_ddrc.flux_rcmd [hisi_sccl1_ddrc1]
                 0      uncore_hisi_ddrc.flux_rcmd [hisi_sccl3_ddrc2]
                 0      uncore_hisi_ddrc.flux_rcmd [hisi_sccl5_ddrc3]
                 0      uncore_hisi_ddrc.flux_rcmd [hisi_sccl3_ddrc0]
                 0      uncore_hisi_ddrc.flux_rcmd [hisi_sccl5_ddrc1]
                 0      uncore_hisi_ddrc.flux_rcmd [hisi_sccl7_ddrc2]
                 0      uncore_hisi_ddrc.flux_rcmd [hisi_sccl7_ddrc0]
            20,421      uncore_hisi_ddrc.flux_rcmd [hisi_sccl1_ddrc2]
                 0      uncore_hisi_ddrc.flux_rcmd [hisi_sccl3_ddrc3]

       1.001559011 seconds time elapsed

The kernel driver is in drivers/perf/hisilicon/hisi_uncore_ddrc_pmu.c
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Hendrik Brueckner <brueckner@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shaokun Zhang <zhangshaokun@hisilicon.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxarm@huawei.com
Link: http://lkml.kernel.org/r/1561732552-143038-3-git-send-email-john.garry@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The jevent "Unit" field is used for uncore PMU alias definition.

The form uncore_pmu_example_X is supported, where "X" is a wildcard, to
support multiple instances of the same PMU in a system.

Unfortunately this format not suitable for all uncore PMUs; take the
Hisi DDRC uncore PMU for example, where the name is in the form
hisi_scclX_ddrcY.

For for current jevent parsing, we would be required to hardcode an
uncore alias translation for each possible value of X. This is not
scalable.

Instead, add support for "Unit" field in the form "hisi_sccl,ddrc",
where we can match by hisi_scclX and ddrcY. Tokens  in Unit field are
delimited by ','.
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Hendrik Brueckner <brueckner@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shaokun Zhang <zhangshaokun@hisilicon.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxarm@huawei.com
Link: http://lkml.kernel.org/r/1561732552-143038-2-git-send-email-john.garry@huawei.com
[ Shut up older gcc complianing about the last arg to strtok_r() being uninitialized, set that tmp to NULL ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Currently KVM_STATE_NESTED_EVMCS is used to signal that eVMCS
capability is enabled on vCPU.
As indicated by vmx->nested.enlightened_vmcs_enabled.

This is quite bizarre as userspace VMM should make sure to expose
same vCPU with same CPUID values in both source and destination.
In case vCPU is exposed with eVMCS support on CPUID, it is also
expected to enable KVM_CAP_HYPERV_ENLIGHTENED_VMCS capability.
Therefore, KVM_STATE_NESTED_EVMCS is redundant.

KVM_STATE_NESTED_EVMCS is currently used on restore path
(vmx_set_nested_state()) only to enable eVMCS capability in KVM
and to signal need_vmcs12_sync such that on next VMEntry to guest
nested_sync_from_vmcs12() will be called to sync vmcs12 content
into eVMCS in guest memory.
However, because restore nested-state is rare enough, we could
have just modified vmx_set_nested_state() to always signal
need_vmcs12_sync.

From all the above, it seems that we could have just removed
the usage of KVM_STATE_NESTED_EVMCS. However, in order to preserve
backwards migration compatibility, we cannot do that.
(vmx_get_nested_state() needs to signal flag when migrating from
new kernel to old kernel).

Returning KVM_STATE_NESTED_EVMCS when just vCPU have eVMCS enabled
have a bad side-effect of userspace VMM having to send nested-state
from source to destination as part of migration stream. Even if
guest have never used eVMCS as it doesn't even run a nested
hypervisor workload. This requires destination userspace VMM and
KVM to support setting nested-state. Which make it more difficult
to migrate from new host to older host.
To avoid this, change KVM_STATE_NESTED_EVMCS to signal eVMCS is
not only enabled but also active. i.e. Guest have made some
eVMCS active via an enlightened VMEntry. i.e. vmcs12 is copied
from eVMCS and therefore should be restored into eVMCS resident
in memory (by copy_vmcs12_to_enlightened()).
Reviewed-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: NMaran Wilson <maran.wilson@oracle.com>
Reviewed-by: NKrish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: NLiran Alon <liran.alon@oracle.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Documentation the new computation selection 'cycles'.

 v4:
 ---
 Change the column 'Block cycles diff [start:end]' to
 '[Program Block Range] Cycles Diff'
Signed-off-by: NJin Yao <yao.jin@linux.intel.com>
Reviewed-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1561713784-30533-8-git-send-email-yao.jin@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

 $ perf record -b ./div
 $ perf record -b ./div

Following is the default perf diff output

 $ perf diff

 # Event 'cycles'
 #
 # Baseline  Delta Abs  Shared Object     Symbol
 # ........  .........  ................  ..................................
 #
     48.75%     +0.33%  div               [.] main
      8.21%     -0.20%  div               [.] compute_flag
     19.02%     -0.12%  libc-2.23.so      [.] __random_r
     16.17%     -0.09%  libc-2.23.so      [.] __random
      2.27%     -0.03%  div               [.] rand@plt
                +0.02%  [i915]            [k] gen8_irq_handler
      5.52%     +0.02%  libc-2.23.so      [.] rand

This patch creates a new computation selection 'cycles'.

 $ perf diff -c cycles

 # Event 'cycles'
 #
 # Baseline       [Program Block Range] Cycles Diff Shared Object Symbol
 # ........ ....................................... .........................................
 #
     48.75%             [div.c:42 -> div.c:45]  147 div           [.] main
     48.75%             [div.c:31 -> div.c:40]    4 div           [.] main
     48.75%             [div.c:40 -> div.c:40]    0 div           [.] main
     48.75%             [div.c:42 -> div.c:42]    0 div           [.] main
     48.75%             [div.c:42 -> div.c:44]    0 div           [.] main
     19.02% [random_r.c:357 -> random_r.c:360]    0 libc-2.23.so  [.] __random_r
     19.02% [random_r.c:357 -> random_r.c:373]    0 libc-2.23.so  [.] __random_r
     19.02% [random_r.c:357 -> random_r.c:376]    0 libc-2.23.so  [.] __random_r
     19.02% [random_r.c:357 -> random_r.c:380]    0 libc-2.23.so  [.] __random_r
     19.02% [random_r.c:357 -> random_r.c:392]    0 libc-2.23.so  [.] __random_r
     16.17%     [random.c:288 -> random.c:291]    0 libc-2.23.so  [.] __random
     16.17%     [random.c:288 -> random.c:291]    0 libc-2.23.so  [.] __random
     16.17%     [random.c:288 -> random.c:295]    0 libc-2.23.so  [.] __random
     16.17%     [random.c:288 -> random.c:297]    0 libc-2.23.so  [.] __random
     16.17%     [random.c:291 -> random.c:291]    0 libc-2.23.so  [.] __random
     16.17%     [random.c:293 -> random.c:293]    0 libc-2.23.so  [.] __random
      8.21%             [div.c:22 -> div.c:22]  148 div           [.] compute_flag
      8.21%             [div.c:22 -> div.c:25]    0 div           [.] compute_flag
      8.21%             [div.c:27 -> div.c:28]    0 div           [.] compute_flag
      5.52%           [rand.c:26 -> rand.c:27]    0 libc-2.23.so  [.] rand
      5.52%           [rand.c:26 -> rand.c:28]    0 libc-2.23.so  [.] rand
      2.27%         [rand@plt+0 -> rand@plt+0]    0 div           [.] rand@plt
      0.01% [entry_64.S:694 -> entry_64.S:694]   16 [vmlinux]     [k] native_irq_return_iret
      0.00%       [fair.c:7676 -> fair.c:7665]  162 [vmlinux]     [k] update_blocked_averages

"[Program Block Range]" indicates the range of program basic block
(start -> end). If we can find the source line it prints the source line
otherwise it prints the symbol+offset instead.

 v4:
 ---
 Use source lines or symbol+offset to indicate the basic block. It should
 be easier to understand.

 v3:
 ---
 Cast 'struct hist_entry' to 'struct block_hist' in hist_entry__block_fprintf.
 Use symbol_conf.report_block to check if executing hist_entry__block_fprintf.

 v2:
 ---
 Keep standard perf diff format and display the 'Baseline' and
 'Shared Object'.

The output is sorted by "Baseline" and the basic blocks in the same
function are sorted by cycles diff.
Signed-off-by: NJin Yao <yao.jin@linux.intel.com>
Reviewed-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1561713784-30533-7-git-send-email-yao.jin@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The target is to compare the performance difference (cycles diff) for
the same basic blocks in different data files.

The same basic block means same function, same start address and same
end address. This patch finds the same basic blocks from different data
files and link them together and resort by the cycles diff.

 v3:
 ---
 The block stuffs are maintained by new structure 'block_hist',
 so this patch is update accordingly.

 v2:
 ---
 Since now the basic block hists is changed to per symbol,
 the patch only links the basic block hists for the same
 symbol in different data files.
Signed-off-by: NJin Yao <yao.jin@linux.intel.com>
Reviewed-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1561713784-30533-6-git-send-email-yao.jin@linux.intel.com
[ sym->name is an array, not a pointer, so no need to check it for NULL, fixes de build in some distros ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The hist__account_cycles() can account cycles per basic block. The basic
block information is saved in cycles_hist structure.

This patch processes each symbol, get basic blocks from cycles_hist and
add the basic block entries to a new hists (in 'struct block_hist').
Using a hists is because we need to compare, sort and print the basic
blocks later.

 v6:
 ---
 Since 'ops' argument is removed from hists__add_entry_block,
 update the code accordingly. No functional change.

 v5:
 ---
 Since now we still carry block_info in 'struct hist_entry'
 we don't need to use our own new/free ops for hist entries.
 And the block_info is released in hist_entry__delete.

 v3:
 ---
 1. In v2, we put block stuffs in 'struct hist_entry', but
 it's not a good design. In v3, we create a new
 'struct block_hist' and cast the 'struct hist_entry' to
 'struct block_hist' in some places, which can avoid adding
 new stuffs in 'struct hist_entry'.

 2. abs() -> labs(), in block_cycles_diff_cmp().

 v2:
 ---
 v1 adds the basic block entries to per data-file hists
 but v2 adds the basic block entries to per symbol hists.
 That is to keep current perf-diff format. Will show the
 result in next patches.
Signed-off-by: NJin Yao <yao.jin@linux.intel.com>
Reviewed-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1561713784-30533-5-git-send-email-yao.jin@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

We will expand perf diff to support diff cycles of individual programs
blocks, so it requires all data files having branch stacks.

This patch checks HEADER_BRANCH_STACK in header, and only set the flag
has_br_stack when HEADER_BRANCH_STACK are set in all data files.

 v2:
 ---
 Move check_file_brstack() from __cmd_diff() to cmd_diff().
 Because later patch will check flag 'has_br_stack' before
 ui_init().
Signed-off-by: NJin Yao <yao.jin@linux.intel.com>
Reviewed-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1561713784-30533-4-git-send-email-yao.jin@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>