The branch history code has a loop detection function. With this, we can
get the number of iterations by calculating the removed loops.

While it would be nice for knowing the average cycles of iterations.
This patch adds up the cycles in branch entries of removed loops and
save the result to the next branch entry (e.g. branch entry A).

Finally it will display the iteration number and average cycles at the
"from" of branch entry A.

For example:
perf record -g -j any,save_type ./div
perf report --branch-history --no-children --stdio

--22.63%--main div.c:42 (RET CROSS_2M)
          compute_flag div.c:28 (cycles:2 iter:173115 avg_cycles:2)
          |
           --10.73%--compute_flag div.c:27 (RET CROSS_2M)
                     rand rand.c:28 (cycles:1)
                     rand rand.c:28 (RET CROSS_2M)
                     __random random.c:298 (cycles:1)
                     __random random.c:297 (COND_BWD CROSS_2M)
                     __random random.c:295 (cycles:1)
                     __random random.c:295 (COND_BWD CROSS_2M)
                     __random random.c:295 (cycles:1)
                     __random random.c:295 (RET CROSS_2M)
Signed-off-by: NYao Jin <yao.jin@linux.intel.com>
Reviewed-by: NAndi Kleen <ak@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1502111115-18305-1-git-send-email-yao.jin@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

During work on perf report for s390 I ran into the following issue:

0 0x318 [0x78]: PERF_RECORD_MMAP -1/0:
        [0x3ff804d6990(0xfffffc007fb2966f) @ 0]:
        x /lib/modules/4.12.0perf1+/kernel/drivers/s390/net/qeth_l2.ko

This is a PERF_RECORD_MMAP entry of the perf.data file with an invalid
module size for qeth_l2.ko (the s390 ethernet device driver).

Even a mainframe does not have 0xfffffc007fb2966f bytes of main memory.

It turned out that this wrong size is created by the perf record
command.  What happens is this function call sequence from
__cmd_record():

  perf_session__new():
    perf_session__create_kernel_maps():
      machine__create_kernel_maps():
        machine__create_modules():   Creates map for all loaded kernel modules.
          modules__parse():   Reads /proc/modules and extracts module name and
                              load address (1st and last column)
            machine__create_module():   Called for every module found in /proc/modules.
                              Creates a new map for every module found and enters
                              module name and start address into the map. Since the
                              module end address is unknown it is set to zero.

This ends up with a kernel module map list sorted by module start
addresses.  All module end addresses are zero.

Last machine__create_kernel_maps() calls function map_groups__fixup_end().
This function iterates through the maps and assigns each map entry's
end address the successor map entry start address. The last entry of the
map group has no successor, so ~0 is used as end to consume the remaining
memory.

Later __cmd_record calls function record__synthesize() which in turn calls
perf_event__synthesize_kernel_mmap() and perf_event__synthesize_modules()
to create PERF_REPORT_MMAP entries into the perf.data file.

On s390 this results in the last module qeth_l2.ko
(which has highest start address, see module table:
        [root@s8360047 perf]# cat /proc/modules
        qeth_l2 86016 1 - Live 0x000003ff804d6000
        qeth 266240 1 qeth_l2, Live 0x000003ff80296000
        ccwgroup 24576 1 qeth, Live 0x000003ff80218000
        vmur 36864 0 - Live 0x000003ff80182000
        qdio 143360 2 qeth_l2,qeth, Live 0x000003ff80002000
        [root@s8360047 perf]# )
to be the last entry and its map has an end address of ~0.

When the PERF_RECORD_MMAP entry is created for kernel module qeth_l2.ko
its start address and length is written. The length is calculated in line:
    event->mmap.len   = pos->end - pos->start;
and results in 0xffffffffffffffff - 0x3ff804d6990(*) = 0xfffffc007fb2966f

(*) On s390 the module start address is actually determined by a __weak function
named arch__fix_module_text_start() in machine__create_module().

I think this improvable. We can use the module size (2nd column of /proc/modules)
to get each loaded kernel module size and calculate its end address.
Only for map entries which do not have a valid end address (end is still zero)
we can use the heuristic we have now, that is use successor start address or ~0.
Signed-off-by: NThomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Reviewed-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Cc: Zvonko Kosic <zvonko.kosic@de.ibm.com>
LPU-Reference: 20170803134902.47207-2-tmricht@linux.vnet.ibm.com
Link: http://lkml.kernel.org/n/tip-nmoqij5b5vxx7rq2ckwu8iaj@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

  perf record -b -g <command>
  perf report --branch-history

This merges the LBRs with the callgraphs.

However it would be nice if it also works without callgraphs (-g) set in
perf record, so that only the LBRs are displayed.  But currently perf
report errors in this case. For example,

  perf record -b <command>
  perf report --branch-history

  Error:
  Selected -g or --branch-history but no callchain data. Did
  you call 'perf record' without -g?

This patch displays the LBRs only even if callgraphs(-g) is not enabled
in perf record.

Change log:

v2: According to Milian Wolff's comment, change the obsolete error
message. Now the error message is:

                 ┌─Error:─────────────────────────────────────┐
                 │Selected -g or --branch-history.            │
                 │But no callchain or branch data.            │
                 │Did you call 'perf record' without -g or -b?│
                 │                                            │
                 │                                            │
                 │Press any key...                            │
                 └────────────────────────────────────────────┘

When passing the last parameter to hists__fprintf,
changes "|" to "||".

  hists__fprintf(hists, !quiet, 0, 0, rep->min_percent, stdout,
                 symbol_conf.use_callchain || symbol_conf.show_branchflag_count);
Signed-off-by: NYao Jin <yao.jin@linux.intel.com>
Reviewed-by: NAndi Kleen <ak@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1494240182-28899-1-git-send-email-yao.jin@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Show branch type in callchain entry. The branch type is printed
with other LBR information (such as cycles/abort/...).

For example:

  perf record -g -j any,save_type
  perf report --branch-history --stdio --no-children

  38.50%  div.c:45                [.] main                    div
          |
          ---main div.c:42 (RET CROSS_2M cycles:2)
             compute_flag div.c:28 (cycles:2)
             compute_flag div.c:27 (RET CROSS_2M cycles:1)
             rand rand.c:28 (cycles:1)
             rand rand.c:28 (RET CROSS_2M cycles:1)
             __random random.c:298 (cycles:1)
             __random random.c:297 (COND_BWD CROSS_2M cycles:1)
             __random random.c:295 (cycles:1)
             __random random.c:295 (COND_BWD CROSS_2M cycles:1)
             __random random.c:295 (cycles:1)
             __random random.c:295 (RET CROSS_2M cycles:9)

Change log

v6: Remove the branch_type_str() since it's moved to branch.c.

v5: Rewrite the branch info print code in util/callchain.c.

v4: Comparing to previous version, the major changes are:
Signed-off-by: NYao Jin <yao.jin@linux.intel.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1500379995-6449-8-git-send-email-yao.jin@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

If a stripped binary is placed in the cache, the user is in a situation
where there's a cached elf file present, but it doesn't have any symtab
to use for name resolution.  Grab the debuginfo for binaries that don't
end in .ko.  This yields a better chance of resolving symbols from older
traces.
Signed-off-by: NKrister Johansen <kjlx@templeofstupid.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1499305693-1599-7-git-send-email-kjlx@templeofstupid.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

If a process is in a mountns and has symbols in /tmp/perf-<pid>.map,
look first in the namespace using the tgid for the pidns that the
process might be in.  If the map isn't found there, try looking in the
mountns where perf is running, and use the tgid that's appropriate for
perf's pid namespace.  If all else fails, use the original pid.

This allows us to locate a symbol map file in the mount namespace, if it
was generated there.  However, we also try the tool's /tmp in case it's
there instead.
Signed-off-by: NKrister Johansen <kjlx@templeofstupid.com>
Tested-by: NBrendan Gregg <brendan.d.gregg@gmail.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1499305693-1599-3-git-send-email-kjlx@templeofstupid.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Which is the case in S/390, where symbols were not being resolved
because machine__get_kernel_start was only setting machine->kernel_start
when the just successfully loaded kernel symtab had its map->start set
to !0, when it was left at (1ULL << 63) assuming a partitioning of the
address space for user/kernel, which is not the case in S/390 nor in
Sparc.

So just check if map__load() was successfull and set
machine->kernel_start to zero, fixing kernel symbol resolution on S/390.

Test performed by Thomas:

 ----

  I like this patch. I have done a new build and removed all my debug output to start
  from scratch. Without your patch I get this:

  # Samples: 4  of event 'cpu-clock'
  # Event count (approx.): 1000000
  #
  # Children      Self  Command  Shared Object     Symbol
  # ........  ........  .......  ................  ........................
      75.00%     0.00%  true     [unknown]         [k] 0x00000000004bedda
              |
              ---0x4bedda
                 |
                 |--50.00%--0x42693a
                 |          |
                 |           --25.00%--0x2a72e0
                 |                     0x2af0ca
                 |                     0x3d1003fe4c0
                 |
                  --25.00%--0x4272bc
                            0x26fa84

  and with your patch (I just rebuilt the perf tool, nothing else and used the same
  perf.data file as input):

  # Samples: 4  of event 'cpu-clock'
  # Event count (approx.): 1000000
  #
  # Children      Self  Command  Shared Object               Symbol
  # ........  ........  .......  ..........................  ..................................
      75.00%     0.00%  true     [kernel.vmlinux]            [k] pgm_check_handler
              |
              ---pgm_check_handler
                 do_dat_exception
                 handle_mm_fault
                 __handle_mm_fault
                 filemap_map_pages
                 |
                 |--25.00%--rcu_read_lock_held
                 |          rcu_lockdep_current_cpu_online
                 |          0x3d1003ff4c0
                 |
                  --25.00%--lock_release

  Looks good to me....
 ----
Reported-and-Tested-by: NThomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Zvonko Kosic <zvonko.kosic@de.ibm.com>
Link: http://lkml.kernel.org/n/tip-dk0n1uzmbe0tbthrpfqlx6bz@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Michael reported the segfault when kernel.kptr_restrict=2 is set.

  $ perf record ls
  ...
  perf: Segmentation fault
  Obtained 16 stack frames.
  ./perf(dump_stack+0x2d) [0x5068df]
  ./perf(sighandler_dump_stack+0x2d) [0x5069bf]
  ./perf() [0x43e47b]
  /lib64/libc.so.6(+0x3594f) [0x7f762004794f]
  /lib64/libc.so.6(strlen+0x26) [0x7f762009ef86]
  /lib64/libc.so.6(__strdup+0xd) [0x7f762009ecbd]
  ./perf(maps__set_kallsyms_ref_reloc_sym+0x4d) [0x51590f]
  ./perf(machine__create_kernel_maps+0x136) [0x50a7de]
  ./perf(perf_session__create_kernel_maps+0x2c) [0x510a81]
  ./perf(perf_session__new+0x13d) [0x510e23]
  ./perf() [0x43fd61]
  ./perf(cmd_record+0x704) [0x441823]
  ./perf() [0x4bc1a0]
  ./perf() [0x4bc40d]
  ./perf() [0x4bc55f]
  ./perf(main+0x2d5) [0x4bc939]
  Segmentation fault (core dumped)

The reason is that with kernel.kptr_restrict=2, we don't get
the symbol from machine__get_running_kernel_start, which we
want to use in maps__set_kallsyms_ref_reloc_sym and we crash.

Check the symbol name value before calling
maps__set_kallsyms_ref_reloc_sym() and succeed without ref_reloc_sym
being set. It's safe because we check its existence before we use it.
Reported-by: NMichael Petlan <mpetlan@redhat.com>
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20170626095153.553-1-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Like machine__findnew_module_dso(), it should set necessary info for
kernel modules to find symbol info from the file.  Factor out
dso__set_module_info() to do it.

This is needed for dso__needs_decompress() to detect such DSOs.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170531120105.21731-2-namhyung@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

That is the case of _text on s390, and we have some functions that return an
address, using address zero to report problems, oops.

This would lead the symbol loading routines to not use "_text" as the reference
relocation symbol, or the first symbol for the kernel, but use instead
"_stext", that is at the same address on x86_64 and others, but not on s390:

  [acme@localhost perf-4.11.0-rc6]$ head -15 /proc/kallsyms
  0000000000000000 T _text
  0000000000000418 t iplstart
  0000000000000800 T start
  000000000000080a t .base
  000000000000082e t .sk8x8
  0000000000000834 t .gotr
  0000000000000842 t .cmd
  0000000000000846 t .parm
  000000000000084a t .lowcase
  0000000000010000 T startup
  0000000000010010 T startup_kdump
  0000000000010214 t startup_kdump_relocated
  0000000000011000 T startup_continue
  00000000000112a0 T _ehead
  0000000000100000 T _stext
  [acme@localhost perf-4.11.0-rc6]$

Which in turn would make 'perf test vmlinux' to fail because it wouldn't find
the symbols before "_stext" in kallsyms.

Fix it by using the return value only for errors and storing the
address, when the symbol is successfully found, in a provided pointer
arg.

Before this patch:

After:

  [acme@localhost perf-4.11.0-rc6]$ tools/perf/perf test -v 1
   1: vmlinux symtab matches kallsyms            :
  --- start ---
  test child forked, pid 40693
  Looking at the vmlinux_path (8 entries long)
  Using /usr/lib/debug/lib/modules/3.10.0-654.el7.s390x/vmlinux for symbols
  ERR : 0: _text not on kallsyms
  ERR : 0x418: iplstart not on kallsyms
  ERR : 0x800: start not on kallsyms
  ERR : 0x80a: .base not on kallsyms
  ERR : 0x82e: .sk8x8 not on kallsyms
  ERR : 0x834: .gotr not on kallsyms
  ERR : 0x842: .cmd not on kallsyms
  ERR : 0x846: .parm not on kallsyms
  ERR : 0x84a: .lowcase not on kallsyms
  ERR : 0x10000: startup not on kallsyms
  ERR : 0x10010: startup_kdump not on kallsyms
  ERR : 0x10214: startup_kdump_relocated not on kallsyms
  ERR : 0x11000: startup_continue not on kallsyms
  ERR : 0x112a0: _ehead not on kallsyms
  <SNIP warnings>
  test child finished with -1
  ---- end ----
  vmlinux symtab matches kallsyms: FAILED!
  [acme@localhost perf-4.11.0-rc6]$

After:

  [acme@localhost perf-4.11.0-rc6]$ tools/perf/perf test -v 1
   1: vmlinux symtab matches kallsyms            :
  --- start ---
  test child forked, pid 47160
  <SNIP warnings>
  test child finished with 0
  ---- end ----
  vmlinux symtab matches kallsyms: Ok
  [acme@localhost perf-4.11.0-rc6]$
Reported-by: NMichael Petlan <mpetlan@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-9x9bwgd3btwdk1u51xie93fz@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Not needed in this header, added to the places that need FILE,
putchar(), access() and a few other prototypes.

Link: http://lkml.kernel.org/n/tip-xxtdsl6nsna82j7puwbdjqhs@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The users of regex and fnmatch functions should include those headers
instead.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ixzm5kuamsq1ixbkuv6kmwzj@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The files using the dirent.h routines should instead include it,
reducing the includes hell that lead to longer build times.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-42g2f4z6nfg7mdb2ae97n7tj@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Removing it from util.h, part of an effort to disentangle the includes
hell, that makes changes to util.h or something included by it to cause
a complete rebuild of the tools.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ztrjy52q1rqcchuy3rubfgt2@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

More stuff that came from git, out of the hodge-podge that is util.h

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-e3lana4gctz3ub4hn4y29hkw@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Needed to use the PRI[xu](32,64) formatting macros.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-wkbho8kaw24q67dd11q0j39f@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Introduce a new option to record PERF_RECORD_NAMESPACES events emitted
by the kernel when fork, clone, setns or unshare are invoked. And update
perf-record documentation with the new option to record namespace
events.

Committer notes:

Combined it with a later patch to allow printing it via 'perf report -D'
and be able to test the feature introduced in this patch. Had to move
here also perf_ns__name(), that was introduced in another later patch.

Also used PRIu64 and PRIx64 to fix the build in some enfironments wrt:

  util/event.c:1129:39: error: format '%lx' expects argument of type 'long unsigned int', but argument 6 has type 'long long unsigned int' [-Werror=format=]
     ret  += fprintf(fp, "%u/%s: %lu/0x%lx%s", idx
                                         ^
Testing it:

  # perf record --namespaces -a
  ^C[ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 1.083 MB perf.data (423 samples) ]
  #
  # perf report -D
  <SNIP>
  3 2028902078892 0x115140 [0xa0]: PERF_RECORD_NAMESPACES 14783/14783 - nr_namespaces: 7
                [0/net: 3/0xf0000081, 1/uts: 3/0xeffffffe, 2/ipc: 3/0xefffffff, 3/pid: 3/0xeffffffc,
                 4/user: 3/0xeffffffd, 5/mnt: 3/0xf0000000, 6/cgroup: 3/0xeffffffb]

  0x1151e0 [0x30]: event: 9
  .
  . ... raw event: size 48 bytes
  .  0000:  09 00 00 00 02 00 30 00 c4 71 82 68 0c 7f 00 00  ......0..q.h....
  .  0010:  a9 39 00 00 a9 39 00 00 94 28 fe 63 d8 01 00 00  .9...9...(.c....
  .  0020:  03 00 00 00 00 00 00 00 ce c4 02 00 00 00 00 00  ................
  <SNIP>
        NAMESPACES events:          1
  <SNIP>
  #
Signed-off-by: NHari Bathini <hbathini@linux.vnet.ibm.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sargun Dhillon <sargun@sargun.me>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/148891930386.25309.18412039920746995488.stgit@hbathini.in.ibm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The refcount_t type and corresponding API should be used instead of atomic_t
when the variable is used as a reference counter.

This allows to avoid accidental refcounter overflows that might lead to
use-after-free situations.
Signed-off-by: NElena Reshetova <elena.reshetova@intel.com>
Signed-off-by: NDavid Windsor <dwindsor@gmail.com>
Signed-off-by: NHans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: NKees Kook <keescook@chromium.org>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Windsor <dwindsor@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hans Liljestrand <ishkamiel@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kees Kook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matija Glavinic Pecotic <matija.glavinic-pecotic.ext@nokia.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: alsa-devel@alsa-project.org
Link: http://lkml.kernel.org/r/1487691303-31858-9-git-send-email-elena.reshetova@intel.com
[ Did missing conversion in __machine__remove_thread() ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

In a few cases we were using 'enum map_type' and that triggered this
warning when using clang:

  util/session.c:1923:16: error: comparison of constant 2 with expression of type 'enum map_type' is always true
      [-Werror,-Wtautological-constant-out-of-range-compare]
        for (i = 0; i < MAP__NR_TYPES; ++i) {

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-i6uyo6bsopa2dghnx8qo7rri@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

As it is an array, so will always evaluate to 'true', as reported by
clang:

  builtin-sched.c:2070:19: error: address of array 'sym->name' will always evaluate to 'true' [-Werror,-Wpointer-bool-conversion]
                  if (sym && sym->name) {
                          ~~ ~~~~~^~~~
  1 warning generated.

So just ditch all those useless checks.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ydpm927col06paixb775jjx5@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To reduce the boilerplate for searching for functions in the running
kernel and modules.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-93iqzayafpaxaguoiwjqezgz@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Since the branch ip has been added to call stack for easier browsing,
this patch adds more branch information. For example, add a flag to
indicate if this ip is a branch, and also add with the branch flag.

Then we can know if the cursor node represents a branch and know what
the branch flag it has.

The branch history code has a loop detection pass that removes loops. It
would be nice for knowing how many loops were removed then in next
steps, we can compute out the average number of iterations.

For example:

Before remove_loops(),
entry0: from = 0x100, to = 0x200
entry1: from = 0x300, to = 0x250
entry2: from = 0x300, to = 0x250
entry3: from = 0x300, to = 0x250
entry4: from = 0x700, to = 0x800

After remove_loops()
entry0: from = 0x100, to = 0x200
entry1: from = 0x300, to = 0x250
entry2: from = 0x700, to = 0x800

The original entry2 and entry3 are removed. So the number of iterations
(from = 0x300, to = 0x250) is equal to removed number + 1 (2 + 1).

iterations = removed number + 1;
average iteractions = Sum(iteractions) / number of samples

This formula ignores other cases, for example, iterations cross multiple
buffers and one buffer contains 2+ loops. Because in practice, it's good
enough.
Signed-off-by: NYao Jin <yao.jin@linux.intel.com>
Acked-by: NAndi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linux-kernel@vger.kernel.org
Cc: Yao Jin <yao.jin@linux.intel.com>
Link: http://lkml.kernel.org/n/1477876794-30749-2-git-send-email-yao.jin@linux.intel.com
[ Renamed 'iter' to 'nr_loop_iter' for clarity ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Experimenting a bit using cppcheck[1], a static checker brought to my
attention by Colin, reducing the scope of some variables, reducing the
line of source code lines in the process:

  $ cppcheck --enable=style tools/perf/util/thread.c
  Checking tools/perf/util/thread.c...
  [tools/perf/util/thread.c:17]: (style) The scope of the variable 'leader' can be reduced.
  [tools/perf/util/thread.c:133]: (style) The scope of the variable 'err' can be reduced.
  [tools/perf/util/thread.c:273]: (style) The scope of the variable 'err' can be reduced.

Will continue later, but these are already useful, keep them.

1: https://sourceforge.net/p/cppcheck/wiki/Home/

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ixws7lbycihhpmq9cc949ti6@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

We're not using it anymore, few users were, but we really could do
without it, simplify lots of functions by removing it.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-1zng8wdznn00iiz08bb7q3vn@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Including machines__set_symbol_filter(), not used anymore.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-7o1qgmrpvzuis4a9f0t8mnri@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

At present, when creating module's map, perf gets 'start' address by
parsing '/proc/modules', but it's the module base address, it isn't the
start address of the '.text' section.

In most arches, it's OK. But for s390, it places 'GOT' and 'PLT'
relocations before '.text' section. So there exists an offset between
module base address and '.text' section, which will incur wrong symbol
resolution for modules.

Fix this bug by getting 'start' address of module's map from parsing
'/sys/module/[module name]/sections/.text', not from '/proc/modules'.
Signed-off-by: NSong Shan Gong <gongss@linux.vnet.ibm.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Link: http://lkml.kernel.org/r/1469070651-6447-2-git-send-email-gongss@linux.vnet.ibm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

And do nothing, just like free(), to avoid having to test it in callers,
usually in error paths.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-q42gj3b3znhho9z1mrbo4jce@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To determine the libunwind methods to use, we should get the
32bit/64bit information from maps of a thread. When a thread is newly
created, the information is not prepared. This patch moves
unwind__prepare_access() into thread__insert_map() so we can get the
information we need from maps. Meanwhile, let thread__insert_map()
return value and show messages on error.
Signed-off-by: NHe Kuang <hekuang@huawei.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ekaterina Tumanova <tumanova@linux.vnet.ibm.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1464924803-22214-5-git-send-email-hekuang@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

As thread__resolve_callchain_sample can be used for handling perf.data
files, that could've been recorded with a large max_stack sysctl setting
than what the system used for analysis has set.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Zefan Li <lizefan@huawei.com>
Link: http://lkml.kernel.org/n/tip-2995bt2g5yq2m05vga4kip6m@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Hook into the libtraceevent plugin kernel symbol resolver to warn the
user that that can't happen with kptr_restrict=1.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-9gc412xx1gl0lvqj1d1xwlyb@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

This means the user can't access /proc/kallsyms, for instance, because
/proc/sys/kernel/kptr_restrict is set to 1.

Instead leave the ref_reloc_sym as NULL and code using it will cope.

This allows 'perf trace' to work on such systems for !root, the only
issue would be when trying to resolve kernel symbols, which happens,
for instance, in some libtracevent plugins.  A warning for that case
will be provided in the next patch in this series.

Noticed in Ubuntu 16.04, that comes with kptr_restrict=1.
Reported-by: NMilian Wolff <milian.wolff@kdab.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-knpu3z4iyp2dxpdfm798fac4@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The perf_sample->ip_callchain->nr value includes all the entries in the
ip_callchain->ip[] array, real addresses and PERF_CONTEXT_{KERNEL,USER,etc},
while what the user expects is that what is in the kernel.perf_event_max_stack
sysctl or in the upcoming per event perf_event_attr.sample_max_stack knob be
honoured in terms of IP addresses in the stack trace.

So match the kernel support and validate chain->nr taking into account
both kernel.perf_event_max_stack and kernel.perf_event_max_contexts_per_stack.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Zefan Li <lizefan@huawei.com>
Link: http://lkml.kernel.org/n/tip-mgx0jpzfdq4uq4abfa40byu0@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Instead of using a raw string, use DSO__NAME_KALLSYMS and
DSO__NAME_KCORE macros for kallsyms and kcore.
Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160515031935.4017.50971.stgit@devboxSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The existing implementation of thread__resolve_callchain, under certain
circumstances, can assemble callchain entries in the incorrect order.

The callchain entries are resolved incorrectly for a sample when all of
the following conditions are met:

1. callchain_param.order is set to ORDER_CALLER

2. thread__resolve_callchain_sample is able to resolve callchain entries
   for the sample.

3. unwind__get_entries is also able to resolve callchain entries for the
   sample.

The fix is accomplished by reversing the order in which
thread__resolve_callchain_sample and unwind__get_entries are called when
callchain_param.order is set to ORDER_CALLER.

Unwind specific code from thread__resolve_callchain is also moved into a
new static function to improve readability of the fix.

How to Reproduce the Existing Bug:

Modifying perf script to print call trees in the opposite order or
applying the remaining patches from this series and comparing the
results output from export-to-postgtresql.py are the easiest ways to see
the bug, however it can still be seen in current builds using perf
report.

Here is how i can reproduce the bug using perf report:

  # perf record --call-graph=dwarf stress -c 1 -t 5

when i run this command:

  # perf report --call-graph=flat,0,0,callee

This callchain, containing kernel (handle_irq_event, etc) and userspace
samples (__libc_start_main, etc) is contained in the output, which looks
correct (callee order):

                gen8_irq_handler
                handle_irq_event_percpu
                handle_irq_event
                handle_edge_irq
                handle_irq
                do_IRQ
                ret_from_intr
                __random
                rand
                0x558f2a04dded
                0x558f2a04c774
                __libc_start_main
                0x558f2a04dcd9

Now run this command using caller order:

  # perf report --call-graph=flat,0,0,caller

It is expected to see the exact reverse of the above when using caller
order (with "0x558f2a04dcd9" at the top and "gen8_irq_handler" at the
bottom) in the output, but it is nowhere to be found.

instead you see this:

                ret_from_intr
                do_IRQ
                handle_irq
                handle_edge_irq
                handle_irq_event
                handle_irq_event_percpu
                gen8_irq_handler
                0x558f2a04dcd9
                __libc_start_main
                0x558f2a04c774
                0x558f2a04dded
                rand
                __random

Notice how internally the kernel symbols are reversed and the user space
symbols are reversed, but the kernel symbols still appear above the user
space symbols.

if this patch is applied and perf script is re-run, you will see the
expected output (with "0x558f2a04dcd9" at the top and "gen8_irq_handler"
at the bottom):

                0x558f2a04dcd9
                __libc_start_main
                0x558f2a04c774
                0x558f2a04dded
                rand
                __random
                ret_from_intr
                do_IRQ
                handle_irq
                handle_edge_irq
                handle_irq_event
                handle_irq_event_percpu
                gen8_irq_handler
Signed-off-by: NChris Phlipot <cphlipot0@gmail.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1461831551-12213-2-git-send-email-cphlipot0@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Now we have sort dimensions private for struct hists, we need to make
dimension booleans hists specific as well.

Moving sort__has_parent into struct perf_hpp_list.
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1462276488-26683-3-git-send-email-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To be used, for instance, for pre-allocating an rb_tree array for
sorting by other keys besides the current pid one.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ja0ifkwue7ttjhbwijn6g6eu@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

There is an upper limit to what tooling considers a valid callchain,
and it was tied to the hardcoded value in the kernel,
PERF_MAX_STACK_DEPTH (127), now that this can be tuned via a sysctl,
make it read it and use that as the upper limit, falling back to
PERF_MAX_STACK_DEPTH for kernels where this sysctl isn't present.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-yjqsd30nnkogvj5oyx9ghir9@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Before the support for using /proc/kcore was introduced, the kallsyms
routines used /proc/modules and the first 'perf test' entry expected
finding maps for each module in the system, which is not the case with
the kcore code. Provide a way to ignore kcore files so that the test can
have its expectations met.

Improving the test to cover kcore files as well needs to be done.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ek5urnu103dlhfk4l6pcw041@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-5i07ivw1yjsweb7gztr255jd@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Signed-off-by: NAdam Buchbinder <adam.buchbinder@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>