Commit Graph

534300 Commits

Author SHA1 Message Date
Kan Liang
f9db0d0f1b perf callchain: Allow disabling call graphs per event
This patch introduce "call-graph=no" to disable per-event callgraph.

Here is an example.

  perf record -e 'cpu/cpu-cycles,call-graph=fp/,cpu/instructions,call-graph=no/' sleep 1

  perf report --stdio

  # To display the perf.data header info, please use
  --header/--header-only options.
  #
  #
  # Total Lost Samples: 0
  #
  # Samples: 6  of event 'cpu/cpu-cycles,call-graph=fp/'
  # Event count (approx.): 774218
  #
  # Children      Self  Command  Shared Object     Symbol
  # ........  ........  .......  ................  ........................................
  #
    61.94%     0.00%  sleep    [kernel.vmlinux]  [k] entry_SYSCALL_64_fastpath
              |
              ---entry_SYSCALL_64_fastpath
                 |
                 |--97.30%-- __brk
                 |
                  --2.70%-- mmap64
                            _dl_check_map_versions
                            _dl_check_all_versions

    61.94%     0.00%  sleep    [kernel.vmlinux]  [k] perf_event_mmap
              |
              ---perf_event_mmap
                 |
                 |--97.30%-- do_brk
                 |          sys_brk
                 |          entry_SYSCALL_64_fastpath
                 |          __brk
                 |
                  --2.70%-- mmap_region
                            do_mmap_pgoff
                            vm_mmap_pgoff
                            sys_mmap_pgoff
                            sys_mmap
                            entry_SYSCALL_64_fastpath
                            mmap64
                            _dl_check_map_versions
                            _dl_check_all_versions
  ......

  # Samples: 6  of event 'cpu/instructions,call-graph=no/'
  # Event count (approx.): 359692
  #
  # Children      Self  Command  Shared Object     Symbol
  # ........  ........  .......  ................  .................................
  #
     89.03%     0.00%  sleep    [unknown]         [.] 0xffff6598ffff6598
     89.03%     0.00%  sleep    ld-2.17.so        [.] _dl_resolve_conflicts
     89.03%     0.00%  sleep    [kernel.vmlinux]  [k] page_fault

Signed-off-by: Kan Liang <kan.liang@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1439289050-40510-2-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-12 13:20:28 -03:00
Kan Liang
d457c96392 perf callchain: Per-event type selection support
This patchkit adds the ability to set callgraph mode (fp, dwarf, lbr) per
event. This in term can reduce sampling overhead and the size of the
perf.data.

Here is an example.

  perf record -e 'cpu/cpu-cycles,period=1000,call-graph=fp,time=1/,cpu/instructions,call-graph=lbr/' sleep 1

 perf evlist -v
 cpu/cpu-cycles,period=1000,call-graph=fp,time=1/: type: 4, size: 112,
 config: 0x3c, { sample_period, sample_freq }: 1000, sample_type:
 IP|TID|TIME|CALLCHAIN|PERIOD|IDENTIFIER, read_format: ID, disabled: 1,
 inherit: 1, mmap: 1, comm: 1, enable_on_exec: 1, task: 1, sample_id_all:
 1, exclude_guest: 1, mmap2: 1, comm_exec: 1
 cpu/instructions,call-graph=lbr/: type: 4, size: 112, config: 0xc0, {
 sample_period, sample_freq }: 4000, sample_type:
 IP|TID|TIME|CALLCHAIN|PERIOD|BRANCH_STACK|IDENTIFIER, read_format: ID,
 disabled: 1, inherit: 1, freq: 1, enable_on_exec: 1, sample_id_all: 1,
 exclude_guest: 1

Signed-off-by: Kan Liang <kan.liang@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1439289050-40510-1-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-12 13:20:27 -03:00
Masami Hiramatsu
75186a9b09 perf probe: Fix to show lines of sys_ functions correctly
"perf probe --lines sys_poll" shows only the first line of sys_poll,
because the SYSCALL_DEFINE macro:

  ----
  SYSCALL_DEFINE*(foo,...)
  {
    body;
  }
  ----

  is expanded as below (on debuginfo)

  ----

  static inline int SYSC_foo(...)
  {
    body;
  }
  int SyS_foo(...) <- is an alias of sys_foo.
  {
    return SYSC_foo(...);
  }
  ----

So, "perf probe --lines sys_foo" decodes SyS_foo function and it also skips
inlined functions(SYSC_foo) inside the target function because those functions
are usually defined somewhere else.

To fix this issue, this fix checks whether the inlined function is defined at
the same point of the target function, and if so, it doesn't skip the inline
function.

Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/20150812012406.11811.94691.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-12 13:20:27 -03:00
Arnaldo Carvalho de Melo
63ab1749f3 perf hists browser: Make ESC unzoom as well
In addition to <-, that may be repurposed for horizontal scrolling.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-w3rctelxr4yxrjufx7z3fclb@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-12 12:46:55 -03:00
Arnaldo Carvalho de Melo
517dfdb315 perf ui browser: Introduce ui_browser__printf()
To remove direct access to libslang functions, with the immediate goal
of implementing horizontal scrolling at the ui_browser level, but also
because we may at some point want to implement ui_browser with other UIs
in addition to the current libslang implementation.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-w0niblabqrkecs4o0eogfy6c@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-12 10:27:05 -03:00
Arnaldo Carvalho de Melo
26270a0082 perf ui browser: Introduce ui_browser__write_nstring()
To remove direct access to libslang functions, with the immediate goal
of implementing horizontal scrolling at the ui_browser level, but also
because we may at some point want to implement ui_browser with other UIs
in addition to the current libslang implementation.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-437ineavoejzou727mr9bxpi@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-12 10:27:04 -03:00
Arnaldo Carvalho de Melo
b62bee1bde perf trace: Beautify keyctl's option arg
8.697 (0.103 ms): pool/2343 keyctl(option: GET_PERSISTENT, arg2: 1000, arg3: 4294967294, arg4: 140703061514067, arg5: 140703692383680) = 1023192809
 8.763 (0.049 ms): pool/2343 keyctl(option: SEARCH, arg2: 1023192809, arg3: 140703745767772, arg4: 140703745767832, arg5: 4294967294) = 140224497
 8.789 (0.016 ms): pool/2343 keyctl(option: SEARCH, arg2: 140224497, arg3: 140703745767814, arg4: 140703745767900) = 512300257
 8.807 (0.011 ms): pool/2343 keyctl(option: READ, arg2: 512300257                                  ) = 13
 8.822 (0.008 ms): pool/2343 keyctl(option: READ, arg2: 512300257, arg3: 140703061514000, arg4: 13 ) = 13
 8.837 (0.007 ms): pool/2343 keyctl(option: READ, arg2: 140224497                                  ) = 4
 8.852 (0.009 ms): pool/2343 keyctl(option: READ, arg2: 140224497, arg3: 140703061514000, arg4: 4  ) = 4
 8.869 (0.010 ms): pool/2343 keyctl(option: SEARCH, arg2: 140224497, arg3: 140703745767772, arg4: 140703061514032) = -1 ENOKEY Required key not available
 8.892 (0.017 ms): pool/2343 keyctl(option: DESCRIBE, arg2: 512300257                              ) = 43
 8.910 (0.012 ms): pool/2343 keyctl(option: DESCRIBE, arg2: 512300257, arg3: 140703061544384, arg4: 43) = 43

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-013ab219irsxngyumrf5gp8s@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-12 10:27:03 -03:00
Arnaldo Carvalho de Melo
8d8c66a248 perf trace: Use the FD beautifier for socket syscall fds
But we really should have something like 'strace -yy' here...

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-eyrt1ypfq68u4ljagyk2nj1i@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-12 10:27:03 -03:00
Andi Kleen
76b1065581 perf sort: Check for SRCLINE_UNKNOWN case in "srcfile" processing
Handle the SRCLINE_UNKNOWN case correctly when processing "srcfile".

Commiter note:

We can't just free it, as it was't allocated via malloc, its a guard
variable.

Reported-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20150811133655.GC4524@tassilo.jf.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-12 10:27:02 -03:00
Arnaldo Carvalho de Melo
28ebb87c73 perf trace: Add missing clockid entries
We were missing:

  CLOCK_BOOTTIME, CLOCK_REALTIME_ALARM, CLOCK_BOOTTIME_ALARM,
  CLOCK_SGI_CYCLE and CLOCK_TAI.

Add them.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-d67rwqtwm9jyenwes98kr0cr@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-12 10:27:02 -03:00
Arnaldo Carvalho de Melo
090389b6d9 perf trace: Associate some more syscall args with the getname beautifier
This time using 'trinity' to test these:

  fchmodat, futimesat, llistxattr, lremovexattr, lstat, mknodat,
  mq_unlink, stat and vmsplice.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-a1uqu249nwwh0ixrhm80k4a4@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-12 10:26:53 -03:00
Ingo Molnar
5f1230c9b8 perf/core improvements and fixes:
User visible:
 
 - Introduce 'srcfile' sort key: (Andi Kleen)
 
   # perf record -F 10000 usleep 1
   # perf report --stdio --dsos '[kernel.vmlinux]' -s srcfile
   <SNIP>
   # Overhead  Source File
       26.49%  copy_page_64.S
        5.49%  signal.c
        0.51%  msr.h
   #
 
   It can be combined with other fields, for instance, experiment with
   '-s srcfile,symbol'.
 
   There are some oddities in some distros and with some specific DSOs, being
   investigated, so your mileage may vary.
 
 - Update the column width for the "srcline" sort key (Arnaldo Carvalho de Melo)
 
 - Support per-event 'freq' term: (Namhyung Kim)
 
   $ perf record -e 'cpu/instructions,freq=1234/',cycles -c 1000 sleep 1
   $ perf evlist -F
   cpu/instructions,freq=1234/: sample_freq=1234
   cycles: sample_period=1000
   $
 
 Infrastructure:
 
 - Move perf_counts struct and functions into separate object (Jiri Olsa)
 
 - Unset perf_event_attr::freq when period term is set (Jiri Olsa)
 
 - Move callchain option parsing code to util.c (Kan Liang)
 
 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJVyQ9wAAoJENZQFvNTUqpAItAP/A7pmI5VtOjute3uHQ8BgbiG
 IRlmNBobYG9ds7Z0llgFtN0IpjSBpsyvoAt6O7X68j+h53/w2dxuiiKeiOQbt0K6
 w2nM3stXv9k67CLLS70qCJ9tHYE0zY7YDp7iw3hAMo4Vs/wqwezh85ksDkxv6TDR
 q8bKOK7jXnBDU6I6XiWb1V2pHVfFgdE7sPt0Oo0EXXT6wzm6EeM7PwcdI2ag5PLf
 zg++5DCrjwdrDD/0+F2gzQFpmGx0UrNMg1MP+bwh9woJ9d974Y5rKspPtWGnLqDE
 HKoKTeyroD4FmnFrRXL75CMJm1Ln6Pa+EB/Cgsm5/4ZeUovd31RKjVwikgziS2fv
 80KU8bt+MK0qxiVYSicKORq/3HerW9Y/Cx/9lP8vTbyBvya8MqfthFjwoqCtUl1M
 tacjCGG4dbBq7hgOs3WwKbrC0dEa1uTL3XpXCq8dFGhzY7OKs88DF5pKxC6epAxy
 Q9IhvDPPAW5tSPrUWJVs5dXbxx6vDuytVH0aZJc7sthvAWoxLaZZeR/O84uVZt27
 5mV5QWLbVsIEA9FJk16bAwtu+i3bk/GcQVGtEpxwehyP7gEW1mQyTYuXgySY+qBm
 hEmMmekCaNOIXPZXjULu7m3YNU23tTkgU/eGXKzF+8Zdr0DJsMyP6IXF/TT37CM/
 JSCs5/4xe0R9govqlTGj
 =JSPY
 -----END PGP SIGNATURE-----

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

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

User visible changes:

  - Introduce 'srcfile' sort key: (Andi Kleen)

    # perf record -F 10000 usleep 1
    # perf report --stdio --dsos '[kernel.vmlinux]' -s srcfile
    <SNIP>
    # Overhead  Source File
        26.49%  copy_page_64.S
         5.49%  signal.c
         0.51%  msr.h
    #

    It can be combined with other fields, for instance, experiment with
    '-s srcfile,symbol'.

    There are some oddities in some distros and with some specific DSOs, being
    investigated, so your mileage may vary.

  - Update the column width for the "srcline" sort key (Arnaldo Carvalho de Melo)

  - Support per-event 'freq' term: (Namhyung Kim)

    $ perf record -e 'cpu/instructions,freq=1234/',cycles -c 1000 sleep 1
    $ perf evlist -F
    cpu/instructions,freq=1234/: sample_freq=1234
    cycles: sample_period=1000
    $

Infrastructure changes:

  - Move perf_counts struct and functions into separate object (Jiri Olsa)

  - Unset perf_event_attr::freq when period term is set (Jiri Olsa)

  - Move callchain option parsing code to util.c (Kan Liang)

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-12 12:16:11 +02:00
Takao Indoh
709bc87192 perf/x86/intel/pt: Clean up files of Intel Processor Trace
This patch just cleans up some files of Intel Processor Trace, does not
change its behavior. This patch removes unused definitions and replaces a
constant value with a macro.

Signed-off-by: Takao Indoh <indou.takao@jp.fujitsu.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin<alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: H.Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1438681015-5124-1-git-send-email-indou.takao@jp.fujitsu.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-12 11:43:22 +02:00
Alexander Shishkin
c2ad6b51ef perf/ring-buffer: Clarify the use of page::private for high-order AUX allocations
A question [1] was raised about the use of page::private in AUX buffer
allocations, so let's add a clarification about its intended use.

The private field and flag are used by perf's rb_alloc_aux() path to
tell the pmu driver the size of each high-order allocation, so that the
driver can program those appropriately into its hardware. This only
matters for PMUs that don't support hardware scatter tables. Otherwise,
every page in the buffer is just a page.

This patch adds a comment about the private field to the AUX buffer
allocation path.

  [1] http://marc.info/?l=linux-kernel&m=143803696607968

Reported-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1438063204-665-1-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-12 11:43:20 +02:00
Peter Zijlstra
19b3340cf5 perf/x86: Fix MSR PMU driver
Currently we only update the sysfs event files per available MSR, we
didn't actually disallow creating unlisted events.

Rework things such that the dectection, sysfs listing and event
creation are better coordinated.

Sadly it appears it's impossible to probe R/O MSRs under virt. This
means we have to do the full model table to avoid listing all MSRs all
the time.

Tested-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-12 11:43:20 +02:00
Ingo Molnar
3d325bf0da Merge branch 'perf/urgent' into perf/core, to pick up fixes before applying new changes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-12 11:39:19 +02:00
Matt Fleming
d7a702f0b1 perf/x86/intel/cqm: Do not access cpu_data() from CPU_UP_PREPARE handler
Tony reports that booting his 144-cpu machine with maxcpus=10 triggers
the following WARN_ON():

[   21.045727] WARNING: CPU: 8 PID: 647 at arch/x86/kernel/cpu/perf_event_intel_cqm.c:1267 intel_cqm_cpu_prepare+0x75/0x90()
[   21.045744] CPU: 8 PID: 647 Comm: systemd-udevd Not tainted 4.2.0-rc4 #1
[   21.045745] Hardware name: Intel Corporation BRICKLAND/BRICKLAND, BIOS BRHSXSD1.86B.0066.R00.1506021730 06/02/2015
[   21.045747]  0000000000000000 0000000082771b09 ffff880856333ba8 ffffffff81669b67
[   21.045748]  0000000000000000 0000000000000000 ffff880856333be8 ffffffff8107b02a
[   21.045750]  ffff88085b789800 ffff88085f68a020 ffffffff819e2470 000000000000000a
[   21.045750] Call Trace:
[   21.045757]  [<ffffffff81669b67>] dump_stack+0x45/0x57
[   21.045759]  [<ffffffff8107b02a>] warn_slowpath_common+0x8a/0xc0
[   21.045761]  [<ffffffff8107b15a>] warn_slowpath_null+0x1a/0x20
[   21.045762]  [<ffffffff81036725>] intel_cqm_cpu_prepare+0x75/0x90
[   21.045764]  [<ffffffff81036872>] intel_cqm_cpu_notifier+0x42/0x160
[   21.045767]  [<ffffffff8109a33d>] notifier_call_chain+0x4d/0x80
[   21.045769]  [<ffffffff8109a44e>] __raw_notifier_call_chain+0xe/0x10
[   21.045770]  [<ffffffff8107b538>] _cpu_up+0xe8/0x190
[   21.045771]  [<ffffffff8107b65a>] cpu_up+0x7a/0xa0
[   21.045774]  [<ffffffff8165e920>] cpu_subsys_online+0x40/0x90
[   21.045777]  [<ffffffff81433b37>] device_online+0x67/0x90
[   21.045778]  [<ffffffff81433bea>] online_store+0x8a/0xa0
[   21.045782]  [<ffffffff81430e78>] dev_attr_store+0x18/0x30
[   21.045785]  [<ffffffff8126b6ba>] sysfs_kf_write+0x3a/0x50
[   21.045786]  [<ffffffff8126ad40>] kernfs_fop_write+0x120/0x170
[   21.045789]  [<ffffffff811f0b77>] __vfs_write+0x37/0x100
[   21.045791]  [<ffffffff811f38b8>] ? __sb_start_write+0x58/0x110
[   21.045795]  [<ffffffff81296d2d>] ? security_file_permission+0x3d/0xc0
[   21.045796]  [<ffffffff811f1279>] vfs_write+0xa9/0x190
[   21.045797]  [<ffffffff811f2075>] SyS_write+0x55/0xc0
[   21.045800]  [<ffffffff81067300>] ? do_page_fault+0x30/0x80
[   21.045804]  [<ffffffff816709ae>] entry_SYSCALL_64_fastpath+0x12/0x71
[   21.045805] ---[ end trace fe228b836d8af405 ]---

The root cause is that CPU_UP_PREPARE is completely the wrong notifier
action from which to access cpu_data(), because smp_store_cpu_info()
won't have been executed by the target CPU at that point, which in turn
means that ->x86_cache_max_rmid and ->x86_cache_occ_scale haven't been
filled out.

Instead let's invoke our handler from CPU_STARTING and rename it
appropriately.

Reported-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Kanaka Juvva <kanaka.d.juvva@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vikas Shivappa <vikas.shivappa@intel.com>
Link: http://lkml.kernel.org/r/1438863163-14083-1-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-12 11:37:23 +02:00
Peter Zijlstra
dbc72b7a0c perf/x86/intel: Fix memory leak on hot-plug allocation fail
We fail to free the shared_regs allocation if the constraint_list
allocation fails.

Cure this and be more consistent in NULL-ing the pointers after free.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-12 11:37:22 +02:00
Peter Zijlstra
c7999c6f3f perf: Fix PERF_EVENT_IOC_PERIOD migration race
I ran the perf fuzzer, which triggered some WARN()s which are due to
trying to stop/restart an event on the wrong CPU.

Use the normal IPI pattern to ensure we run the code on the correct CPU.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: bad7192b84 ("perf: Fix PERF_EVENT_IOC_PERIOD to force-reset the period")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-12 11:37:22 +02:00
Ben Hutchings
ee9397a6fb perf: Fix double-free of the AUX buffer
If rb->aux_refcount is decremented to zero before rb->refcount,
__rb_free_aux() may be called twice resulting in a double free of
rb->aux_pages.  Fix this by adding a check to __rb_free_aux().

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Fixes: 57ffc5ca67 ("perf: Fix AUX buffer refcounting")
Link: http://lkml.kernel.org/r/1437953468.12842.17.camel@decadent.org.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-12 11:37:21 +02:00
Namhyung Kim
4605bb55b9 perf evlist: Be more specific on -F/--freq
Currently perf evlist -F shows the number as if it's always sampling
frequency.  But we now support per-event freq/period settings.  So it'd
better to show more detailed info whether it's freq or period.

  $ perf record -e 'cpu/config=1/,cpu/config=2,period=300000/' sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.017 MB perf.data ]

  $ perf evlist -F
  cpu/config=1/: sample_freq=4000
  cpu/config=2,period=300000/: sample_period=300000

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1439102724-14079-2-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-10 17:20:26 -03:00
Namhyung Kim
09af2a5535 perf record: Support per-event freq term
Now perf can set per-event value of time and (sampling) period.  But I
guess most users like me just want to set frequency rather than period.
So add the 'freq' term in the event parser.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1439102724-14079-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-10 17:20:26 -03:00
Andi Kleen
31191a85fb perf report: Add support for srcfile sort key
In some cases it's useful to characterize samples by file. This is
useful to get a higher level categorization, for example to map cost to
subsystems.

Add a srcfile sort key to perf report. It builds on top of the existing
srcline support.

Commiter notes:

E.g.:

  # perf record -F 10000 usleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.016 MB perf.data (13 samples) ]
  [root@zoo ~]# perf report -s srcfile --stdio
  # Total Lost Samples: 0
  #
  # Samples: 13  of event 'cycles'
  # Event count (approx.): 869878
  #
  # Overhead  Source File
  # ........  ...........
      60.99%  .
      20.62%  paravirt.h
      14.23%  rmap.c
       4.04%  signal.c
       0.11%  msr.h

  #

The first line is collecting all the files for which srcfiles couldn't somehow
get resolved to:

  # perf report -s srcfile,dso --stdio
  # Total Lost Samples: 0
  #
  # Samples: 13  of event 'cycles'
  # Event count (approx.): 869878
  #
  # Overhead  Source File  Shared Object
  # ........  ...........  ................
      40.97%  .            ld-2.20.so
      20.62%  paravirt.h   [kernel.vmlinux]
      20.02%  .            libc-2.20.so
      14.23%  rmap.c       [kernel.vmlinux]
       4.04%  signal.c     [kernel.vmlinux]
       0.11%  msr.h        [kernel.vmlinux]

  #

XXX: Investigate why that is not resolving on Fedora 21, Andi says he hasn't
     seen this on Fedora 22.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1438988064-21834-1-git-send-email-andi@firstfloor.org
[ Added column length update, from 0e65bdb3f90f ('perf hists: Update the column width for the "srcline" sort key') ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-10 17:20:25 -03:00
Arnaldo Carvalho de Melo
e8e6d37e73 perf hists: Update the column width for the "srcline" sort key
When we introduce a new sort key, we need to update the
hists__calc_col_len() function accordingly, otherwise the width
will be limited to strlen(header).

We can't update it when obtaining a line value for a column (for
instance, in sort__srcline_cmp()), because we reset it all when doing a
resort (see hists__output_recalc_col_len()), so we need to, from what is
in the hist_entry fields, set each of the column widths.

Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Fixes: 409a8be615 ("perf tools: Add sort by src line/number")
Link: http://lkml.kernel.org/n/tip-jgbe0yx8v1gs89cslr93pvz2@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-10 17:19:59 -03:00
Arnaldo Carvalho de Melo
5cef897652 perf hists: hist_entry__cmp() may use he_tmp.hists, initialize it
The iter_add_next_cumulative_entry() function calls hist_entry__cmp(),
which may want to access the hists where this hist_entry is stored,
initialize it to let that happen and avoid segfaults.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-iqg98sfn4fvwcxp0pdvqauie@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-10 17:01:00 -03:00
Jiri Olsa
ab35a7d0ee perf tools: Unset perf_event_attr::freq when period term is set
We need to unset 'perf_event_attr::freq' bit (default 1) when
'period' term is specified within event definition like:

  -e 'cpu/cpu-cycles,call-graph=fp,time,period=100000'

otherwise it will handle the period value as frequency
(and fail if it crossed the maximum allowed frequency value).

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/20150808171210.GC17040@krava.brq.redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-10 11:58:05 -03:00
Andi Kleen
a9710ba091 perf tools: Support full source file paths for srcline
For perf report/script srcline currently only the base file name of the
source file is printed. This is a good default because it usually fits
on the screen.

But in some cases we want to know the full file name, for example to
aggregate hits per file.

In the later case we need more than the base file name to resolve file
naming collisions: for example the kernel source has ~70 files named
"core.c"

It's also useful as input to post processing tools which want to point
to the right file.

Add a flag to allow full file name output.

Add an option to perf report/script to enable this option.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1438986245-15191-1-git-send-email-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-10 11:58:05 -03:00
Kan Liang
076a30c411 perf callchain: Move option parsing code to util.c
Move callchain option parse related code to util.c, to avoid dragging
more object files into the python binding.

Signed-off-by: Kan Liang <kan.liang@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1438890294-33409-1-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-08 14:16:49 -03:00
Jiri Olsa
d809560b36 perf stat: Move perf_counts struct and functions into separate object
Moving 'struct perf_counts' and associated functions into separate
object, so we could remove stat.c object dependency from python build.

It makes the python code to build properly, because it fails to load due
to missing stat-shadow.c object dependency if some patches from Kan
Liang are applied.

So apply this one, then Kan's.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/20150807105103.GB8624@krava.brq.redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-08 14:16:49 -03:00
Ingo Molnar
f1d800bf61 perf/ebpf library + llvm/clang infrastructure
Infrastructure:
 
 - library for interfacing with the kernel eBPF infrastructure, with
   tools/perf/ targeted as a first user (Wang Nan)
 
 - llvm/clang infrastructure for building BPF object files from C source
   code (Wang Nan)
 
 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJVxMUTAAoJENZQFvNTUqpA0qIP/3gQOMyvc7JFEQV0xOBQSlZ2
 qEwR0gXpHqrEhiQ8jYPAaY+Ei8moWohF6DOg3ein75kmsGJDP2rfr0d/6U0K5S7t
 3tkxA7QWhEYOqAo/UDfc5WygQF794w8UQxApzox6DnrUjeeJ0VfdkZU7fpnwQS5Z
 K4hJjWdg9lxvJ+QJM3DgxqLNlyI8TfalQGnWmKS5m0184kBDaXz/MtEQKCRB5X5S
 khw/VW+F4Er1mDGmzwZrzHRuXJJcZsLCCz4jIERlKe7a7vUHaH5KPM2OSqlf0asK
 62o1EVNNpCszfJKa69BjA/vvtiaWKdWkfBko6+C+ARYRTqOXoPR6X10QsneVrwXM
 DZ8dkgSdzgE9CbbAa+Fo46i+u3TPoDQfk/LB1ZIzy0BD+gwXZcdnVZLBLK+zMziI
 IsKidf/aHykgaKfjXUmeocO/LUnvsoEcYEqkLsoT45br38p7OQ/0DWfguSFNuVpR
 1onyuYEa8vHD4vjgjlUKV8UEoL11lEKLcUPvK/z2pQwUQnlrdmVx1V7dGNYGCiTI
 uhvjHYaMCifKKn52LdnjkYZqyfIqBLBwlAu49i0ONCIfYiJ+IoIEdBIXbog3mThC
 JI60I1VsWp2PyUoQ8E93T8AQTMZs8umzKr1LX+/5pZBTXKL+26ZsC7qwcSExom3n
 erfehyibJDo/4Gqj1CEx
 =E+oR
 -----END PGP SIGNATURE-----

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

Pull perf/ebpf library + llvm/clang infrastructure changes from Arnaldo Carvalho de Melo:

Infrastructure changes:

  - Add library for interfacing with the kernel eBPF infrastructure, with
    tools/perf/ targeted as a first user. (Wang Nan)

  - Add llvm/clang infrastructure for building BPF object files from C source
    code. (Wang Nan)

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-08 10:05:17 +02:00
Wang Nan
9bc898c701 perf tests: Add LLVM test for eBPF on-the-fly compiling
Previous patches introduce llvm__compile_bpf() to compile source file to
eBPF object. This patch adds testcase to test it. It also tests libbpf
by opening generated object after applying next patch which introduces
HAVE_LIBBPF_SUPPORT option.

Since llvm__compile_bpf() prints long messages which users who don't
explicitly test llvm doesn't care, this patch set verbose to -1 to
suppress all debug, warning and error message, and hint user use 'perf
test -v' to see the full output.

For the same reason, if clang is not found in PATH and there's no [llvm]
section in .perfconfig, skip this test.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/n/1436445342-1402-17-git-send-email-wangnan0@huawei.com
[ Add tools/lib/bpf/ to tools/perf/MANIFEST, so that the tarball targets build ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-07 10:57:24 -03:00
Wang Nan
0c6d18bfd5 perf tools: Auto detecting kernel include options
To help user find correct kernel include options, this patch extracts
them from kbuild system by an embedded script kinc_fetch_script, which
creates a temporary directory, generates Makefile and an empty dummy.o
then use the Makefile to fetch $(NOSTDINC_FLAGS), $(LINUXINCLUDE) and
$(EXTRA_CFLAGS) options. The result is passed to compiler script using
'KERNEL_INC_OPTIONS' environment variable.

Because options from kbuild contains relative path like
'Iinclude/generated/uapi', the work directory must be changed. This is
done by previous patch.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1436445342-1402-16-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-07 10:57:23 -03:00
Wang Nan
d325d7887b perf tools: Auto detecting kernel build directory
This patch detects kernel build directory by checking the existence of
include/generated/autoconf.h.

clang working directory is changed to kbuild directory if it is found,
to help user use relative include path. Following patch will detect
kernel include directory, which contains relative include patch so this
workdir changing is needed.

Users are allowed to set 'kbuild-dir = ""' manually to disable this
checking.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/n/tip-owyfwfbemrjn0tlj6tgk2nf5@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-07 10:57:16 -03:00
Wang Nan
4cea3a9cb3 perf tools: Call clang to compile C source to object code
This is the core patch for supporting eBPF on-the-fly compiling, does
the following work:

 1. Search clang compiler using search_program().

 2. Run command template defined in llvm-bpf-cmd-template option in
    [llvm] config section using read_from_pipe(). Patch of clang and
    source code path is injected into shell command using environment
    variable using force_set_env().

  Commiter notice:

  When building with DEBUG=1 we get a compiler error that gets fixed with
  the same approach described in commit b236512280:

    perf kmem: Fix compiler warning about may be accessing uninitialized variable

    The last argument to strtok_r doesn't need to be initialized, its
    just a placeholder to make this routine reentrant, but gcc doesn't know
    about that and complains, breaking the build, fix it by setting it to
    NULL.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/n/1436445342-1402-14-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-07 10:16:59 -03:00
Wang Nan
aa61fd05ca perf tools: Introduce llvm config options
This patch introduces [llvm] config section with 5 options. Following
patches will use then to config llvm dynamica compiling.

'llvm-utils.[ch]' is introduced in this patch for holding all
llvm/clang related stuffs.

Example:

  [llvm]
        # Path to clang. If omit, search it from $PATH.
	clang-path = "/path/to/clang"

        # Cmdline template. Following line shows its default value.
        # Environment variable is used to passing options.
        #
        # *NOTE*: -D__KERNEL__ MUST appears before $CLANG_OPTIONS,
        # so user have a chance to use -U__KERNEL__ in $CLANG_OPTIONS
        # to cancel it.
	clang-bpf-cmd-template = "$CLANG_EXEC -D__KERNEL__ $CLANG_OPTIONS \
				  $KERNEL_INC_OPTIONS -Wno-unused-value \
				  -Wno-pointer-sign -working-directory \
				  $WORKING_DIR  -c $CLANG_SOURCE -target \
				  bpf -O2 -o -"

        # Options passed to clang, will be passed to cmdline by
        # $CLANG_OPTIONS.
	clang-opt = "-Wno-unused-value -Wno-pointer-sign"

        # kbuild directory. If not set, use /lib/modules/`uname -r`/build.
        # If set to "" deliberately, skip kernel header auto-detector.
	kbuild-dir = "/path/to/kernel/build"

        # Options passed to 'make' when detecting kernel header options.
	kbuild-opts = "ARCH=x86_64"

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1437477214-149684-1-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-07 10:16:59 -03:00
Wang Nan
9a208effd1 bpf tools: Link all bpf objects onto a list
To allow enumeration of all bpf_objects, keep them in a list (hidden to
caller). bpf_object__for_each_safe() is introduced to do this iteration.
It is safe even user close the object during iteration.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-23-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-07 10:16:59 -03:00
Wang Nan
aa9b1ac33c bpf tools: Introduce accessors for struct bpf_program
This patch introduces accessors for user of libbpf to retrieve section
name and fd of a opened/loaded eBPF program. 'struct bpf_prog_handler'
is used for that purpose. Accessors of programs section name and file
descriptor are provided. Set/get private data are also impelmented.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Link: http://lkml.kernel.org/r/1435716878-189507-21-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-07 10:16:59 -03:00
Wang Nan
55cffde2e1 bpf tools: Load eBPF programs in object files into kernel
This patch utilizes previous introduced bpf_load_program to load
programs in the ELF file into kernel. Result is stored in 'fd' field in
'struct bpf_program'.

During loading, it allocs a log buffer and free it before return.  Note
that that buffer is not passed to bpf_load_program() if the first
loading try is successful. Doesn't use a statically allocated log buffer
to avoid potention multi-thread problem.

Instructions collected during opening is cleared after loading.

load_program() is created for loading a 'struct bpf_insn' array into
kernel, bpf_program__load() calls it. By this design we have a function
loads instructions into kernel. It will be used by further patches,
which creates different instances from a program and load them into
kernel.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-20-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-07 10:16:59 -03:00
Wang Nan
7bf98369a7 bpf tools: Introduce bpf_load_program() to bpf.c
bpf_load_program() can be used to load bpf program into kernel. To make
loading faster, first try to load without logbuf. Try again with logbuf
if the first try failed.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-19-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-07 10:16:58 -03:00
Wang Nan
8a47a6c522 bpf tools: Relocate eBPF programs
If an eBPF program accesses a map, LLVM generates a load instruction
which loads an absolute address into a register, like this:

  ld_64   r1, <MCOperand Expr:(mymap)>
  ...
  call    2

That ld_64 instruction will be recorded in relocation section.
To enable the usage of that map, relocation must be done by replacing
the immediate value by real map file descriptor so it can be found by
eBPF map functions.

This patch to the relocation work based on information collected by
patches:

'bpf tools: Collect symbol table from SHT_SYMTAB section',
'bpf tools: Collect relocation sections from SHT_REL sections'
and
'bpf tools: Record map accessing instructions for each program'.

For each instruction which needs relocation, it inject corresponding
file descriptor to imm field. As a part of protocol, src_reg is set to
BPF_PSEUDO_MAP_FD to notify kernel this is a map loading instruction.

This is the final part of map relocation patch. The principle of map
relocation is described in commit message of 'bpf tools: Collect symbol
table from SHT_SYMTAB section'.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-18-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-07 10:16:58 -03:00
Wang Nan
52d3352e79 bpf tools: Create eBPF maps defined in an object file
This patch creates maps based on 'map' section in object file using
bpf_create_map(), and stores the fds into an array in 'struct
bpf_object'.

Previous patches parse ELF object file and collects required data, but
doesn't play with the kernel. They belong to the 'opening' phase. This
patch is the first patch in 'loading' phase. The 'loaded' field is
introduced in 'struct bpf_object' to avoid loading an object twice,
because the loading phase clears resources collected during the opening
which becomes useless after loading. In this patch, maps_buf is cleared.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-17-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-07 10:16:58 -03:00
Wang Nan
e3ed2fef22 bpf tools: Add bpf.c/h for common bpf operations
This patch introduces bpf.c and bpf.h, which hold common functions
issuing bpf syscall. The goal of these two files is to hide syscall
completely from user. Note that bpf.c and bpf.h deal with kernel
interface only. Things like structure of 'map' section in the ELF object
is not cared by of bpf.[ch].

We first introduce bpf_create_map().

Note that, since functions in bpf.[ch] are wrapper of sys_bpf, they
don't use OO style naming.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-16-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-07 10:16:58 -03:00
Wang Nan
340909152a bpf tools: Record map accessing instructions for each program
This patch records the indices of instructions which are needed to be
relocated. That information is saved in the 'reloc_desc' field in
'struct bpf_program'. In the loading phase (this patch takes effect in
the opening phase), the collected instructions will be replaced by map
loading instructions.

Since we are going to close the ELF file and clear all data at the end
of the 'opening' phase, the ELF information will no longer be valid in
the 'loading' phase. We have to locate the instructions before maps are
loaded, instead of directly modifying the instruction.

'struct bpf_map_def' is introduced in this patch to let us know how many
maps are defined in the object.

This is the third part of map relocation. The principle of map relocation
is described in commit message of 'bpf tools: Collect symbol table from
SHT_SYMTAB section'.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-15-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-07 10:16:58 -03:00
Wang Nan
b62f06e81b bpf tools: Collect relocation sections from SHT_REL sections
This patch collects relocation sections into 'struct object'.  Such
sections are used for connecting maps to bpf programs. 'reloc' field in
'struct bpf_object' is introduced for storing such information.

This patch simply store the data into 'reloc' field. Following patch
will parse them to know the exact instructions which are needed to be
relocated.

Note that the collected data will be invalid after ELF object file is
closed.

This is the second patch related to map relocation. The first one is
'bpf tools: Collect symbol table from SHT_SYMTAB section'. The
principle of map relocation is described in its commit message.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-14-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-07 10:16:57 -03:00
Wang Nan
a5b8bd47dc bpf tools: Collect eBPF programs from their own sections
This patch collects all programs in an object file into an array of
'struct bpf_program' for further processing. That structure is for
representing each eBPF program. 'bpf_prog' should be a better name, but
it has been used by linux/filter.h. Although it is a kernel space name,
I still prefer to call it 'bpf_program' to prevent possible confusion.

bpf_object__add_program() creates a new 'struct bpf_program' object.
It first init a variable in stack using bpf_program__init(), then if
success, enlarges obj->programs array and copy the new object in.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-13-git-send-email-wangnan0@huawei.com
[ Made bpf_object__add_program() propagate the error (-EINVAL or -ENOMEM) ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-07 10:16:57 -03:00
Wang Nan
bec7d68cb5 bpf tools: Collect symbol table from SHT_SYMTAB section
This patch collects symbols section. This section is useful when linking
BPF maps.

What 'bpf_map_xxx()' functions actually require are map's file
descriptors (and the internal verifier converts fds into pointers to
'struct bpf_map'), which we don't know when compiling. Therefore, we
should make compiler generate a 'ldr_64 r1, <imm>' instruction, and
fill the 'imm' field with the actual file descriptor when loading in
libbpf.

BPF programs should be written in this way:

 struct bpf_map_def SEC("maps") my_map = {
    .type = BPF_MAP_TYPE_HASH,
    .key_size = sizeof(unsigned long),
    .value_size = sizeof(unsigned long),
    .max_entries = 1000000,
 };

 SEC("my_func=sys_write")
 int my_func(void *ctx)
 {
     ...
     bpf_map_update_elem(&my_map, &key, &value, BPF_ANY);
     ...
 }

Compiler should convert '&my_map' into a 'ldr_64, r1, <imm>'
instruction, where imm should be the address of 'my_map'. According to
the address, libbpf knows which map it actually referenced, and then
fills the imm field with the 'fd' of that map created by it.

However, since we never really 'link' the object file, the imm field is
only a record in relocation section. Therefore libbpf should do the
relocation:

 1. In relocation section (type == SHT_REL), positions of each such
    'ldr_64' instruction are recorded with a reference of an entry in
    symbol table (SHT_SYMTAB);

 2. From records in symbol table we can find the indics of map
    variables.

Libbpf first record SHT_SYMTAB and positions of each instruction which
required bu such operation. Then create file descriptor. Finally, after
map creation complete, replace the imm field.

This is the first patch of BPF map related stuff. It records SHT_SYMTAB
into object's efile field for further use.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-12-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-07 10:16:57 -03:00
Wang Nan
0b3d1efade bpf tools: Collect map definitions from 'maps' section
If maps are used by eBPF programs, corresponding object file(s) should
contain a section named 'map'. Which contains map definitions. This
patch copies the data of the whole section. Map data parsing should be
acted just before map loading.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-11-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-07 10:16:57 -03:00
Wang Nan
cb1e5e9619 bpf tools: Collect version and license from ELF sections
Expand bpf_obj_elf_collect() to collect license and kernel version
information in eBPF object file. eBPF object file should have a section
named 'license', which contains a string. It should also have a section
named 'version', contains a u32 LINUX_VERSION_CODE.

bpf_obj_validate() is introduced to validate object file after loaded.
Currently it only check existence of 'version' section.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-10-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-07 10:16:57 -03:00
Wang Nan
296036653a bpf tools: Iterate over ELF sections to collect information
bpf_obj_elf_collect() is introduced to iterate over each elf sections to
collection information in eBPF object files. This function will futher
enhanced to collect license, kernel version, programs, configs and map
information.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-9-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-07 10:16:56 -03:00
Wang Nan
cc4228d57c bpf tools: Check endianness and make libbpf fail early
Check endianness according to EHDR. Code is taken from
tools/perf/util/symbol-elf.c.

Libbpf doesn't magically convert missmatched endianness. Even if we swap
eBPF instructions to correct byte order, we are unable to deal with
endianness in code logical generated by LLVM.

Therefore, libbpf should simply reject missmatched ELF object, and let
LLVM to create good code.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-8-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-07 10:16:56 -03:00