提交 · 97365e81366f5ca16a9ce66cff4dd4c5b0d9f4db · openanolis / cloud-kernel

04 7月, 2017 1 次提交

perf evsel: Set attr.exclude_kernel when probing max attr.precise_ip · 97365e81

由 Arnaldo Carvalho de Melo 提交于 7月 03, 2017

We should set attr.exclude_kernel when probing for attr.precise_ip
level, otherwise !CAP_SYS_ADMIN users will not default to skidless
samples in capable hardware.

The increase in the paranoid level in commit 0161028b ("perf/core:
Change the default paranoia level to 2") broke this, fix it by excluding
kernel samples when probing.

Before:

  $ perf record usleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.018 MB perf.data (6 samples) ]
  $ perf evlist -v
  cycles:u: sample_freq: 4000, sample_type: IP|TID|TIME|PERIOD, exclude_kernel: 1

After:

  $ perf record usleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.018 MB perf.data (8 samples) ]
  $ perf evlist -v
  cycles:ppp: sample_freq: 4000, sample_type: IP|TID|TIME|PERIOD, exclude_kernel: 1, precise_ip: 3
                                                                                     ^^^^^^^^^^^^^
                                                                                     ^^^^^^^^^^^^^
                                                                                     ^^^^^^^^^^^^^
  $

To further clarify: we always set .exclude_kernel when non !CAP_SYS_ADMIN
users profile, its just on the attr.precise_ip probing that we weren't doing
so, fix it.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 7f8d1ade ("perf tools: By default use the most precise "cycles" hw counter available")
Link: http://lkml.kernel.org/n/tip-t2qttwhbnua62o5gt75cueml@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

97365e81

26 6月, 2017 1 次提交

perf machine: Fix segfault for kernel.kptr_restrict=2 · 3f938ee2

由 Jiri Olsa 提交于 6月 26, 2017

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>

3f938ee2

23 6月, 2017 1 次提交

perf probe: Fix probe definition for inlined functions · 7598f8bc

由 Björn Töpel 提交于 6月 21, 2017

In commit 613f050d ("perf probe: Fix to probe on gcc generated
functions in modules"), the offset from symbol is, incorrectly, added
to the trace point address. This leads to incorrect probe trace points
for inlined functions and when using relative line number on symbols.

Prior this patch:
  $ perf probe -m nf_nat -D in_range
  p:probe/in_range nf_nat:in_range.isra.9+0
  $ perf probe -m i40e -D i40e_clean_rx_irq
  p:probe/i40e_clean_rx_irq i40e:i40e_napi_poll+2212
  $ perf probe -m i40e -D i40e_clean_rx_irq:16
  p:probe/i40e_clean_rx_irq i40e:i40e_lan_xmit_frame+626

After:
  $ perf probe -m nf_nat -D in_range
  p:probe/in_range nf_nat:in_range.isra.9+0
  $ perf probe -m i40e -D i40e_clean_rx_irq
  p:probe/i40e_clean_rx_irq i40e:i40e_napi_poll+1106
  $ perf probe -m i40e -D i40e_clean_rx_irq:16
  p:probe/i40e_clean_rx_irq i40e:i40e_napi_poll+2665

Committer testing:

Using 'pfunct', a tool found in the 'dwarves' package [1], one can ask what are
the functions that while not being explicitely marked as inline, were inlined
by the compiler:

  # pfunct --cc_inlined /lib/modules/4.12.0-rc4+/kernel/drivers/net/ethernet/intel/e1000e/e1000e.ko | head
  __ew32
  e1000_regdump
  e1000e_dump_ps_pages
  e1000_desc_unused
  e1000e_systim_to_hwtstamp
  e1000e_rx_hwtstamp
  e1000e_update_rdt_wa
  e1000e_update_tdt_wa
  e1000_put_txbuf
  e1000_consume_page

Then ask 'perf probe' to produce the kprobe_tracer probe definitions for two of
them:

  # perf probe -m e1000e -D e1000e_rx_hwtstamp
  p:probe/e1000e_rx_hwtstamp e1000e:e1000_receive_skb+74

  # perf probe -m e1000e -D e1000_consume_page
  p:probe/e1000_consume_page e1000e:e1000_clean_jumbo_rx_irq+876
  p:probe/e1000_consume_page_1 e1000e:e1000_clean_jumbo_rx_irq+1506
  p:probe/e1000_consume_page_2 e1000e:e1000_clean_rx_irq_ps+1074

Now lets concentrate on the 'e1000_consume_page' one, that was inlined twice in
e1000_clean_jumbo_rx_irq(), lets see what readelf says about the DWARF tags for
that function:

  $ readelf -wi /lib/modules/4.12.0-rc4+/kernel/drivers/net/ethernet/intel/e1000e/e1000e.ko
  <SNIP>
  <1><13e27b>: Abbrev Number: 121 (DW_TAG_subprogram)
    <13e27c>   DW_AT_name        : (indirect string, offset: 0xa8945): e1000_clean_jumbo_rx_irq
    <13e287>   DW_AT_low_pc      : 0x17a30
  <3><13e6ef>: Abbrev Number: 119 (DW_TAG_inlined_subroutine)
    <13e6f0>   DW_AT_abstract_origin: <0x13ed2c>
    <13e6f4>   DW_AT_low_pc      : 0x17be6
  <SNIP>
  <1><13ed2c>: Abbrev Number: 142 (DW_TAG_subprogram)
     <13ed2e>   DW_AT_name        : (indirect string, offset: 0xa54c3): e1000_consume_page

So, the first time in e1000_clean_jumbo_rx_irq() where e1000_consume_page() is
inlined is at PC 0x17be6, which subtracted from e1000_clean_jumbo_rx_irq()'s
address, gives us the offset we should use in the probe definition:

  0x17be6 - 0x17a30 = 438

but above we have 876, which is twice as much.

Lets see the second inline expansion of e1000_consume_page() in
e1000_clean_jumbo_rx_irq():

  <3><13e86e>: Abbrev Number: 119 (DW_TAG_inlined_subroutine)
    <13e86f>   DW_AT_abstract_origin: <0x13ed2c>
    <13e873>   DW_AT_low_pc      : 0x17d21

  0x17d21 - 0x17a30 = 753

So we where adding it at twice the offset from the containing function as we
should.

And then after this patch:

  # perf probe -m e1000e -D e1000e_rx_hwtstamp
  p:probe/e1000e_rx_hwtstamp e1000e:e1000_receive_skb+37

  # perf probe -m e1000e -D e1000_consume_page
  p:probe/e1000_consume_page e1000e:e1000_clean_jumbo_rx_irq+438
  p:probe/e1000_consume_page_1 e1000e:e1000_clean_jumbo_rx_irq+753
  p:probe/e1000_consume_page_2 e1000e:e1000_clean_jumbo_rx_irq+1353
  #

Which matches the two first expansions and shows that because we were
doubling the offset it would spill over the next function:

  readelf -sw /lib/modules/4.12.0-rc4+/kernel/drivers/net/ethernet/intel/e1000e/e1000e.ko
   673: 0000000000017a30  1626 FUNC    LOCAL  DEFAULT    2 e1000_clean_jumbo_rx_irq
   674: 0000000000018090  2013 FUNC    LOCAL  DEFAULT    2 e1000_clean_rx_irq_ps

This is the 3rd inline expansion of e1000_consume_page() in
e1000_clean_jumbo_rx_irq():

   <3><13ec77>: Abbrev Number: 119 (DW_TAG_inlined_subroutine)
    <13ec78>   DW_AT_abstract_origin: <0x13ed2c>
    <13ec7c>   DW_AT_low_pc      : 0x17f79

  0x17f79 - 0x17a30 = 1353

 So:

   0x17a30 + 2 * 1353 = 0x184c2

  And:

   0x184c2 - 0x18090 = 1074

Which explains the bogus third expansion for e1000_consume_page() to end up at:

   p:probe/e1000_consume_page_2 e1000e:e1000_clean_rx_irq_ps+1074

All fixed now :-)

[1] https://git.kernel.org/pub/scm/devel/pahole/pahole.git/Signed-off-by: NBjörn Töpel <bjorn.topel@intel.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: NMagnus Karlsson <magnus.karlsson@intel.com>
Acked-by: NMasami Hiramatsu <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 613f050d ("perf probe: Fix to probe on gcc generated functions in modules")
Link: http://lkml.kernel.org/r/20170621164134.5701-1-bjorn.topel@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

7598f8bc

20 6月, 2017 1 次提交

NTB: ntb_test: fix bug printing ntb_perf results · 07b0b22b

由 Logan Gunthorpe 提交于 6月 05, 2017

The code mistakenly prints the local perf results for the remote test
so the script reports identical results for both directions. Fix this
by ensuring we print the remote result.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Fixes: a9c59ef7 ("ntb_test: Add a selftest script for the NTB subsystem")
Acked-by: NAllen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

07b0b22b

17 6月, 2017 1 次提交

perf unwind: Report module before querying isactivation in dwfl unwind · 9126cbba

由 Milian Wolff 提交于 6月 02, 2017

The PC returned by dwfl_frame_pc() may map into a not-yet-reported
module. We have to report it before we continue unwinding. But when we
query for the isactivation flag in dwfl_frame_pc, libdw will actually do
one more unwinding step internally which can then break and lead to
missed frames or broken stacks.

With libunwind we get e.g.:

~~~~~
heaptrack_gui 2228 135073.400474: 613969 cycles:
108c8e [unknown] (/usr/lib/libQt5Core.so.5.8.0)
1093bc [unknown] (/usr/lib/libQt5Core.so.5.8.0)
109e7b QLocale::QLocale (/usr/lib/libQt5Core.so.5.8.0)
1470ff [unknown] (/usr/lib/libQt5Core.so.5.8.0)
147f67 QSystemLocale::query (/usr/lib/libQt5Core.so.5.8.0)
109fbf QLocalePrivate::updateSystemPrivate (/usr/lib/libQt5Core.so.5.8.0)
10aa27 QLocale::QLocale (/usr/lib/libQt5Core.so.5.8.0)
1e02c3 [unknown] (/usr/lib/libQt5Core.so.5.8.0)
2113bb [unknown] (/usr/lib/libQt5Core.so.5.8.0)
211505 [unknown] (/usr/lib/libQt5Core.so.5.8.0)
1b5df0 QFileInfo::exists (/usr/lib/libQt5Core.so.5.8.0)
92eb2 [unknown] (/usr/lib/libQt5Core.so.5.8.0)
93423 [unknown] (/usr/lib/libQt5Core.so.5.8.0)
93d2a QLibraryInfo::location (/usr/lib/libQt5Core.so.5.8.0)
2170af [unknown] (/usr/lib/libQt5Core.so.5.8.0)
297c53 QCoreApplicationPrivate::init (/usr/lib/libQt5Core.so.5.8.0)
f7cde QGuiApplicationPrivate::init (/usr/lib/libQt5Gui.so.5.8.0)
1589e8 QApplicationPrivate::init (/usr/lib/libQt5Widgets.so.5.8.0)
78622 main (/home/milian/projects/compiled/other/bin/heaptrack_gui)
20439 __libc_start_main (/usr/lib/libc-2.25.so)
78299 _start (/home/milian/projects/compiled/other/bin/heaptrack_gui)

heaptrack_gui 2228 135073.401156: 569521 cycles:
131633 QString::endsWith (/usr/lib/libQt5Core.so.5.8.0)
1a0701 QDir::cleanPath (/usr/lib/libQt5Core.so.5.8.0)
21b82d [unknown] (/usr/lib/libQt5Core.so.5.8.0)
1b3727 QFileInfo::canonicalFilePath (/usr/lib/libQt5Core.so.5.8.0)
2780c7 QFactoryLoader::update (/usr/lib/libQt5Core.so.5.8.0)
279525 QFactoryLoader::QFactoryLoader (/usr/lib/libQt5Core.so.5.8.0)
e5bd0 QPlatformIntegrationFactory::create (/usr/lib/libQt5Gui.so.5.8.0)
f5a1c QGuiApplicationPrivate::createPlatformIntegration (/usr/lib/libQt5Gui.so.5.8.0)
f650c QGuiApplicationPrivate::createEventDispatcher (/usr/lib/libQt5Gui.so.5.8.0)
298524 QCoreApplicationPrivate::init (/usr/lib/libQt5Core.so.5.8.0)
f7cde QGuiApplicationPrivate::init (/usr/lib/libQt5Gui.so.5.8.0)
1589e8 QApplicationPrivate::init (/usr/lib/libQt5Widgets.so.5.8.0)
78622 main (/home/milian/projects/compiled/other/bin/heaptrack_gui)
20439 __libc_start_main (/usr/lib/libc-2.25.so)
78299 _start (/home/milian/projects/compiled/other/bin/heaptrack_gui)
~~~~~

Note the two frames 1589e8 and 78622 in the first sample. These are
missing when unwinding with libdw. The second sample's breakage is
more obvious:

~~~~~
heaptrack_gui 2228 135073.400474: 613969 cycles:
108c8e [unknown] (/usr/lib/libQt5Core.so.5.8.0)
1093bc [unknown] (/usr/lib/libQt5Core.so.5.8.0)
109e7b QLocale::QLocale (/usr/lib/libQt5Core.so.5.8.0)
1470ff [unknown] (/usr/lib/libQt5Core.so.5.8.0)
147f67 QSystemLocale::query (/usr/lib/libQt5Core.so.5.8.0)
109fbf QLocalePrivate::updateSystemPrivate (/usr/lib/libQt5Core.so.5.8.0)
10aa27 QLocale::QLocale (/usr/lib/libQt5Core.so.5.8.0)
1e02c3 [unknown] (/usr/lib/libQt5Core.so.5.8.0)
2113bb [unknown] (/usr/lib/libQt5Core.so.5.8.0)
211505 [unknown] (/usr/lib/libQt5Core.so.5.8.0)
1b5df0 QFileInfo::exists (/usr/lib/libQt5Core.so.5.8.0)
92eb2 [unknown] (/usr/lib/libQt5Core.so.5.8.0)
93423 [unknown] (/usr/lib/libQt5Core.so.5.8.0)
93d2a QLibraryInfo::location (/usr/lib/libQt5Core.so.5.8.0)
2170af [unknown] (/usr/lib/libQt5Core.so.5.8.0)
297c53 QCoreApplicationPrivate::init (/usr/lib/libQt5Core.so.5.8.0)
f7cde QGuiApplicationPrivate::init (/usr/lib/libQt5Gui.so.5.8.0)
20439 __libc_start_main (/usr/lib/libc-2.25.so)
78299 _start (/home/milian/projects/compiled/other/bin/heaptrack_gui)

This patch fixes this issue and the libdw unwinder mimicks the libunwind
behavior more closely.
Signed-off-by: NMilian Wolff <milian.wolff@kdab.com>
Acked-by: NJan Kratochvil <jan.kratochvil@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/20170602143753.16907-2-milian.wolff@kdab.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

9126cbba

16 6月, 2017 1 次提交

objtool: Add fortify_panic as __noreturn function · 92b0a141

由 Kees Cook 提交于 6月 15, 2017

CONFIG_FORTIFY_SOURCE=y implements fortify_panic() as a __noreturn function,
so objtool needs to know about it too.
Suggested-by: NDaniel Micay <danielmicay@gmail.com>
Tested-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.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/1497532835-32704-1-git-send-email-jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

92b0a141

15 6月, 2017 2 次提交

perf tools: Fix build with ARCH=x86_64 · 7a759cd8

由 Jiada Wang 提交于 4月 09, 2017

With commit: 0a943cb1 (tools build: Add HOSTARCH Makefile variable)
when building for ARCH=x86_64, ARCH=x86_64 is passed to perf instead of
ARCH=x86, so the perf build process searchs header files from
tools/arch/x86_64/include, which doesn't exist.

The following build failure is seen:

  In file included from util/event.c:2:0:
    tools/include/uapi/linux/mman.h:4:27: fatal error: uapi/asm/mman.h: No such file or directory
    compilation terminated.

Fix this issue by using SRCARCH instead of ARCH in perf, just like the
main kernel Makefile and tools/objtool's.
Signed-off-by: NJiada Wang <jiada_wang@mentor.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Eugeniu Rosca <erosca@de.adit-jv.com>
Cc: Jan Stancek <jstancek@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Rui Teng <rui.teng@linux.vnet.ibm.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 0a943cb1 ("tools build: Add HOSTARCH Makefile variable")
Link: http://lkml.kernel.org/r/1491793357-14977-2-git-send-email-jiada_wang@mentor.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

7a759cd8

perf evsel: Fix probing of precise_ip level for default cycles event · 7a1ac110

由 Arnaldo Carvalho de Melo 提交于 6月 09, 2017

Since commit 18e7a45a ("perf/x86: Reject non sampling events with
precise_ip") returns -EINVAL for sys_perf_event_open() with an attribute
with (attr.precise_ip > 0 && attr.sample_period == 0), just like is done
in the routine used to probe the max precise level when no events were
passed to 'perf record' or 'perf top', i.e.:

	perf_evsel__new_cycles()
		perf_event_attr__set_max_precise_ip()

The x86 code, in x86_pmu_hw_config(), which is called all the way from
sys_perf_event_open() did, starting with the aforementioned commit:

                /* There's no sense in having PEBS for non sampling events: */
                if (!is_sampling_event(event))
                        return -EINVAL;

Which makes it fail for cycles:ppp, cycles:pp and cycles:p, always using
just the non precise cycles variant.

To make sure that this is the case, I tested it, before this patch,
with:

  # perf probe -L x86_pmu_hw_config
  <x86_pmu_hw_config@/home/acme/git/linux/arch/x86/events/core.c:0>
        0  int x86_pmu_hw_config(struct perf_event *event)
        1  {
        2         if (event->attr.precise_ip) {
<SNIP>
       17                 if (event->attr.precise_ip > precise)
       18                         return -EOPNOTSUPP;

                          /* There's no sense in having PEBS for non sampling events: */
       21                 if (!is_sampling_event(event))
       22                         return -EINVAL;
                  }
<SNIP>
  # perf probe x86_pmu_hw_config:22
  Added new events:
    probe:x86_pmu_hw_config (on x86_pmu_hw_config:22)
    probe:x86_pmu_hw_config_1 (on x86_pmu_hw_config:22)

  You can now use it in all perf tools, such as:

        perf record -e probe:x86_pmu_hw_config_1 -aR sleep 1

  # perf trace -e perf_event_open,probe:x86_pmu_hwconfig*/max-stack=16/ perf record usleep 1
     0.000 ( 0.015 ms): perf/4150 perf_event_open(attr_uptr: 0x7ffebc8ba110, cpu: -1, group_fd: -1      ) ...
     0.015 (         ): probe:x86_pmu_hw_config:(ffffffff9c0065e1))
                                       x86_pmu_hw_config ([kernel.kallsyms])
                                       hsw_hw_config ([kernel.kallsyms])
                                       x86_pmu_event_init ([kernel.kallsyms])
                                       perf_try_init_event ([kernel.kallsyms])
                                       perf_event_alloc ([kernel.kallsyms])
                                       SYSC_perf_event_open ([kernel.kallsyms])
                                       sys_perf_event_open ([kernel.kallsyms])
                                       do_syscall_64 ([kernel.kallsyms])
                                       return_from_SYSCALL_64 ([kernel.kallsyms])
                                       syscall (/usr/lib64/libc-2.24.so)
                                       perf_event_attr__set_max_precise_ip (/home/acme/bin/perf)
                                       perf_evsel__new_cycles (/home/acme/bin/perf)
                                       perf_evlist__add_default (/home/acme/bin/perf)
                                       cmd_record (/home/acme/bin/perf)
                                       run_builtin (/home/acme/bin/perf)
                                       handle_internal_command (/home/acme/bin/perf)
     0.000 ( 0.021 ms): perf/4150  ... [continued]: perf_event_open()) = -1 EINVAL Invalid argument
     0.023 ( 0.002 ms): perf/4150 perf_event_open(attr_uptr: 0x7ffebc8ba110, cpu: -1, group_fd: -1      ) ...
     0.025 (         ): probe:x86_pmu_hw_config:(ffffffff9c0065e1))
                                       x86_pmu_hw_config ([kernel.kallsyms])
                                       hsw_hw_config ([kernel.kallsyms])
                                       x86_pmu_event_init ([kernel.kallsyms])
                                       perf_try_init_event ([kernel.kallsyms])
                                       perf_event_alloc ([kernel.kallsyms])
                                       SYSC_perf_event_open ([kernel.kallsyms])
                                       sys_perf_event_open ([kernel.kallsyms])
                                       do_syscall_64 ([kernel.kallsyms])
                                       return_from_SYSCALL_64 ([kernel.kallsyms])
                                       syscall (/usr/lib64/libc-2.24.so)
                                       perf_event_attr__set_max_precise_ip (/home/acme/bin/perf)
                                       perf_evsel__new_cycles (/home/acme/bin/perf)
                                       perf_evlist__add_default (/home/acme/bin/perf)
                                       cmd_record (/home/acme/bin/perf)
                                       run_builtin (/home/acme/bin/perf)
                                       handle_internal_command (/home/acme/bin/perf)
     0.023 ( 0.004 ms): perf/4150  ... [continued]: perf_event_open()) = -1 EINVAL Invalid argument
     0.028 ( 0.002 ms): perf/4150 perf_event_open(attr_uptr: 0x7ffebc8ba110, cpu: -1, group_fd: -1      ) ...
     0.030 (         ): probe:x86_pmu_hw_config:(ffffffff9c0065e1))
                                       x86_pmu_hw_config ([kernel.kallsyms])
                                       hsw_hw_config ([kernel.kallsyms])
                                       x86_pmu_event_init ([kernel.kallsyms])
                                       perf_try_init_event ([kernel.kallsyms])
                                       perf_event_alloc ([kernel.kallsyms])
                                       SYSC_perf_event_open ([kernel.kallsyms])
                                       sys_perf_event_open ([kernel.kallsyms])
                                       do_syscall_64 ([kernel.kallsyms])
                                       return_from_SYSCALL_64 ([kernel.kallsyms])
                                       syscall (/usr/lib64/libc-2.24.so)
                                       perf_event_attr__set_max_precise_ip (/home/acme/bin/perf)
                                       perf_evsel__new_cycles (/home/acme/bin/perf)
                                       perf_evlist__add_default (/home/acme/bin/perf)
                                       cmd_record (/home/acme/bin/perf)
                                       run_builtin (/home/acme/bin/perf)
                                       handle_internal_command (/home/acme/bin/perf)
     0.028 ( 0.004 ms): perf/4150  ... [continued]: perf_event_open()) = -1 EINVAL Invalid argument
    41.018 ( 0.012 ms): perf/4150 perf_event_open(attr_uptr: 0x7ffebc8b5dd0, pid: -1, group_fd: -1, flags: FD_CLOEXEC) = 4
    41.065 ( 0.011 ms): perf/4150 perf_event_open(attr_uptr: 0x3c7db78, pid: -1, group_fd: -1, flags: FD_CLOEXEC) = 4
    41.080 ( 0.006 ms): perf/4150 perf_event_open(attr_uptr: 0x3c7db78, pid: -1, group_fd: -1, flags: FD_CLOEXEC) = 4
    41.103 ( 0.010 ms): perf/4150 perf_event_open(attr_uptr: 0x3c4e748, pid: 4151 (perf), group_fd: -1, flags: FD_CLOEXEC) = 4
    41.115 ( 0.006 ms): perf/4150 perf_event_open(attr_uptr: 0x3c4e748, pid: 4151 (perf), cpu: 1, group_fd: -1, flags: FD_CLOEXEC) = 5
    41.122 ( 0.004 ms): perf/4150 perf_event_open(attr_uptr: 0x3c4e748, pid: 4151 (perf), cpu: 2, group_fd: -1, flags: FD_CLOEXEC) = 6
    41.128 ( 0.008 ms): perf/4150 perf_event_open(attr_uptr: 0x3c4e748, pid: 4151 (perf), cpu: 3, group_fd: -1, flags: FD_CLOEXEC) = 8
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.017 MB perf.data (2 samples) ]
  #

I.e. that return -EINVAL in x86_pmu_hw_config() is hit three times.

So fix it by just setting attr.sample_period

Now, after this patch:

  # perf trace --max-stack=2 -e perf_event_open,probe:x86_pmu_hw_config* perf record usleep 1
  [ perf record: Woken up 1 times to write data ]
     0.000 ( 0.017 ms): perf/8469 perf_event_open(attr_uptr: 0x7ffe36c27d10, pid: -1, cpu: 3, group_fd: -1, flags: FD_CLOEXEC) = 4
                                       syscall (/usr/lib64/libc-2.24.so)
                                       perf_event_open_cloexec_flag (/home/acme/bin/perf)
     0.050 ( 0.031 ms): perf/8469 perf_event_open(attr_uptr: 0x24ebb78, pid: -1, group_fd: -1, flags: FD_CLOEXEC) = 4
                                       syscall (/usr/lib64/libc-2.24.so)
                                       perf_evlist__config (/home/acme/bin/perf)
     0.092 ( 0.040 ms): perf/8469 perf_event_open(attr_uptr: 0x24ebb78, pid: -1, group_fd: -1, flags: FD_CLOEXEC) = 4
                                       syscall (/usr/lib64/libc-2.24.so)
                                       perf_evlist__config (/home/acme/bin/perf)
     0.143 ( 0.007 ms): perf/8469 perf_event_open(attr_uptr: 0x24bc748, cpu: -1, group_fd: -1           ) = 4
                                       syscall (/usr/lib64/libc-2.24.so)
                                       perf_event_attr__set_max_precise_ip (/home/acme/bin/perf)
     0.161 ( 0.007 ms): perf/8469 perf_event_open(attr_uptr: 0x24bc748, pid: 8470 (perf), group_fd: -1, flags: FD_CLOEXEC) = 4
                                       syscall (/usr/lib64/libc-2.24.so)
                                       perf_evsel__open (/home/acme/bin/perf)
     0.171 ( 0.005 ms): perf/8469 perf_event_open(attr_uptr: 0x24bc748, pid: 8470 (perf), cpu: 1, group_fd: -1, flags: FD_CLOEXEC) = 5
                                       syscall (/usr/lib64/libc-2.24.so)
                                       perf_evsel__open (/home/acme/bin/perf)
     0.180 ( 0.007 ms): perf/8469 perf_event_open(attr_uptr: 0x24bc748, pid: 8470 (perf), cpu: 2, group_fd: -1, flags: FD_CLOEXEC) = 6
                                       syscall (/usr/lib64/libc-2.24.so)
                                       perf_evsel__open (/home/acme/bin/perf)
     0.190 ( 0.005 ms): perf/8469 perf_event_open(attr_uptr: 0x24bc748, pid: 8470 (perf), cpu: 3, group_fd: -1, flags: FD_CLOEXEC) = 8
                                       syscall (/usr/lib64/libc-2.24.so)
                                       perf_evsel__open (/home/acme/bin/perf)
  [ perf record: Captured and wrote 0.017 MB perf.data (7 samples) ]
  #

The probe one called from perf_event_attr__set_max_precise_ip() works
the first time, with attr.precise_ip = 3, wit hthe next ones being the
per cpu ones for the cycles:ppp event.

And here is the text from a report and alternative proposed patch by
Thomas-Mich Richter:

 ---

On s390 the counter and sampling facility do not support a precise IP
skid level and sometimes returns EOPNOTSUPP when structure member
precise_ip in struct perf_event_attr is not set to zero.

On s390 commnd 'perf record -- true' fails with error EOPNOTSUPP.  This
happens only when no events are specified on command line.

The functions called are
...
  --> perf_evlist__add_default
      --> perf_evsel__new_cycles
          --> perf_event_attr__set_max_precise_ip

The last function determines the value of structure member precise_ip by
invoking the perf_event_open() system call and checking the return code.
The first successful open is the value for precise_ip.

However the value is determined without setting member sample_period and
indicates no sampling.

On s390 the counter facility and sampling facility are different.  The
above procedure determines a precise_ip value of 3 using the counter
facility. Later it uses the sampling facility with a value of 3 and
fails with EOPNOTSUPP.

 ---

v2: Older compilers (e.g. gcc 4.4.7) don't support referencing members
    of unnamed union members in the container struct initialization, so
    move from:

	struct perf_event_attr attr = {
		...
		.sample_period = 1,
	};

to right after it as:

	struct perf_event_attr attr = {
		...
	};

	attr.sample_period = 1;

v3: We need to reset .sample_period to 0 to let the users of
perf_evsel__new_cycles() to properly setup attr.sample_period or
attr.sample_freq. Reported by Ingo Molnar.
Reported-and-Acked-by: NThomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Acked-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Acked-by: NJiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 18e7a45a ("perf/x86: Reject non sampling events with precise_ip")
Link: http://lkml.kernel.org/n/tip-yv6nnkl7tzqocrm0hl3x7vf1@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

7a1ac110

09 6月, 2017 10 次提交

bpf, tests: fix endianness selection · 78a5a93c

由 Daniel Borkmann 提交于 6月 08, 2017

I noticed that test_l4lb was failing in selftests:

  # ./test_progs
  test_pkt_access:PASS:ipv4 77 nsec
  test_pkt_access:PASS:ipv6 44 nsec
  test_xdp:PASS:ipv4 2933 nsec
  test_xdp:PASS:ipv6 1500 nsec
  test_l4lb:PASS:ipv4 377 nsec
  test_l4lb:PASS:ipv6 544 nsec
  test_l4lb:FAIL:stats 6297600000 200000
  test_tcp_estats:PASS: 0 nsec
  Summary: 7 PASSED, 1 FAILED

Tracking down the issue actually revealed that endianness selection
in bpf_endian.h is broken when compiled with clang with bpf target.
test_pkt_access.c, test_l4lb.c is compiled with __BYTE_ORDER as
__BIG_ENDIAN, test_xdp.c as __LITTLE_ENDIAN! test_l4lb noticeably
fails, because the test accounts bytes via bpf_ntohs(ip6h->payload_len)
and bpf_ntohs(iph->tot_len), and compares them against a defined
value and given a wrong endianness, the test outcome is different,
of course.

Turns out that there are actually two bugs: i) when we do __BYTE_ORDER
comparison with __LITTLE_ENDIAN/__BIG_ENDIAN, then depending on the
include order we see different outcomes. Reason is that __BYTE_ORDER
is undefined due to missing endian.h include. Before we include the
asm/byteorder.h (e.g. through linux/in.h), then __BYTE_ORDER equals
__LITTLE_ENDIAN since both are undefined, after the include which
correctly pulls in linux/byteorder/little_endian.h, __LITTLE_ENDIAN
is defined, but given __BYTE_ORDER is still undefined, we match on
__BYTE_ORDER equals to __BIG_ENDIAN since __BIG_ENDIAN is also
undefined at that point, sigh. ii) But even that would be wrong,
since when compiling the test cases with clang, one can select between
bpfeb and bpfel targets for cross compilation. Hence, we can also not
rely on what the system's endian.h provides, but we need to look at
the compiler's defined endianness. The compiler defines __BYTE_ORDER__,
and we can match __ORDER_LITTLE_ENDIAN__ and __ORDER_BIG_ENDIAN__,
which also reflects targets bpf (native), bpfel, bpfeb correctly,
thus really only rely on that. After patch:

  # ./test_progs
  test_pkt_access:PASS:ipv4 74 nsec
  test_pkt_access:PASS:ipv6 42 nsec
  test_xdp:PASS:ipv4 2340 nsec
  test_xdp:PASS:ipv6 1461 nsec
  test_l4lb:PASS:ipv4 400 nsec
  test_l4lb:PASS:ipv6 530 nsec
  test_tcp_estats:PASS: 0 nsec
  Summary: 7 PASSED, 0 FAILED

Fixes: 43bcf707 ("bpf: fix _htons occurences in test_progs")
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

78a5a93c

perf symbols: Kill dso__build_id_is_kmod() · b89fe63f