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  1. 20 5月, 2022 1 次提交
    • A
      perf build: Fix check for btf__load_from_kernel_by_id() in libbpf · 0ae065a5
      由 Arnaldo Carvalho de Melo 提交于 
      Avi Kivity reported a problem where the __weak
btf__load_from_kernel_by_id() in tools/perf/util/bpf-event.c was being
used and it called btf__get_from_id() in tools/lib/bpf/btf.c that in
turn called back to btf__load_from_kernel_by_id(), resulting in an
endless loop.

Fix this by adding a feature test to check if
btf__load_from_kernel_by_id() is available when building perf with
LIBBPF_DYNAMIC=1, and if not then provide the fallback to the old
btf__get_from_id(), that doesn't call back to btf__load_from_kernel_by_id()
since at that time it didn't exist at all.

Tested on Fedora 35 where we have libbpf-devel 0.4.0 with LIBBPF_DYNAMIC
where we don't have btf__load_from_kernel_by_id() and thus its feature
test fail, not defining HAVE_LIBBPF_BTF__LOAD_FROM_KERNEL_BY_ID:

  $ cat /tmp/build/perf-urgent/feature/test-libbpf-btf__load_from_kernel_by_id.make.output
  test-libbpf-btf__load_from_kernel_by_id.c: In function ‘main’:
  test-libbpf-btf__load_from_kernel_by_id.c:6:16: error: implicit declaration of function ‘btf__load_from_kernel_by_id’ [-Werror=implicit-function-declaration]
      6 |         return btf__load_from_kernel_by_id(20151128, NULL);
        |                ^~~~~~~~~~~~~~~~~~~~~~~~~~~
  cc1: all warnings being treated as errors
  $

  $ nm /tmp/build/perf-urgent/perf | grep btf__load_from_kernel_by_id
  00000000005ba180 T btf__load_from_kernel_by_id
  $

  $ objdump --disassemble=btf__load_from_kernel_by_id -S /tmp/build/perf-urgent/perf

  /tmp/build/perf-urgent/perf:     file format elf64-x86-64
  <SNIP>
  00000000005ba180 <btf__load_from_kernel_by_id>:
  #include "record.h"
  #include "util/synthetic-events.h"

  #ifndef HAVE_LIBBPF_BTF__LOAD_FROM_KERNEL_BY_ID
  struct btf *btf__load_from_kernel_by_id(__u32 id)
  {
    5ba180:	55                   	push   %rbp
    5ba181:	48 89 e5             	mov    %rsp,%rbp
    5ba184:	48 83 ec 10          	sub    $0x10,%rsp
    5ba188:	64 48 8b 04 25 28 00 	mov    %fs:0x28,%rax
    5ba18f:	00 00
    5ba191:	48 89 45 f8          	mov    %rax,-0x8(%rbp)
    5ba195:	31 c0                	xor    %eax,%eax
         struct btf *btf;
  #pragma GCC diagnostic push
  #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
         int err = btf__get_from_id(id, &btf);
    5ba197:	48 8d 75 f0          	lea    -0x10(%rbp),%rsi
    5ba19b:	e8 a0 57 e5 ff       	call   40f940 <btf__get_from_id@plt>
    5ba1a0:	89 c2                	mov    %eax,%edx
  #pragma GCC diagnostic pop

         return err ? ERR_PTR(err) : btf;
    5ba1a2:	48 98                	cltq
    5ba1a4:	85 d2                	test   %edx,%edx
    5ba1a6:	48 0f 44 45 f0       	cmove  -0x10(%rbp),%rax
  }
  <SNIP>

Fixes: 218e7b77 ("perf bpf: Provide a weak btf__load_from_kernel_by_id() for older libbpf versions")
Reported-by: NAvi Kivity <avi@scylladb.com>
Link: https://lore.kernel.org/linux-perf-users/f0add43b-3de5-20c5-22c4-70aff4af959f@scylladb.com
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/linux-perf-users/YobjjFOblY4Xvwo7@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      0ae065a5
  3. 15 2月, 2022 2 次提交
    • I
      perf maps: Use a pointer for kmaps · 1a97cee6
      由 Ian Rogers 提交于 
      struct maps is reference counted, using a pointer is more idiomatic.

Committer notes:

Delay:

   maps = machine__kernel_maps(&vmlinux);

To after:

  machine__init(&vmlinux, "", HOST_KERNEL_ID);

To avoid this on f34:

  In file included from /var/home/acme/git/perf/tools/perf/util/build-id.h:10,
                   from /var/home/acme/git/perf/tools/perf/util/dso.h:13,
                   from tests/vmlinux-kallsyms.c:8:
  In function ‘machine__kernel_maps’,
      inlined from ‘test__vmlinux_matches_kallsyms’ at tests/vmlinux-kallsyms.c:122:22:
  /var/home/acme/git/perf/tools/perf/util/machine.h:86:23: error: ‘vmlinux.kmaps’ is used uninitialized [-Werror=uninitialized]
     86 |         return machine->kmaps;
        |                ~~~~~~~^~~~~~~
  tests/vmlinux-kallsyms.c: In function ‘test__vmlinux_matches_kallsyms’:
  tests/vmlinux-kallsyms.c:121:34: note: ‘vmlinux’ declared here
    121 |         struct machine kallsyms, vmlinux;
        |                                  ^~~~~~~
  cc1: all warnings being treated as errors
Signed-off-by: NIan Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: André Almeida <andrealmeid@collabora.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: German Gomez <german.gomez@arm.com>
Cc: Hao Luo <haoluo@google.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.garry@huawei.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Miaoqian Lin <linmq006@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Riccardo Mancini <rickyman7@gmail.com>
Cc: Shunsuke Nakamura <nakamura.shun@fujitsu.com>
Cc: Song Liu <song@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Stephen Brennan <stephen.s.brennan@oracle.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Yury Norov <yury.norov@gmail.com>
Link: http://lore.kernel.org/lkml/20220211103415.2737789-6-irogers@google.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      1a97cee6
    • C
      perf bpf: Stop using deprecated bpf_load_program() API · 710f6c38
      由 Christy Lee 提交于 
      bpf_load_program() API is deprecated, remove perf's usage of the
deprecated function. Add a __weak function declaration for libbpf
version compatibility.
Signed-off-by: NChristy Lee <christylee@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: bpf@vger.kernel.org
Cc: kernel-team@fb.com
Link: https://lore.kernel.org/bpf/20220212073054.1052880-2-andrii@kernel.orgSigned-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      710f6c38
  5. 14 11月, 2021 2 次提交
    • J
      perf tools: Add more weak libbpf functions · 2a4898fc
      由 Jiri Olsa 提交于 
      We hit the window where perf uses libbpf functions, that did not make it
to the official libbpf release yet and it's breaking perf build with
dynamicly linked libbpf.

Fixing this by providing the new interface as weak functions which calls
the original libbpf functions. Fortunatelly the changes were just
renames.
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20211109140707.1689940-2-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      2a4898fc
    • I
      perf bpf: Avoid memory leak from perf_env__insert_btf() · 4924b1f7
      由 Ian Rogers 提交于 
      perf_env__insert_btf() doesn't insert if a duplicate BTF id is
encountered and this causes a memory leak. Modify the function to return
a success/error value and then free the memory if insertion didn't
happen.

v2. Adds a return -1 when the insertion error occurs in
    perf_env__fetch_btf. This doesn't affect anything as the result is
    never checked.

Fixes: 3792cb2f ("perf bpf: Save BTF in a rbtree in perf_env")
Signed-off-by: NIan Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Yonghong Song <yhs@fb.com>
Cc: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org
Link: http://lore.kernel.org/lkml/20211112074525.121633-1-irogers@google.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      4924b1f7
  7. 07 11月, 2021 1 次提交
    • I
      perf bpf: Add missing free to bpf_event__print_bpf_prog_info() · 88c42f4d
      由 Ian Rogers 提交于 
      If btf__new() is called then there needs to be a corresponding btf__free().

Fixes: f8dfeae0 ("perf bpf: Show more BPF program info in print_bpf_prog_info()")
Signed-off-by: NIan Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Yonghong Song <yhs@fb.com>
Cc: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org
Link: http://lore.kernel.org/lkml/20211106053733.3580931-2-irogers@google.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      88c42f4d
  9. 04 11月, 2021 1 次提交
  11. 02 11月, 2021 1 次提交
  13. 23 10月, 2021 1 次提交
  15. 19 9月, 2021 1 次提交
  17. 16 9月, 2021 1 次提交
  19. 11 9月, 2021 1 次提交
  21. 01 9月, 2021 1 次提交
  23. 30 7月, 2021 2 次提交
  25. 16 3月, 2021 1 次提交
  27. 30 11月, 2020 1 次提交
  29. 06 5月, 2020 1 次提交
  31. 16 4月, 2020 1 次提交
    • J
      perf tools: Synthesize bpf_trampoline/dispatcher ksymbol event · 943930e4
      由 Jiri Olsa 提交于 
      Synthesize bpf images (trampolines/dispatchers) on start, as ksymbol
events from /proc/kallsyms. Having this perf can recognize samples from
those images and perf report and top shows them correctly.

The rest of the ksymbol handling is already in place from for the bpf
programs monitoring, so only the initial state was needed.

perf report output:

  # Overhead  Command     Shared Object                  Symbol

    12.37%  test_progs  [kernel.vmlinux]                 [k] entry_SYSCALL_64
    11.80%  test_progs  [kernel.vmlinux]                 [k] syscall_return_via_sysret
     9.63%  test_progs  bpf_prog_bcf7977d3b93787c_prog2  [k] bpf_prog_bcf7977d3b93787c_prog2
     6.90%  test_progs  bpf_trampoline_24456             [k] bpf_trampoline_24456
     6.36%  test_progs  [kernel.vmlinux]                 [k] memcpy_erms

Committer notes:

Use scnprintf() instead of strncpy() to overcome this on fedora:32,
rawhide and OpenMandriva Cooker:

    CC       /tmp/build/perf/util/bpf-event.o
  In file included from /usr/include/string.h:495,
                   from /git/linux/tools/lib/bpf/libbpf_common.h:12,
                   from /git/linux/tools/lib/bpf/bpf.h:31,
                   from util/bpf-event.c:4:
  In function 'strncpy',
      inlined from 'process_bpf_image' at util/bpf-event.c:323:2,
      inlined from 'kallsyms_process_symbol' at util/bpf-event.c:358:9:
  /usr/include/bits/string_fortified.h:106:10: error: '__builtin_strncpy' specified bound 256 equals destination size [-Werror=stringop-truncation]
    106 |   return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
        |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  cc1: all warnings being treated as errors
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Acked-by: NSong Liu <songliubraving@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andriin@fb.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David S. Miller <davem@redhat.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jesper Dangaard Brouer <hawk@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200312195610.346362-14-jolsa@kernel.org/Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      943930e4
  33. 26 11月, 2019 1 次提交
    • A
      perf maps: Merge 'struct maps' with 'struct map_groups' · 79b6bb73
      由 Arnaldo Carvalho de Melo 提交于 
      And pick the shortest name: 'struct maps'.

The split existed because we used to have two groups of maps, one for
functions and one for variables, but that only complicated things,
sometimes we needed to figure out what was at some address and then had
to first try it on the functions group and if that failed, fall back to
the variables one.

That split is long gone, so for quite a while we had only one struct
maps per struct map_groups, simplify things by combining those structs.

First patch is the minimum needed to merge both, follow up patches will
rename 'thread->mg' to 'thread->maps', etc.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-hom6639ro7020o708trhxh59@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      79b6bb73
  35. 20 9月, 2019 1 次提交
  37. 01 9月, 2019 1 次提交
  39. 27 8月, 2019 4 次提交
  41. 26 8月, 2019 1 次提交
  43. 30 7月, 2019 1 次提交
  45. 21 3月, 2019 4 次提交
    • S
      perf bpf: Show more BPF program info in print_bpf_prog_info() · f8dfeae0
      由 Song Liu 提交于 
      This patch enables showing bpf program name, address, and size in the
header.

Before the patch:

  perf report --header-only
  ...
  # bpf_prog_info of id 9
  # bpf_prog_info of id 10
  # bpf_prog_info of id 13

After the patch:

  # bpf_prog_info 9: bpf_prog_7be49e3934a125ba addr 0xffffffffa0024947 size 229
  # bpf_prog_info 10: bpf_prog_2a142ef67aaad174 addr 0xffffffffa007c94d size 229
  # bpf_prog_info 13: bpf_prog_47368425825d7384_task__task_newt addr 0xffffffffa0251137 size 369

Committer notes:

Fix the fallback definition when HAVE_LIBBPF_SUPPORT is not defined,
i.e. add the missing 'static inline' and add the __maybe_unused to the
args. Also add stdio.h since we now use FILE * in bpf-event.h.
Signed-off-by: NSong Liu <songliubraving@fb.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stanislav Fomichev <sdf@google.com>
Link: http://lkml.kernel.org/r/20190319165454.1298742-3-songliubraving@fb.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      f8dfeae0
    • S
      perf bpf: Extract logic to create program names from perf_event__synthesize_one_bpf_prog() · fc462ac7
      由 Song Liu 提交于 
      Extract logic to create program names to synthesize_bpf_prog_name(), so
that it can be reused in header.c:print_bpf_prog_info().

This commit doesn't change the behavior.
Signed-off-by: NSong Liu <songliubraving@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stanislav Fomichev <sdf@google.com>
Link: http://lkml.kernel.org/r/20190319165454.1298742-2-songliubraving@fb.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      fc462ac7
    • S
      perf tools: Save bpf_prog_info and BTF of new BPF programs · d56354dc
      由 Song Liu 提交于 
      To fully annotate BPF programs with source code mapping, 4 different
information are needed:

    1) PERF_RECORD_KSYMBOL
    2) PERF_RECORD_BPF_EVENT
    3) bpf_prog_info
    4) btf

This patch handles 3) and 4) for BPF programs loaded after 'perf
record|top'.

For timely process of these information, a dedicated event is added to
the side band evlist.

When PERF_RECORD_BPF_EVENT is received via the side band event, the
polling thread gathers 3) and 4) vis sys_bpf and store them in perf_env.

This information is saved to perf.data at the end of 'perf record'.

Committer testing:

The 'wakeup_watermark' member in 'struct perf_event_attr' is inside a
unnamed union, so can't be used in a struct designated initialization
with older gccs, get it out of that, isolating as 'attr.wakeup_watermark
= 1;' to work with all gcc versions.

We also need to add '--no-bpf-event' to the 'perf record'
perf_event_attr tests in 'perf test', as the way that that test goes is
to intercept the events being setup and looking if they match the fields
described in the control files, since now it finds first the side band
event used to catch the PERF_RECORD_BPF_EVENT, they all fail.

With these issues fixed:

Same scenario as for testing BPF programs loaded before 'perf record' or
'perf top' starts, only start the BPF programs after 'perf record|top',
so that its information get collected by the sideband threads, the rest
works as for the programs loaded before start monitoring.

Add missing 'inline' to the bpf_event__add_sb_event() when
HAVE_LIBBPF_SUPPORT is not defined, fixing the build in systems without
binutils devel files installed.
Signed-off-by: NSong Liu <songliubraving@fb.com>
Reviewed-by: NJiri Olsa <jolsa@kernel.org>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stanislav Fomichev <sdf@google.com>
Link: http://lkml.kernel.org/r/20190312053051.2690567-16-songliubraving@fb.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      d56354dc
    • S
      perf annotate: Enable annotation of BPF programs · 6987561c
      由 Song Liu 提交于 
      In symbol__disassemble(), DSO_BINARY_TYPE__BPF_PROG_INFO dso calls into
a new function symbol__disassemble_bpf(), where annotation line
information is filled based on the bpf_prog_info and btf data saved in
given perf_env.

symbol__disassemble_bpf() uses binutils's libopcodes to disassemble bpf
programs.

Committer testing:

After fixing this:

  -               u64 *addrs = (u64 *)(info_linear->info.jited_ksyms);
  +               u64 *addrs = (u64 *)(uintptr_t)(info_linear->info.jited_ksyms);

Detected when crossbuilding to a 32-bit arch.

And making all this dependent on HAVE_LIBBFD_SUPPORT and
HAVE_LIBBPF_SUPPORT:

1) Have a BPF program running, one that has BTF info, etc, I used
   the tools/perf/examples/bpf/augmented_raw_syscalls.c put in place
   by 'perf trace'.

  # grep -B1 augmented_raw ~/.perfconfig
  [trace]
	add_events = /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.c
  #
  # perf trace -e *mmsg
  dnf/6245 sendmmsg(20, 0x7f5485a88030, 2, MSG_NOSIGNAL) = 2
  NetworkManager/10055 sendmmsg(22<socket:[1056822]>, 0x7f8126ad1bb0, 2, MSG_NOSIGNAL) = 2

2) Then do a 'perf record' system wide for a while:

  # perf record -a
  ^C[ perf record: Woken up 68 times to write data ]
  [ perf record: Captured and wrote 19.427 MB perf.data (366891 samples) ]
  #

3) Check that we captured BPF and BTF info in the perf.data file:

  # perf report --header-only | grep 'b[pt]f'
  # event : name = cycles:ppp, , id = { 294789, 294790, 294791, 294792, 294793, 294794, 294795, 294796 }, size = 112, { sample_period, sample_freq } = 4000, sample_type = IP|TID|TIME|CPU|PERIOD, read_format = ID, disabled = 1, inherit = 1, mmap = 1, comm = 1, freq = 1, task = 1, precise_ip = 3, sample_id_all = 1, exclude_guest = 1, mmap2 = 1, comm_exec = 1, ksymbol = 1, bpf_event = 1
  # bpf_prog_info of id 13
  # bpf_prog_info of id 14
  # bpf_prog_info of id 15
  # bpf_prog_info of id 16
  # bpf_prog_info of id 17
  # bpf_prog_info of id 18
  # bpf_prog_info of id 21
  # bpf_prog_info of id 22
  # bpf_prog_info of id 41
  # bpf_prog_info of id 42
  # btf info of id 2
  #

4) Check which programs got recorded:

   # perf report | grep bpf_prog | head
     0.16%  exe              bpf_prog_819967866022f1e1_sys_enter      [k] bpf_prog_819967866022f1e1_sys_enter
     0.14%  exe              bpf_prog_c1bd85c092d6e4aa_sys_exit       [k] bpf_prog_c1bd85c092d6e4aa_sys_exit
     0.08%  fuse-overlayfs   bpf_prog_819967866022f1e1_sys_enter      [k] bpf_prog_819967866022f1e1_sys_enter
     0.07%  fuse-overlayfs   bpf_prog_c1bd85c092d6e4aa_sys_exit       [k] bpf_prog_c1bd85c092d6e4aa_sys_exit
     0.01%  clang-4.0        bpf_prog_c1bd85c092d6e4aa_sys_exit       [k] bpf_prog_c1bd85c092d6e4aa_sys_exit
     0.01%  clang-4.0        bpf_prog_819967866022f1e1_sys_enter      [k] bpf_prog_819967866022f1e1_sys_enter
     0.00%  clang            bpf_prog_c1bd85c092d6e4aa_sys_exit       [k] bpf_prog_c1bd85c092d6e4aa_sys_exit
     0.00%  runc             bpf_prog_819967866022f1e1_sys_enter      [k] bpf_prog_819967866022f1e1_sys_enter
     0.00%  clang            bpf_prog_819967866022f1e1_sys_enter      [k] bpf_prog_819967866022f1e1_sys_enter
     0.00%  sh               bpf_prog_c1bd85c092d6e4aa_sys_exit       [k] bpf_prog_c1bd85c092d6e4aa_sys_exit
  #

  This was with the default --sort order for 'perf report', which is:

    --sort comm,dso,symbol

  If we just look for the symbol, for instance:

   # perf report --sort symbol | grep bpf_prog | head
     0.26%  [k] bpf_prog_819967866022f1e1_sys_enter                -      -
     0.24%  [k] bpf_prog_c1bd85c092d6e4aa_sys_exit                 -      -
   #

  or the DSO:

   # perf report --sort dso | grep bpf_prog | head
     0.26%  bpf_prog_819967866022f1e1_sys_enter
     0.24%  bpf_prog_c1bd85c092d6e4aa_sys_exit
  #

We'll see the two BPF programs that augmented_raw_syscalls.o puts in
place,  one attached to the raw_syscalls:sys_enter and another to the
raw_syscalls:sys_exit tracepoints, as expected.

Now we can finally do, from the command line, annotation for one of
those two symbols, with the original BPF program source coude intermixed
with the disassembled JITed code:

  # perf annotate --stdio2 bpf_prog_819967866022f1e1_sys_enter

  Samples: 950  of event 'cycles:ppp', 4000 Hz, Event count (approx.): 553756947, [percent: local period]
  bpf_prog_819967866022f1e1_sys_enter() bpf_prog_819967866022f1e1_sys_enter
  Percent      int sys_enter(struct syscall_enter_args *args)
   53.41         push   %rbp

    0.63         mov    %rsp,%rbp
    0.31         sub    $0x170,%rsp
    1.93         sub    $0x28,%rbp
    7.02         mov    %rbx,0x0(%rbp)
    3.20         mov    %r13,0x8(%rbp)
    1.07         mov    %r14,0x10(%rbp)
    0.61         mov    %r15,0x18(%rbp)
    0.11         xor    %eax,%eax
    1.29         mov    %rax,0x20(%rbp)
    0.11         mov    %rdi,%rbx
               	return bpf_get_current_pid_tgid();
    2.02       → callq  *ffffffffda6776d9
    2.76         mov    %eax,-0x148(%rbp)
                 mov    %rbp,%rsi
               int sys_enter(struct syscall_enter_args *args)
                 add    $0xfffffffffffffeb8,%rsi
               	return bpf_map_lookup_elem(pids, &pid) != NULL;
                 movabs $0xffff975ac2607800,%rdi

    1.26       → callq  *ffffffffda6789e9
                 cmp    $0x0,%rax
    2.43       → je     0
                 add    $0x38,%rax
    0.21         xor    %r13d,%r13d
               	if (pid_filter__has(&pids_filtered, getpid()))
    0.81         cmp    $0x0,%rax
               → jne    0
                 mov    %rbp,%rdi
               	probe_read(&augmented_args.args, sizeof(augmented_args.args), args);
    2.22         add    $0xfffffffffffffeb8,%rdi
    0.11         mov    $0x40,%esi
    0.32         mov    %rbx,%rdx
    2.74       → callq  *ffffffffda658409
               	syscall = bpf_map_lookup_elem(&syscalls, &augmented_args.args.syscall_nr);
    0.22         mov    %rbp,%rsi
    1.69         add    $0xfffffffffffffec0,%rsi
               	syscall = bpf_map_lookup_elem(&syscalls, &augmented_args.args.syscall_nr);
                 movabs $0xffff975bfcd36000,%rdi

                 add    $0xd0,%rdi
    0.21         mov    0x0(%rsi),%eax
    0.93         cmp    $0x200,%rax
               → jae    0
    0.10         shl    $0x3,%rax

    0.11         add    %rdi,%rax
    0.11       → jmp    0
                 xor    %eax,%eax
               	if (syscall == NULL || !syscall->enabled)
    1.07         cmp    $0x0,%rax
               → je     0
               	if (syscall == NULL || !syscall->enabled)
    6.57         movzbq 0x0(%rax),%rdi

               	if (syscall == NULL || !syscall->enabled)
                 cmp    $0x0,%rdi
    0.95       → je     0
                 mov    $0x40,%r8d
               	switch (augmented_args.args.syscall_nr) {
                 mov    -0x140(%rbp),%rdi
               	switch (augmented_args.args.syscall_nr) {
                 cmp    $0x2,%rdi
               → je     0
                 cmp    $0x101,%rdi
               → je     0
                 cmp    $0x15,%rdi
               → jne    0
               	case SYS_OPEN:	 filename_arg = (const void *)args->args[0];
                 mov    0x10(%rbx),%rdx
               → jmp    0
               	case SYS_OPENAT: filename_arg = (const void *)args->args[1];
                 mov    0x18(%rbx),%rdx
               	if (filename_arg != NULL) {
                 cmp    $0x0,%rdx
               → je     0
                 xor    %edi,%edi
               		augmented_args.filename.reserved = 0;
                 mov    %edi,-0x104(%rbp)
               		augmented_args.filename.size = probe_read_str(&augmented_args.filename.value,
                 mov    %rbp,%rdi
                 add    $0xffffffffffffff00,%rdi
               		augmented_args.filename.size = probe_read_str(&augmented_args.filename.value,
                 mov    $0x100,%esi
               → callq  *ffffffffda658499
                 mov    $0x148,%r8d
               		augmented_args.filename.size = probe_read_str(&augmented_args.filename.value,
                 mov    %eax,-0x108(%rbp)
               		augmented_args.filename.size = probe_read_str(&augmented_args.filename.value,
                 mov    %rax,%rdi
                 shl    $0x20,%rdi

                 shr    $0x20,%rdi

               		if (augmented_args.filename.size < sizeof(augmented_args.filename.value)) {
                 cmp    $0xff,%rdi
               → ja     0
               			len -= sizeof(augmented_args.filename.value) - augmented_args.filename.size;
                 add    $0x48,%rax
               			len &= sizeof(augmented_args.filename.value) - 1;
                 and    $0xff,%rax
                 mov    %rax,%r8
                 mov    %rbp,%rcx
               	return perf_event_output(args, &__augmented_syscalls__, BPF_F_CURRENT_CPU, &augmented_args, len);
                 add    $0xfffffffffffffeb8,%rcx
                 mov    %rbx,%rdi
                 movabs $0xffff975fbd72d800,%rsi

                 mov    $0xffffffff,%edx
               → callq  *ffffffffda658ad9
                 mov    %rax,%r13
               }
                 mov    %r13,%rax
    0.72         mov    0x0(%rbp),%rbx
                 mov    0x8(%rbp),%r13
    1.16         mov    0x10(%rbp),%r14
    0.10         mov    0x18(%rbp),%r15
    0.42         add    $0x28,%rbp
    0.54         leaveq
    0.54       ← retq
  #

Please see 'man perf-config' to see how to control what should be seen,
via ~/.perfconfig [annotate] section, for instance, one can suppress the
source code and see just the disassembly, etc.

Alternatively, use the TUI bu just using 'perf annotate', press
'/bpf_prog' to see the bpf symbols, press enter and do the interactive
annotation, which allows for dumping to a file after selecting the
the various output tunables, for instance, the above without source code
intermixed, plus showing all the instruction offsets:

  # perf annotate bpf_prog_819967866022f1e1_sys_enter

Then press: 's' to hide the source code + 'O' twice to show all
instruction offsets, then 'P' to print to the
bpf_prog_819967866022f1e1_sys_enter.annotation file, which will have:

  # cat bpf_prog_819967866022f1e1_sys_enter.annotation
  bpf_prog_819967866022f1e1_sys_enter() bpf_prog_819967866022f1e1_sys_enter
  Event: cycles:ppp

   53.41    0:   push   %rbp

    0.63    1:   mov    %rsp,%rbp
    0.31    4:   sub    $0x170,%rsp
    1.93    b:   sub    $0x28,%rbp
    7.02    f:   mov    %rbx,0x0(%rbp)
    3.20   13:   mov    %r13,0x8(%rbp)
    1.07   17:   mov    %r14,0x10(%rbp)
    0.61   1b:   mov    %r15,0x18(%rbp)
    0.11   1f:   xor    %eax,%eax
    1.29   21:   mov    %rax,0x20(%rbp)
    0.11   25:   mov    %rdi,%rbx
    2.02   28: → callq  *ffffffffda6776d9
    2.76   2d:   mov    %eax,-0x148(%rbp)
           33:   mov    %rbp,%rsi
           36:   add    $0xfffffffffffffeb8,%rsi
           3d:   movabs $0xffff975ac2607800,%rdi

    1.26   47: → callq  *ffffffffda6789e9
           4c:   cmp    $0x0,%rax
    2.43   50: → je     0
           52:   add    $0x38,%rax
    0.21   56:   xor    %r13d,%r13d
    0.81   59:   cmp    $0x0,%rax
           5d: → jne    0
           63:   mov    %rbp,%rdi
    2.22   66:   add    $0xfffffffffffffeb8,%rdi
    0.11   6d:   mov    $0x40,%esi
    0.32   72:   mov    %rbx,%rdx
    2.74   75: → callq  *ffffffffda658409
    0.22   7a:   mov    %rbp,%rsi
    1.69   7d:   add    $0xfffffffffffffec0,%rsi
           84:   movabs $0xffff975bfcd36000,%rdi

           8e:   add    $0xd0,%rdi
    0.21   95:   mov    0x0(%rsi),%eax
    0.93   98:   cmp    $0x200,%rax
           9f: → jae    0
    0.10   a1:   shl    $0x3,%rax

    0.11   a5:   add    %rdi,%rax
    0.11   a8: → jmp    0
           aa:   xor    %eax,%eax
    1.07   ac:   cmp    $0x0,%rax
           b0: → je     0
    6.57   b6:   movzbq 0x0(%rax),%rdi

           bb:   cmp    $0x0,%rdi
    0.95   bf: → je     0
           c5:   mov    $0x40,%r8d
           cb:   mov    -0x140(%rbp),%rdi
           d2:   cmp    $0x2,%rdi
           d6: → je     0
           d8:   cmp    $0x101,%rdi
           df: → je     0
           e1:   cmp    $0x15,%rdi
           e5: → jne    0
           e7:   mov    0x10(%rbx),%rdx
           eb: → jmp    0
           ed:   mov    0x18(%rbx),%rdx
           f1:   cmp    $0x0,%rdx
           f5: → je     0
           f7:   xor    %edi,%edi
           f9:   mov    %edi,-0x104(%rbp)
           ff:   mov    %rbp,%rdi
          102:   add    $0xffffffffffffff00,%rdi
          109:   mov    $0x100,%esi
          10e: → callq  *ffffffffda658499
          113:   mov    $0x148,%r8d
          119:   mov    %eax,-0x108(%rbp)
          11f:   mov    %rax,%rdi
          122:   shl    $0x20,%rdi

          126:   shr    $0x20,%rdi

          12a:   cmp    $0xff,%rdi
          131: → ja     0
          133:   add    $0x48,%rax
          137:   and    $0xff,%rax
          13d:   mov    %rax,%r8
          140:   mov    %rbp,%rcx
          143:   add    $0xfffffffffffffeb8,%rcx
          14a:   mov    %rbx,%rdi
          14d:   movabs $0xffff975fbd72d800,%rsi

          157:   mov    $0xffffffff,%edx
          15c: → callq  *ffffffffda658ad9
          161:   mov    %rax,%r13
          164:   mov    %r13,%rax
    0.72  167:   mov    0x0(%rbp),%rbx
          16b:   mov    0x8(%rbp),%r13
    1.16  16f:   mov    0x10(%rbp),%r14
    0.10  173:   mov    0x18(%rbp),%r15
    0.42  177:   add    $0x28,%rbp
    0.54  17b:   leaveq
    0.54  17c: ← retq

Another cool way to test all this is to symple use 'perf top' look for
those symbols, go there and press enter, annotate it live :-)
Signed-off-by: NSong Liu <songliubraving@fb.com>
Reviewed-by: NJiri Olsa <jolsa@kernel.org>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stanislav Fomichev <sdf@google.com>
Link: http://lkml.kernel.org/r/20190312053051.2690567-13-songliubraving@fb.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      6987561c
  47. 20 3月, 2019 6 次提交
  49. 21 2月, 2019 1 次提交
  51. 15 2月, 2019 1 次提交