linux/tools
Song Liu 45178a928a perf tools: Handle PERF_RECORD_BPF_EVENT
This patch adds basic handling of PERF_RECORD_BPF_EVENT.  Tracking of
PERF_RECORD_BPF_EVENT is OFF by default. Option --bpf-event is added to
turn it on.

Committer notes:

Add dummy machine__process_bpf_event() variant that returns zero for
systems without HAVE_LIBBPF_SUPPORT, such as Alpine Linux, unbreaking
the build in such systems.

Remove the needless include <machine.h> from bpf->event.h, provide just
forward declarations for the structs and unions in the parameters, to
reduce compilation time and needless rebuilds when machine.h gets
changed.

Committer testing:

When running with:

 # perf record --bpf-event

On an older kernel where PERF_RECORD_BPF_EVENT and PERF_RECORD_KSYMBOL
is not present, we fallback to removing those two bits from
perf_event_attr, making the tool to continue to work on older kernels:

  perf_event_attr:
    size                             112
    { sample_period, sample_freq }   4000
    sample_type                      IP|TID|TIME|PERIOD
    read_format                      ID
    disabled                         1
    inherit                          1
    mmap                             1
    comm                             1
    freq                             1
    enable_on_exec                   1
    task                             1
    precise_ip                       3
    sample_id_all                    1
    exclude_guest                    1
    mmap2                            1
    comm_exec                        1
    ksymbol                          1
    bpf_event                        1
  ------------------------------------------------------------
  sys_perf_event_open: pid 5779  cpu 0  group_fd -1  flags 0x8
  sys_perf_event_open failed, error -22
  switching off bpf_event
  ------------------------------------------------------------
  perf_event_attr:
    size                             112
    { sample_period, sample_freq }   4000
    sample_type                      IP|TID|TIME|PERIOD
    read_format                      ID
    disabled                         1
    inherit                          1
    mmap                             1
    comm                             1
    freq                             1
    enable_on_exec                   1
    task                             1
    precise_ip                       3
    sample_id_all                    1
    exclude_guest                    1
    mmap2                            1
    comm_exec                        1
    ksymbol                          1
  ------------------------------------------------------------
  sys_perf_event_open: pid 5779  cpu 0  group_fd -1  flags 0x8
  sys_perf_event_open failed, error -22
  switching off ksymbol
  ------------------------------------------------------------
  perf_event_attr:
    size                             112
    { sample_period, sample_freq }   4000
    sample_type                      IP|TID|TIME|PERIOD
    read_format                      ID
    disabled                         1
    inherit                          1
    mmap                             1
    comm                             1
    freq                             1
    enable_on_exec                   1
    task                             1
    precise_ip                       3
    sample_id_all                    1
    exclude_guest                    1
    mmap2                            1
    comm_exec                        1
  ------------------------------------------------------------

And then proceeds to work without those two features.

As passing --bpf-event is an explicit action performed by the user, perhaps we
should emit a warning telling that the kernel has no such feature, but this can
be done on top of this patch.

Now with a kernel that supports these events, start the 'record --bpf-event -a'
and then run 'perf trace sleep 10000' that will use the BPF
augmented_raw_syscalls.o prebuilt (for another kernel version even) and thus
should generate PERF_RECORD_BPF_EVENT events:

  [root@quaco ~]# perf record -e dummy -a --bpf-event
  ^C[ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.713 MB perf.data ]

  [root@quaco ~]# bpftool prog
  13: cgroup_skb  tag 7be49e3934a125ba  gpl
  	loaded_at 2019-01-19T09:09:43-0300  uid 0
  	xlated 296B  jited 229B  memlock 4096B  map_ids 13,14
  14: cgroup_skb  tag 2a142ef67aaad174  gpl
  	loaded_at 2019-01-19T09:09:43-0300  uid 0
  	xlated 296B  jited 229B  memlock 4096B  map_ids 13,14
  15: cgroup_skb  tag 7be49e3934a125ba  gpl
  	loaded_at 2019-01-19T09:09:43-0300  uid 0
  	xlated 296B  jited 229B  memlock 4096B  map_ids 15,16
  16: cgroup_skb  tag 2a142ef67aaad174  gpl
  	loaded_at 2019-01-19T09:09:43-0300  uid 0
  	xlated 296B  jited 229B  memlock 4096B  map_ids 15,16
  17: cgroup_skb  tag 7be49e3934a125ba  gpl
  	loaded_at 2019-01-19T09:09:44-0300  uid 0
  	xlated 296B  jited 229B  memlock 4096B  map_ids 17,18
  18: cgroup_skb  tag 2a142ef67aaad174  gpl
  	loaded_at 2019-01-19T09:09:44-0300  uid 0
  	xlated 296B  jited 229B  memlock 4096B  map_ids 17,18
  21: cgroup_skb  tag 7be49e3934a125ba  gpl
  	loaded_at 2019-01-19T09:09:45-0300  uid 0
  	xlated 296B  jited 229B  memlock 4096B  map_ids 21,22
  22: cgroup_skb  tag 2a142ef67aaad174  gpl
  	loaded_at 2019-01-19T09:09:45-0300  uid 0
  	xlated 296B  jited 229B  memlock 4096B  map_ids 21,22
  31: tracepoint  name sys_enter  tag 12504ba9402f952f  gpl
  	loaded_at 2019-01-19T09:19:56-0300  uid 0
  	xlated 512B  jited 374B  memlock 4096B  map_ids 30,29,28
  32: tracepoint  name sys_exit  tag c1bd85c092d6e4aa  gpl
  	loaded_at 2019-01-19T09:19:56-0300  uid 0
  	xlated 256B  jited 191B  memlock 4096B  map_ids 30,29
  # perf report -D | grep PERF_RECORD_BPF_EVENT | nl
     1	0 55834574849 0x4fc8 [0x18]: PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 13
     2	0 60129542145 0x5118 [0x18]: PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 14
     3	0 64424509441 0x5268 [0x18]: PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 15
     4	0 68719476737 0x53b8 [0x18]: PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 16
     5	0 73014444033 0x5508 [0x18]: PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 17
     6	0 77309411329 0x5658 [0x18]: PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 18
     7	0 90194313217 0x57a8 [0x18]: PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 21
     8	0 94489280513 0x58f8 [0x18]: PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 22
     9	7 620922484360 0xb6390 [0x30]: PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 29
    10	7 620922486018 0xb6410 [0x30]: PERF_RECORD_BPF_EVENT bpf event with type 2, flags 0, id 29
    11	7 620922579199 0xb6490 [0x30]: PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 30
    12	7 620922580240 0xb6510 [0x30]: PERF_RECORD_BPF_EVENT bpf event with type 2, flags 0, id 30
    13	7 620922765207 0xb6598 [0x30]: PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 31
    14	7 620922874543 0xb6620 [0x30]: PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 32
  #

There, the 31 and 32 tracepoint BPF programs put in place by 'perf trace'.

Signed-off-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: kernel-team@fb.com
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/20190117161521.1341602-7-songliubraving@fb.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-01-21 17:00:57 -03:00
..
accounting delayacct: track delays from thrashing cache pages 2018-10-26 16:26:32 -07:00
arch Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-01-11 09:44:05 -08:00
bpf tools/bpf: fix bpftool map dump with bitfields 2019-01-11 10:40:54 +01:00
build perf build: Don't unconditionally link the libbfd feature test to -liberty and -lz 2018-12-21 09:42:46 -03:00
cgroup
crypto crypto: user - rename err_cnt parameter 2018-12-07 14:15:00 +08:00
firewire
firmware tools: Add 'firmware' category and add ihex2fw tool 2018-11-11 12:58:27 -08:00
gpio tools gpio: Allow overriding CFLAGS 2018-12-28 16:33:08 -03:00
hv Tools: hv: kvp: Fix a warning of buffer overflow with gcc 8.0.1 2018-11-11 12:58:27 -08:00
iio tools iio: Override CFLAGS assignments 2019-01-04 12:54:49 -03:00
include tools headers uapi: Sync tools/include/uapi/linux/perf_event.h 2019-01-21 17:00:57 -03:00
kvm/kvm_stat tools/kvm_stat: switch to python3 2018-11-27 12:53:44 +01:00
laptop
leds
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-01-16 05:13:36 +12:00
memory-model
nfsd
objtool objtool: Fix segfault in .cold detection with -ffunction-sections 2018-11-20 18:59:00 +01:00
pci
pcmcia
perf perf tools: Handle PERF_RECORD_BPF_EVENT 2019-01-21 17:00:57 -03:00
power perf/core improvements and fixes: 2019-01-03 14:05:16 +01:00
scripts
spi
testing tools/bpf: test btf bitfield with >=256 struct member offset 2019-01-11 10:40:54 +01:00
thermal/tmon tools thermal tmon: Use -O3 instead of -O1 if available 2019-01-04 12:54:49 -03:00
time
usb usbip: tools: fix atoi() on non-null terminated string 2018-10-18 19:44:39 +02:00
virtio virtio: fix test build after uio.h change 2018-12-19 18:23:49 -05:00
vm tools/vm/page_owner: use page_owner_sort in the use example 2019-01-08 17:15:11 -08:00
wmi
Makefile tools: Add 'firmware' category and add ihex2fw tool 2018-11-11 12:58:27 -08:00