perf tools: Synthesize PERF_RECORD_* for loaded BPF programs

This patch synthesize PERF_RECORD_KSYMBOL and PERF_RECORD_BPF_EVENT for
BPF programs loaded before perf-record. This is achieved by gathering
information about all BPF programs via sys_bpf.

Committer notes:

Fix the build on some older systems such as amazonlinux:1 where it was
breaking with:

  util/bpf-event.c: In function 'perf_event__synthesize_one_bpf_prog':
  util/bpf-event.c:52:9: error: missing initializer for field 'type' of 'struct bpf_prog_info' [-Werror=missing-field-initializers]
    struct bpf_prog_info info = {};
           ^
  In file included from /git/linux/tools/lib/bpf/bpf.h:26:0,
                   from util/bpf-event.c:3:
  /git/linux/tools/include/uapi/linux/bpf.h:2699:8: note: 'type' declared here
    __u32 type;
          ^
  cc1: all warnings being treated as errors

Further fix on a centos:6 system:

  cc1: warnings being treated as errors
  util/bpf-event.c: In function 'perf_event__synthesize_one_bpf_prog':
  util/bpf-event.c:50: error: 'func_info_rec_size' may be used uninitialized in this function

The compiler is wrong, but to silence it, initialize that variable to
zero.

One more fix, this time for debian:experimental-x-mips, x-mips64 and
x-mipsel:

  util/bpf-event.c: In function 'perf_event__synthesize_one_bpf_prog':
  util/bpf-event.c:93:16: error: implicit declaration of function 'calloc' [-Werror=implicit-function-declaration]
     func_infos = calloc(sub_prog_cnt, func_info_rec_size);
                  ^~~~~~
  util/bpf-event.c:93:16: error: incompatible implicit declaration of built-in function 'calloc' [-Werror]
  util/bpf-event.c:93:16: note: include '<stdlib.h>' or provide a declaration of 'calloc'

Add the missing header.

Committer testing:

  # perf record --bpf-event sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.021 MB perf.data (7 samples) ]
  # perf report -D | grep PERF_RECORD_BPF_EVENT | nl
     1	0 0x4b10 [0x18]: PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 13
     2	0 0x4c60 [0x18]: PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 14
     3	0 0x4db0 [0x18]: PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 15
     4	0 0x4f00 [0x18]: PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 16
     5	0 0x5050 [0x18]: PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 17
     6	0 0x51a0 [0x18]: PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 18
     7	0 0x52f0 [0x18]: PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 21
     8	0 0x5440 [0x18]: PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 22
  # 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
  #

  # perf report -D | grep -B22 PERF_RECORD_KSYMBOL
  . ... raw event: size 312 bytes
  .  0000:  11 00 00 00 00 00 38 01 ff 44 06 c0 ff ff ff ff  ......8..D......
  .  0010:  e5 00 00 00 01 00 00 00 62 70 66 5f 70 72 6f 67  ........bpf_prog
  .  0020:  5f 37 62 65 34 39 65 33 39 33 34 61 31 32 35 62  _7be49e3934a125b
  .  0030:  61 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  a...............
   <SNIP zeroes>
  .  0110:  00 00 00 00 00 00 00 00 21 00 00 00 00 00 00 00  ........!.......
  .  0120:  7b e4 9e 39 34 a1 25 ba 00 00 00 00 00 00 00 00  {..94.%.........
  .  0130:  00 00 00 00 00 00 00 00                          ........

  0 0x49d8 [0x138]: PERF_RECORD_KSYMBOL ksymbol event with addr ffffffffc00644ff len 229 type 1 flags 0x0 name bpf_prog_7be49e3934a125ba
  --
  . ... raw event: size 312 bytes
  .  0000:  11 00 00 00 00 00 38 01 48 6d 06 c0 ff ff ff ff  ......8.Hm......
  .  0010:  e5 00 00 00 01 00 00 00 62 70 66 5f 70 72 6f 67  ........bpf_prog
  .  0020:  5f 32 61 31 34 32 65 66 36 37 61 61 61 64 31 37  _2a142ef67aaad17
  .  0030:  34 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  4...............
   <SNIP zeroes>
  .  0110:  00 00 00 00 00 00 00 00 21 00 00 00 00 00 00 00  ........!.......
  .  0120:  2a 14 2e f6 7a aa d1 74 00 00 00 00 00 00 00 00  *...z..t........
  .  0130:  00 00 00 00 00 00 00 00                          ........

  0 0x4b28 [0x138]: PERF_RECORD_KSYMBOL ksymbol event with addr ffffffffc0066d48 len 229 type 1 flags 0x0 name bpf_prog_2a142ef67aaad174
  --
  . ... raw event: size 312 bytes
  .  0000:  11 00 00 00 00 00 38 01 04 cf 03 c0 ff ff ff ff  ......8.........
  .  0010:  e5 00 00 00 01 00 00 00 62 70 66 5f 70 72 6f 67  ........bpf_prog
  .  0020:  5f 37 62 65 34 39 65 33 39 33 34 61 31 32 35 62  _7be49e3934a125b
  .  0030:  61 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  a...............
   <SNIP zeroes>
  .  0110:  00 00 00 00 00 00 00 00 21 00 00 00 00 00 00 00  ........!.......
  .  0120:  7b e4 9e 39 34 a1 25 ba 00 00 00 00 00 00 00 00  {..94.%.........
  .  0130:  00 00 00 00 00 00 00 00                          ........

  0 0x4c78 [0x138]: PERF_RECORD_KSYMBOL ksymbol event with addr ffffffffc003cf04 len 229 type 1 flags 0x0 name bpf_prog_7be49e3934a125ba
  --
  . ... raw event: size 312 bytes
  .  0000:  11 00 00 00 00 00 38 01 96 28 04 c0 ff ff ff ff  ......8..(......
  .  0010:  e5 00 00 00 01 00 00 00 62 70 66 5f 70 72 6f 67  ........bpf_prog
  .  0020:  5f 32 61 31 34 32 65 66 36 37 61 61 61 64 31 37  _2a142ef67aaad17
  .  0030:  34 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  4...............
   <SNIP zeroes>
  .  0110:  00 00 00 00 00 00 00 00 21 00 00 00 00 00 00 00  ........!.......
  .  0120:  2a 14 2e f6 7a aa d1 74 00 00 00 00 00 00 00 00  *...z..t........
  .  0130:  00 00 00 00 00 00 00 00                          ........

  0 0x4dc8 [0x138]: PERF_RECORD_KSYMBOL ksymbol event with addr ffffffffc0042896 len 229 type 1 flags 0x0 name bpf_prog_2a142ef67aaad174
  --
  . ... raw event: size 312 bytes
  .  0000:  11 00 00 00 00 00 38 01 05 13 17 c0 ff ff ff ff  ......8.........
  .  0010:  e5 00 00 00 01 00 00 00 62 70 66 5f 70 72 6f 67  ........bpf_prog
  .  0020:  5f 37 62 65 34 39 65 33 39 33 34 61 31 32 35 62  _7be49e3934a125b
  .  0030:  61 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  a...............
   <SNIP zeroes>
  .  0110:  00 00 00 00 00 00 00 00 21 00 00 00 00 00 00 00  ........!.......
  .  0120:  7b e4 9e 39 34 a1 25 ba 00 00 00 00 00 00 00 00  {..94.%.........
  .  0130:  00 00 00 00 00 00 00 00                          ........

  0 0x4f18 [0x138]: PERF_RECORD_KSYMBOL ksymbol event with addr ffffffffc0171305 len 229 type 1 flags 0x0 name bpf_prog_7be49e3934a125ba
  --
  . ... raw event: size 312 bytes
  .  0000:  11 00 00 00 00 00 38 01 0a 8c 23 c0 ff ff ff ff  ......8...#.....
  .  0010:  e5 00 00 00 01 00 00 00 62 70 66 5f 70 72 6f 67  ........bpf_prog
  .  0020:  5f 32 61 31 34 32 65 66 36 37 61 61 61 64 31 37  _2a142ef67aaad17
  .  0030:  34 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  4...............
   <SNIP zeroes>
  .  0110:  00 00 00 00 00 00 00 00 21 00 00 00 00 00 00 00  ........!.......
  .  0120:  2a 14 2e f6 7a aa d1 74 00 00 00 00 00 00 00 00  *...z..t........
  .  0130:  00 00 00 00 00 00 00 00                          ........

  0 0x5068 [0x138]: PERF_RECORD_KSYMBOL ksymbol event with addr ffffffffc0238c0a len 229 type 1 flags 0x0 name bpf_prog_2a142ef67aaad174
  --
  . ... raw event: size 312 bytes
  .  0000:  11 00 00 00 00 00 38 01 2a a5 a4 c0 ff ff ff ff  ......8.*.......
  .  0010:  e5 00 00 00 01 00 00 00 62 70 66 5f 70 72 6f 67  ........bpf_prog
  .  0020:  5f 37 62 65 34 39 65 33 39 33 34 61 31 32 35 62  _7be49e3934a125b
  .  0030:  61 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  a...............
   <SNIP zeroes>
  .  0110:  00 00 00 00 00 00 00 00 21 00 00 00 00 00 00 00  ........!.......
  .  0120:  7b e4 9e 39 34 a1 25 ba 00 00 00 00 00 00 00 00  {..94.%.........
  .  0130:  00 00 00 00 00 00 00 00                          ........

  0 0x51b8 [0x138]: PERF_RECORD_KSYMBOL ksymbol event with addr ffffffffc0a4a52a len 229 type 1 flags 0x0 name bpf_prog_7be49e3934a125ba
  --
  . ... raw event: size 312 bytes
  .  0000:  11 00 00 00 00 00 38 01 9b c9 a4 c0 ff ff ff ff  ......8.........
  .  0010:  e5 00 00 00 01 00 00 00 62 70 66 5f 70 72 6f 67  ........bpf_prog
  .  0020:  5f 32 61 31 34 32 65 66 36 37 61 61 61 64 31 37  _2a142ef67aaad17
  .  0030:  34 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  4...............
   <SNIP zeroes>
  .  0110:  00 00 00 00 00 00 00 00 21 00 00 00 00 00 00 00  ........!.......
  .  0120:  2a 14 2e f6 7a aa d1 74 00 00 00 00 00 00 00 00  *...z..t........
  .  0130:  00 00 00 00 00 00 00 00                          ........

  0 0x5308 [0x138]: PERF_RECORD_KSYMBOL ksymbol event with addr ffffffffc0a4c99b len 229 type 1 flags 0x0 name bpf_prog_2a142ef67aaad174

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/20190117161521.1341602-8-songliubraving@fb.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/tools/perf/util/bpf-event.h b/tools/perf/util/bpf-event.h
index da0dfc035fc6..7890067e1a37 100644
--- a/tools/perf/util/bpf-event.h
+++ b/tools/perf/util/bpf-event.h
@@ -3,14 +3,22 @@
 #define __PERF_BPF_EVENT_H
 
 #include <linux/compiler.h>
+#include "event.h"
 
 struct machine;
 union perf_event;
 struct perf_sample;
+struct perf_tool;
+struct record_opts;
 
 #ifdef HAVE_LIBBPF_SUPPORT
 int machine__process_bpf_event(struct machine *machine, union perf_event *event,
 			       struct perf_sample *sample);
+
+int perf_event__synthesize_bpf_events(struct perf_tool *tool,
+				      perf_event__handler_t process,
+				      struct machine *machine,
+				      struct record_opts *opts);
 #else
 static inline int machine__process_bpf_event(struct machine *machine __maybe_unused,
 					     union perf_event *event __maybe_unused,
@@ -18,5 +26,13 @@ static inline int machine__process_bpf_event(struct machine *machine __maybe_unu
 {
 	return 0;
 }
+
+static inline int perf_event__synthesize_bpf_events(struct perf_tool *tool __maybe_unused,
+						    perf_event__handler_t process __maybe_unused,
+						    struct machine *machine __maybe_unused,
+						    struct record_opts *opts __maybe_unused)
+{
+	return 0;
+}
 #endif // HAVE_LIBBPF_SUPPORT
 #endif