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authorSong Liu <songliubraving@fb.com>2019-01-17 19:15:18 +0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2019-01-21 23:00:57 +0300
commit45178a928a4b7c6093f6621e627d09909e81cc13 (patch)
tree367071cf5de539147b7ca03ffffb79957acca7e3 /tools/perf/util/bpf-event.c
parent9aa0bfa370b278a539077002b3c660468d66b5e7 (diff)
downloadlinux-45178a928a4b7c6093f6621e627d09909e81cc13.tar.xz
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>
Diffstat (limited to 'tools/perf/util/bpf-event.c')
-rw-r--r--tools/perf/util/bpf-event.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
new file mode 100644
index 000000000000..87004706874f
--- /dev/null
+++ b/tools/perf/util/bpf-event.c
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <errno.h>
+#include <bpf/bpf.h>
+#include "bpf-event.h"
+#include "debug.h"
+#include "symbol.h"
+
+int machine__process_bpf_event(struct machine *machine __maybe_unused,
+ union perf_event *event,
+ struct perf_sample *sample __maybe_unused)
+{
+ if (dump_trace)
+ perf_event__fprintf_bpf_event(event, stdout);
+ return 0;
+}