diff options
author | Song Liu <songliubraving@fb.com> | 2019-01-17 08:15:19 -0800 |
---|---|---|
committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2019-01-21 17:36:39 -0300 |
commit | 7b612e291a5affb12b9d0b87332c71bcbe9c5db4 (patch) | |
tree | d5eef02ea0b3308bc0ebd9c82ceec1a9a34d5c7f /tools/perf/util/bpf-event.c | |
parent | 45178a928a4b7c6093f6621e627d09909e81cc13 (diff) | |
download | linux-7b612e291a5affb12b9d0b87332c71bcbe9c5db4.tar.bz2 |
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>
Diffstat (limited to 'tools/perf/util/bpf-event.c')
-rw-r--r-- | tools/perf/util/bpf-event.c | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c index 87004706874f..01e1dc1bb7fb 100644 --- a/tools/perf/util/bpf-event.c +++ b/tools/perf/util/bpf-event.c @@ -1,10 +1,25 @@ // SPDX-License-Identifier: GPL-2.0 #include <errno.h> +#include <stdlib.h> #include <bpf/bpf.h> +#include <bpf/btf.h> +#include <linux/btf.h> #include "bpf-event.h" #include "debug.h" #include "symbol.h" +#define ptr_to_u64(ptr) ((__u64)(unsigned long)(ptr)) + +static int snprintf_hex(char *buf, size_t size, unsigned char *data, size_t len) +{ + int ret = 0; + size_t i; + + for (i = 0; i < len; i++) + ret += snprintf(buf + ret, size - ret, "%02x", data[i]); + return ret; +} + int machine__process_bpf_event(struct machine *machine __maybe_unused, union perf_event *event, struct perf_sample *sample __maybe_unused) @@ -13,3 +28,230 @@ int machine__process_bpf_event(struct machine *machine __maybe_unused, perf_event__fprintf_bpf_event(event, stdout); return 0; } + +/* + * Synthesize PERF_RECORD_KSYMBOL and PERF_RECORD_BPF_EVENT for one bpf + * program. One PERF_RECORD_BPF_EVENT is generated for the program. And + * one PERF_RECORD_KSYMBOL is generated for each sub program. + * + * Returns: + * 0 for success; + * -1 for failures; + * -2 for lack of kernel support. + */ +static int perf_event__synthesize_one_bpf_prog(struct perf_tool *tool, + perf_event__handler_t process, + struct machine *machine, + int fd, + union perf_event *event, + struct record_opts *opts) +{ + struct ksymbol_event *ksymbol_event = &event->ksymbol_event; + struct bpf_event *bpf_event = &event->bpf_event; + u32 sub_prog_cnt, i, func_info_rec_size = 0; + u8 (*prog_tags)[BPF_TAG_SIZE] = NULL; + struct bpf_prog_info info = { .type = 0, }; + u32 info_len = sizeof(info); + void *func_infos = NULL; + u64 *prog_addrs = NULL; + struct btf *btf = NULL; + u32 *prog_lens = NULL; + bool has_btf = false; + char errbuf[512]; + int err = 0; + + /* Call bpf_obj_get_info_by_fd() to get sizes of arrays */ + err = bpf_obj_get_info_by_fd(fd, &info, &info_len); + + if (err) { + pr_debug("%s: failed to get BPF program info: %s, aborting\n", + __func__, str_error_r(errno, errbuf, sizeof(errbuf))); + return -1; + } + if (info_len < offsetof(struct bpf_prog_info, prog_tags)) { + pr_debug("%s: the kernel is too old, aborting\n", __func__); + return -2; + } + + /* number of ksyms, func_lengths, and tags should match */ + sub_prog_cnt = info.nr_jited_ksyms; + if (sub_prog_cnt != info.nr_prog_tags || + sub_prog_cnt != info.nr_jited_func_lens) + return -1; + + /* check BTF func info support */ + if (info.btf_id && info.nr_func_info && info.func_info_rec_size) { + /* btf func info number should be same as sub_prog_cnt */ + if (sub_prog_cnt != info.nr_func_info) { + pr_debug("%s: mismatch in BPF sub program count and BTF function info count, aborting\n", __func__); + return -1; + } + if (btf__get_from_id(info.btf_id, &btf)) { + pr_debug("%s: failed to get BTF of id %u, aborting\n", __func__, info.btf_id); + return -1; + } + func_info_rec_size = info.func_info_rec_size; + func_infos = calloc(sub_prog_cnt, func_info_rec_size); + if (!func_infos) { + pr_debug("%s: failed to allocate memory for func_infos, aborting\n", __func__); + return -1; + } + has_btf = true; + } + + /* + * We need address, length, and tag for each sub program. + * Allocate memory and call bpf_obj_get_info_by_fd() again + */ + prog_addrs = calloc(sub_prog_cnt, sizeof(u64)); + if (!prog_addrs) { + pr_debug("%s: failed to allocate memory for prog_addrs, aborting\n", __func__); + goto out; + } + prog_lens = calloc(sub_prog_cnt, sizeof(u32)); + if (!prog_lens) { + pr_debug("%s: failed to allocate memory for prog_lens, aborting\n", __func__); + goto out; + } + prog_tags = calloc(sub_prog_cnt, BPF_TAG_SIZE); + if (!prog_tags) { + pr_debug("%s: failed to allocate memory for prog_tags, aborting\n", __func__); + goto out; + } + + memset(&info, 0, sizeof(info)); + info.nr_jited_ksyms = sub_prog_cnt; + info.nr_jited_func_lens = sub_prog_cnt; + info.nr_prog_tags = sub_prog_cnt; + info.jited_ksyms = ptr_to_u64(prog_addrs); + info.jited_func_lens = ptr_to_u64(prog_lens); + info.prog_tags = ptr_to_u64(prog_tags); + info_len = sizeof(info); + if (has_btf) { + info.nr_func_info = sub_prog_cnt; + info.func_info_rec_size = func_info_rec_size; + info.func_info = ptr_to_u64(func_infos); + } + + err = bpf_obj_get_info_by_fd(fd, &info, &info_len); + if (err) { + pr_debug("%s: failed to get BPF program info, aborting\n", __func__); + goto out; + } + + /* Synthesize PERF_RECORD_KSYMBOL */ + for (i = 0; i < sub_prog_cnt; i++) { + const struct bpf_func_info *finfo; + const char *short_name = NULL; + const struct btf_type *t; + int name_len; + + *ksymbol_event = (struct ksymbol_event){ + .header = { + .type = PERF_RECORD_KSYMBOL, + .size = sizeof(struct ksymbol_event), + }, + .addr = prog_addrs[i], + .len = prog_lens[i], + .ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF, + .flags = 0, + }; + name_len = snprintf(ksymbol_event->name, KSYM_NAME_LEN, + "bpf_prog_"); + name_len += snprintf_hex(ksymbol_event->name + name_len, + KSYM_NAME_LEN - name_len, + prog_tags[i], BPF_TAG_SIZE); + if (has_btf) { + finfo = func_infos + i * info.func_info_rec_size; + t = btf__type_by_id(btf, finfo->type_id); + short_name = btf__name_by_offset(btf, t->name_off); + } else if (i == 0 && sub_prog_cnt == 1) { + /* no subprog */ + if (info.name[0]) + short_name = info.name; + } else + short_name = "F"; + if (short_name) + name_len += snprintf(ksymbol_event->name + name_len, + KSYM_NAME_LEN - name_len, + "_%s", short_name); + + ksymbol_event->header.size += PERF_ALIGN(name_len + 1, + sizeof(u64)); + err = perf_tool__process_synth_event(tool, event, + machine, process); + } + + /* Synthesize PERF_RECORD_BPF_EVENT */ + if (opts->bpf_event) { + *bpf_event = (struct bpf_event){ + .header = { + .type = PERF_RECORD_BPF_EVENT, + .size = sizeof(struct bpf_event), + }, + .type = PERF_BPF_EVENT_PROG_LOAD, + .flags = 0, + .id = info.id, + }; + memcpy(bpf_event->tag, prog_tags[i], BPF_TAG_SIZE); + err = perf_tool__process_synth_event(tool, event, + machine, process); + } + +out: + free(prog_tags); + free(prog_lens); + free(prog_addrs); + free(func_infos); + free(btf); + return err ? -1 : 0; +} + +int perf_event__synthesize_bpf_events(struct perf_tool *tool, + perf_event__handler_t process, + struct machine *machine, + struct record_opts *opts) +{ + union perf_event *event; + __u32 id = 0; + int err; + int fd; + + event = malloc(sizeof(event->bpf_event) + KSYM_NAME_LEN); + if (!event) + return -1; + while (true) { + err = bpf_prog_get_next_id(id, &id); + if (err) { + if (errno == ENOENT) { + err = 0; + break; + } + pr_debug("%s: can't get next program: %s%s", + __func__, strerror(errno), + errno == EINVAL ? " -- kernel too old?" : ""); + /* don't report error on old kernel */ + err = (errno == EINVAL) ? 0 : -1; + break; + } + fd = bpf_prog_get_fd_by_id(id); + if (fd < 0) { + pr_debug("%s: failed to get fd for prog_id %u\n", + __func__, id); + continue; + } + + err = perf_event__synthesize_one_bpf_prog(tool, process, + machine, fd, + event, opts); + close(fd); + if (err) { + /* do not return error for old kernel */ + if (err == -2) + err = 0; + break; + } + } + free(event); + return err; +} |