Messages in this thread Patch in this message | | | From | Arnaldo Carvalho de Melo <> | Subject | [PATCH 5/6] perf tools: Load eBPF object into kernel | Date | Thu, 29 Oct 2015 08:17:01 -0300 |
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From: Wang Nan <wangnan0@huawei.com>
This patch utilizes bpf_object__load() provided by libbpf to load all objects into kernel.
Committer notes:
Testing it:
When using an incorrect kernel version number, i.e., having this in your eBPF proggie:
int _version __attribute__((section("version"), used)) = 0x40100;
For a 4.3.0-rc6+ kernel, say, this happens and needs checking at event parsing time, to provide a better error report to the user:
# perf record --event /tmp/foo.o sleep 1 libbpf: load bpf program failed: Invalid argument libbpf: -- BEGIN DUMP LOG --- libbpf:
libbpf: -- END LOG -- libbpf: failed to load program 'fork=_do_fork' libbpf: failed to load object '/tmp/foo.o' event syntax error: '/tmp/foo.o' \___ Invalid argument: Are you root and runing a CONFIG_BPF_SYSCALL kernel?
(add -v to see detail) Run 'perf list' for a list of valid events
Usage: perf record [<options>] [<command>] or: perf record [<options>] -- <command> [<options>]
-e, --event <event> event selector. use 'perf list' to list available events
If we instead make it match, i.e. use 0x40300 on this v4.3.0-rc6+ kernel, the whole process goes thru:
# perf record --event /tmp/foo.o -a usleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.202 MB perf.data ] # perf evlist -v /tmp/foo.o: type: 1, size: 112, config: 0x9, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|CPU|PERIOD, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1 #
Signed-off-by: Wang Nan <wangnan0@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David Ahern <dsahern@gmail.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kaixu Xia <xiakaixu@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1444826502-49291-6-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> --- tools/perf/util/bpf-loader.c | 22 ++++++++++++++++++++++ tools/perf/util/bpf-loader.h | 11 +++++++++++ tools/perf/util/parse-events.c | 6 ++++++ 3 files changed, 39 insertions(+)
diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c index 56f6fe8cf318..727955858d00 100644 --- a/tools/perf/util/bpf-loader.c +++ b/tools/perf/util/bpf-loader.c @@ -243,6 +243,18 @@ int bpf__unprobe(struct bpf_object *obj) return ret; } +int bpf__load(struct bpf_object *obj) +{ + int err; + + err = bpf_object__load(obj); + if (err) { + pr_debug("bpf: load objects failed\n"); + return err; + } + return 0; +} + #define bpf__strerror_head(err, buf, size) \ char sbuf[STRERR_BUFSIZE], *emsg;\ if (!size)\ @@ -275,3 +287,13 @@ int bpf__strerror_probe(struct bpf_object *obj __maybe_unused, bpf__strerror_end(buf, size); return 0; } + +int bpf__strerror_load(struct bpf_object *obj __maybe_unused, + int err, char *buf, size_t size) +{ + bpf__strerror_head(err, buf, size); + bpf__strerror_entry(EINVAL, "%s: Are you root and runing a CONFIG_BPF_SYSCALL kernel?", + emsg) + bpf__strerror_end(buf, size); + return 0; +} diff --git a/tools/perf/util/bpf-loader.h b/tools/perf/util/bpf-loader.h index b819622dc7ce..b091ceb19c48 100644 --- a/tools/perf/util/bpf-loader.h +++ b/tools/perf/util/bpf-loader.h @@ -23,6 +23,9 @@ int bpf__unprobe(struct bpf_object *obj); int bpf__strerror_probe(struct bpf_object *obj, int err, char *buf, size_t size); +int bpf__load(struct bpf_object *obj); +int bpf__strerror_load(struct bpf_object *obj, int err, + char *buf, size_t size); #else static inline struct bpf_object * bpf__prepare_load(const char *filename __maybe_unused) @@ -35,6 +38,7 @@ static inline void bpf__clear(void) { } static inline int bpf__probe(struct bpf_object *obj __maybe_unused) { return 0;} static inline int bpf__unprobe(struct bpf_object *obj __maybe_unused) { return 0;} +static inline int bpf__load(struct bpf_object *obj __maybe_unused) { return 0; } static inline int __bpf_strerror(char *buf, size_t size) @@ -55,5 +59,12 @@ bpf__strerror_probe(struct bpf_object *obj __maybe_unused, { return __bpf_strerror(buf, size); } + +static inline int bpf__strerror_load(struct bpf_object *obj __maybe_unused, + int err __maybe_unused, + char *buf, size_t size) +{ + return __bpf_strerror(buf, size); +} #endif #endif diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c index 10a946779f46..c3aabeb63e88 100644 --- a/tools/perf/util/parse-events.c +++ b/tools/perf/util/parse-events.c @@ -561,6 +561,12 @@ int parse_events_load_bpf_obj(struct parse_events_evlist *data, goto errout; } + err = bpf__load(obj); + if (err) { + bpf__strerror_load(obj, err, errbuf, sizeof(errbuf)); + goto errout; + } + /* * Temporary add a dummy event here so we can check whether * basic bpf loader works. Following patches will replace -- 2.1.0
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