From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D1BA0C43387 for ; Fri, 11 Jan 2019 18:44:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9438521848 for ; Fri, 11 Jan 2019 18:44:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1547232258; bh=uv05aVhMx3vXrCSPrA44C1FdVzt8inbxXJlP+3a4Bms=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=cYWEupcZC/tl/AjQz5542TNhxHRSpwz2Dx89Mk2LaiaKEOsDv9NQSSL5I4BNI9mw/ AvfGg16mVF2tVDBYpPFhNeSE2v9t1ruV62ogWnw7+DLTBs+L+KQ2MH2UhnJBvMo3hc 1WHj6X8EuWDND079PlfcTRIySTWAoIHsa9L3Ing0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390107AbfAKSoR (ORCPT ); Fri, 11 Jan 2019 13:44:17 -0500 Received: from mail.kernel.org ([198.145.29.99]:55896 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730785AbfAKSoQ (ORCPT ); Fri, 11 Jan 2019 13:44:16 -0500 Received: from quaco.ghostprotocols.net (unknown [190.15.121.82]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4516020878; Fri, 11 Jan 2019 18:44:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1547232255; bh=uv05aVhMx3vXrCSPrA44C1FdVzt8inbxXJlP+3a4Bms=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=N3tp0B5AxedDYp1BfoFEOwnAwQRO1MGFIOFNwBx6EWbAhJfj7jTGCMfJzCwJL2H90 AaL6dOxBGPBLqGCFp5tuQVh5TyV90OzWR0dos0SuCRne1J2QCuSYA57RSEY/t6qWAK 1fBJrgpmbIqlhyE+Z3i6NSUVlivEivYcwvFaxBzg= Received: by quaco.ghostprotocols.net (Postfix, from userid 1000) id E6D8941AB5; Fri, 11 Jan 2019 15:44:12 -0300 (-03) Date: Fri, 11 Jan 2019 15:44:12 -0300 From: Arnaldo Carvalho de Melo To: Song Liu Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, peterz@infradead.org, ast@kernel.org, daniel@iogearbox.net, kernel-team@fb.com, dsahern@gmail.com Subject: Re: [PATCH v7 perf, bpf-next 8/8] perf tools: synthesize PERF_RECORD_* for loaded BPF programs Message-ID: <20190111184412.GA22483@kernel.org> References: <20190111001933.4153792-1-songliubraving@fb.com> <20190111001933.4153792-9-songliubraving@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190111001933.4153792-9-songliubraving@fb.com> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Thu, Jan 10, 2019 at 04:19:33PM -0800, Song Liu escreveu: > 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. > > Signed-off-by: Song Liu > --- > tools/perf/builtin-record.c | 6 ++ > tools/perf/util/bpf-event.c | 205 ++++++++++++++++++++++++++++++++++++ > tools/perf/util/bpf-event.h | 5 + > 3 files changed, 216 insertions(+) > > diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c > index deaf9b902094..88ea11d57c6f 100644 > --- a/tools/perf/builtin-record.c > +++ b/tools/perf/builtin-record.c > @@ -41,6 +41,7 @@ > #include "util/perf-hooks.h" > #include "util/time-utils.h" > #include "util/units.h" > +#include "util/bpf-event.h" > #include "asm/bug.h" > > #include > @@ -1082,6 +1083,11 @@ static int record__synthesize(struct record *rec, bool tail) > return err; > } > > + err = perf_event__synthesize_bpf_events(tool, process_synthesized_event, > + machine, opts); > + if (err < 0) > + pr_warning("Couldn't synthesize bpf events.\n"); > + There should be no warnings on older systems, I build a kernel and tools with your changes and then, before rebooting, I tried: [root@quaco ~]# perf record ls Couldn't synthesize bpf events. [root@quaco ~]# uname -a Linux quaco 4.19.13-300.fc29.x86_64 #1 SMP Sat Dec 29 22:54:28 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux [root@quaco ~]# At most this should be a pr_debug(), but then it should check if the system is bpf capable and if not only warn if the user explicitely asked for bpf events. - Arnaldo > err = __machine__synthesize_threads(machine, tool, &opts->target, rec->evlist->threads, > process_synthesized_event, opts->sample_address, > 1); > diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c > index f24f75506f51..ee60c8b1e636 100644 > --- a/tools/perf/util/bpf-event.c > +++ b/tools/perf/util/bpf-event.c > @@ -1,10 +1,24 @@ > // SPDX-License-Identifier: GPL-2.0 > #include > #include > +#include > +#include > #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 +27,194 @@ int machine__process_bpf_event(struct machine *machine __maybe_unused, > perf_event__fprintf_bpf_event(event, stderr); > 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. > + */ > +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; > + u8 (*prog_tags)[BPF_TAG_SIZE] = NULL; > + struct bpf_prog_info info = {}; > + 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; > + 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 || info_len < 192 /* need field prog_tags */) > + return -1; > + > + /* 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) > + return -1; > + if (btf__get_from_id(info.btf_id, &btf)) > + return -1; > + func_info_rec_size = info.func_info_rec_size; > + func_infos = malloc(sub_prog_cnt * func_info_rec_size); > + if (!func_infos) > + 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 = (u64 *)malloc(sizeof(u64) * sub_prog_cnt); > + prog_lens = (u32 *)malloc(sizeof(u64) * sub_prog_cnt); > + prog_tags = malloc(sizeof(u8) * BPF_TAG_SIZE * sub_prog_cnt); > + > + err = !prog_addrs || !prog_lens || !prog_tags; > + if (err) > + 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) > + 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_err("can't get next program: %s%s", > + strerror(errno), > + errno == EINVAL ? " -- kernel too old?" : ""); > + err = -1; > + break; > + } > + fd = bpf_prog_get_fd_by_id(id); > + if (fd < 0) { > + pr_debug("Failed to get fd for prog_id %u\n", id); > + continue; > + } > + > + err = perf_event__synthesize_one_bpf_prog( > + tool, process, machine, fd, event, opts); > + close(fd); > + if (err) > + break; > + } > + free(event); > + return err; > +} > diff --git a/tools/perf/util/bpf-event.h b/tools/perf/util/bpf-event.h > index d5ca355dd298..38aee4040f12 100644 > --- a/tools/perf/util/bpf-event.h > +++ b/tools/perf/util/bpf-event.h > @@ -8,4 +8,9 @@ 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); > + > #endif > -- > 2.17.1 -- - Arnaldo