From patchwork Sun Feb 16 19:30:03 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 1238832 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 48LHLM1FPQz9sP7 for ; Mon, 17 Feb 2020 06:31:55 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726037AbgBPTby convert rfc822-to-8bit (ORCPT ); Sun, 16 Feb 2020 14:31:54 -0500 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:30654 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726656AbgBPTby (ORCPT ); Sun, 16 Feb 2020 14:31:54 -0500 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-307-7nDvYxAmN4exEtzLaotL_Q-1; Sun, 16 Feb 2020 14:31:45 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D10801005516; Sun, 16 Feb 2020 19:31:42 +0000 (UTC) Received: from krava.redhat.com (ovpn-204-28.brq.redhat.com [10.40.204.28]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8C6318AC5B; Sun, 16 Feb 2020 19:31:39 +0000 (UTC) From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, Andrii Nakryiko , Yonghong Song , Song Liu , Martin KaFai Lau , Jakub Kicinski , David Miller , =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= , John Fastabend , Jesper Dangaard Brouer , Arnaldo Carvalho de Melo Subject: [PATCH 16/18] perf tools: Synthesize bpf_trampoline/dispatcher ksymbol event Date: Sun, 16 Feb 2020 20:30:03 +0100 Message-Id: <20200216193005.144157-17-jolsa@kernel.org> In-Reply-To: <20200216193005.144157-1-jolsa@kernel.org> References: <20200216193005.144157-1-jolsa@kernel.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-MC-Unique: 7nDvYxAmN4exEtzLaotL_Q-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kernel.org Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Synthesize bpf images (trampolines/dispatchers) on start, as ksymbol events from /proc/kallsyms. Having this perf can recognize samples from those images and perf report and top shows them correctly. The rest of the ksymbol handling is already in place from for the bpf programs monitoring, so only the initial state was needed. perf report output: # Overhead Command Shared Object Symbol 12.37% test_progs [kernel.vmlinux] [k] entry_SYSCALL_64 11.80% test_progs [kernel.vmlinux] [k] syscall_return_via_sysret 9.63% test_progs bpf_prog_bcf7977d3b93787c_prog2 [k] bpf_prog_bcf7977d3b93787c_prog2 6.90% test_progs bpf_trampoline_24456 [k] bpf_trampoline_24456 6.36% test_progs [kernel.vmlinux] [k] memcpy_erms Signed-off-by: Jiri Olsa --- tools/perf/util/bpf-event.c | 98 +++++++++++++++++++++++++++++++++++++ 1 file changed, 98 insertions(+) diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c index a3207d900339..120ec547ae75 100644 --- a/tools/perf/util/bpf-event.c +++ b/tools/perf/util/bpf-event.c @@ -6,6 +6,9 @@ #include #include #include +#include +#include +#include #include "bpf-event.h" #include "debug.h" #include "dso.h" @@ -290,11 +293,87 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_session *session, return err ? -1 : 0; } +struct kallsyms_parse { + union perf_event *event; + perf_event__handler_t process; + struct machine *machine; + struct perf_tool *tool; +}; + +static int +process_bpf_image(char *name, u64 addr, struct kallsyms_parse *data) +{ + struct machine *machine = data->machine; + union perf_event *event = data->event; + struct perf_record_ksymbol *ksymbol; + u32 size; + + ksymbol = &event->ksymbol; + + /* + * The bpf image (trampoline/dispatcher) size is aligned to + * page, while it starts little bit after the page boundary. + */ + size = page_size - (addr - PERF_ALIGN(addr, page_size)); + + *ksymbol = (struct perf_record_ksymbol) { + .header = { + .type = PERF_RECORD_KSYMBOL, + .size = offsetof(struct perf_record_ksymbol, name), + }, + .addr = addr, + .len = size, + .ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF, + .flags = 0, + }; + + strncpy(ksymbol->name, name, KSYM_NAME_LEN); + ksymbol->header.size += PERF_ALIGN(strlen(name) + 1, sizeof(u64)); + memset((void *) event + event->header.size, 0, machine->id_hdr_size); + event->header.size += machine->id_hdr_size; + + return perf_tool__process_synth_event(data->tool, event, machine, + data->process); +} + +static int +kallsyms_process_symbol(void *data, const char *_name, + char type __maybe_unused, u64 start) +{ + char *module, *name; + unsigned long id; + int err = 0; + + module = strchr(_name, '\t'); + if (!module) + return 0; + + /* We are going after [bpf] module ... */ + if (strcmp(module + 1, "[bpf]")) + return 0; + + name = memdup(_name, (module - _name) + 1); + if (!name) + return -ENOMEM; + + name[module - _name] = 0; + + /* .. and only for trampolines and dispatchers */ + if ((sscanf(name, "bpf_trampoline_%lu", &id) == 1) || + (sscanf(name, "bpf_dispatcher_%lu", &id) == 1)) + err = process_bpf_image(name, start, data); + + free(name); + return err; +} + int perf_event__synthesize_bpf_events(struct perf_session *session, perf_event__handler_t process, struct machine *machine, struct record_opts *opts) { + const char *kallsyms_filename = "/proc/kallsyms"; + struct kallsyms_parse arg; union perf_event *event; __u32 id = 0; int err; @@ -303,6 +382,8 @@ int perf_event__synthesize_bpf_events(struct perf_session *session, event = malloc(sizeof(event->bpf) + KSYM_NAME_LEN + machine->id_hdr_size); if (!event) return -1; + + /* Synthesize all the bpf programs in system. */ while (true) { err = bpf_prog_get_next_id(id, &id); if (err) { @@ -335,6 +416,23 @@ int perf_event__synthesize_bpf_events(struct perf_session *session, break; } } + + /* Synthesize all the bpf images - trampolines/dispatchers. */ + if (symbol_conf.kallsyms_name != NULL) + kallsyms_filename = symbol_conf.kallsyms_name; + + arg = (struct kallsyms_parse) { + .event = event, + .process = process, + .machine = machine, + .tool = session->tool, + }; + + if (kallsyms__parse(kallsyms_filename, &arg, kallsyms_process_symbol)) { + pr_err("%s: failed to synthesize bpf images: %s\n", + __func__, strerror(errno)); + } + free(event); return err; }