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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 4F967C3A5A0 for ; Mon, 20 Apr 2020 11:53:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 27E2D22202 for ; Mon, 20 Apr 2020 11:53:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383618; bh=BeMfiKoM1HPrk5N7B8y8DbFVG2B/mSoTaSD4GFKpvrc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=t2/rIp7ZyFp8IZ9SgvHcFNuO/J6lbN2bGPEU9rGGrydjMxTKOMUjAYAY605kxcl9y f66tf1sEz9O4OgFSg3WnhUDKsooLOAa9l2A8sKsOE1khyapGO6XfeKGGmjmzAtIPJT TFzhNbtcUWFcNi7Sf8fw01TzzFpEPt+KH59UK+uM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726495AbgDTLxh (ORCPT ); Mon, 20 Apr 2020 07:53:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:36574 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725886AbgDTLxd (ORCPT ); Mon, 20 Apr 2020 07:53:33 -0400 Received: from quaco.ghostprotocols.net (unknown [179.97.37.151]) (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 D24BB20724; Mon, 20 Apr 2020 11:53:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383613; bh=BeMfiKoM1HPrk5N7B8y8DbFVG2B/mSoTaSD4GFKpvrc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LBB7ZNHMnmgyNKQFvRtQfRGa3AW9YZ7ejDaGDUu1xTJd7nsPUdZhv1rGTwmayZYTR 2ZnJXzv4JoE2w2KNoI+FQrEaTCdrSyzP8w69LQXzHEuv/ld+VyAhKympDCdJIYKFRH g9eHlXoLphv/VQPy8p4ovm1m1jYx5t/sa1bWSu5U= From: Arnaldo Carvalho de Melo To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Song Liu , Alexei Starovoitov , Andrii Nakryiko , =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= , Daniel Borkmann , "David S . Miller" , Jakub Kicinski , Jesper Dangaard Brouer , John Fastabend , Martin KaFai Lau , Yonghong Song , Arnaldo Carvalho de Melo Subject: [PATCH 02/60] perf tools: Synthesize bpf_trampoline/dispatcher ksymbol event Date: Mon, 20 Apr 2020 08:52:18 -0300 Message-Id: <20200420115316.18781-3-acme@kernel.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200420115316.18781-1-acme@kernel.org> References: <20200420115316.18781-1-acme@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jiri Olsa 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 Committer notes: Use scnprintf() instead of strncpy() to overcome this on fedora:32, rawhide and OpenMandriva Cooker: CC /tmp/build/perf/util/bpf-event.o In file included from /usr/include/string.h:495, from /git/linux/tools/lib/bpf/libbpf_common.h:12, from /git/linux/tools/lib/bpf/bpf.h:31, from util/bpf-event.c:4: In function 'strncpy', inlined from 'process_bpf_image' at util/bpf-event.c:323:2, inlined from 'kallsyms_process_symbol' at util/bpf-event.c:358:9: /usr/include/bits/string_fortified.h:106:10: error: '__builtin_strncpy' specified bound 256 equals destination size [-Werror=stringop-truncation] 106 | return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors Signed-off-by: Jiri Olsa Acked-by: Song Liu Cc: Alexei Starovoitov Cc: Andrii Nakryiko Cc: Björn Töpel Cc: Daniel Borkmann Cc: David S. Miller Cc: Jakub Kicinski Cc: Jesper Dangaard Brouer Cc: John Fastabend Cc: Martin KaFai Lau Cc: Yonghong Song Link: https://lore.kernel.org/bpf/20200312195610.346362-14-jolsa@kernel.org/ Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/bpf-event.c | 93 +++++++++++++++++++++++++++++++++++++ 1 file changed, 93 insertions(+) diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c index a3207d900339..0cd41a862952 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 +293,82 @@ 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; + int len; + + ksymbol = &event->ksymbol; + + *ksymbol = (struct perf_record_ksymbol) { + .header = { + .type = PERF_RECORD_KSYMBOL, + .size = offsetof(struct perf_record_ksymbol, name), + }, + .addr = addr, + .len = page_size, + .ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF, + .flags = 0, + }; + + len = scnprintf(ksymbol->name, KSYM_NAME_LEN, "%s", name); + ksymbol->header.size += PERF_ALIGN(len + 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 disp[KSYM_NAME_LEN]; + 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_%s", disp) == 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 +377,8 @@ 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 +411,23 @@ 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; } -- 2.21.1