From patchwork Tue Jun 20 16:30:08 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yafang Shao X-Patchwork-Id: 13286170 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A826BEB64D7 for ; Tue, 20 Jun 2023 16:30:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231728AbjFTQas (ORCPT ); Tue, 20 Jun 2023 12:30:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56440 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231750AbjFTQam (ORCPT ); Tue, 20 Jun 2023 12:30:42 -0400 Received: from mail-oa1-x2c.google.com (mail-oa1-x2c.google.com [IPv6:2001:4860:4864:20::2c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5BD86172C; Tue, 20 Jun 2023 09:30:38 -0700 (PDT) Received: by mail-oa1-x2c.google.com with SMTP id 586e51a60fabf-1a991886254so5059019fac.2; Tue, 20 Jun 2023 09:30:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1687278637; x=1689870637; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=e641tFJX/stK/Gf39GAsqpBjczt5QRhwdI0UiLVax+o=; b=pW8QvMR2l+3bX+GuR0TYeF+/a7vATEw1uuSwYhPNbpq7ygJCrf88aapb2wqi0mpjkR UTp6A4aUCyO/YCKjK7zx8vu/U/BWOpSMhcewirPVekXc1f59PzcCWBQ4B0/NinM6pAGH JbULN9Use2+8QhIyI4hf2IPOae/bP48BVVPVDhk45Mm/nXgqMrwawRpU3TIrtfSSJoEt kt2ki2n2lO+UB2DS0SECwC/rpQ0Vr6MRXE/iGUe34wSyDK1VS69CLY14xgnZ7lZWswQA NbmbrK/TGea7+k2Cd0tY3rg4GoFaGrrCwNaf8P7KUfrzUHHa1hn/9AKIklWOp2WVYMDN AEGg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687278637; x=1689870637; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=e641tFJX/stK/Gf39GAsqpBjczt5QRhwdI0UiLVax+o=; b=B/8WJyhzoqHFjFFDlm06d2r3MdJMgEfbBifY2vyKHFYdPxO+973+xJygXDgtHfC6z4 fRlteLxAZTDLHrHQMYUQjOZtCOdZ3N+zLrLL/qRNuGKp2NscQSvb15jHRRBOeLOJMjih zX1iKcw1+PDSiEKf9HUlTkKKBiDYSaBBzEAG+kso8IW0hhtpAkX/xtya/BwVDw+GAc0s Qc/s65M0W+DMkRMG0AhNdSjHzCPlD6yvmVFOl9SQFdSWe78qtfOOVWBGLsIfaxDx532P R/id4MWFpQByOnqWHMXUo2slxEJI9wnqAvAXkwKc61JTBmOe+4YMFAJRTeP0GH9KMka6 8V0Q== X-Gm-Message-State: AC+VfDzqoEupdfdPfjjlIu81EcLBI8thkTuLZzi13O+Q5NwHKsSWnOY/ xzABQZfL2n2CsaLW/pt3e/s= X-Google-Smtp-Source: ACHHUZ41imBWC0XOT7Up9PojBIuhDPwtwS9OQqfM417nMpWBTb++09H2wQvCYjiOgFP+WiQD2p7FOQ== X-Received: by 2002:a05:6808:1188:b0:39c:532b:fe43 with SMTP id j8-20020a056808118800b0039c532bfe43mr15748512oil.21.1687278637540; Tue, 20 Jun 2023 09:30:37 -0700 (PDT) Received: from vultr.guest ([2001:19f0:ac02:b96:5400:4ff:fe7b:3b23]) by smtp.gmail.com with ESMTPSA id t8-20020a17090a3b4800b0025c1cfdb93esm1854286pjf.13.2023.06.20.09.30.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 20 Jun 2023 09:30:36 -0700 (PDT) From: Yafang Shao To: ast@kernel.org, daniel@iogearbox.net, john.fastabend@gmail.com, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, quentin@isovalent.com, rostedt@goodmis.org, mhiramat@kernel.org Cc: bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org, Yafang Shao Subject: [PATCH v4 bpf-next 11/11] bpftool: Show perf link info Date: Tue, 20 Jun 2023 16:30:08 +0000 Message-Id: <20230620163008.3718-12-laoar.shao@gmail.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20230620163008.3718-1-laoar.shao@gmail.com> References: <20230620163008.3718-1-laoar.shao@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-trace-kernel@vger.kernel.org Enhance bpftool to display comprehensive information about exposed perf_event links, covering uprobe, kprobe, tracepoint, and generic perf event. The resulting output will include the following details: $ tools/bpf/bpftool/bpftool link show 4: perf_event prog 23 uprobe /home/dev/waken/bpf/uprobe/a.out+0x1338 bpf_cookie 0 pids uprobe(27503) 5: perf_event prog 24 uretprobe /home/dev/waken/bpf/uprobe/a.out+0x1338 bpf_cookie 0 pids uprobe(27503) 6: perf_event prog 31 kprobe ffffffffa90a9660 kernel_clone bpf_cookie 0 pids kprobe(27777) 7: perf_event prog 30 kretprobe ffffffffa90a9660 kernel_clone bpf_cookie 0 pids kprobe(27777) 8: perf_event prog 37 tracepoint sched_switch bpf_cookie 0 pids tracepoint(28036) 9: perf_event prog 43 event software:cpu-clock bpf_cookie 0 pids perf_event(28261) 10: perf_event prog 43 event hw-cache:LLC-load-misses bpf_cookie 0 pids perf_event(28261) 11: perf_event prog 43 event hardware:cpu-cycles bpf_cookie 0 pids perf_event(28261) $ tools/bpf/bpftool/bpftool link show -j [{"id":4,"type":"perf_event","prog_id":23,"retprobe":false,"file":"/home/dev/waken/bpf/uprobe/a.out","offset":4920,"bpf_cookie":0,"pids":[{"pid":27503,"comm":"uprobe"}]},{"id":5,"type":"perf_event","prog_id":24,"retprobe":true,"file":"/home/dev/waken/bpf/uprobe/a.out","offset":4920,"bpf_cookie":0,"pids":[{"pid":27503,"comm":"uprobe"}]},{"id":6,"type":"perf_event","prog_id":31,"retprobe":false,"addr":18446744072250627680,"func":"kernel_clone","offset":0,"bpf_cookie":0,"pids":[{"pid":27777,"comm":"kprobe"}]},{"id":7,"type":"perf_event","prog_id":30,"retprobe":true,"addr":18446744072250627680,"func":"kernel_clone","offset":0,"bpf_cookie":0,"pids":[{"pid":27777,"comm":"kprobe"}]},{"id":8,"type":"perf_event","prog_id":37,"tracepoint":"sched_switch","bpf_cookie":0,"pids":[{"pid":28036,"comm":"tracepoint"}]},{"id":9,"type":"perf_event","prog_id":43,"event_type":"software","event_config":"cpu-clock","bpf_cookie":0,"pids":[{"pid":28261,"comm":"perf_event"}]},{"id":10,"type":"perf_event","prog_id":43,"event_type":"hw-cache","event_config":"LLC-load-misses","bpf_cookie":0,"pids":[{"pid":28261,"comm":"perf_event"}]},{"id":11,"type":"perf_event","prog_id":43,"event_type":"hardware","event_config":"cpu-cycles","bpf_cookie":0,"pids":[{"pid":28261,"comm":"perf_event"}]}] For generic perf events, the displayed information in bpftool is limited to the type and configuration, while other attributes such as sample_period, sample_freq, etc., are not included. The kernel function address won't be exposed if it is not permitted by kptr_restrict. The result as follows when kptr_restrict is 2. $ tools/bpf/bpftool/bpftool link show 4: perf_event prog 23 uprobe /home/dev/waken/bpf/uprobe/a.out+0x1338 5: perf_event prog 24 uretprobe /home/dev/waken/bpf/uprobe/a.out+0x1338 6: perf_event prog 31 kprobe kernel_clone 7: perf_event prog 30 kretprobe kernel_clone 8: perf_event prog 37 tracepoint sched_switch 9: perf_event prog 43 event software:cpu-clock 10: perf_event prog 43 event hw-cache:LLC-load-misses 11: perf_event prog 43 event hardware:cpu-cycles Signed-off-by: Yafang Shao --- tools/bpf/bpftool/link.c | 237 ++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 236 insertions(+), 1 deletion(-) diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c index 9274d59..0173d4e 100644 --- a/tools/bpf/bpftool/link.c +++ b/tools/bpf/bpftool/link.c @@ -17,6 +17,8 @@ #include "main.h" #include "xlated_dumper.h" +#define PERF_HW_CACHE_LEN 128 + static struct hashmap *link_table; static struct dump_data dd = {}; @@ -274,6 +276,110 @@ static int cmp_u64(const void *A, const void *B) jsonw_end_array(json_wtr); } +static void +show_perf_event_kprobe_json(struct bpf_link_info *info, json_writer_t *wtr) +{ + jsonw_bool_field(wtr, "retprobe", info->perf_event.kprobe.flags & 0x1); + jsonw_uint_field(wtr, "addr", info->perf_event.kprobe.addr); + jsonw_string_field(wtr, "func", + u64_to_ptr(info->perf_event.kprobe.func_name)); + jsonw_uint_field(wtr, "offset", info->perf_event.kprobe.offset); +} + +static void +show_perf_event_uprobe_json(struct bpf_link_info *info, json_writer_t *wtr) +{ + jsonw_bool_field(wtr, "retprobe", info->perf_event.uprobe.flags & 0x1); + jsonw_string_field(wtr, "file", + u64_to_ptr(info->perf_event.uprobe.file_name)); + jsonw_uint_field(wtr, "offset", info->perf_event.uprobe.offset); +} + +static void +show_perf_event_tracepoint_json(struct bpf_link_info *info, json_writer_t *wtr) +{ + jsonw_string_field(wtr, "tracepoint", + u64_to_ptr(info->perf_event.tracepoint.tp_name)); +} + +static char *perf_config_hw_cache_str(__u64 config) +{ + const char *hw_cache, *result, *op; + char *str = malloc(PERF_HW_CACHE_LEN); + + if (!str) { + p_err("mem alloc failed"); + return NULL; + } + + hw_cache = perf_event_name(evsel__hw_cache, config & 0xff); + if (hw_cache) + snprintf(str, PERF_HW_CACHE_LEN, "%s-", hw_cache); + else + snprintf(str, PERF_HW_CACHE_LEN, "%lld-", config & 0xff); + + op = perf_event_name(evsel__hw_cache_op, (config >> 8) & 0xff); + if (op) + snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str), + "%s-", op); + else + snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str), + "%lld-", (config >> 8) & 0xff); + + result = perf_event_name(evsel__hw_cache_result, config >> 16); + if (result) + snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str), + "%s", result); + else + snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str), + "%lld", config >> 16); + return str; +} + +static const char *perf_config_str(__u32 type, __u64 config) +{ + const char *perf_config; + + switch (type) { + case PERF_TYPE_HARDWARE: + perf_config = perf_event_name(event_symbols_hw, config); + break; + case PERF_TYPE_SOFTWARE: + perf_config = perf_event_name(event_symbols_sw, config); + break; + case PERF_TYPE_HW_CACHE: + perf_config = perf_config_hw_cache_str(config); + break; + default: + perf_config = NULL; + break; + } + return perf_config; +} + +static void +show_perf_event_event_json(struct bpf_link_info *info, json_writer_t *wtr) +{ + __u64 config = info->perf_event.event.config; + __u32 type = info->perf_event.event.type; + const char *perf_type, *perf_config; + + perf_type = perf_event_name(perf_type_name, type); + if (perf_type) + jsonw_string_field(wtr, "event_type", perf_type); + else + jsonw_uint_field(wtr, "event_type", type); + + perf_config = perf_config_str(type, config); + if (perf_config) + jsonw_string_field(wtr, "event_config", perf_config); + else + jsonw_uint_field(wtr, "event_config", config); + + if (type == PERF_TYPE_HW_CACHE && perf_config) + free((void *)perf_config); +} + static int show_link_close_json(int fd, struct bpf_link_info *info) { struct bpf_prog_info prog_info; @@ -329,6 +435,24 @@ static int show_link_close_json(int fd, struct bpf_link_info *info) case BPF_LINK_TYPE_KPROBE_MULTI: show_kprobe_multi_json(info, json_wtr); break; + case BPF_LINK_TYPE_PERF_EVENT: + switch (info->perf_event.type) { + case BPF_PERF_EVENT_EVENT: + show_perf_event_event_json(info, json_wtr); + break; + case BPF_PERF_EVENT_TRACEPOINT: + show_perf_event_tracepoint_json(info, json_wtr); + break; + case BPF_PERF_EVENT_KPROBE: + show_perf_event_kprobe_json(info, json_wtr); + break; + case BPF_PERF_EVENT_UPROBE: + show_perf_event_uprobe_json(info, json_wtr); + break; + default: + break; + } + break; default: break; } @@ -500,6 +624,75 @@ static void show_kprobe_multi_plain(struct bpf_link_info *info) } } +static void show_perf_event_kprobe_plain(struct bpf_link_info *info) +{ + const char *buf; + + buf = (const char *)u64_to_ptr(info->perf_event.kprobe.func_name); + if (buf[0] == '\0' && !info->perf_event.kprobe.addr) + return; + + if (info->perf_event.kprobe.flags & 0x1) + printf("\n\tkretprobe "); + else + printf("\n\tkprobe "); + if (info->perf_event.kprobe.addr) + printf("%llx ", info->perf_event.kprobe.addr); + printf("%s", buf); + if (info->perf_event.kprobe.offset) + printf("+%#x", info->perf_event.kprobe.offset); + printf(" "); +} + +static void show_perf_event_uprobe_plain(struct bpf_link_info *info) +{ + const char *buf; + + buf = (const char *)u64_to_ptr(info->perf_event.uprobe.file_name); + if (buf[0] == '\0') + return; + + if (info->perf_event.uprobe.flags & 0x1) + printf("\n\turetprobe "); + else + printf("\n\tuprobe "); + printf("%s+%#x ", buf, info->perf_event.uprobe.offset); +} + +static void show_perf_event_tracepoint_plain(struct bpf_link_info *info) +{ + const char *buf; + + buf = (const char *)u64_to_ptr(info->perf_event.tracepoint.tp_name); + if (buf[0] == '\0') + return; + + printf("\n\ttracepoint %s ", buf); +} + +static void show_perf_event_event_plain(struct bpf_link_info *info) +{ + __u64 config = info->perf_event.event.config; + __u32 type = info->perf_event.event.type; + const char *perf_type, *perf_config; + + printf("\n\tevent "); + perf_type = perf_event_name(perf_type_name, type); + if (perf_type) + printf("%s:", perf_type); + else + printf("%u :", type); + + perf_config = perf_config_str(type, config); + if (perf_config) + printf("%s ", perf_config); + else + printf("%llu ", config); + + if (type == PERF_TYPE_HW_CACHE && perf_config) + free((void *)perf_config); +} + static int show_link_close_plain(int fd, struct bpf_link_info *info) { struct bpf_prog_info prog_info; @@ -548,6 +741,24 @@ static int show_link_close_plain(int fd, struct bpf_link_info *info) case BPF_LINK_TYPE_KPROBE_MULTI: show_kprobe_multi_plain(info); break; + case BPF_LINK_TYPE_PERF_EVENT: + switch (info->perf_event.type) { + case BPF_PERF_EVENT_EVENT: + show_perf_event_event_plain(info); + break; + case BPF_PERF_EVENT_TRACEPOINT: + show_perf_event_tracepoint_plain(info); + break; + case BPF_PERF_EVENT_KPROBE: + show_perf_event_kprobe_plain(info); + break; + case BPF_PERF_EVENT_UPROBE: + show_perf_event_uprobe_plain(info); + break; + default: + break; + } + break; default: break; } @@ -570,11 +781,12 @@ static int do_show_link(int fd) struct bpf_link_info info; __u32 len = sizeof(info); __u64 *addrs = NULL; - char buf[256]; + char buf[PATH_MAX]; int count; int err; memset(&info, 0, sizeof(info)); + buf[0] = '\0'; again: err = bpf_link_get_info_by_fd(fd, &info, &len); if (err) { @@ -609,7 +821,30 @@ static int do_show_link(int fd) goto again; } } + if (info.type == BPF_LINK_TYPE_PERF_EVENT) { + if (info.perf_event.type == BPF_PERF_EVENT_EVENT) + goto out; + if (info.perf_event.type == BPF_PERF_EVENT_TRACEPOINT && + !info.perf_event.tracepoint.tp_name) { + info.perf_event.tracepoint.tp_name = (unsigned long)&buf; + info.perf_event.tracepoint.name_len = sizeof(buf); + goto again; + } + if (info.perf_event.type == BPF_PERF_EVENT_KPROBE && + !info.perf_event.kprobe.func_name) { + info.perf_event.kprobe.func_name = (unsigned long)&buf; + info.perf_event.kprobe.name_len = sizeof(buf); + goto again; + } + if (info.perf_event.type == BPF_PERF_EVENT_UPROBE && + !info.perf_event.uprobe.file_name) { + info.perf_event.uprobe.file_name = (unsigned long)&buf; + info.perf_event.uprobe.name_len = sizeof(buf); + goto again; + } + } +out: if (json_output) show_link_close_json(fd, &info); else