From patchwork Mon Jun 12 15:16:08 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yafang Shao X-Patchwork-Id: 13276827 X-Patchwork-Delegate: bpf@iogearbox.net Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A2DA319511 for ; Mon, 12 Jun 2023 15:16:34 +0000 (UTC) Received: from mail-vk1-xa31.google.com (mail-vk1-xa31.google.com [IPv6:2607:f8b0:4864:20::a31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B5E92E63; Mon, 12 Jun 2023 08:16:27 -0700 (PDT) Received: by mail-vk1-xa31.google.com with SMTP id 71dfb90a1353d-4635c158e2aso1218375e0c.3; Mon, 12 Jun 2023 08:16:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1686582987; x=1689174987; 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=ipOtOLH0eCoqdtlt4P3S4Nuxsk5nZTTtOt/GxTeUjs8=; b=CHtHcUWeBWcutxQa80MWMJ2lA2Gxm8IJLN0dsqKweKUfslEJ5q8VY4d3td+/lY+hzh h+8XiIaxX9lVtXee2DFhBUGmGAMnf7wgy2KK3CXHNMj/W3Ev+TMOlvCl03VWhGJwPgSg GnLOwl1Q81kG96tDbaqlL7vkDCA2GjIqIeypKHQe16axaSbQp8iyW7lsTI8Tm61gVydv aZPtT2CtxRkO640cDjWZEi8bHFe8u6ROGIIwTVel6Nu1oPSeYeuEgxVkJf+LZBF0D8Xr /jNQZ8t4T4RTzb4lLpcl7h0F0eZc2BVdLw3cJZjQEykpCeLNyE6Vxy5nuD2wpumCen9G 6D+g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686582987; x=1689174987; 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=ipOtOLH0eCoqdtlt4P3S4Nuxsk5nZTTtOt/GxTeUjs8=; b=UsmivWSNywN1qA15POgZlqQ+H+m++jtYMT/9JMSzl3I9XtXzeO05kC7pT3xosiM3/B yAek2JaL3t4QBBTtAAgnQc3DTU8u8sfBGeglXJSp5Q5oflK94II7stBYJ+1E6mOAQTIk XkmZlkADB3LVjQx1+5v4HuFzZR7VLJ3iGoqPSGDKkSWZSvTnXkXYwKDnTM+7L1yx1L79 i6O8V9ttOiIYov9XWar6WzPo+XJfecm7jkRA8ZVulf8qD7Hj60HKkZYhG48xKGtxEUze LfzudMZ/TZNrqptkDGL2yPZw7s9JyVeB/luVI4BQBcmN1ati68Xp92X3ZF7dvc4yPTqb Ee2A== X-Gm-Message-State: AC+VfDxyZcLKawp9cgS0t8pzV9/k64IrrmbARDXshd/Ez7YF5t+Ao+Gr 9Qwuiyv9pmEGYDQYZ7Fmgh8= X-Google-Smtp-Source: ACHHUZ4wcRSYDYhtp4x0qNwiAiDt5y0y7uLIBXM4hjsOVnTBdWj+5IXeliZLFS6VJAIgLLxTk8a7PA== X-Received: by 2002:a67:e418:0:b0:439:5904:6f6d with SMTP id d24-20020a67e418000000b0043959046f6dmr2893417vsf.33.1686582986757; Mon, 12 Jun 2023 08:16:26 -0700 (PDT) Received: from vultr.guest ([108.61.23.146]) by smtp.gmail.com with ESMTPSA id o17-20020a0cf4d1000000b0062de0dde008sm1533953qvm.64.2023.06.12.08.16.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 12 Jun 2023 08:16:26 -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 v3 bpf-next 10/10] bpftool: Show probed function in perf_event link info Date: Mon, 12 Jun 2023 15:16:08 +0000 Message-Id: <20230612151608.99661-11-laoar.shao@gmail.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20230612151608.99661-1-laoar.shao@gmail.com> References: <20230612151608.99661-1-laoar.shao@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: bpf@iogearbox.net 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 3: perf_event prog 14 event_type software event_config cpu-clock bpf_cookie 0 pids perf_event(1379330) 4: perf_event prog 14 event_type hw-cache event_config LLC-load-misses bpf_cookie 0 pids perf_event(1379330) 5: perf_event prog 14 event_type hardware event_config cpu-cycles bpf_cookie 0 pids perf_event(1379330) 6: perf_event prog 20 retprobe 0 file_name /home/yafang/bpf/uprobe/a.out offset 0x1338 bpf_cookie 0 pids uprobe(1379706) 7: perf_event prog 21 retprobe 1 file_name /home/yafang/bpf/uprobe/a.out offset 0x1338 bpf_cookie 0 pids uprobe(1379706) 8: perf_event prog 27 tp_name sched_switch bpf_cookie 0 pids tracepoint(1381734) 10: perf_event prog 43 retprobe 0 func_name kernel_clone addr ffffffffad0a9660 bpf_cookie 0 pids kprobe(1384186) 11: perf_event prog 41 retprobe 1 func_name kernel_clone addr ffffffffad0a9660 bpf_cookie 0 pids kprobe(1384186) $ tools/bpf/bpftool/bpftool link show -j [{"id":3,"type":"perf_event","prog_id":14,"event_type":"software","event_config":"cpu-clock","bpf_cookie":0,"pids":[{"pid":1379330,"comm":"perf_event"}]},{"id":4,"type":"perf_event","prog_id":14,"event_type":"hw-cache","event_config":"LLC-load-misses","bpf_cookie":0,"pids":[{"pid":1379330,"comm":"perf_event"}]},{"id":5,"type":"perf_event","prog_id":14,"event_type":"hardware","event_config":"cpu-cycles","bpf_cookie":0,"pids":[{"pid":1379330,"comm":"perf_event"}]},{"id":6,"type":"perf_event","prog_id":20,"retprobe":0,"file_name":"/home/yafang/bpf/uprobe/a.out","offset":4920,"bpf_cookie":0,"pids":[{"pid":1379706,"comm":"uprobe"}]},{"id":7,"type":"perf_event","prog_id":21,"retprobe":1,"file_name":"/home/yafang/bpf/uprobe/a.out","offset":4920,"bpf_cookie":0,"pids":[{"pid":1379706,"comm":"uprobe"}]},{"id":8,"type":"perf_event","prog_id":27,"tp_name":"sched_switch","bpf_cookie":0,"pids":[{"pid":1381734,"comm":"tracepoint"}]},{"id":10,"type":"perf_event","prog_id":43,"retprobe":0,"func_name":"kernel_clone","offset":0,"addr":18446744072317736544,"bpf_cookie":0,"pids":[{"pid":1384186,"comm":"kprobe"}]},{"id":11,"type":"perf_event","prog_id":41,"retprobe":1,"func_name":"kernel_clone","offset":0,"addr":18446744072317736544,"bpf_cookie":0,"pids":[{"pid":1384186,"comm":"kprobe"}]}] 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 3: perf_event prog 14 event_type software event_config cpu-clock 4: perf_event prog 14 event_type hw-cache event_config LLC-load-misses 5: perf_event prog 14 event_type hardware event_config cpu-cycles 6: perf_event prog 20 retprobe 0 file_name /home/yafang/bpf/uprobe/a.out offset 0x1338 7: perf_event prog 21 retprobe 1 file_name /home/yafang/bpf/uprobe/a.out offset 0x1338 8: perf_event prog 27 tp_name sched_switch 10: perf_event prog 43 retprobe 0 func_name kernel_clone 11: perf_event prog 41 retprobe 1 func_name kernel_clone Signed-off-by: Yafang Shao --- tools/bpf/bpftool/link.c | 213 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 213 insertions(+) diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c index 0015582..c16f71d 100644 --- a/tools/bpf/bpftool/link.c +++ b/tools/bpf/bpftool/link.c @@ -15,6 +15,7 @@ #include "json_writer.h" #include "main.h" #include "xlated_dumper.h" +#include "perf.h" static struct hashmap *link_table; static struct dump_data dd = {}; @@ -207,6 +208,109 @@ 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_uint_field(wtr, "retprobe", info->kprobe.flags & 0x1); + jsonw_string_field(wtr, "func_name", + u64_to_ptr(info->kprobe.func_name)); + jsonw_uint_field(wtr, "offset", info->kprobe.offset); + jsonw_uint_field(wtr, "addr", info->kprobe.addr); +} + +static void +show_perf_event_uprobe_json(struct bpf_link_info *info, json_writer_t *wtr) +{ + jsonw_uint_field(wtr, "retprobe", info->uprobe.flags & 0x1); + jsonw_string_field(wtr, "file_name", + u64_to_ptr(info->uprobe.file_name)); + jsonw_uint_field(wtr, "offset", info->uprobe.offset); +} + +static void +show_perf_event_tp_json(struct bpf_link_info *info, json_writer_t *wtr) +{ + jsonw_string_field(wtr, "tp_name", + u64_to_ptr(info->tracepoint.tp_name)); +} + +static const char *perf_config_hw_cache_str(__u64 config) +{ +#define PERF_HW_CACHE_LEN 128 + 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_hw_cache_str(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_hw_cache_op_str((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_hw_cache_op_result_str(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_hw_str(config); + break; + case PERF_TYPE_SOFTWARE: + perf_config = perf_sw_str(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.config; + __u32 type = info->perf_event.type; + const char *perf_type, *perf_config; + + perf_type = perf_type_str(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; @@ -262,6 +366,16 @@ 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: + if (info->perf_link_type == BPF_PERF_LINK_PERF_EVENT) + show_perf_event_event_json(info, json_wtr); + else if (info->perf_link_type == BPF_PERF_LINK_TRACEPOINT) + show_perf_event_tp_json(info, json_wtr); + else if (info->perf_link_type == BPF_PERF_LINK_KPROBE) + show_perf_event_kprobe_json(info, json_wtr); + else if (info->perf_link_type == BPF_PERF_LINK_UPROBE) + show_perf_event_uprobe_json(info, json_wtr); + break; default: break; } @@ -433,6 +547,71 @@ 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; + __u32 retprobe; + + buf = (const char *)u64_to_ptr(info->kprobe.func_name); + if (buf[0] == '\0' && !info->kprobe.addr) + return; + + retprobe = info->kprobe.flags & 0x1; + printf("\n\tretprobe %u func_name %s ", retprobe, buf); + if (info->kprobe.offset) + printf("offset %#x ", info->kprobe.offset); + if (info->kprobe.addr) + printf("addr %llx ", info->kprobe.addr); +} + +static void show_perf_event_uprobe_plain(struct bpf_link_info *info) +{ + const char *buf; + __u32 retprobe; + + buf = (const char *)u64_to_ptr(info->uprobe.file_name); + if (buf[0] == '\0') + return; + + retprobe = info->uprobe.flags & 0x1; + printf("\n\tretprobe %u file_name %s ", retprobe, buf); + if (info->uprobe.offset) + printf("offset %#x ", info->kprobe.offset); +} + +static void show_perf_event_tp_plain(struct bpf_link_info *info) +{ + const char *buf; + + buf = (const char *)u64_to_ptr(info->tracepoint.tp_name); + if (buf[0] == '\0') + return; + + printf("\n\ttp_name %s ", buf); +} + +static void show_perf_event_event_plain(struct bpf_link_info *info) +{ + __u64 config = info->perf_event.config; + __u32 type = info->perf_event.type; + const char *perf_type, *perf_config; + + perf_type = perf_type_str(type); + if (perf_type) + printf("\n\tevent_type %s ", perf_type); + else + printf("\n\tevent_type %u ", type); + + perf_config = perf_config_str(type, config); + if (perf_config) + printf("event_config %s ", perf_config); + else + printf("event_config %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; @@ -481,6 +660,16 @@ 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: + if (info->perf_link_type == BPF_PERF_LINK_PERF_EVENT) + show_perf_event_event_plain(info); + else if (info->perf_link_type == BPF_PERF_LINK_TRACEPOINT) + show_perf_event_tp_plain(info); + else if (info->perf_link_type == BPF_PERF_LINK_KPROBE) + show_perf_event_kprobe_plain(info); + else if (info->perf_link_type == BPF_PERF_LINK_UPROBE) + show_perf_event_uprobe_plain(info); + break; default: break; } @@ -508,6 +697,7 @@ static int do_show_link(int fd) int err; memset(&info, 0, sizeof(info)); + buf[0] = '\0'; again: err = bpf_link_get_info_by_fd(fd, &info, &len); if (err) { @@ -542,7 +732,30 @@ static int do_show_link(int fd) goto again; } } + if (info.type == BPF_LINK_TYPE_PERF_EVENT) { + if (info.perf_link_type == BPF_PERF_LINK_PERF_EVENT) + goto out; + if (info.perf_link_type == BPF_PERF_LINK_TRACEPOINT && + !info.tracepoint.tp_name) { + info.tracepoint.tp_name = (unsigned long)&buf; + info.tracepoint.name_len = sizeof(buf); + goto again; + } + if (info.perf_link_type == BPF_PERF_LINK_KPROBE && + !info.kprobe.func_name) { + info.kprobe.func_name = (unsigned long)&buf; + info.kprobe.name_len = sizeof(buf); + goto again; + } + if (info.perf_link_type == BPF_PERF_LINK_UPROBE && + !info.uprobe.file_name) { + info.uprobe.file_name = (unsigned long)&buf; + info.uprobe.name_len = sizeof(buf); + goto again; + } + } +out: if (json_output) show_link_close_json(fd, &info); else