From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-186.mta0.migadu.com (out-186.mta0.migadu.com [91.218.175.186]) (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 0A57B1F416B for ; Wed, 4 Jun 2025 16:37:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.186 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749055077; cv=none; b=riJh+ylzKQ/hSo+qesCvrlauCa6MC16p57R59FI31WhCDcoRAJGusL6CAnmVW3cG/qWS7qFpVTzBTWTp/+SeDUph31myya5h/vEr0EB8xuQ52x/MnyoDvWqa819QVsY6ttqw+o5/gIAZU+cz57ehFw1YGoN8YwG6MnHz3rkh79o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749055077; c=relaxed/simple; bh=k1VAhtvWn1mdnc82A42urCXNfSl687+frp/shs2RzIQ=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=pGJ7HxCrTkTl5f5kLuJnDrTlwNGnnj0aVEAE4X/wHmdl0rUP8VEOcHpiJ5rFW8oF13UMNHvXfIwvSe+dS/xwN96Qzg/Z2jQUyKaIuNRhFdu7ycBZ4B7FdX1bNGatF4cG8prUp3jFJjzkOgcyvIFhtSTutyi6hPI2mw6O7HJRq1U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=aMePBzl/; arc=none smtp.client-ip=91.218.175.186 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="aMePBzl/" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1749055062; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=LpQJtvbQ0WTNzxLrRi6c5eMnvReMC88RFvMxCl1x3Ss=; b=aMePBzl/Kpp/mc2Qthi84fsO91CCWhQU6s10DjhzRzngNpjRGDzyOpYaS/Vd78OtVKBHmU B6XxJLcdvcmWF8gxU20PBS6FgsEhyiBp81BcOpkjUcwC6EOgZK7h6DExgVCL/pUBulrwJn cTL90JD5YNNQiu0R0zBQlYz7tjIvNXg= From: Tao Chen To: ast@kernel.org, daniel@iogearbox.net, john.fastabend@gmail.com, andrii@kernel.org, martin.lau@linux.dev, eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, jolsa@kernel.org Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, Tao Chen Subject: [PATCH bpf-next] bpf: Add show_fdinfo for perf_event Date: Thu, 5 Jun 2025 00:37:22 +0800 Message-Id: <20250604163723.3175258-1-chen.dylane@linux.dev> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT After commit 1b715e1b0ec5 ("bpf: Support ->fill_link_info for perf_event") add perf_event info, we can also show the info with the method of cat /proc/[fd]/fdinfo. kprobe fdinfo: link_type: perf link_id: 2 prog_tag: bcf7977d3b93787c prog_id: 18 name: bpf_fentry_test1 offset: 0 missed: 0 addr: ffffffffaea8d134 event_type: 3 cookie: 3735928559 uprobe fdinfo: link_type: perf link_id: 6 prog_tag: bcf7977d3b93787c prog_id: 7 name: /proc/self/exe offset: 6507541 event_type: 1 cookie: 3735928559 tracepoint fdinfo: link_type: perf link_id: 4 prog_tag: bcf7977d3b93787c prog_id: 8 tp_name: sched_switch event_type: 5 cookie: 3735928559 perf_event fdinfo: link_type: perf link_id: 5 prog_tag: bcf7977d3b93787c prog_id: 9 type: 1 config: 2 event_type: 6 cookie: 3735928559 Signed-off-by: Tao Chen --- kernel/bpf/syscall.c | 126 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 126 insertions(+) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 9794446bc8..9af54852eb 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -3793,6 +3793,35 @@ static int bpf_perf_link_fill_kprobe(const struct perf_event *event, info->perf_event.kprobe.cookie = event->bpf_cookie; return 0; } + +static void bpf_perf_link_fdinfo_kprobe(const struct perf_event *event, + struct seq_file *seq) +{ + const char *name; + int err; + u32 prog_id, type; + u64 offset, addr; + unsigned long missed; + + err = bpf_get_perf_event_info(event, &prog_id, &type, &name, + &offset, &addr, &missed); + if (err) + return; + + if (type == BPF_FD_TYPE_KRETPROBE) + type = BPF_PERF_EVENT_KRETPROBE; + else + type = BPF_PERF_EVENT_KPROBE; + + seq_printf(seq, + "name:\t%s\n" + "offset:\t%llu\n" + "missed:\t%lu\n" + "addr:\t%llx\n" + "event_type:\t%u\n" + "cookie:\t%llu\n", + name, offset, missed, addr, type, event->bpf_cookie); +} #endif #ifdef CONFIG_UPROBE_EVENTS @@ -3820,6 +3849,34 @@ static int bpf_perf_link_fill_uprobe(const struct perf_event *event, info->perf_event.uprobe.cookie = event->bpf_cookie; return 0; } + +static void bpf_perf_link_fdinfo_uprobe(const struct perf_event *event, + struct seq_file *seq) +{ + const char *name; + int err; + u32 prog_id, type; + u64 offset, addr; + unsigned long missed; + + err = bpf_get_perf_event_info(event, &prog_id, &type, &name, + &offset, &addr, &missed); + if (err) + return; + + if (type == BPF_FD_TYPE_URETPROBE) + type = BPF_PERF_EVENT_URETPROBE; + else + type = BPF_PERF_EVENT_UPROBE; + + seq_printf(seq, + "name:\t%s\n" + "offset:\t%llu\n" + "event_type:\t%u\n" + "cookie:\t%llu\n", + name, offset, type, event->bpf_cookie); + +} #endif static int bpf_perf_link_fill_probe(const struct perf_event *event, @@ -3888,10 +3945,79 @@ static int bpf_perf_link_fill_link_info(const struct bpf_link *link, } } +static void bpf_perf_event_link_show_fdinfo(const struct perf_event *event, + struct seq_file *seq) +{ + seq_printf(seq, + "type:\t%u\n" + "config:\t%llu\n" + "event_type:\t%u\n" + "cookie:\t%llu\n", + event->attr.type, event->attr.config, + BPF_PERF_EVENT_EVENT, event->bpf_cookie); +} + +static void bpf_tracepoint_link_show_fdinfo(const struct perf_event *event, + struct seq_file *seq) +{ + int err; + const char *name; + u32 prog_id; + + err = bpf_get_perf_event_info(event, &prog_id, NULL, &name, NULL, + NULL, NULL); + if (err) + return; + + seq_printf(seq, + "tp_name:\t%s\n" + "event_type:\t%u\n" + "cookie:\t%llu\n", + name, BPF_PERF_EVENT_TRACEPOINT, event->bpf_cookie); +} + +static void bpf_probe_link_show_fdinfo(const struct perf_event *event, + struct seq_file *seq) +{ +#ifdef CONFIG_KPROBE_EVENTS + if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE) + return bpf_perf_link_fdinfo_kprobe(event, seq); +#endif + +#ifdef CONFIG_UPROBE_EVENTS + if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE) + return bpf_perf_link_fdinfo_uprobe(event, seq); +#endif +} + +static void bpf_perf_link_show_fdinfo(const struct bpf_link *link, + struct seq_file *seq) +{ + struct bpf_perf_link *perf_link; + const struct perf_event *event; + + perf_link = container_of(link, struct bpf_perf_link, link); + event = perf_get_event(perf_link->perf_file); + if (IS_ERR(event)) + return; + + switch (event->prog->type) { + case BPF_PROG_TYPE_PERF_EVENT: + return bpf_perf_event_link_show_fdinfo(event, seq); + case BPF_PROG_TYPE_TRACEPOINT: + return bpf_tracepoint_link_show_fdinfo(event, seq); + case BPF_PROG_TYPE_KPROBE: + return bpf_probe_link_show_fdinfo(event, seq); + default: + return; + } +} + static const struct bpf_link_ops bpf_perf_link_lops = { .release = bpf_perf_link_release, .dealloc = bpf_perf_link_dealloc, .fill_link_info = bpf_perf_link_fill_link_info, + .show_fdinfo = bpf_perf_link_show_fdinfo, }; static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) -- 2.43.0