From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-173.mta0.migadu.com (out-173.mta0.migadu.com [91.218.175.173]) (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 4920F7FD for ; Fri, 6 Jun 2025 02:36:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749177420; cv=none; b=bgw15XtatuiT9UeKZcV24itJsxMdFfXwMrUq1J/L1vd2UZRb4A2+cAwNuWmS8yEDbh5rjNMFQ1PayhDpxr2rYPWID0/53hFbH0rNC8hXigOCAATqjSrFzvSL6k3jcwzNV2P99W/RXir6DwX+TqUs9CiS4kOtsHx3+PYGAxUFoBA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749177420; c=relaxed/simple; bh=nzEsZobLXTdTuO4MlKPwcKlAos+/+mkMxxOXaTfoxWE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=H5gz5NoV/8tny/K+IaBR2JEXoGnr71L5o+m3aipYR21TOk+bOc1MO/t2ryKcFSnwBN2bNqEycdPXTkJM8uXX1IYubDsoSxsk+juLk4U30N2yLhtbtFrZeKsQprhTsR/ivr4OwE4uiPRMMO+3YWlvO7+OfRElOrTFk636qi3wdeU= 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=PJWV9GbY; arc=none smtp.client-ip=91.218.175.173 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="PJWV9GbY" Message-ID: <674ffa66-1145-4e89-b30f-04c55ff8eb02@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1749177416; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=t3hBQ1RXDJy1XF60ulrHvm75Jbv4mZNH1cILrTi8a3I=; b=PJWV9GbYBpr6PAAfmpKx+JYdZOUeG1jL1Z0n0xQWk0AIukfcsmjaU/9K701fXIQXlxiK68 4og42AaH4MWancw7dP5aQSTm0GV3WiChcXsWPrgAII/R2Y73avSxhNeXpC5r3tA0tIXaR0 6vl2x8wtZbOVkpPJUEtfKC14H6jbU7A= Date: Fri, 6 Jun 2025 10:36:49 +0800 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH bpf-next] bpf: Add show_fdinfo for perf_event To: Andrii Nakryiko Cc: 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, bpf@vger.kernel.org, linux-kernel@vger.kernel.org References: <20250604163723.3175258-1-chen.dylane@linux.dev> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Tao Chen In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT 在 2025/6/6 02:41, Andrii Nakryiko 写道: > On Wed, Jun 4, 2025 at 9:37 AM Tao Chen wrote: >> >> 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; > > maybe use "kretprobe" and "kprobe" strings? > It looks more readable, i will change it in v2, thanks. >> + >> + seq_printf(seq, >> + "name:\t%s\n" >> + "offset:\t%llu\n" > > llx, hex makes most sense (we had similar discussion within the > context of bpftool reporting) > > pw-bot: cr > >> + "missed:\t%lu\n" >> + "addr:\t%llx\n" > > ditto, address -> hex > will change it in v2, thanks. >> + "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; > > strings, just as above > get it. >> + >> + seq_printf(seq, >> + "name:\t%s\n" >> + "offset:\t%llu\n" > > hex get it. > >> + "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" > > string? > sure. >> + "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" > > string > get it. >> + "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 >> -- Best Regards Tao Chen