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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 94259C433FE for ; Mon, 23 May 2022 20:18:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232730AbiEWUSB (ORCPT ); Mon, 23 May 2022 16:18:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52420 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233018AbiEWUPy (ORCPT ); Mon, 23 May 2022 16:15:54 -0400 Received: from mail-io1-xd31.google.com (mail-io1-xd31.google.com [IPv6:2607:f8b0:4864:20::d31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5F53EA889F for ; Mon, 23 May 2022 13:14:44 -0700 (PDT) Received: by mail-io1-xd31.google.com with SMTP id y12so16470353ior.7 for ; Mon, 23 May 2022 13:14:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=2vp0MMS/nvxu6duSf/XEnD4yOQ25zTvmWT7ui8yftHI=; b=EdZ3EoZNsBfIF3vb1gybA4QEABs1GgsVjZAOwUbNskNs6gqaa+1mGIdZsiVE3FWno9 RAdfS9kwfjSlmHdIz2H/oeCWvq6WF7SVHGywATmRIsSOSbcMalHoMxseo68lHAskg1ZN rNJXRKMV18WA/dqlhvDFrjgqD41e0Rh7HqGPZvzaibysFy5K7GZfVPQwgyjdgyzX71T0 encoD5PY9rOu17eULUcVOyjbAKauaKhI+Q+eu7UP9oLA0K46GseesCox5CtiREtXR8Fh rbuJ2xTvT/vnR+ONmFcpQ+0jgzQT5n2FiF78UWKT6WN8EIuvsncu5ELomMUqgaHu+cFh ilrA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=2vp0MMS/nvxu6duSf/XEnD4yOQ25zTvmWT7ui8yftHI=; b=e4MgP/ha+DfsemDejwW/PZ/9r8HcJuNfDwKV6jowWq107UqzGJxKWzGJdWrto3S2pD HzpubYXavg5zd4eJesdFk+5rvllfd9FVdpljOg1jJFJG42+NgjBMdFXxckKeuzMZ3drZ ohZexpaSFVEqfOkd6RRPrF6aKaOQmvQeQUYLlOW4yWrurRTZDHS+3wSYjsW4mMghNKuU JuXxU+k50cMYH+3XwVpmWkAP3an84QajzWrdn5EeenpPvgkgbI9Nxk5o429Ywfapnczw MtS0Mr+djXXdgwdBXben5SbMcIi0HA/tDCgZGSCsIggJe3sAOcSmLkRIq5ooyg5YfGT0 zCCg== X-Gm-Message-State: AOAM531e5M7MVFXqYcuO9x5mz6ByV4EkE5MjHjg2GDM4gqOH8EhxJxMV q1lTBZxkoC9KXe4HOAU5o77NJNhS5aEXVaEoX8FuZw== X-Google-Smtp-Source: ABdhPJzXVZsMlIcsfTWmHEvgkX+Yekfi/Nst5WNbxO8+xV3NtL2uQPX45xtzoDCC87H6sQybG3k4+UaeXo/yeImQbr4= X-Received: by 2002:a02:90ce:0:b0:32e:e2ce:b17c with SMTP id c14-20020a0290ce000000b0032ee2ceb17cmr615703jag.268.1653336883586; Mon, 23 May 2022 13:14:43 -0700 (PDT) MIME-Version: 1.0 References: <20220521075736.1225397-1-zenczykowski@gmail.com> In-Reply-To: From: =?UTF-8?Q?Maciej_=C5=BBenczykowski?= Date: Mon, 23 May 2022 13:14:31 -0700 Message-ID: Subject: Re: [PATCH bpf-next] bpf: print a little more info about maps via cat /sys/fs/bpf/pinned_name To: Alexei Starovoitov Cc: Alexei Starovoitov , Daniel Borkmann , Linux Network Development Mailing List , Linux Kernel Mailing List , BPF Mailing List , "David S . Miller" Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 23, 2022 at 12:32 PM Alexei Starovoitov wrote: > > On Sat, May 21, 2022 at 12:57 AM Maciej =C5=BBenczykowski > wrote: > > > > From: Maciej =C5=BBenczykowski > > > > While this information can be fetched via bpftool, > > the cli tool itself isn't always available on more limited systems. > > > > From the information printed particularly the 'id' is useful since > > when combined with /proc/pid/fd/X and /proc/pid/fdinfo/X it allows > > tracking down which bpf maps a process has open (which can be > > useful for tracking down fd leaks). > > > > Signed-off-by: Maciej =C5=BBenczykowski > > --- > > kernel/bpf/inode.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c > > index 4f841e16779e..784266e258fe 100644 > > --- a/kernel/bpf/inode.c > > +++ b/kernel/bpf/inode.c > > @@ -257,6 +257,9 @@ static int map_seq_show(struct seq_file *m, void *v= ) > > if (unlikely(v =3D=3D SEQ_START_TOKEN)) { > > seq_puts(m, "# WARNING!! The output is for debug purpos= e only\n"); > > seq_puts(m, "# WARNING!! The output format will change\= n"); > > + seq_printf(m, "# type: %d, key_size: %d, value_size: %d= , max_entries: %d, id: %d\n", > > + map->map_type, map->key_size, map->value_siz= e, map->max_entries, > > + map->id); > > Maybe use cat /sys/fs/bpf/maps.debug instead? > It prints map id. Is this something that was very recently added? I'm not seeing it on my 5.16 machine with bpffs mounted at /sys/fs/bpf.