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 X-Spam-Level: X-Spam-Status: No, score=-3.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3DD15C2BB85 for ; Fri, 10 Apr 2020 03:00:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 12AF120936 for ; Fri, 10 Apr 2020 03:00:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="lHVW7mQV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726595AbgDJDAX (ORCPT ); Thu, 9 Apr 2020 23:00:23 -0400 Received: from mail-pj1-f68.google.com ([209.85.216.68]:50798 "EHLO mail-pj1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726552AbgDJDAX (ORCPT ); Thu, 9 Apr 2020 23:00:23 -0400 Received: by mail-pj1-f68.google.com with SMTP id b7so303368pju.0; Thu, 09 Apr 2020 20:00:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=AQk4mNPo1rM91Nw8K13eaCa0gv8MYDldNLpKlwDrZFQ=; b=lHVW7mQVsZzwww/iWDUQJIpgCMJ2jxDDqrxeEIAO9xkq/TyuKo1u21PLccMFAa/lBz rqt7omDIsHJseYPOFiqe1eBmn8u0GkAxafxGnT9UC2h8insR0vSSSzDWBHW0gUOxtCOJ 4tEm3/eoEDig9tuG+iPSo4SYuEtSK1PqjA7Niv/b2Dl/jhgMwF49zo/ElF40tOijGcKH Zp/cfYX9BQwGC3RWdWATAu1E7w8/cajQSzonUd4yh2VB6UQ2lJFCp3SQJ4cMkoFmEa6/ gjhWfVjQTBRYOrNa+O9N/9p7WHYB+fPsAaRLieH4TEaVGrn8zFy5se5Ah3Il+EQ2GlvZ Al4A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=AQk4mNPo1rM91Nw8K13eaCa0gv8MYDldNLpKlwDrZFQ=; b=M9YdZSEta90qZXC9B1+Hp5lM8i4LCEKHCUKp9b9iI46XXWDzjz275gEo1E6uNshOMT KJIoA6grzW4gtodz0IwzK+PdBgJknVypro0QrGb8/DlRFO+Gurjwaol7n8gJvjJXx+oc IpcNsLo/MrYpj7AzNf6txtL37/tfuTiTpDxhqwmxTnvp0wx/rjzQ+qCJNHuzfNPPTDp1 3znDIiFboxto+Rr7TDqNi7r09PgWNF7eDWoTem9rkqox5HUgEmmmyau+cp7WMniOgK8t T9L2e57Zon59mHLOnJOk55L2yIxN1oODW2zjB1ncFHvgj9PCGmxNLokJOor2eFTRqDCd r/Tg== X-Gm-Message-State: AGi0PuZWRid2Nyckou5rtrztqIr71yVKfbf6VsJqIXZqMN8Vya+Qdu7g 2LdkoOqOsiYR3zFg0WkWPfs= X-Google-Smtp-Source: APiQypJlaKS5U3gT7aBUovoy0iPXJNzhHe46NT5UwqPGJKVUu+1Fzy5bwlDah7St3wVVfjTYT7CMvg== X-Received: by 2002:a17:90a:80ca:: with SMTP id k10mr2949132pjw.45.1586487621076; Thu, 09 Apr 2020 20:00:21 -0700 (PDT) Received: from ast-mbp.dhcp.thefacebook.com ([2620:10d:c090:400::5:f219]) by smtp.gmail.com with ESMTPSA id f9sm477692pjt.45.2020.04.09.20.00.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Apr 2020 20:00:20 -0700 (PDT) Date: Thu, 9 Apr 2020 20:00:17 -0700 From: Alexei Starovoitov To: Yonghong Song Cc: Andrii Nakryiko , bpf@vger.kernel.org, Martin KaFai Lau , netdev@vger.kernel.org, Alexei Starovoitov , Daniel Borkmann , kernel-team@fb.com Subject: Re: [RFC PATCH bpf-next 05/16] bpf: create file or anonymous dumpers Message-ID: <20200410030017.errh35srmbmd7uk5@ast-mbp.dhcp.thefacebook.com> References: <20200408232520.2675265-1-yhs@fb.com> <20200408232526.2675664-1-yhs@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200408232526.2675664-1-yhs@fb.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, Apr 08, 2020 at 04:25:26PM -0700, Yonghong Song wrote: > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > index 0f1cbed446c1..b51d56fc77f9 100644 > --- a/include/uapi/linux/bpf.h > +++ b/include/uapi/linux/bpf.h > @@ -354,6 +354,7 @@ enum { > /* Flags for accessing BPF object from syscall side. */ > BPF_F_RDONLY = (1U << 3), > BPF_F_WRONLY = (1U << 4), > + BPF_F_DUMP = (1U << 5), ... > static int bpf_obj_pin(const union bpf_attr *attr) > { > - if (CHECK_ATTR(BPF_OBJ) || attr->file_flags != 0) > + if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_DUMP) > return -EINVAL; > > + if (attr->file_flags == BPF_F_DUMP) > + return bpf_dump_create(attr->bpf_fd, > + u64_to_user_ptr(attr->dumper_name)); > + > return bpf_obj_pin_user(attr->bpf_fd, u64_to_user_ptr(attr->pathname)); > } I think kernel can be a bit smarter here. There is no need for user space to pass BPF_F_DUMP flag to kernel just to differentiate the pinning. Can prog attach type be used instead?