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=-6.6 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,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 26F45C33CA2 for ; Thu, 9 Jan 2020 13:23:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F1B2E206ED for ; Thu, 9 Jan 2020 13:23:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="b9C+6E6y" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730746AbgAINXL (ORCPT ); Thu, 9 Jan 2020 08:23:11 -0500 Received: from mail-qv1-f67.google.com ([209.85.219.67]:42841 "EHLO mail-qv1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727861AbgAINXL (ORCPT ); Thu, 9 Jan 2020 08:23:11 -0500 Received: by mail-qv1-f67.google.com with SMTP id dc14so2913155qvb.9; Thu, 09 Jan 2020 05:23:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=gHn0DTphjj03asL3iOA7THQryvYrwo9Swn5bZMEu/Uo=; b=b9C+6E6yblXFpvQVBMn7gtrDQWz729YAwVEOl+5LFkbKdWVFNG9+9P1Z4o3jl+3moX o/8h48cBrHsjQJ38tt1gb9ZktrB8H+m6wLKAeRe/p+VtnU19DC53uz+Xjf2nDOtK5QeS s/1QDQAzrS9OJGn1cnzCCSvBcAk28XuZO9Wk2yOTtOuQpMJb9QThp2TUi1aQhV2jv2hJ 0fDOaGXD/WGX8xfNF8NdNK9f3bCFNKK4zXVGAaCOFZdYkiB3TmqJmVkpVGDhvyTPOteL RVSNFwWYI446zE73eXLEleBwMiJexQPHb7qZnqrD2x1kRmEs1dEg9WSp+B2xu2vQGQGN FpMA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:date:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=gHn0DTphjj03asL3iOA7THQryvYrwo9Swn5bZMEu/Uo=; b=O5tWhiK0bnSM8u+PHSOht83dn/tkfnmXB7JOZlq1tUAYb2b9gmnl4Rs1HF20ostgVu TjoywWOUdTs+Er0UTesgEzCI/T9KJOKkZPxo9AHxD54jkHdrbfZ3zatAutN7Eq2p6snS jKFRlJqH41iZkkItpMgovrQTYCxxQf7r2XUQ5OfkRMYFtlqr7tL5zOQXzGvzHLpmWARs O23Xe/o1l9nEAeuI2kyUeTaAnfyiNmnUXT0rcu+Hh7qnZr5jAc3Re1c8nBbQgEUaxD9S ZJGb56QSsWjCDhEgsASZjL7BR0KJTPQn5sOf7EoE08U24ny6loKECq/sPyRMF7IIdupm pB6A== X-Gm-Message-State: APjAAAVedLfGuifzuGTLWN0D1t0jWAkW8NcHKH9O0KiARAMY3JWpK/g5 onL9hqVwzw5a5dfwDfxEo0Y= X-Google-Smtp-Source: APXvYqzRJEThNlX0fsuuLm2WmQbGJXLyGL76XM7lMYUKN6wZ/0iULCQ/rvx1/+CYO5gmklP08MRlzQ== X-Received: by 2002:a0c:e58e:: with SMTP id t14mr8629177qvm.131.1578576190161; Thu, 09 Jan 2020 05:23:10 -0800 (PST) Received: from quaco.ghostprotocols.net ([179.97.37.151]) by smtp.gmail.com with ESMTPSA id r28sm3419391qtr.3.2020.01.09.05.23.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Jan 2020 05:23:09 -0800 (PST) From: Arnaldo Carvalho de Melo X-Google-Original-From: Arnaldo Carvalho de Melo Received: by quaco.ghostprotocols.net (Postfix, from userid 1000) id 71A0740DFD; Thu, 9 Jan 2020 10:23:07 -0300 (-03) Date: Thu, 9 Jan 2020 10:23:07 -0300 To: Martin Lau Cc: Arnaldo Carvalho de Melo , "bpf@vger.kernel.org" , Alexei Starovoitov , Daniel Borkmann , David Miller , Kernel Team , "netdev@vger.kernel.org" Subject: Re: [PATCH bpf-next v4 01/11] bpf: Save PTR_TO_BTF_ID register state when spilling to stack Message-ID: <20200109132307.GA32252@kernel.org> References: <20200109003453.3854769-1-kafai@fb.com> <20200109004424.3894196-1-kafai@fb.com> <9EC7DCC9-B219-4545-BA93-E2AC0569C843@kernel.org> <20200109054701.bog4btwk4724gwfw@kafai-mbp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200109054701.bog4btwk4724gwfw@kafai-mbp> X-Url: http://acmel.wordpress.com Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Em Thu, Jan 09, 2020 at 05:47:06AM +0000, Martin Lau escreveu: > On Wed, Jan 08, 2020 at 10:06:44PM -0300, Arnaldo Carvalho de Melo wrote: > > On January 8, 2020 9:44:24 PM GMT-03:00, Martin KaFai Lau wrote: > > >This patch makes the verifier save the PTR_TO_BTF_ID register state > > >when > > >spilling to the stack. > > > > You say what it does, but not why that is needed :-/ > It is the same as other existing bpf_reg_type (i.e. the above switch > cases in is_spillable_regtype()). > > When a register spills to the stack, the verifier decides if the reg's > state can be saved (i.e. what the is_spillable_regtype() is checking). > If the state is not saved, the verifier cannot recognize its state > later. Thanks for the explanation, I suggest that next time you include it in the cset comment, to help make sense of the patch by having a why + how to match with the actual patch. - Arnaldo > > - Arnaldo > > > > > >Acked-by: Yonghong Song > > >Signed-off-by: Martin KaFai Lau > > >--- > > > kernel/bpf/verifier.c | 1 + > > > 1 file changed, 1 insertion(+) > > > > > >diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c > > >index 6f63ae7a370c..d433d70022fd 100644 > > >--- a/kernel/bpf/verifier.c > > >+++ b/kernel/bpf/verifier.c > > >@@ -1916,6 +1916,7 @@ static bool is_spillable_regtype(enum > > >bpf_reg_type type) > > > case PTR_TO_TCP_SOCK: > > > case PTR_TO_TCP_SOCK_OR_NULL: > > > case PTR_TO_XDP_SOCK: > > >+ case PTR_TO_BTF_ID: > > > return true; > > > default: > > > return false; > > -- - Arnaldo