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=-10.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 97939C433B4 for ; Thu, 15 Apr 2021 21:59:39 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id AC2C5610F7 for ; Thu, 15 Apr 2021 21:59:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AC2C5610F7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=isovalent.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4FLtY51gYcz3c7s for ; Fri, 16 Apr 2021 07:59:37 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=isovalent-com.20150623.gappssmtp.com header.i=@isovalent-com.20150623.gappssmtp.com header.a=rsa-sha256 header.s=20150623 header.b=BEj/1/8X; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=isovalent.com (client-ip=2a00:1450:4864:20::42a; helo=mail-wr1-x42a.google.com; envelope-from=quentin@isovalent.com; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=isovalent-com.20150623.gappssmtp.com header.i=@isovalent-com.20150623.gappssmtp.com header.a=rsa-sha256 header.s=20150623 header.b=BEj/1/8X; dkim-atps=neutral Received: from mail-wr1-x42a.google.com (mail-wr1-x42a.google.com [IPv6:2a00:1450:4864:20::42a]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4FLk8x2Pnyz2yZR for ; Fri, 16 Apr 2021 01:41:35 +1000 (AEST) Received: by mail-wr1-x42a.google.com with SMTP id a4so23782583wrr.2 for ; Thu, 15 Apr 2021 08:41:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isovalent-com.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=qzCmIc5xh7d+ubWNy7gZo3UPfbkyUvg8kMmWmppBNes=; b=BEj/1/8XPncnjRfRK8mLiZ1SoZ2+BwrE+a39LxPwB/MsIFJnzBAICQLZ2jiwGGbQov 4zqh7un0jhEP1iNaKM1PurWOo4uOYi/n2gtxwCVm76y8egSWq0m6KnadRWC5DH8hi34C K41+UsN0jCiClEebcR9kPZsL0Lx6/VJV5Li9dNkP8mG/+bW6Uxqyyarpphfbe13+sVlb FizX/3RV1YXqCKanusixVoY8OxsNOXFXCWpfkOB2NeLmRvAHXodqwMYxxCYasGQZQftV OsBicx1g9iYrnNMRoDBiJ4p9GtlEji++P0zPJAhhkeDvxObWb1E6q5IO+XBq+ah9VkM2 b8CQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=qzCmIc5xh7d+ubWNy7gZo3UPfbkyUvg8kMmWmppBNes=; b=LqvYh5xyUJQMaiqo751ujE3UviMh++OhlQUE5rJNAeb+nmqA0fyl84ACSWcY0TdwEe 1YSSsttwOXvtC9gn2zXXO/PGAj83bNwNpquwkKjwkewfT1Jl1VBq8rTX4W4pysKpkSzi yzGv1FTc85utbYg6+oSfhFZ/6lit/Qiavpa+L3ewUnWhvwwi4xFpyxpq5Hs94MfrxoPt fE2lKJUJpYOLrjg2W6N1BCFxoIlYpKd4J0mQGIt9F1q1AdXhjPJL0gbiCKQ55Pj7nVQt It3mumAifIic5CNHENncMq+9WJAM1lulDYnIaNGXLj6SV7C8VP4CxYr4zZ72InJXV7Wf OaJg== X-Gm-Message-State: AOAM530uoYQupJGuRTK0RBu3hNnug/vD917GTsPtHILRqa2QVctba8an e1aVtkrWmgCs//T8oba7A2I4oA== X-Google-Smtp-Source: ABdhPJyLNMOWPYjLpplPAmINNkz2Fou+qVJXho8kWclmtHcejA/NRHvG9yzn7ifRTNHYBMXjICP1Nw== X-Received: by 2002:a05:6000:ca:: with SMTP id q10mr4272021wrx.104.1618501286182; Thu, 15 Apr 2021 08:41:26 -0700 (PDT) Received: from [192.168.1.8] ([149.86.87.196]) by smtp.gmail.com with ESMTPSA id l14sm1920076wmq.4.2021.04.15.08.41.24 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 15 Apr 2021 08:41:25 -0700 (PDT) Subject: Re: [PATCH bpf-next 1/2] bpf: Remove bpf_jit_enable=2 debugging mode To: Daniel Borkmann , Jianlin Lv , bpf@vger.kernel.org References: <20210415093250.3391257-1-Jianlin.Lv@arm.com> <9c4a78d2-f73c-832a-e6e2-4b4daa729e07@iogearbox.net> From: Quentin Monnet Message-ID: Date: Thu, 15 Apr 2021 16:41:23 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.9.1 MIME-Version: 1.0 In-Reply-To: <9c4a78d2-f73c-832a-e6e2-4b4daa729e07@iogearbox.net> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit X-Mailman-Approved-At: Fri, 16 Apr 2021 07:58:52 +1000 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: irogers@google.com, songliubraving@fb.com, catalin.marinas@arm.com, linux-doc@vger.kernel.org, zlim.lnx@gmail.com, paul.walmsley@sifive.com, ast@kernel.org, andrii@kernel.org, paulus@samba.org, sandipan@linux.ibm.com, hpa@zytor.com, sparclinux@vger.kernel.org, illusionist.neo@gmail.com, maheshb@google.com, will@kernel.org, nicolas.dichtel@6wind.com, linux-s390@vger.kernel.org, iii@linux.ibm.com, paulburton@kernel.org, corbet@lwn.net, mchehab+huawei@kernel.org, masahiroy@kernel.org, x86@kernel.org, john.fastabend@gmail.com, linux@armlinux.org.uk, linux-riscv@lists.infradead.org, borntraeger@de.ibm.com, mingo@redhat.com, linux-arm-kernel@lists.infradead.org, naveen.n.rao@linux.ibm.com, kuba@kernel.org, tklauser@distanz.ch, linux-mips@vger.kernel.org, grantseltzer@gmail.com, xi.wang@gmail.com, aou@eecs.berkeley.edu, keescook@chromium.org, gor@linux.ibm.com, luke.r.nels@gmail.com, linux-kernel@vger.kernel.org, hca@linux.ibm.com, kpsingh@kernel.org, iecedge@gmail.com, horms@verge.net.au, bp@alien8.de, viro@zeniv.linux.org.uk, yhs@fb.com, tglx@linutronix.de, dvyukov@google.com, tsbogend@alpha.franken.de, yoshfuji@linux-ipv6.org, netdev@vger.kernel.org, dsahern@kernel.org, udknight@gmail.com, kafai@fb.com, bjorn@kernel.org, palmer@dabbelt.com, linuxppc-dev@lists.ozlabs.org, davem@davemloft.net Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" 2021-04-15 16:37 UTC+0200 ~ Daniel Borkmann > On 4/15/21 11:32 AM, Jianlin Lv wrote: >> For debugging JITs, dumping the JITed image to kernel log is discouraged, >> "bpftool prog dump jited" is much better way to examine JITed dumps. >> This patch get rid of the code related to bpf_jit_enable=2 mode and >> update the proc handler of bpf_jit_enable, also added auxiliary >> information to explain how to use bpf_jit_disasm tool after this change. >> >> Signed-off-by: Jianlin Lv Hello, For what it's worth, I have already seen people dump the JIT image in kernel logs in Qemu VMs running with just a busybox, not for kernel development, but in a context where buiding/using bpftool was not possible. Maybe not a common case, but still, removing the debugging mode will make that impossible. Is there a particular incentive to remove the feature? Best regards, Quentin