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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 0774BC4363D for ; Thu, 24 Sep 2020 14:17:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8B3E6221EB for ; Thu, 24 Sep 2020 14:17:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="SJimvUVK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728182AbgIXORB (ORCPT ); Thu, 24 Sep 2020 10:17:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56030 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727859AbgIXORB (ORCPT ); Thu, 24 Sep 2020 10:17:01 -0400 Received: from mail-pl1-x642.google.com (mail-pl1-x642.google.com [IPv6:2607:f8b0:4864:20::642]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F4073C0613CE; Thu, 24 Sep 2020 07:17:00 -0700 (PDT) Received: by mail-pl1-x642.google.com with SMTP id r19so1770422pls.1; Thu, 24 Sep 2020 07:17:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=EATK8UYhF6QjpQ7ze5Yh7cYtMGpiiPgRYaZZWNM3PGw=; b=SJimvUVKP3YEpu5dbZp6nclj4PoP4GI+5FVjQ8crLl6qV9jI/jhWrK0lfimZtmOx6+ mL4TiT24Ma+WYUyPm+d9i/NzLQTlpIIkM91dkJRza3wdWcUvcX5mO2ztLegu+Faz13bd aiYvSWKry4Go4mqNuA5xJHEhFAaeXzsmB0kYAg5AATlP8PnkJGbZCsxUOcfc4AYJt66h O7ToiK+nkRI+ZdMGXj7ytt9vV2U+R6zRBE/aCMP6VGIVfFUpwaCm65KWSw2OLULeAsLM 2kBAw7c0HTRDuFAeQTVSMTpwMKMuvLnTsAN+qr4gGxfCU2iIa4w6Befzl0JtV/W8B7ks geOw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=EATK8UYhF6QjpQ7ze5Yh7cYtMGpiiPgRYaZZWNM3PGw=; b=hsz/qBwC4cxYixlW2CoDEKqz4YGV6rWIOwtxJv5D7ZlDgfR1u3MU+ggpMeNt/Z28+/ +QWcw1l7f4e6OUVpBFLEVHQz+yKOehQ4eA+DNfIR4HUBRlyMoHAFAM9c42oZ6r5Z5suG /x+v3x27xoPy1g1BoXN0gmBMQTOa/BmiW9RfFgLra2ONNKDonRtYOM4pqkdC96+Ez4dw P+mBCzoqHGgTRAr55LAWF9XhpTfCsmPLCb7Z9SEIjRJVutnyc3smQ3MdCny6cjcFBNiU nFLPLYpAok76XRU6wSn6urQ+w7Q0vRQeccqJ01w80qBXdHh/u99cYwB2wg6Q/Y/i5OtD 5oBg== X-Gm-Message-State: AOAM5331FKPz2Uj76VqA/Dx1BmCLFYjgjynSfrI2oHp2MuZM1E0cibBe 6SzVTLxd+NGdR2pvQWRwymm4uoX7Wja35n8J3kA= X-Google-Smtp-Source: ABdhPJze9G2qwEgOsJcOLC/ZCpO1uGYoNBkKLhCAFaz0fKNffXetdfSN0Vxop7ofH0HuYNasmu+o57YdIiwKDNMuHvs= X-Received: by 2002:a17:90b:3252:: with SMTP id jy18mr4034944pjb.1.1600957020491; Thu, 24 Sep 2020 07:17:00 -0700 (PDT) MIME-Version: 1.0 References: <20bbc8ed4b9f2c83d0f67f37955eb2d789268525.1600951211.git.yifeifz2@illinois.edu> <7042ba3307b34ce3b95e5fede823514e@AcuMS.aculab.com> In-Reply-To: <7042ba3307b34ce3b95e5fede823514e@AcuMS.aculab.com> From: YiFei Zhu Date: Thu, 24 Sep 2020 09:16:48 -0500 Message-ID: Subject: Re: [PATCH v2 seccomp 2/6] asm/syscall.h: Add syscall_arches[] array To: David Laight Cc: "containers@lists.linux-foundation.org" , YiFei Zhu , "bpf@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Aleksa Sarai , Andrea Arcangeli , Andy Lutomirski , Dimitrios Skarlatos , Giuseppe Scrivano , Hubertus Franke , Jack Chen , Jann Horn , Josep Torrellas , Kees Cook , Tianyin Xu , Tobin Feldman-Fitzthum , Tycho Andersen , Valentin Rothberg , Will Drewry Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 24, 2020 at 8:47 AM David Laight wrote: > I doubt the compiler will do what you want. > Looking at it, in most cases there are one or two entries. > I think only MIPS has three. It does ;) GCC 10.2.0: $ objdump -d kernel/seccomp.o | less [...] 0000000000001520 <__seccomp_filter>: [...] 1587: 41 8b 54 24 04 mov 0x4(%r12),%edx 158c: b9 08 01 00 00 mov $0x108,%ecx 1591: 81 fa 3e 00 00 c0 cmp $0xc000003e,%edx 1597: 75 2e jne 15c7 <__seccomp_filter+0xa7> [...] 15c7: 81 fa 03 00 00 40 cmp $0x40000003,%edx 15cd: b9 40 01 00 00 mov $0x140,%ecx 15d2: 74 c5 je 1599 <__seccomp_filter+0x79> 15d4: 0f 0b ud2 [...] 0000000000001cb0 : [...] 1cc4: 41 b9 3e 00 00 c0 mov $0xc000003e,%r9d [...] 1dba: 41 b9 03 00 00 40 mov $0x40000003,%r9d [...] 0000000000002e30 : [...] 2e72: ba 3e 00 00 c0 mov $0xc000003e,%edx [...] 2eb5: ba 03 00 00 40 mov $0x40000003,%edx Granted, I have CC_OPTIMIZE_FOR_PERFORMANCE rather than CC_OPTIMIZE_FOR_SIZE, but this patch itself is trying to sacrifice some of the memory for speed. YiFei Zhu