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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6F86AC433EF for ; Sat, 30 Apr 2022 01:02:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:To:Subject:Message-ID:Date:From: In-Reply-To:References:MIME-Version:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=v2T3wixLzRtm122pC3r3YPvSEjAs0kuvaJ6j/QPOG+Y=; b=IZ0+2IVdxBzt5x LvfGolpjwcHcqsKG+zEWJU5bPt+CmYvXQ9knWxGyR4T8R8FY+KYxtH5uGviySDQPZegSiOVJfe5Eo RvBn5GqK2PoYbF+GSnYVHKRyolkLI0WC78XUqICWl2ipS4cW6Cm3TYimOZnt3Oqth1HIb7On6ki5p wLa9OKo9B/CvKPvQX0132BpBPE4+tWs6zVBOUb19P9t6AM0Np3wjWCoGoNBmPpA+NbSku+9rIKkti R3UhsZUM8m4hkGX0sePDbAokphuXwrms+s7loc7s78f25uTm5m4yjvSmlSKiZAGJ9BzXC5mNwfrSu tvTXqwcgtP4TNz3NMoig==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nkbTa-00DLoN-Rs; Sat, 30 Apr 2022 01:00:46 +0000 Received: from mail-yb1-xb2c.google.com ([2607:f8b0:4864:20::b2c]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nkbTX-00DLnC-G1 for linux-arm-kernel@lists.infradead.org; Sat, 30 Apr 2022 01:00:45 +0000 Received: by mail-yb1-xb2c.google.com with SMTP id d12so17222645ybc.4 for ; Fri, 29 Apr 2022 18:00:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=v+/lXmWN9a4yBqHcUhGldW2cPmJygtUYS178VCmvTIc=; b=sae9+FjGo9T5Lw9oasK5TSXV+WiJ9kOd1rZxgJTdRsikk6ZkRbafNdUGY5LNRGAq7z KLeLF9me10KOS2tdhq3QqUpedIvCKSr1k5DC/BpSJXrYAbYGX36I/OHi5sPl2+ZQlekd 66J+Wwfye+d+OmHrkDF8heOen1RhSJWCYyaI2bN5JBrcN16V9XbLRRbXVKl4swa18OO5 tjzIGXovtKoxHb2BPhqhs7CQ8j16lH/BUJJAJBpzv9rkOq3Qi4oG9OwF3Ppi6ZYwQt7t c0tGVoQRbXL9RFIYG+2HjirHMKUjpclTwnxrV6ci7lqAUdDwRL4xfTYawAje7RdrXeb3 Ouqg== 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; bh=v+/lXmWN9a4yBqHcUhGldW2cPmJygtUYS178VCmvTIc=; b=Fnu5O2LvmauYwvXBd6feFBh7dPsMMUXnzrrlAfpn3C1s5RAc4S+VrXtbd0eXF47wyb eUPXl0gLumEocemNoTd0iEry+1FacxDdA5fZM70L6XlfUdApJnhw+dqTBSUqH+L6c1rI gVj6Y0+C9l8mbOw4egqHGj4S4fjLhpAB7mGtdULhNKv25nsN1UQuIknprp6Ky3KE5wpR NZqbH/GzFV/jWtLSZrnaH7ft+MenpT+t5kBCt/QjNm8jn3if7SuRWTGaLAsv9kYR6oC4 saVT7qrzyP5q6TWU2Mbjx9HYUQBRJG6PdkEJNTZ62APiycKH6EYz/l+TzKig4YNDeCXR 3qOA== X-Gm-Message-State: AOAM533EBJKe57zbSAy+jLLkLhx0qvJi5OliJydTiExy/rCtSxtVg6l/ qMYVe7Cw71l9kEyUXVK4zez4mhB8gsSeMYVqvJ29iw== X-Google-Smtp-Source: ABdhPJyhcCyxowcmxR+EC+1LVLQSQWfwL5P0ozbbvft+6vNS3yhM7DK8vGFq8LI/3sHN0lOaYWVuT+28wwYR2ixEuLk= X-Received: by 2002:a5b:2c9:0:b0:644:b7c9:3766 with SMTP id h9-20020a5b02c9000000b00644b7c93766mr1986227ybp.428.1651280439211; Fri, 29 Apr 2022 18:00:39 -0700 (PDT) MIME-Version: 1.0 References: <20220429203644.2868448-1-samitolvanen@google.com> <20220429203644.2868448-17-samitolvanen@google.com> In-Reply-To: From: Sami Tolvanen Date: Fri, 29 Apr 2022 18:00:03 -0700 Message-ID: Subject: Re: [RFC PATCH 16/21] objtool: Add support for CONFIG_CFI_CLANG To: Peter Zijlstra Cc: LKML , Kees Cook , Josh Poimboeuf , X86 ML , Catalin Marinas , Will Deacon , Mark Rutland , Nathan Chancellor , Nick Desaulniers , Joao Moreira , Sedat Dilek , Steven Rostedt , linux-hardening@vger.kernel.org, linux-arm-kernel , llvm@lists.linux.dev X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220429_180043_575907_B1D69B68 X-CRM114-Status: GOOD ( 12.67 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Apr 29, 2022 at 4:30 PM Peter Zijlstra wrote: > Urgh, what does this do for decode speed? This is a hash-lookup for > every single instruction. Two actually, since .kcfi_traps only contains compiler-emitted locations and we also have to check for manual type annotations. I haven't measured performance yet, but I also didn't notice a significant impact here. > Is that kcfi location array sorted by the compiler? Because then you can > keep a running iterator and replace the whole lookup with a simple > equality comparison. The compiler generates a separate .kcfi_types section for each text section and the entries are emitted in order, so this should be doable. Sami _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel