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 593C7ECAAA4 for ; Mon, 29 Aug 2022 18:09:39 +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:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=95mqfIaf0YEgW2tYtU3u4LgfXuujAiOXEyS9CTxpO2k=; b=QXrGLB/I6Wr7dV jogPTiAJ/NtjzNmLa4asUh1cdx7RDHuJiYJfeBYAyyb7rL/R25itXQxcAvARkuQD4jMSsW/dAEaJl DMCuUggXG8daWBXRbZMB3qbTwPx7mSJovYfbh0nMPcoHfdTAUhfsG8hHO8eTkO12vUshq3h82OGn4 Q24oMWRsEutgOEpI6FMzlMN76fHIDv/Cg1YHK6TzwKVMr5BJdL0A8yxrAgXM/zAwHlnscTqyiNO78 CL0/eYQDT7FNWpSiIto9EHLLDjrLYi5LIvDnWeo+v1grXbJUoTRkMxlIwWhPw4qx3GXD0dWQSKvu7 +6NkJlIIzdjM1mdvjaNw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oSjBU-00CAMW-0O; Mon, 29 Aug 2022 18:08:28 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oSjBO-00CAKn-MJ for linux-arm-kernel@lists.infradead.org; Mon, 29 Aug 2022 18:08:24 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 081896130A; Mon, 29 Aug 2022 18:08:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 49751C433D6; Mon, 29 Aug 2022 18:08:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1661796500; bh=h41PGKQB9pe7pe7VyewCaeAHUyzSkkZqPJT6d53vlas=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=PQIJM+CIH2z7ZKFBpr8qKbXq6K/s7cUzt0xjb2LDDtMydJCn1LULT+0J/eTO8Dt8o V2fkODXOq1xIJ/RPfEnq/dZ1aBNLyuo7G574J8g3pf+dU3RYCMii0txmwPp/KQJLr9 iOV9M+RJyZRDF+Rh2fXBgcsUEZl0VhBMeOT/gv2TVhyCj7Jjft5DNztnpXDYd9KhHH Alg9PzPSmPM3eoNZ4cohMvxmlcJTtCG4dAYfPqt04Pd+PhbMOm8Uxl1s+VhqIC6VKI WF/pmCD6WHGwEzAU3R53YV2gGHIJ2+odLpC9gDNHngd8HVnKYJ9zVMLmeQ2vgz2FF5 IhPc/JGj6NQ1A== Date: Mon, 29 Aug 2022 18:08:07 +0000 From: Eric Biggers To: "Jason A. Donenfeld" Cc: x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, Adam Langley , Ard Biesheuvel Subject: Re: Should Linux set the new constant-time mode CPU flags? Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220829_110822_847406_83839AB9 X-CRM114-Status: GOOD ( 27.34 ) 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="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org T24gTW9uLCBBdWcgMjksIDIwMjIgYXQgMTI6Mzk6NTNQTSAtMDQwMCwgSmFzb24gQS4gRG9uZW5m ZWxkIHdyb3RlOgo+IEhpIEVyaWMsCj4gCj4gT24gVGh1LCBBdWcgMjUsIDIwMjIgYXQgMTE6MTU6 NThQTSArMDAwMCwgRXJpYyBCaWdnZXJzIHdyb3RlOgo+ID4gSSdtIHdvbmRlcmluZyBpZiBwZW9w bGUgYXJlIGF3YXJlIG9mIHRoaXMgaXNzdWUsIGFuZCB3aGV0aGVyIGFueW9uZSBoYXMgYW55Cj4g PiB0aG91Z2h0cyBvbiB3aGV0aGVyL3doZXJlIHRoZSBrZXJuZWwgc2hvdWxkIGJlIHNldHRpbmcg dGhlc2UgbmV3IENQVSBmbGFncy4KPiA+IFRoZXJlIGRvbid0IGFwcGVhciB0byBoYXZlIGJlZW4g YW55IHByaW9yIGRpc2N1c3Npb25zIGFib3V0IHRoaXMuICAoVGhhbmtzIHRvCj4gCj4gTWF5YmUg aXQgc2hvdWxkIGJlIHNldCB1bmNvbmRpdGlvbmFsbHkgbm93LCB1bnRpbCB3ZSBmaWd1cmUgb3V0 IGhvdyB0bwo+IG1ha2UgaXQgbW9yZSBncmFudWxhci4KPiAKPiBJbiB0ZXJtcyBvZiBncmFudWxh cml0eSwgSSBzYXcgb3RoZXIgZm9sa3Mgc3VnZ2VzdGluZyBtYWtpbmcgaXQgcGVyLXRhc2sKPiAo c28sIHByZXN1bWFibHksIGEgcHJjdGwoKSBrbm9iKSwgYW5kIG90aGVycyBtZW50aW9uaW5nIGRv aW5nIGl0IGp1c3QKPiBmb3Iga2VybmVsIGNyeXB0by4gRm9yIHRoZSBsYXR0ZXIsIEkgZ3Vlc3Mg dGhlIGNyeXB0byBBUEkgY291bGQgc2V0IGl0Cj4gaW5zaWRlIG9mIGl0cyBhYnN0cmFjdGlvbnMs IGFuZCB0aGUgdmFyaW91cyBsaWIvY3J5cHRvIEFQSXMgY291bGQgc2V0IGl0Cj4gYXQgaW52b2Nh dGlvbiB0aW1lLiBJIHdvbmRlciwgdGhvdWdoLCB3aGF0J3MgdGhlIGNvc3Qgb2YKPiBlbmFibGlu Zy9kaXNhYmxpbmcgaXQ/IFdvdWxkIHdlIGluIGZhY3QgbmVlZCBhIGtpbmQgb2YgbGF6eS1kZWZl cnJlZAo+IGRpc2FibGluZywgbGlrZSB3ZSBoYXZlIHdpdGgga2VybmVsX2ZwdV9lbmQoKT8gSSBh bHNvIHdvbmRlciB3aGF0Cj4gY3J5cHRvLWFkamFjZW50IGNvZGUgbWlnaHQgd2luZCB1cCBiZWlu ZyBtaXNzZWQgaWYgd2UncmUgZ29pbmcgZnVuY3Rpb24KPiBieSBmdW5jdGlvbi4gTGlrZSwgb2J2 aW91c2x5IHdlJ2Qgc2V0IHRoaXMgZm9yIGNyeXB0b19tZW1uZXEsIGJ1dCB3aGF0Cj4gYWJvdXQg cG90ZW50aWFsIHVucHJvdGVjdGVkIGA9PWAgb2YgSUQgbnVtYmVycyB0aGF0IGNvdWxkIGxlYWsg c29tZSBpbmZvCj4gaW4gdmFyaW91cyBwcm90b2NvbHM/IFdoYXQgb3RoZXIgc3VidGxlIG5lYXJi eSBjb2RlIHNob3VsZCB3ZSBiZQo+IHRoaW5raW5nIGFib3V0LCB0aGF0IHJlbGllcyBvbiBjb25z dGFudCB0aW1lIGxvZ2ljIGJ1dCBpc24ndCBuZWF0bHkKPiBmb2xkZWQgaW5zaWRlIGEgY3J5cHRv X2RvX3NvbWV0aGluZygpIGZ1bmN0aW9uPwo+IAoKSSdkIG11Y2ggcHJlZmVyIGl0IGJlaW5nIHNl dCB1bmNvbmRpdGlvbmFsbHkgYnkgZGVmYXVsdCBhcyB3ZWxsLCBhcyBtYWtpbmcKZXZlcnlvbmUg KGJvdGgga2VybmVsIGFuZCB1c2Vyc3BhY2UpIHR1cm4gaXQgb24gYW5kIG9mZiBjb25zdGFudGx5 IHdvdWxkIGJlIGEKbmlnaHRtYXJlLgoKTm90ZSB0aGF0IEludGVsJ3MgZG9jdW1lbnRhdGlvbiBz YXlzIHRoYXQgQ1BVcyBiZWZvcmUgSWNlIExha2UgYmVoYXZlIGFzIGlmCkRPSVRNIGlzIGFsd2F5 cyBzZXQ6CgogICAgIkZvciBJbnRlbMKuIENvcmXihKIgZmFtaWx5IHByb2Nlc3NvcnMgYmFzZWQg b24gbWljcm9hcmNoaXRlY3R1cmVzIGJlZm9yZSBJY2UKICAgIExha2UgYW5kIEludGVsIEF0b23C riBmYW1pbHkgcHJvY2Vzc29ycyBiYXNlZCBvbiBtaWNyb2FyY2hpdGVjdHVyZXMgYmVmb3JlCiAg ICBHcmFjZW1vbnQgdGhhdCBkbyBub3QgZW51bWVyYXRlIElBMzJfVUFSQ0hfTUlTQ19DVEwsIGRl dmVsb3BlcnMgbWF5IGFzc3VtZQogICAgdGhhdCB0aGUgaW5zdHJ1Y3Rpb25zIGxpc3RlZCBoZXJl IG9wZXJhdGUgYXMgaWYgRE9JVE0gaXMgZW5hYmxlZC4iCgooSXQncyBhIGJpdCBhbWJpZ3VvdXMs IGFzIGl0IGxlYXZlcyB0aGUgZG9vciBvcGVuIHRvIElBMzJfVUFSQ0hfTUlTQ19DVEwgYmVpbmcK cmV0cm9hY3RpdmVseSBhZGRlZCB0byBvbGQgQ1BVcy4gIEJ1dCBJIGFzc3VtZSB0aGF0IGhhc24n dCBhY3R1YWxseSBoYXBwZW5lZC4pCgpTbyBJIHRoaW5rIHRoZSBsb2dpY2FsIGFwcHJvYWNoIGlz IHRvIHVuY29uZGl0aW9uYWxseSBzZXQgRE9JVE0gYnkgZGVmYXVsdCwgdG8KZml4IHRoaXMgQ1BV IGJ1ZyBpbiBJY2UgTGFrZSBhbmQgbGF0ZXIgYW5kIGp1c3QgYnJpbmcgdGhpbmdzIGJhY2sgdG8g dGhlIHdheQp0aGV5IHdlcmUgaW4gQ1BVcyBiZWZvcmUgSWNlIExha2UuICBXaXRoIHRoYXQgYXMg YSBiYXNlbGluZSwgd2UgY2FuIHRoZW4gZGlzY3Vzcwp3aGV0aGVyIGl0J3MgdXNlZnVsIHRvIHBy b3ZpZGUgd2F5cyB0byByZS1lbmFibGUgdGhpcyBDUFUgYnVnIC8gImZlYXR1cmUiLCBmb3IKcGVv cGxlIHdobyB3YW50IHRvIGdldCB0aGUgcGVyZm9ybWFuY2UgYm9vc3QgKGlmIG9uZSBhY3R1YWxs eSBleGlzdHMpIG9mIGRhdGEKZGVwZW5kZW50IHRpbWluZyBhZnRlciBjYXJlZnVsbHkgYXNzZXNz aW5nIHRoZSByaXNrcy4KClRoZSBvdGhlciB3YXkgYXJvdW5kLCBvZiBtYWtpbmcgZXZlcnl0aGlu ZyBpbnNlY3VyZSBieSBkZWZhdWx0LCBzZWVtcyBsaWtlIGEKcmVhbGx5IGJhZCBpZGVhLgoKLSBF cmljCgpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwpsaW51 eC1hcm0ta2VybmVsIG1haWxpbmcgbGlzdApsaW51eC1hcm0ta2VybmVsQGxpc3RzLmluZnJhZGVh ZC5vcmcKaHR0cDovL2xpc3RzLmluZnJhZGVhZC5vcmcvbWFpbG1hbi9saXN0aW5mby9saW51eC1h cm0ta2VybmVsCg==