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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 926F2EB64DD for ; Mon, 3 Jul 2023 09:18:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230075AbjGCJSP (ORCPT ); Mon, 3 Jul 2023 05:18:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59980 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230341AbjGCJSJ (ORCPT ); Mon, 3 Jul 2023 05:18:09 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CE133196; Mon, 3 Jul 2023 02:17:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=MIME-Version:Content-Type:References: In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=t7o2rmfPLhYslNYoOujyShh3+93sZwFvRpTrs9N8Hs0=; b=eh1FxzZh0WVr/7S3QujKESedO+ iriMrAMMgptzM94W6Mw1Wa94rchrJ95WRI0uKb3eB6OuhDeF+j+81wcFeKAtM3uZRddcQfW9lSiaF 3vYQnI7fqvPo9MLMp9eHSj/fxyMPUQx06FYB9KW9N07yub5zfJwqY0Dd+D+n5YUK1uPp0Tcm967bC gIJBC41tnMEjvsP33FktRQVPMeMcpTdmLj07Egtqf0qcRvYdd1Q3aJr7ZpHqOSkI2nDPkcpqo08TC cpaJGGf8SlCDJbZAX0HHErNIDXMxDAtPDGivvM1zwlvWl7VXB2hoH1W6X/kwJUXV4m42YD3SpuKYe pBAMKQSQ==; Received: from [2001:8b0:10b:5:86a3:26f9:cd4a:d44b] (helo=u3832b3a9db3152.ant.amazon.com) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1qGFgr-0085o0-2O; Mon, 03 Jul 2023 09:17:49 +0000 Message-ID: <77ce6f91f163f333d4b2146e6ea66b7f5fe38d9e.camel@infradead.org> Subject: Re: [PATCH AUTOSEL 6.4 01/15] cpu/hotplug: Reset task stack state in _cpu_up() From: David Woodhouse To: Sasha Levin , linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Thomas Gleixner , Peter Zijlstra , Mark Rutland , Michael Kelley , Oleksandr Natalenko , Helge Deller , "Guilherme G . Piccoli" Date: Mon, 03 Jul 2023 10:17:48 +0100 In-Reply-To: <20230702194020.1776895-1-sashal@kernel.org> References: <20230702194020.1776895-1-sashal@kernel.org> Content-Type: multipart/signed; micalg="sha-256"; protocol="application/pkcs7-signature"; boundary="=-6A6huHxieyiyGhNnwQ9y" User-Agent: Evolution 3.44.4-0ubuntu1 MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-6A6huHxieyiyGhNnwQ9y Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Sun, 2023-07-02 at 15:40 -0400, Sasha Levin wrote: > From: David Woodhouse >=20 > [ Upstream commit 6d712b9b3a58018259fb40ddd498d1f7dfa1f4ec ] >=20 > Commit dce1ca0525bf ("sched/scs: Reset task stack state in bringup_cpu()"= ) > ensured that the shadow call stack and KASAN poisoning were removed from > a CPU's stack each time that CPU is brought up, not just once. >=20 > This is not incorrect. No really, it *wasn't* incorrect. This isn't a bugfix that needs backporting; it's preparation for the parallel CPU bringup which I *hope* you aren't planning to backport in its entirety :) Unless I'm missing something, I don't think you want this for stable (in any of the trees it was just sent out for). --=-6A6huHxieyiyGhNnwQ9y Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Disposition: attachment; filename="smime.p7s" Content-Transfer-Encoding: base64 MIAGCSqGSIb3DQEHAqCAMIACAQExDzANBglghkgBZQMEAgEFADCABgkqhkiG9w0BBwEAAKCCEkQw ggYQMIID+KADAgECAhBNlCwQ1DvglAnFgS06KwZPMA0GCSqGSIb3DQEBDAUAMIGIMQswCQYDVQQG EwJVUzETMBEGA1UECBMKTmV3IEplcnNleTEUMBIGA1UEBxMLSmVyc2V5IENpdHkxHjAcBgNVBAoT FVRoZSBVU0VSVFJVU1QgTmV0d29yazEuMCwGA1UEAxMlVVNFUlRydXN0IFJTQSBDZXJ0aWZpY2F0 aW9uIEF1dGhvcml0eTAeFw0xODExMDIwMDAwMDBaFw0zMDEyMzEyMzU5NTlaMIGWMQswCQYDVQQG EwJHQjEbMBkGA1UECBMSR3JlYXRlciBNYW5jaGVzdGVyMRAwDgYDVQQHEwdTYWxmb3JkMRgwFgYD VQQKEw9TZWN0aWdvIExpbWl0ZWQxPjA8BgNVBAMTNVNlY3RpZ28gUlNBIENsaWVudCBBdXRoZW50 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