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 DC7F3C433FE for ; Tue, 18 Oct 2022 09:35:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229864AbiJRJfd (ORCPT ); Tue, 18 Oct 2022 05:35:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33114 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230030AbiJRJfZ (ORCPT ); Tue, 18 Oct 2022 05:35:25 -0400 Received: from jabberwock.ucw.cz (jabberwock.ucw.cz [46.255.230.98]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BDEEB6D862; Tue, 18 Oct 2022 02:35:11 -0700 (PDT) Received: by jabberwock.ucw.cz (Postfix, from userid 1017) id 8F19B1C09D8; Tue, 18 Oct 2022 11:35:10 +0200 (CEST) Date: Tue, 18 Oct 2022 11:35:09 +0200 From: Pavel Machek To: Sasha Levin Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Marco Elver , Dmitry Vyukov , Peter Zijlstra , Ian Rogers , mpe@ellerman.id.au, christophe.leroy@csgroup.eu, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH AUTOSEL 5.10 04/16] powerpc/hw_breakpoint: Avoid relying on caller synchronization Message-ID: <20221018093509.GB1264@duo.ucw.cz> References: <20221018001029.2731620-1-sashal@kernel.org> <20221018001029.2731620-4-sashal@kernel.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="mojUlQ0s9EVzWg2t" Content-Disposition: inline In-Reply-To: <20221018001029.2731620-4-sashal@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --mojUlQ0s9EVzWg2t Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > From: Marco Elver >=20 > [ Upstream commit f95e5a3d59011eec1257d0e76de1e1f8969d426f ] >=20 > Internal data structures (cpu_bps, task_bps) of powerpc's hw_breakpoint > implementation have relied on nr_bp_mutex serializing access to them. >=20 > Before overhauling synchronization of kernel/events/hw_breakpoint.c, > introduce 2 spinlocks to synchronize cpu_bps and task_bps respectively, > thus avoiding reliance on callers synchronizing powerpc's > hw_breakpoint. This is preparation, not a bugfix, not sure why it was picked for 5.10. Best regards, Pavel --=20 DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany --mojUlQ0s9EVzWg2t Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABECAB0WIQRPfPO7r0eAhk010v0w5/Bqldv68gUCY05zTQAKCRAw5/Bqldv6 8hDCAJ93uULfn3AoJWhDD3Cg+mHOSVqtLwCeL4eiZsmL+Ra5uL3L03wLx5hvocg= =NwNt -----END PGP SIGNATURE----- --mojUlQ0s9EVzWg2t-- 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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id B37EFC4332F for ; Tue, 18 Oct 2022 09:43:56 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4Ms87v0FDRz3dtT for ; Tue, 18 Oct 2022 20:43:55 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=neutral (access neither permitted nor denied) smtp.mailfrom=denx.de (client-ip=46.255.230.98; helo=jabberwock.ucw.cz; envelope-from=pavel@denx.de; receiver=) X-Greylist: delayed 482 seconds by postgrey-1.36 at boromir; Tue, 18 Oct 2022 20:43:19 AEDT Received: from jabberwock.ucw.cz (jabberwock.ucw.cz [46.255.230.98]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4Ms87C6hZCz3bjY for ; Tue, 18 Oct 2022 20:43:19 +1100 (AEDT) Received: by jabberwock.ucw.cz (Postfix, from userid 1017) id 8F19B1C09D8; Tue, 18 Oct 2022 11:35:10 +0200 (CEST) Date: Tue, 18 Oct 2022 11:35:09 +0200 From: Pavel Machek To: Sasha Levin Subject: Re: [PATCH AUTOSEL 5.10 04/16] powerpc/hw_breakpoint: Avoid relying on caller synchronization Message-ID: <20221018093509.GB1264@duo.ucw.cz> References: <20221018001029.2731620-1-sashal@kernel.org> <20221018001029.2731620-4-sashal@kernel.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="mojUlQ0s9EVzWg2t" Content-Disposition: inline In-Reply-To: <20221018001029.2731620-4-sashal@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) 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: Ian Rogers , Marco Elver , Peter Zijlstra , linux-kernel@vger.kernel.org, stable@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Dmitry Vyukov Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" --mojUlQ0s9EVzWg2t Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > From: Marco Elver >=20 > [ Upstream commit f95e5a3d59011eec1257d0e76de1e1f8969d426f ] >=20 > Internal data structures (cpu_bps, task_bps) of powerpc's hw_breakpoint > implementation have relied on nr_bp_mutex serializing access to them. >=20 > Before overhauling synchronization of kernel/events/hw_breakpoint.c, > introduce 2 spinlocks to synchronize cpu_bps and task_bps respectively, > thus avoiding reliance on callers synchronizing powerpc's > hw_breakpoint. This is preparation, not a bugfix, not sure why it was picked for 5.10. Best regards, Pavel --=20 DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany --mojUlQ0s9EVzWg2t Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABECAB0WIQRPfPO7r0eAhk010v0w5/Bqldv68gUCY05zTQAKCRAw5/Bqldv6 8hDCAJ93uULfn3AoJWhDD3Cg+mHOSVqtLwCeL4eiZsmL+Ra5uL3L03wLx5hvocg= =NwNt -----END PGP SIGNATURE----- --mojUlQ0s9EVzWg2t--