From patchwork Fri Feb 24 16:49:59 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Josh Poimboeuf X-Patchwork-Id: 61402 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:5915:0:0:0:0:0 with SMTP id v21csp1025429wrd; Fri, 24 Feb 2023 09:02:52 -0800 (PST) X-Google-Smtp-Source: AK7set9utnMiDcGZrO+1RWFPaFGB4lQmzsu/S486tVnyPqRbXq7RuWYT0N/Jwzwg8WAgbUxA1Qkt X-Received: by 2002:aa7:d3c8:0:b0:4af:6e95:72b4 with SMTP id o8-20020aa7d3c8000000b004af6e9572b4mr5553531edr.15.1677258172567; Fri, 24 Feb 2023 09:02:52 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1677258172; cv=none; d=google.com; s=arc-20160816; b=y54APXKMPgp6lFKu9a5D5GuEVJKzoIcS2OPCcdArJ44fo9NhU/h8gso4jM95teKVbv c+uQtNEFe0xrscK3bLYr2I+ntg07aUBkNZCEVRQ2plvVoeRMhRCM9rgZ8KNE7nR3hgQh oXmUkF7kPg8rvgjNIP620wnpbN9ouL4T3tfKdEY6915w/qWSFgK5NUZNMulIb6vKvvRA kwd0NBohjt0J1FrYNQHLAMVR4UMHGVAAKHru0WJzWJmBD0pmSabe8fCehPLMgg3yKq2l M6Zn5CdCeVGWF8cSVkFfG3LRH2sfIaSoEFX92AKNcJ9pfp9dyQb8KBmY7I7UjlKFor68 sOEQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=4jU+SGCwX400pg3X4OgbqE9w71eYcYGFHVV8AI/hOxc=; b=Gq0Q2SZDSzw/QcOKievL+Om4TqxSWm5IenJBe9mBLG2KJeGPI30SwcgeCVMBsNl3Gx ho0P2NeRGrcz0wYyd/wNAMZJFeb1nc/XAP8jI47hMd2xMCWfSle+kh4ZgwteUqmc8a+n q5MU+CqWjL+naoqYgYvI+ZnYcvIYH3fdycD2bzTiXeOTQfpyVz9W/BwgSCfHY7ioAwXf g2v4n+lMl2kecCSMa5ymbt9Xake2Ec9J3dmgiZ1tRCVOi2zprgjowx4L7LFasDuZ1DlT nc2HxyQRlmXCLk9pWSBXu4YYaimwZYZG7zxXRUYKzLLoqDvhG4DB+2hB8M7LOXBLMxeT e2lg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=CjuG2KvI; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id s10-20020a056402164a00b004ad7ceba692si8257272edx.20.2023.02.24.09.02.28; Fri, 24 Feb 2023 09:02:52 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=CjuG2KvI; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230039AbjBXQuT (ORCPT + 99 others); Fri, 24 Feb 2023 11:50:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49962 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230023AbjBXQuQ (ORCPT ); Fri, 24 Feb 2023 11:50:16 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AA6B54617A; Fri, 24 Feb 2023 08:50:14 -0800 (PST) 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 415F16194B; Fri, 24 Feb 2023 16:50:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 30298C433EF; Fri, 24 Feb 2023 16:50:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1677257413; bh=nDYIubJTBPWH5ktJId6VhvPlAhhjbmackYfSKNUBnA8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CjuG2KvIvxcQ+B/eSRKm+PTo7G6vaKPGQgIU4hFyQs5wXnomIMM8b84GLT0O4Dnxe QWNkVDuQ1LSFLD75KKIO2nbosAgOXkj7ZRn7zUfbJs9Us+nqb3WkGIsp0fwlnwVmb4 dziFmuO5RmZlg2XCPkckA6GTPkq/+V6lRfEVFGwnWxWXY2EGWu/RqRsfd2LVcnEUwJ OvR8GULbhHEn7F9zn7ez5vg60FBy9A+cPDiw+ei2E+b1+FZcxvG/b/nQydeoRE3TWG chzdnusNMa6FPIev2fEZjRfPq+laArTHe4isK2ASKzh1Je7tudeigh2zidFin6awuM 2Y9+HwyejfjbQ== From: Josh Poimboeuf To: live-patching@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Seth Forshee , Peter Zijlstra , Song Liu , Mark Rutland , Petr Mladek , Joe Lawrence , Miroslav Benes , Jiri Kosina , Ingo Molnar , Rik van Riel Subject: [PATCH v3 1/3] livepatch: Skip task_call_func() for current task Date: Fri, 24 Feb 2023 08:49:59 -0800 Message-Id: <4b92e793462d532a05f03767151fa29db3e68e13.1677257135.git.jpoimboe@kernel.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: References: MIME-Version: 1.0 Content-type: text/plain X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1758732665726688184?= X-GMAIL-MSGID: =?utf-8?q?1758732665726688184?= The current task doesn't need the scheduler's protection to unwind its own stack. Tested-by: Seth Forshee (DigitalOcean) Reviewed-by: Petr Mladek Signed-off-by: Josh Poimboeuf --- kernel/livepatch/transition.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c index f1b25ec581e0..4d1f443778f7 100644 --- a/kernel/livepatch/transition.c +++ b/kernel/livepatch/transition.c @@ -307,7 +307,11 @@ static bool klp_try_switch_task(struct task_struct *task) * functions. If all goes well, switch the task to the target patch * state. */ - ret = task_call_func(task, klp_check_and_switch_task, &old_name); + if (task == current) + ret = klp_check_and_switch_task(current, &old_name); + else + ret = task_call_func(task, klp_check_and_switch_task, &old_name); + switch (ret) { case 0: /* success */ break;