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 X-Spam-Level: X-Spam-Status: No, score=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ED520C433E1 for ; Thu, 25 Mar 2021 09:31:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B006961A24 for ; Thu, 25 Mar 2021 09:31:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229619AbhCYJbK (ORCPT ); Thu, 25 Mar 2021 05:31:10 -0400 Received: from mx2.suse.de ([195.135.220.15]:57434 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229781AbhCYJai (ORCPT ); Thu, 25 Mar 2021 05:30:38 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 1A2C7AA55; Thu, 25 Mar 2021 09:30:37 +0000 (UTC) Date: Thu, 25 Mar 2021 10:30:36 +0100 (CET) From: Miroslav Benes To: Joe Lawrence cc: Dong Kai , jpoimboe@redhat.com, jikos@kernel.org, pmladek@suse.com, axboe@kernel.dk, live-patching@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] livepatch: klp_send_signal should treat PF_IO_WORKER like PF_KTHREAD In-Reply-To: Message-ID: References: <20210325014836.40649-1-dongkai11@huawei.com> User-Agent: Alpine 2.21 (LSU 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > (PF_KTHREAD | PF_IO_WORKER) is open coded in soo many places maybe this is a > silly question, but... > > If the livepatch code could use fake_signal_wake_up(), we could consolidate > the pattern in klp_send_signals() with the one in freeze_task(). Then there > would only one place for wake up / fake signal logic. > > I don't fully understand the differences in the freeze_task() version, so I > only pose this as a question and not v2 request. The plan was to remove our live patching fake signal completely and use the new infrastructure Jens proposed in the past. Something like diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c index f6310f848f34..3a4beb9395c4 100644 --- a/kernel/livepatch/transition.c +++ b/kernel/livepatch/transition.c @@ -9,6 +9,7 @@ #include #include +#include #include "core.h" #include "patch.h" #include "transition.h" @@ -369,9 +370,7 @@ static void klp_send_signals(void) * Send fake signal to all non-kthread tasks which are * still not migrated. */ - spin_lock_irq(&task->sighand->siglock); - signal_wake_up(task, 0); - spin_unlock_irq(&task->sighand->siglock); + set_notify_signal(task); } } read_unlock(&tasklist_lock); diff --git a/kernel/signal.c b/kernel/signal.c index a15c584a0455..b7cf4eda8611 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -181,8 +181,7 @@ void recalc_sigpending_and_wake(struct task_struct *t) void recalc_sigpending(void) { - if (!recalc_sigpending_tsk(current) && !freezing(current) && - !klp_patch_pending(current)) + if (!recalc_sigpending_tsk(current) && !freezing(current)) clear_thread_flag(TIF_SIGPENDING); } Let me verify it still works and there are all the needed pieces merged for all the architectures we support (x86_64, ppc64le and s390x). I'll send a proper patch then. Miroslav