From patchwork Mon Jun 6 16:56:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Osipenko X-Patchwork-Id: 12870716 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 379F6CCA473 for ; Mon, 6 Jun 2022 17:10:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229759AbiFFRKo (ORCPT ); Mon, 6 Jun 2022 13:10:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41060 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229490AbiFFRJp (ORCPT ); Mon, 6 Jun 2022 13:09:45 -0400 Received: from madras.collabora.co.uk (madras.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e5ab]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1098EE01; Mon, 6 Jun 2022 09:57:40 -0700 (PDT) Received: from dimapc.. (109-252-138-163.dynamic.spd-mgts.ru [109.252.138.163]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: dmitry.osipenko) by madras.collabora.co.uk (Postfix) with ESMTPSA id 60BFF6601C72; Mon, 6 Jun 2022 17:57:38 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1654534658; bh=FIM8GIMepvfnT4TQY6iQ3wpMknXZhv7KK8TRc4lbx5s=; h=From:To:Cc:Subject:Date:From; b=YONWZn/EaULMwx0P2lLlZ6TNlQne7C9taGsOhCqpOvnf/WD5a+7HtSra1qVT8PzO5 ojtHkBlPKFJ7IswrQoiHmRsp4hGCVBCGLefXiJ5hX46H848bwPCdDFxkw0hC0II95d mFLlTR17jOKfrUYCPn0q905VuZ2WfEErlUGYqbDAGHPpMXexGYXEFjCR3rGDff7bW5 Mmko2QII3kn72nAvQLANVJimNKekHDYoDJUT7AJ+VKfHd/SOAvwHqAC53na/UYrxqg SuRCTnfA0MEreVTueWYbJZaA6NpF6flNj1j+5Tyd5gEfPQc9Kgit/hIBKsUcDJ3S8/ BALJPxR8zhZPw== From: Dmitry Osipenko To: "Rafael J . Wysocki" , Michael Ellerman Cc: Geert Uytterhoeven , linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH v1] kernel/reboot: Fix powering off using a non-syscall code paths Date: Mon, 6 Jun 2022 19:56:40 +0300 Message-Id: <20220606165640.634811-1-dmitry.osipenko@collabora.com> X-Mailer: git-send-email 2.35.3 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org There are other methods of powering off machine than the reboot syscall. Previously we missed to coved those methods and it created power-off regression for some machines, like the PowerPC e500. Fix this problem by moving the legacy sys-off handler registration to the latest phase of power-off process and making the kernel_can_power_off() to check the legacy pm_power_off presence. Tested-by: Michael Ellerman # ppce500 Reported-by: Michael Ellerman # ppce500 Fixes: da007f171fc9 ("kernel/reboot: Change registration order of legacy power-off handler") Signed-off-by: Dmitry Osipenko --- kernel/reboot.c | 46 ++++++++++++++++++++++++++-------------------- 1 file changed, 26 insertions(+), 20 deletions(-) diff --git a/kernel/reboot.c b/kernel/reboot.c index 3b19b123efec..b5a71d1ff603 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -320,6 +320,7 @@ static struct sys_off_handler platform_sys_off_handler; static struct sys_off_handler *alloc_sys_off_handler(int priority) { struct sys_off_handler *handler; + gfp_t flags; /* * Platforms like m68k can't allocate sys_off handler dynamically @@ -330,7 +331,12 @@ static struct sys_off_handler *alloc_sys_off_handler(int priority) if (handler->cb_data) return ERR_PTR(-EBUSY); } else { - handler = kzalloc(sizeof(*handler), GFP_KERNEL); + if (system_state > SYSTEM_RUNNING) + flags = GFP_ATOMIC; + else + flags = GFP_KERNEL; + + handler = kzalloc(sizeof(*handler), flags); if (!handler) return ERR_PTR(-ENOMEM); } @@ -440,7 +446,7 @@ void unregister_sys_off_handler(struct sys_off_handler *handler) { int err; - if (!handler) + if (IS_ERR_OR_NULL(handler)) return; if (handler->blocking) @@ -615,7 +621,23 @@ static void do_kernel_power_off_prepare(void) */ void do_kernel_power_off(void) { + struct sys_off_handler *sys_off = NULL; + + /* + * Register sys-off handlers for legacy PM callback. This allows + * legacy PM callbacks temporary co-exist with the new sys-off API. + * + * TODO: Remove legacy handlers once all legacy PM users will be + * switched to the sys-off based APIs. + */ + if (pm_power_off) + sys_off = register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, + SYS_OFF_PRIO_DEFAULT, + legacy_pm_power_off, NULL); + atomic_notifier_call_chain(&power_off_handler_list, 0, NULL); + + unregister_sys_off_handler(sys_off); } /** @@ -626,7 +648,8 @@ void do_kernel_power_off(void) */ bool kernel_can_power_off(void) { - return !atomic_notifier_call_chain_is_empty(&power_off_handler_list); + return !atomic_notifier_call_chain_is_empty(&power_off_handler_list) || + pm_power_off; } EXPORT_SYMBOL_GPL(kernel_can_power_off); @@ -661,7 +684,6 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, void __user *, arg) { struct pid_namespace *pid_ns = task_active_pid_ns(current); - struct sys_off_handler *sys_off = NULL; char buffer[256]; int ret = 0; @@ -686,21 +708,6 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, if (ret) return ret; - /* - * Register sys-off handlers for legacy PM callback. This allows - * legacy PM callbacks temporary co-exist with the new sys-off API. - * - * TODO: Remove legacy handlers once all legacy PM users will be - * switched to the sys-off based APIs. - */ - if (pm_power_off) { - sys_off = register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, - SYS_OFF_PRIO_DEFAULT, - legacy_pm_power_off, NULL); - if (IS_ERR(sys_off)) - return PTR_ERR(sys_off); - } - /* Instead of trying to make the power_off code look like * halt when pm_power_off is not set do it the easy way. */ @@ -758,7 +765,6 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, break; } mutex_unlock(&system_transition_mutex); - unregister_sys_off_handler(sys_off); return ret; }