From patchwork Thu Dec 19 07:31:22 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ahmad Fatoum X-Patchwork-Id: 13914598 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 95646217703 for ; Thu, 19 Dec 2024 07:31:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734593521; cv=none; b=dRcLcMFeSyLJJzwf5mCde4kT1VHt2quHgKygXsU546lfp6PEvb2Xuj0AGDn2b9clytkioGf5JyngzwHt8WjBg31Y/poeHFyUxptJruWAfg84UmZXPoT4LkBoXWLfiyGjh7Yl0YSnx3ffBK2Yz99NBn3T2I1SGjw/VLh5CBbvZgo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734593521; c=relaxed/simple; bh=w1Y0I3/qSUoo/iH5tfBjW87bvXpJZD1VvJ1gBWyIYr8=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=koKtiRh2FUEjTJA73OtE1QK6fGjIGPP0Ps9nv0W4EnoxrQ0bLpBs8uAwo9xISR6xvTS9BRTcEda4jcnSOTDlx4TuEQnRaBwA9V6LcDWa0Uy6eHK6rtc0oxUM+FUtCPWQzym5UhdrNO/zzfrttK2HpRJM7iHRbTXroICGVWLxkk4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1tOB0O-00088S-1W; Thu, 19 Dec 2024 08:31:32 +0100 Received: from dude05.red.stw.pengutronix.de ([2a0a:edc0:0:1101:1d::54]) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1tOB0L-004APn-1n; Thu, 19 Dec 2024 08:31:30 +0100 Received: from localhost ([::1] helo=dude05.red.stw.pengutronix.de) by dude05.red.stw.pengutronix.de with esmtp (Exim 4.96) (envelope-from ) id 1tOB0M-00GkbH-0k; Thu, 19 Dec 2024 08:31:30 +0100 From: Ahmad Fatoum Date: Thu, 19 Dec 2024 08:31:22 +0100 Subject: [PATCH 01/11] reboot: replace __hw_protection_shutdown bool action parameter with an enum Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20241219-hw_protection-reboot-v1-1-263a0c1df802@pengutronix.de> References: <20241219-hw_protection-reboot-v1-0-263a0c1df802@pengutronix.de> In-Reply-To: <20241219-hw_protection-reboot-v1-0-263a0c1df802@pengutronix.de> To: Daniel Lezcano , Fabio Estevam , "Rafael J. Wysocki" , Zhang Rui , Lukasz Luba , Jonathan Corbet , Serge Hallyn , Liam Girdwood , Mark Brown , Matti Vaittinen , Benson Leung , Tzung-Bi Shih , Guenter Roeck , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-doc@vger.kernel.org, linux-security-module@vger.kernel.org, chrome-platform@lists.linux.dev, devicetree@vger.kernel.org, kernel@pengutronix.de, Ahmad Fatoum X-Mailer: b4 0.14.2 X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: a.fatoum@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-security-module@vger.kernel.org Currently __hw_protection_shutdown() either reboots or shuts down the system according to its shutdown argument. To make the logic easier to follow, both inside __hw_protection_shutdown and at caller sites, lets replace the bool parameter with an enum. This will be extra useful, when in a later commit, a third action is added to the enumeration. No functional change. Signed-off-by: Ahmad Fatoum --- include/linux/reboot.h | 10 +++++++--- kernel/reboot.c | 9 +++++---- 2 files changed, 12 insertions(+), 7 deletions(-) diff --git a/include/linux/reboot.h b/include/linux/reboot.h index abcdde4df697969a8027bcb052efc00daabbbf6a..d6780fbf51535e1f98b576da0a06701402dfd447 100644 --- a/include/linux/reboot.h +++ b/include/linux/reboot.h @@ -177,16 +177,20 @@ void ctrl_alt_del(void); extern void orderly_poweroff(bool force); extern void orderly_reboot(void); -void __hw_protection_shutdown(const char *reason, int ms_until_forced, bool shutdown); + +enum hw_protection_action { HWPROT_ACT_SHUTDOWN, HWPROT_ACT_REBOOT }; + +void __hw_protection_shutdown(const char *reason, int ms_until_forced, + enum hw_protection_action action); static inline void hw_protection_reboot(const char *reason, int ms_until_forced) { - __hw_protection_shutdown(reason, ms_until_forced, false); + __hw_protection_shutdown(reason, ms_until_forced, HWPROT_ACT_REBOOT); } static inline void hw_protection_shutdown(const char *reason, int ms_until_forced) { - __hw_protection_shutdown(reason, ms_until_forced, true); + __hw_protection_shutdown(reason, ms_until_forced, HWPROT_ACT_SHUTDOWN); } /* diff --git a/kernel/reboot.c b/kernel/reboot.c index a701000bab3470df28665e8c9591cd82a033c6c2..f92aa66cbfec0f57ded43ba352a39c54d0c24a25 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -994,7 +994,8 @@ static void hw_failure_emergency_poweroff(int poweroff_delay_ms) * pending even if the previous request has given a large timeout for forced * shutdown/reboot. */ -void __hw_protection_shutdown(const char *reason, int ms_until_forced, bool shutdown) +void __hw_protection_shutdown(const char *reason, int ms_until_forced, + enum hw_protection_action action) { static atomic_t allow_proceed = ATOMIC_INIT(1); @@ -1009,10 +1010,10 @@ void __hw_protection_shutdown(const char *reason, int ms_until_forced, bool shut * orderly_poweroff failure */ hw_failure_emergency_poweroff(ms_until_forced); - if (shutdown) - orderly_poweroff(true); - else + if (action == HWPROT_ACT_REBOOT) orderly_reboot(); + else + orderly_poweroff(true); } EXPORT_SYMBOL_GPL(__hw_protection_shutdown); From patchwork Thu Dec 19 07:31:23 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ahmad Fatoum X-Patchwork-Id: 13914603 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7EDE314A630 for ; Thu, 19 Dec 2024 07:32:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734593545; cv=none; b=p+OJcfVmMiT0+axMZTBG7O+GiO/Ixb5r/Sxek3Rpu2zpzHDTYgAhmpgVVweGQbz6xyeJQlWqsH0W5PTR6ssUTig87uXL1gs8y3pJmtYr0xX6J7HaaJ90s5kJ54uACrmSDw6FW6Npj96PfYurscsrrrLwwU3eJkAbr7ex+wVD8Oc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734593545; 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Thu, 19 Dec 2024 08:31:30 +0100 Received: from localhost ([::1] helo=dude05.red.stw.pengutronix.de) by dude05.red.stw.pengutronix.de with esmtp (Exim 4.96) (envelope-from ) id 1tOB0M-00GkbH-0l; Thu, 19 Dec 2024 08:31:30 +0100 From: Ahmad Fatoum Date: Thu, 19 Dec 2024 08:31:23 +0100 Subject: [PATCH 02/11] reboot: reboot, not shutdown, on hw_protection_reboot timeout Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20241219-hw_protection-reboot-v1-2-263a0c1df802@pengutronix.de> References: <20241219-hw_protection-reboot-v1-0-263a0c1df802@pengutronix.de> In-Reply-To: <20241219-hw_protection-reboot-v1-0-263a0c1df802@pengutronix.de> To: Daniel Lezcano , Fabio Estevam , "Rafael J. Wysocki" , Zhang Rui , Lukasz Luba , Jonathan Corbet , Serge Hallyn , Liam Girdwood , Mark Brown , Matti Vaittinen , Benson Leung , Tzung-Bi Shih , Guenter Roeck , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-doc@vger.kernel.org, linux-security-module@vger.kernel.org, chrome-platform@lists.linux.dev, devicetree@vger.kernel.org, kernel@pengutronix.de, Ahmad Fatoum X-Mailer: b4 0.14.2 X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: a.fatoum@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-security-module@vger.kernel.org hw_protection_shutdown() will kick off an orderly shutdown and if that takes longer than a configurable amount of time, an emergency shutdown will occur. Recently, hw_protection_reboot() was added for those systems that don't implement a proper shutdown and are better served by rebooting and having the boot firmware worry about doing something about the critical condition. On timeout of the orderly reboot of hw_protection_reboot(), the system would go into shutdown, instead of reboot. This is not a good idea, as going into shutdown was explicitly not asked for. Fix this by always doing an emergency reboot if hw_protection_reboot() is called and the orderly reboot takes too long. Fixes: 79fa723ba84c ("reboot: Introduce thermal_zone_device_critical_reboot()") Signed-off-by: Ahmad Fatoum --- kernel/reboot.c | 46 +++++++++++++++++++++++++++++++++++----------- 1 file changed, 35 insertions(+), 11 deletions(-) diff --git a/kernel/reboot.c b/kernel/reboot.c index f92aa66cbfec0f57ded43ba352a39c54d0c24a25..8e3680d36654587b57db44806a3d7b0228b10f67 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -932,6 +932,20 @@ void orderly_reboot(void) } EXPORT_SYMBOL_GPL(orderly_reboot); +static const char *hw_protection_action_str(enum hw_protection_action action) +{ + switch (action) { + case HWPROT_ACT_SHUTDOWN: + return "shutdown"; + case HWPROT_ACT_REBOOT: + return "reboot"; + default: + return "undefined"; + } +} + +static enum hw_protection_action hw_failure_emergency_action; + /** * hw_failure_emergency_poweroff_func - emergency poweroff work after a known delay * @work: work_struct associated with the emergency poweroff function @@ -941,21 +955,29 @@ EXPORT_SYMBOL_GPL(orderly_reboot); */ static void hw_failure_emergency_poweroff_func(struct work_struct *work) { + const char *action_str = hw_protection_action_str(hw_failure_emergency_action); + + pr_emerg("Hardware protection timed-out. Trying forced %s\n", + action_str); + /* - * We have reached here after the emergency shutdown waiting period has - * expired. This means orderly_poweroff has not been able to shut off - * the system for some reason. + * We have reached here after the emergency action waiting period has + * expired. This means orderly_poweroff/reboot has not been able to + * shut off the system for some reason. * - * Try to shut down the system immediately using kernel_power_off - * if populated + * Try to shut off the system immediately if possible */ - pr_emerg("Hardware protection timed-out. Trying forced poweroff\n"); - kernel_power_off(); + + if (hw_failure_emergency_action == HWPROT_ACT_REBOOT) + kernel_restart(NULL); + else + kernel_power_off(); /* * Worst of the worst case trigger emergency restart */ - pr_emerg("Hardware protection shutdown failed. Trying emergency restart\n"); + pr_emerg("Hardware protection %s failed. Trying emergency restart\n", + action_str); emergency_restart(); } @@ -963,15 +985,17 @@ static DECLARE_DELAYED_WORK(hw_failure_emergency_poweroff_work, hw_failure_emergency_poweroff_func); /** - * hw_failure_emergency_poweroff - Trigger an emergency system poweroff + * hw_failure_emergency_schedule - Schedule an emergency system shutdown or reboot * * This may be called from any critical situation to trigger a system shutdown * after a given period of time. If time is negative this is not scheduled. */ -static void hw_failure_emergency_poweroff(int poweroff_delay_ms) +static void hw_failure_emergency_schedule(enum hw_protection_action action, + int poweroff_delay_ms) { if (poweroff_delay_ms <= 0) return; + hw_failure_emergency_action = action; schedule_delayed_work(&hw_failure_emergency_poweroff_work, msecs_to_jiffies(poweroff_delay_ms)); } @@ -1009,7 +1033,7 @@ void __hw_protection_shutdown(const char *reason, int ms_until_forced, * Queue a backup emergency shutdown in the event of * orderly_poweroff failure */ - hw_failure_emergency_poweroff(ms_until_forced); + hw_failure_emergency_schedule(action, ms_until_forced); if (action == HWPROT_ACT_REBOOT) orderly_reboot(); else From patchwork Thu Dec 19 07:31:24 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ahmad Fatoum X-Patchwork-Id: 13914600 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0FF33216E34 for ; Thu, 19 Dec 2024 07:32:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734593529; cv=none; b=ftkB0eUWeFYjmdZ+yVsJkZw55yl8hxjeC9zY5KT9hLnK3mvVJ6il1i3VmrPHKoKf0eDCAFlA+8N4MqC3cGev5aSfQE8baRqF+pbVILJLsAS0SZXk/r+ZqcxxamiLmFlWKHji1QMdNCzo7BE1oG2/ub2DVHbHa0DkkAp5BI6zjkk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734593529; c=relaxed/simple; bh=PGN16QmMe1LWFrGJXR91wUJh6Nw6XmzM1zRMS3Litmo=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=eLeg1gVv/WgwRUmp+NklnVfkDkeAQue0UhsoZpGDRERqQpM2yGheBFb2FXUdoyGtBXzLaoMsnFqkoKRKQSglHgKpB82UqHZ/F2z9gyna3V12PWG8MC6Y5x2XoiOuCw7b+kTOJShSULD9dqUw9RQDhA96j0IuR5PghMszEmVRkRk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1tOB0O-00088V-1h; Thu, 19 Dec 2024 08:31:32 +0100 Received: from dude05.red.stw.pengutronix.de ([2a0a:edc0:0:1101:1d::54]) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1tOB0L-004APq-22; Thu, 19 Dec 2024 08:31:30 +0100 Received: from localhost ([::1] helo=dude05.red.stw.pengutronix.de) by dude05.red.stw.pengutronix.de with esmtp (Exim 4.96) (envelope-from ) id 1tOB0M-00GkbH-0m; Thu, 19 Dec 2024 08:31:30 +0100 From: Ahmad Fatoum Date: Thu, 19 Dec 2024 08:31:24 +0100 Subject: [PATCH 03/11] docs: thermal: sync hardware protection doc with code Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20241219-hw_protection-reboot-v1-3-263a0c1df802@pengutronix.de> References: <20241219-hw_protection-reboot-v1-0-263a0c1df802@pengutronix.de> In-Reply-To: <20241219-hw_protection-reboot-v1-0-263a0c1df802@pengutronix.de> To: Daniel Lezcano , Fabio Estevam , "Rafael J. Wysocki" , Zhang Rui , Lukasz Luba , Jonathan Corbet , Serge Hallyn , Liam Girdwood , Mark Brown , Matti Vaittinen , Benson Leung , Tzung-Bi Shih , Guenter Roeck , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-doc@vger.kernel.org, linux-security-module@vger.kernel.org, chrome-platform@lists.linux.dev, devicetree@vger.kernel.org, kernel@pengutronix.de, Ahmad Fatoum X-Mailer: b4 0.14.2 X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: a.fatoum@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-security-module@vger.kernel.org Originally, the thermal framework's only hardware protection action was to trigger a shutdown. This has been changed a little over a year ago to also support rebooting as alternative hardware protection action. Update the documentation to reflect this. Fixes: 62e79e38b257 ("thermal/thermal_of: Allow rebooting after critical temp") Signed-off-by: Ahmad Fatoum --- Documentation/driver-api/thermal/sysfs-api.rst | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-) diff --git a/Documentation/driver-api/thermal/sysfs-api.rst b/Documentation/driver-api/thermal/sysfs-api.rst index c803b89b7248f9f26ac24608b0144db5e9c2ddb4..6b481364457b8ec56302e80bb443291c2b4a94d5 100644 --- a/Documentation/driver-api/thermal/sysfs-api.rst +++ b/Documentation/driver-api/thermal/sysfs-api.rst @@ -413,18 +413,21 @@ This function serves as an arbitrator to set the state of a cooling device. It sets the cooling device to the deepest cooling state if possible. -5. thermal_emergency_poweroff -============================= +5. Critical Events +================== -On an event of critical trip temperature crossing the thermal framework -shuts down the system by calling hw_protection_shutdown(). The -hw_protection_shutdown() first attempts to perform an orderly shutdown -but accepts a delay after which it proceeds doing a forced power-off -or as last resort an emergency_restart. +On an event of critical trip temperature crossing, the thermal framework +will trigger a hardware protection power-off (shutdown) or reboot, +depending on configuration. + +At first, the kernel will attempt an orderly power-off or reboot, but +accepts a delay after which it proceeds to do a forced power-off or +reboot, respectively. If this fails, ``emergency restart()`` is invoked +as last resort. The delay should be carefully profiled so as to give adequate time for -orderly poweroff. +orderly power-off or reboot. -If the delay is set to 0 emergency poweroff will not be supported. So a -carefully profiled non-zero positive value is a must for emergency -poweroff to be triggered. +If the delay is set to 0, the emergency action will not be supported. So a +carefully profiled non-zero positive value is a must for the emergency +action to be triggered. From patchwork Thu Dec 19 07:31:25 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ahmad Fatoum X-Patchwork-Id: 13914605 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 09715218AC0 for ; Thu, 19 Dec 2024 07:32:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734593551; cv=none; b=qp28PgznvzwZ5gMJPVOb/HcAEovtbJnmfNKhgvEsbEtkAxw7cgIKZ0/h9a/lxzDRXwA5ufB31DwHUJct8CIrORqkOU0frkcPLql+58HRXgTHrLf72sCy9KVe2owbG1AKAE5i8h+mL+AR2jkqCX3Al7p6mNynzRO+rGVa1quhzIE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734593551; c=relaxed/simple; bh=nnySu/T6vxGoHdqmXCcTqun4NtEMjOGvzUrN/x/++lM=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=TuwGwrTrL/l+S5gG5ORmynZGLzl7DQIVlbtOH8g09AgnotYwF+C4Cdcf1Kj1QpWypRXZz/iLNJi6csCorJrJp6NjDvaehxReVf3AnMpCUYq3Zll14c8hQYcHMIJVxzW0RuUMosjpa6Lq2wdfrQhonO2inMOL1+E+W6BKaulEccY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1tOB0O-00088W-1f; Thu, 19 Dec 2024 08:31:32 +0100 Received: from dude05.red.stw.pengutronix.de ([2a0a:edc0:0:1101:1d::54]) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1tOB0L-004APr-25; Thu, 19 Dec 2024 08:31:30 +0100 Received: from localhost ([::1] helo=dude05.red.stw.pengutronix.de) by dude05.red.stw.pengutronix.de with esmtp (Exim 4.96) (envelope-from ) id 1tOB0M-00GkbH-0n; Thu, 19 Dec 2024 08:31:30 +0100 From: Ahmad Fatoum Date: Thu, 19 Dec 2024 08:31:25 +0100 Subject: [PATCH 04/11] reboot: rename now misleading hw_protection symbols Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20241219-hw_protection-reboot-v1-4-263a0c1df802@pengutronix.de> References: <20241219-hw_protection-reboot-v1-0-263a0c1df802@pengutronix.de> In-Reply-To: <20241219-hw_protection-reboot-v1-0-263a0c1df802@pengutronix.de> To: Daniel Lezcano , Fabio Estevam , "Rafael J. Wysocki" , Zhang Rui , Lukasz Luba , Jonathan Corbet , Serge Hallyn , Liam Girdwood , Mark Brown , Matti Vaittinen , Benson Leung , Tzung-Bi Shih , Guenter Roeck , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-doc@vger.kernel.org, linux-security-module@vger.kernel.org, chrome-platform@lists.linux.dev, devicetree@vger.kernel.org, kernel@pengutronix.de, Ahmad Fatoum X-Mailer: b4 0.14.2 X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: a.fatoum@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-security-module@vger.kernel.org The __hw_protection_shutdown, hw_failure_emergency_poweroff_work and hw_failure_emergency_poweroff_func symbol names have become misleading, because they can either cause a shutdown (poweroff) or a reboot depending on an argument or a global variable. To avoid further confusion, let's rename them, so they don't suggest that a poweroff is all they can do. Signed-off-by: Ahmad Fatoum --- include/linux/reboot.h | 8 ++++---- kernel/reboot.c | 22 +++++++++++----------- 2 files changed, 15 insertions(+), 15 deletions(-) diff --git a/include/linux/reboot.h b/include/linux/reboot.h index d6780fbf51535e1f98b576da0a06701402dfd447..b1e2c86d29a281abbcfe69bc00321df185c32c91 100644 --- a/include/linux/reboot.h +++ b/include/linux/reboot.h @@ -180,17 +180,17 @@ extern void orderly_reboot(void); enum hw_protection_action { HWPROT_ACT_SHUTDOWN, HWPROT_ACT_REBOOT }; -void __hw_protection_shutdown(const char *reason, int ms_until_forced, - enum hw_protection_action action); +void __hw_protection_trigger(const char *reason, int ms_until_forced, + enum hw_protection_action action); static inline void hw_protection_reboot(const char *reason, int ms_until_forced) { - __hw_protection_shutdown(reason, ms_until_forced, HWPROT_ACT_REBOOT); + __hw_protection_trigger(reason, ms_until_forced, HWPROT_ACT_REBOOT); } static inline void hw_protection_shutdown(const char *reason, int ms_until_forced) { - __hw_protection_shutdown(reason, ms_until_forced, HWPROT_ACT_SHUTDOWN); + __hw_protection_trigger(reason, ms_until_forced, HWPROT_ACT_SHUTDOWN); } /* diff --git a/kernel/reboot.c b/kernel/reboot.c index 8e3680d36654587b57db44806a3d7b0228b10f67..da6c8bdeeefe627a76c7ec6e8926138ebbe3ae4e 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -947,13 +947,13 @@ static const char *hw_protection_action_str(enum hw_protection_action action) static enum hw_protection_action hw_failure_emergency_action; /** - * hw_failure_emergency_poweroff_func - emergency poweroff work after a known delay - * @work: work_struct associated with the emergency poweroff function + * hw_failure_emergency_action_func - emergency action after a known delay + * @work: work_struct associated with the emergency action function * * This function is called in very critical situations to force - * a kernel poweroff after a configurable timeout value. + * a kernel poweroff or reboot after a configurable timeout value. */ -static void hw_failure_emergency_poweroff_func(struct work_struct *work) +static void hw_failure_emergency_action_func(struct work_struct *work) { const char *action_str = hw_protection_action_str(hw_failure_emergency_action); @@ -981,8 +981,8 @@ static void hw_failure_emergency_poweroff_func(struct work_struct *work) emergency_restart(); } -static DECLARE_DELAYED_WORK(hw_failure_emergency_poweroff_work, - hw_failure_emergency_poweroff_func); +static DECLARE_DELAYED_WORK(hw_failure_emergency_action_work, + hw_failure_emergency_action_func); /** * hw_failure_emergency_schedule - Schedule an emergency system shutdown or reboot @@ -996,12 +996,12 @@ static void hw_failure_emergency_schedule(enum hw_protection_action action, if (poweroff_delay_ms <= 0) return; hw_failure_emergency_action = action; - schedule_delayed_work(&hw_failure_emergency_poweroff_work, + schedule_delayed_work(&hw_failure_emergency_action_work, msecs_to_jiffies(poweroff_delay_ms)); } /** - * __hw_protection_shutdown - Trigger an emergency system shutdown or reboot + * __hw_protection_trigger - Trigger an emergency system shutdown or reboot * * @reason: Reason of emergency shutdown or reboot to be printed. * @ms_until_forced: Time to wait for orderly shutdown or reboot before @@ -1018,8 +1018,8 @@ static void hw_failure_emergency_schedule(enum hw_protection_action action, * pending even if the previous request has given a large timeout for forced * shutdown/reboot. */ -void __hw_protection_shutdown(const char *reason, int ms_until_forced, - enum hw_protection_action action) +void __hw_protection_trigger(const char *reason, int ms_until_forced, + enum hw_protection_action action) { static atomic_t allow_proceed = ATOMIC_INIT(1); @@ -1039,7 +1039,7 @@ void __hw_protection_shutdown(const char *reason, int ms_until_forced, else orderly_poweroff(true); } -EXPORT_SYMBOL_GPL(__hw_protection_shutdown); +EXPORT_SYMBOL_GPL(__hw_protection_trigger); static int __init reboot_setup(char *str) { From patchwork Thu Dec 19 07:31:26 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ahmad Fatoum X-Patchwork-Id: 13914596 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D0B79216E37 for ; Thu, 19 Dec 2024 07:31:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734593516; cv=none; b=favCrFQDJ0ta0SnJEk/Wc4UAJz0Qo6LiLEmL+O2k3VspyZzGYPR1juFQEU46NdvC2kCNlRF3Tnmao70z3FONZXm6c3vopPTV2npM7T4NY4ZbWs0ZCfok2BEijHcCy836yXhEchMQP5f6K6kmb+uiIrgvwFEwSb8yuGMNEF0CTDA= ARC-Message-Signature: i=1; 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Thu, 19 Dec 2024 08:31:32 +0100 Received: from dude05.red.stw.pengutronix.de ([2a0a:edc0:0:1101:1d::54]) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1tOB0L-004APs-23; Thu, 19 Dec 2024 08:31:30 +0100 Received: from localhost ([::1] helo=dude05.red.stw.pengutronix.de) by dude05.red.stw.pengutronix.de with esmtp (Exim 4.96) (envelope-from ) id 1tOB0M-00GkbH-0o; Thu, 19 Dec 2024 08:31:30 +0100 From: Ahmad Fatoum Date: Thu, 19 Dec 2024 08:31:26 +0100 Subject: [PATCH 05/11] reboot: indicate whether it is a HARDWARE PROTECTION reboot or shutdown Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20241219-hw_protection-reboot-v1-5-263a0c1df802@pengutronix.de> References: <20241219-hw_protection-reboot-v1-0-263a0c1df802@pengutronix.de> In-Reply-To: <20241219-hw_protection-reboot-v1-0-263a0c1df802@pengutronix.de> To: Daniel Lezcano , Fabio Estevam , "Rafael J. Wysocki" , Zhang Rui , Lukasz Luba , Jonathan Corbet , Serge Hallyn , Liam Girdwood , Mark Brown , Matti Vaittinen , Benson Leung , Tzung-Bi Shih , Guenter Roeck , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-doc@vger.kernel.org, linux-security-module@vger.kernel.org, chrome-platform@lists.linux.dev, devicetree@vger.kernel.org, kernel@pengutronix.de, Ahmad Fatoum X-Mailer: b4 0.14.2 X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: a.fatoum@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-security-module@vger.kernel.org It currently depends on the caller, whether we attempt a hardware protection shutdown (poweroff) or a reboot. A follow-up commit will make this partially user-configurable, so it's a good idea to have the emergency message clearly state whether the kernel is going for a reboot or a shutdown. Signed-off-by: Ahmad Fatoum --- kernel/reboot.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/reboot.c b/kernel/reboot.c index da6c8bdeeefe627a76c7ec6e8926138ebbe3ae4e..aa6317939af41c9730ec5a74b7faf03f7c0f25a7 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -1023,7 +1023,8 @@ void __hw_protection_trigger(const char *reason, int ms_until_forced, { static atomic_t allow_proceed = ATOMIC_INIT(1); - pr_emerg("HARDWARE PROTECTION shutdown (%s)\n", reason); + pr_emerg("HARDWARE PROTECTION %s (%s)\n", + hw_protection_action_str(action), reason); /* Shutdown should be initiated only once. */ if (!atomic_dec_and_test(&allow_proceed)) From patchwork Thu Dec 19 07:31:27 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ahmad Fatoum X-Patchwork-Id: 13914601 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 07EE9218840 for ; Thu, 19 Dec 2024 07:32:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734593540; cv=none; b=q1FmPIN0iXnN8Eono6bkfs5CKD9eYcXKeG2j8gJq43n9LvSimCiIOibNgKIMwxoAsDKmCtpXpJDkwMSdFQnKw+rRqjkJrmzQ0Lev5IUqDsP0FRY9QXJI3M/+fkYGqDiv6hcl+AEcJ9qROevu0WCuXV148hkxqmgRAkO5uucPz5g= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734593540; c=relaxed/simple; bh=HHo8+7k6wjJQsKsAJamXMeH66rzfbDBe1zv14LpyGCs=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=GSKROfyF0OuOeetgpk3B1HsB0OqDkAugg9T8GAEoczA7VF5uaSe81qjUMqs00sCAYJdht1lnH5auaVBox6V2mLOVyWjpUBg7DN8YvMzGJR2wjO5Iv2UmBm8Az2dKHXnm4IWMmwVeg2OLgpKIPbmL8HtlY4Hm2RauQ8evFdkGoAY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1tOB0O-00088b-1Y; Thu, 19 Dec 2024 08:31:32 +0100 Received: from dude05.red.stw.pengutronix.de ([2a0a:edc0:0:1101:1d::54]) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1tOB0L-004APt-2B; Thu, 19 Dec 2024 08:31:30 +0100 Received: from localhost ([::1] helo=dude05.red.stw.pengutronix.de) by dude05.red.stw.pengutronix.de with esmtp (Exim 4.96) (envelope-from ) id 1tOB0M-00GkbH-0p; Thu, 19 Dec 2024 08:31:30 +0100 From: Ahmad Fatoum Date: Thu, 19 Dec 2024 08:31:27 +0100 Subject: [PATCH 06/11] reboot: add support for configuring emergency hardware protection action Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20241219-hw_protection-reboot-v1-6-263a0c1df802@pengutronix.de> References: <20241219-hw_protection-reboot-v1-0-263a0c1df802@pengutronix.de> In-Reply-To: <20241219-hw_protection-reboot-v1-0-263a0c1df802@pengutronix.de> To: Daniel Lezcano , Fabio Estevam , "Rafael J. Wysocki" , Zhang Rui , Lukasz Luba , Jonathan Corbet , Serge Hallyn , Liam Girdwood , Mark Brown , Matti Vaittinen , Benson Leung , Tzung-Bi Shih , Guenter Roeck , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-doc@vger.kernel.org, linux-security-module@vger.kernel.org, chrome-platform@lists.linux.dev, devicetree@vger.kernel.org, kernel@pengutronix.de, Ahmad Fatoum , Matteo Croce X-Mailer: b4 0.14.2 X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: a.fatoum@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-security-module@vger.kernel.org We currently leave the decision of whether to shutdown or reboot to protect hardware in an emergency situation to the individual drivers. This works out in some cases, where the driver detecting the critical failure has inside knowledge: It binds to the system management controller for example or is guided by hardware description that defines what to do. In the general case, however, the driver detecting the issue can't know what the appropriate course of action is and shouldn't be dictating the policy of dealing with it. Therefore, add a global hw_protection toggle that allows the user to specify whether shutdown or reboot should be the default action when the driver doesn't set policy. This introduces no functional change yet as hw_protection_trigger() has no callers, but these will be added in subsequent commits. Signed-off-by: Ahmad Fatoum --- Documentation/ABI/testing/sysfs-kernel-reboot | 8 +++++ Documentation/admin-guide/kernel-parameters.txt | 6 ++++ include/linux/reboot.h | 19 +++++++++- include/uapi/linux/capability.h | 1 + kernel/reboot.c | 46 +++++++++++++++++++++++++ 5 files changed, 79 insertions(+), 1 deletion(-) diff --git a/Documentation/ABI/testing/sysfs-kernel-reboot b/Documentation/ABI/testing/sysfs-kernel-reboot index 837330fb251134ffdf29cd68f0b2a845b088e5a0..133f54707d533665c68a5946394540ec50b149e5 100644 --- a/Documentation/ABI/testing/sysfs-kernel-reboot +++ b/Documentation/ABI/testing/sysfs-kernel-reboot @@ -30,3 +30,11 @@ KernelVersion: 5.11 Contact: Matteo Croce Description: Don't wait for any other CPUs on reboot and avoid anything that could hang. + +What: /sys/kernel/reboot/hw_protection +Date: Feb 2025 +KernelVersion: 6.14 +Contact: Ahmad Fatoum +Description: Hardware protection action taken on critical events like + overtemperature or imminent voltage loss. + Valid values are: reboot shutdown diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 3872bc6ec49d63772755504966ae70113f24a1db..ff244e6a0e04d2c172825818defd5d94448f8518 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1921,6 +1921,12 @@ which allow the hypervisor to 'idle' the guest on lock contention. + hw_protection= [HW] + Format: reboot | shutdown + + Hardware protection action taken on critical events like + overtemperature or imminent voltage loss. + i2c_bus= [HW] Override the default board specific I2C bus speed or register an additional I2C bus that is not registered from board initialization code. diff --git a/include/linux/reboot.h b/include/linux/reboot.h index b1e2c86d29a281abbcfe69bc00321df185c32c91..281696f509932e444eadd453fb0233aa7a07fbce 100644 --- a/include/linux/reboot.h +++ b/include/linux/reboot.h @@ -178,11 +178,28 @@ void ctrl_alt_del(void); extern void orderly_poweroff(bool force); extern void orderly_reboot(void); -enum hw_protection_action { HWPROT_ACT_SHUTDOWN, HWPROT_ACT_REBOOT }; +enum hw_protection_action { HWPROT_ACT_DEFAULT, HWPROT_ACT_SHUTDOWN, HWPROT_ACT_REBOOT }; void __hw_protection_trigger(const char *reason, int ms_until_forced, enum hw_protection_action action); +/** + * hw_protection_trigger - Trigger default emergency system hardware protection action + * + * @reason: Reason of emergency shutdown or reboot to be printed. + * @ms_until_forced: Time to wait for orderly shutdown or reboot before + * triggering it. Negative value disables the forced + * shutdown or reboot. + * + * Initiate an emergency system shutdown or reboot in order to protect + * hardware from further damage. The exact action taken is controllable at + * runtime and defaults to shutdown. + */ +static inline void hw_protection_trigger(const char *reason, int ms_until_forced) +{ + __hw_protection_trigger(reason, ms_until_forced, HWPROT_ACT_DEFAULT); +} + static inline void hw_protection_reboot(const char *reason, int ms_until_forced) { __hw_protection_trigger(reason, ms_until_forced, HWPROT_ACT_REBOOT); diff --git a/include/uapi/linux/capability.h b/include/uapi/linux/capability.h index 5bb9060986974726025eaabee24a0b720ff94657..2e21b5594f81313e8e17aeeb98a09f098355515f 100644 --- a/include/uapi/linux/capability.h +++ b/include/uapi/linux/capability.h @@ -275,6 +275,7 @@ struct vfs_ns_cap_data { /* Allow setting encryption key on loopback filesystem */ /* Allow setting zone reclaim policy */ /* Allow everything under CAP_BPF and CAP_PERFMON for backward compatibility */ +/* Allow setting hardware protection emergency action */ #define CAP_SYS_ADMIN 21 diff --git a/kernel/reboot.c b/kernel/reboot.c index aa6317939af41c9730ec5a74b7faf03f7c0f25a7..08e7e5f00308ae66120688b83771a1b7fc8403cb 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -36,6 +36,8 @@ enum reboot_mode reboot_mode DEFAULT_REBOOT_MODE; EXPORT_SYMBOL_GPL(reboot_mode); enum reboot_mode panic_reboot_mode = REBOOT_UNDEFINED; +static enum hw_protection_action hw_protection_action = HWPROT_ACT_SHUTDOWN; + /* * This variable is used privately to keep track of whether or not * reboot_type is still set to its default value (i.e., reboot= hasn't @@ -1023,6 +1025,9 @@ void __hw_protection_trigger(const char *reason, int ms_until_forced, { static atomic_t allow_proceed = ATOMIC_INIT(1); + if (action == HWPROT_ACT_DEFAULT) + action = hw_protection_action; + pr_emerg("HARDWARE PROTECTION %s (%s)\n", hw_protection_action_str(action), reason); @@ -1042,6 +1047,46 @@ void __hw_protection_trigger(const char *reason, int ms_until_forced, } EXPORT_SYMBOL_GPL(__hw_protection_trigger); +static bool hw_protection_action_parse(const char *str, + enum hw_protection_action *action) +{ + if (sysfs_streq(str, "shutdown")) + *action = HWPROT_ACT_SHUTDOWN; + else if (sysfs_streq(str, "reboot")) + *action = HWPROT_ACT_REBOOT; + else + return false; + + return true; +} + +static int __init hw_protection_setup(char *str) +{ + hw_protection_action_parse(str, &hw_protection_action); + return 1; +} +__setup("hw_protection=", hw_protection_setup); + +static ssize_t hw_protection_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%s\n", + hw_protection_action_str(hw_protection_action)); +} +static ssize_t hw_protection_store(struct kobject *kobj, + struct kobj_attribute *attr, const char *buf, + size_t count) +{ + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + if (!hw_protection_action_parse(buf, &hw_protection_action)) + return -EINVAL; + + return count; +} +static struct kobj_attribute hw_protection_attr = __ATTR_RW(hw_protection); + static int __init reboot_setup(char *str) { for (;;) { @@ -1301,6 +1346,7 @@ static struct kobj_attribute reboot_cpu_attr = __ATTR_RW(cpu); #endif static struct attribute *reboot_attrs[] = { + &hw_protection_attr.attr, &reboot_mode_attr.attr, #ifdef CONFIG_X86 &reboot_force_attr.attr, From patchwork Thu Dec 19 07:31:28 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ahmad Fatoum X-Patchwork-Id: 13914604 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 07ECF218AAF for ; Thu, 19 Dec 2024 07:32:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734593551; cv=none; b=HPqLoVBVgE4K6b7xK1yzOHBnHX1aRpmZolEuVC0xDXRXrZfwNSCUpAD52gVRE144cQWSEChlRee1Ut3VMhX+N6GTR/53CfuyQK0JoId+r1BHQnQHc5WqJPOGfd+wft3XpICB5dDS6s23uwTkS5T1e19Dl+qe4hXrlKhRLVORhHw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734593551; c=relaxed/simple; bh=e2IbsiOoO3EPFUAOqg25iHCtvCfjnHRVHByLTl6MTlI=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=dOSn+/qOKgqXlrA7CDhmPrJ2qxEcjyz0ll5IOIeBWXjoVwU04fnFOarGnO+X5Cnl3N7GTYzc63eg6G7ic0Fq93ImE16g76/Z6/ZQQQCutkFzZZJSgLPfS5iJ27FOGtcJ9l5LRzt6qRdi3g8Wa7GqfJshMUvQBZ0h8ApzYzs+C2A= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1tOB0O-00088Z-1R; Thu, 19 Dec 2024 08:31:32 +0100 Received: from dude05.red.stw.pengutronix.de ([2a0a:edc0:0:1101:1d::54]) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1tOB0L-004APu-25; Thu, 19 Dec 2024 08:31:30 +0100 Received: from localhost ([::1] helo=dude05.red.stw.pengutronix.de) by dude05.red.stw.pengutronix.de with esmtp (Exim 4.96) (envelope-from ) id 1tOB0M-00GkbH-0q; Thu, 19 Dec 2024 08:31:30 +0100 From: Ahmad Fatoum Date: Thu, 19 Dec 2024 08:31:28 +0100 Subject: [PATCH 07/11] regulator: allow user configuration of hardware protection action Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20241219-hw_protection-reboot-v1-7-263a0c1df802@pengutronix.de> References: <20241219-hw_protection-reboot-v1-0-263a0c1df802@pengutronix.de> In-Reply-To: <20241219-hw_protection-reboot-v1-0-263a0c1df802@pengutronix.de> To: Daniel Lezcano , Fabio Estevam , "Rafael J. Wysocki" , Zhang Rui , Lukasz Luba , Jonathan Corbet , Serge Hallyn , Liam Girdwood , Mark Brown , Matti Vaittinen , Benson Leung , Tzung-Bi Shih , Guenter Roeck , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-doc@vger.kernel.org, linux-security-module@vger.kernel.org, chrome-platform@lists.linux.dev, devicetree@vger.kernel.org, kernel@pengutronix.de, Ahmad Fatoum X-Mailer: b4 0.14.2 X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: a.fatoum@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-security-module@vger.kernel.org When the core detects permanent regulator hardware failure or imminent power failure of a critical supply, it will call hw_protection_shutdown in an attempt to do a limited orderly shutdown followed by powering off the system. This doesn't work out well for many unattended embedded systems that don't have support for shutdown and that power on automatically when power is supplied: - A brief power cycle gets detected by the driver - The kernel powers down the system and SoC goes into shutdown mode - Power is restored - The system remains oblivious to the restored power - System needs to be manually power cycled for a duration long enough to drain the capacitors Allow users to fix this by calling the newly introduced hw_protection_trigger() instead: This way the hw_protection commandline or sysfs parameter is used to dictate the policy of dealing with the regulator fault. Signed-off-by: Ahmad Fatoum --- drivers/regulator/core.c | 4 ++-- drivers/regulator/irq_helpers.c | 16 ++++++++-------- 2 files changed, 10 insertions(+), 10 deletions(-) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 8cb948a91e60d958c6b5ec97d736e6e3bf4b47eb..74c8f1262f2cd4e796ba8f4f1bdf17b685a615c1 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -5137,8 +5137,8 @@ static void regulator_handle_critical(struct regulator_dev *rdev, if (!reason) return; - hw_protection_shutdown(reason, - rdev->constraints->uv_less_critical_window_ms); + hw_protection_trigger(reason, + rdev->constraints->uv_less_critical_window_ms); } /** diff --git a/drivers/regulator/irq_helpers.c b/drivers/regulator/irq_helpers.c index 0aa188b2bbb26797b7907cbfb581459ef41df286..5742faee8071dd8104c094587d66693f48fb0f9b 100644 --- a/drivers/regulator/irq_helpers.c +++ b/drivers/regulator/irq_helpers.c @@ -64,16 +64,16 @@ static void regulator_notifier_isr_work(struct work_struct *work) reread: if (d->fatal_cnt && h->retry_cnt > d->fatal_cnt) { if (!d->die) - return hw_protection_shutdown("Regulator HW failure? - no IC recovery", - REGULATOR_FORCED_SAFETY_SHUTDOWN_WAIT_MS); + return hw_protection_trigger("Regulator HW failure? - no IC recovery", + REGULATOR_FORCED_SAFETY_SHUTDOWN_WAIT_MS); ret = d->die(rid); /* * If the 'last resort' IC recovery failed we will have * nothing else left to do... */ if (ret) - return hw_protection_shutdown("Regulator HW failure. IC recovery failed", - REGULATOR_FORCED_SAFETY_SHUTDOWN_WAIT_MS); + return hw_protection_trigger("Regulator HW failure. IC recovery failed", + REGULATOR_FORCED_SAFETY_SHUTDOWN_WAIT_MS); /* * If h->die() was implemented we assume recovery has been @@ -263,14 +263,14 @@ static irqreturn_t regulator_notifier_isr(int irq, void *data) if (d->fatal_cnt && h->retry_cnt > d->fatal_cnt) { /* If we have no recovery, just try shut down straight away */ if (!d->die) { - hw_protection_shutdown("Regulator failure. Retry count exceeded", - REGULATOR_FORCED_SAFETY_SHUTDOWN_WAIT_MS); + hw_protection_trigger("Regulator failure. Retry count exceeded", + REGULATOR_FORCED_SAFETY_SHUTDOWN_WAIT_MS); } else { ret = d->die(rid); /* If die() failed shut down as a last attempt to save the HW */ if (ret) - hw_protection_shutdown("Regulator failure. Recovery failed", - REGULATOR_FORCED_SAFETY_SHUTDOWN_WAIT_MS); + hw_protection_trigger("Regulator failure. Recovery failed", + REGULATOR_FORCED_SAFETY_SHUTDOWN_WAIT_MS); } } From patchwork Thu Dec 19 07:31:29 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ahmad Fatoum X-Patchwork-Id: 13914597 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 17439216E3D for ; Thu, 19 Dec 2024 07:31:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734593516; cv=none; b=fAeEwqFeS80I4GDJiWiEeXaKFxPjz6ab6IUxeuH1GPG6qaTJT5ftZ2Va16smR1v9+8H84Ln4+JrYJ6MdGiWOThKHNZ250Iqk03O1+LWMIMToAfybylUeC97TCJncPArn9aTni8CdYhjoJP1hB3WxU4aChv3RzKzJ/85mvGROT4g= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734593516; c=relaxed/simple; bh=kv7H/2Fmdq5NzjHdH9WlL1ylasJJ18efPHXVIQWM2Hk=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=e8teMNomYuBALtdJ4WpjaFtPbFfV3O5VD9uWEWZ2kxsDfXcJ01nYpaCoLzFET5zC/7iC6+cLyxvxw4K+jEGErMIjHM1uTCZOfc9tfi9DqgWIlmRlBNVvCuYZ4xLMvAx7p42twvRXRjYaWfdxzaGZF6jK6tGVPgf6bAUNDDf+CoA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1tOB0O-00088a-1R; Thu, 19 Dec 2024 08:31:32 +0100 Received: from dude05.red.stw.pengutronix.de ([2a0a:edc0:0:1101:1d::54]) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1tOB0L-004APv-2A; Thu, 19 Dec 2024 08:31:30 +0100 Received: from localhost ([::1] helo=dude05.red.stw.pengutronix.de) by dude05.red.stw.pengutronix.de with esmtp (Exim 4.96) (envelope-from ) id 1tOB0M-00GkbH-0r; Thu, 19 Dec 2024 08:31:30 +0100 From: Ahmad Fatoum Date: Thu, 19 Dec 2024 08:31:29 +0100 Subject: [PATCH 08/11] platform/chrome: cros_ec_lpc: prepare for hw_protection_shutdown removal Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20241219-hw_protection-reboot-v1-8-263a0c1df802@pengutronix.de> References: <20241219-hw_protection-reboot-v1-0-263a0c1df802@pengutronix.de> In-Reply-To: <20241219-hw_protection-reboot-v1-0-263a0c1df802@pengutronix.de> To: Daniel Lezcano , Fabio Estevam , "Rafael J. Wysocki" , Zhang Rui , Lukasz Luba , Jonathan Corbet , Serge Hallyn , Liam Girdwood , Mark Brown , Matti Vaittinen , Benson Leung , Tzung-Bi Shih , Guenter Roeck , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-doc@vger.kernel.org, linux-security-module@vger.kernel.org, chrome-platform@lists.linux.dev, devicetree@vger.kernel.org, kernel@pengutronix.de, Ahmad Fatoum X-Mailer: b4 0.14.2 X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: a.fatoum@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-security-module@vger.kernel.org In the general case, a driver doesn't know which of system shutdown or reboot is the better action to take to protect hardware in an emergency situation. For this reason, hw_protection_shutdown is going to be removed in favor of hw_protection_trigger, which defaults to shutdown, but may be configured at kernel runtime to be a reboot instead. The ChromeOS EC situation is different as we do know that shutdown is the correct action as the EC is programmed to force reset after the short period, thus replace hw_protection_shutdown with __hw_protection_trigger with HWPROT_ACT_SHUTDOWN as argument to maintain the same behavior. No functional change. Signed-off-by: Ahmad Fatoum --- drivers/platform/chrome/cros_ec_lpc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/platform/chrome/cros_ec_lpc.c b/drivers/platform/chrome/cros_ec_lpc.c index 924bf4d3cc77b9f27d415a10c61ae06886fa7f80..068781b75529d80b51b3773845bcf457fa958710 100644 --- a/drivers/platform/chrome/cros_ec_lpc.c +++ b/drivers/platform/chrome/cros_ec_lpc.c @@ -414,7 +414,7 @@ static void cros_ec_lpc_acpi_notify(acpi_handle device, u32 value, void *data) blocking_notifier_call_chain(&ec_dev->panic_notifier, 0, ec_dev); kobject_uevent_env(&ec_dev->dev->kobj, KOBJ_CHANGE, (char **)env); /* Begin orderly shutdown. EC will force reset after a short period. */ - hw_protection_shutdown("CrOS EC Panic", -1); + __hw_protection_trigger("CrOS EC Panic", -1, HWPROT_ACT_SHUTDOWN); /* Do not query for other events after a panic is reported */ return; } From patchwork Thu Dec 19 07:31:30 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ahmad Fatoum X-Patchwork-Id: 13914599 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0BC3A217F46 for ; Thu, 19 Dec 2024 07:32:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734593521; cv=none; b=D128cfGKtk3mUh9A18ydgSKGtE+srFM3/HhPAWhKyeBx1qORX7O5xuct50e/jR595vGfRK6l1NDtBtu6345jfJdHSADmhSh1AcXHHt90CofhChFoe2Zs2Za93y8h3Wql7ZzrcVbkuVKf1qUUukAmCk5TGfnqsnDq/dRlGFtQuSY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734593521; c=relaxed/simple; bh=PUPdXfLUsQ8yTAia2r3rOB3zzTzJrVUz+cfOw1iUE6o=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=Rlr8VjuBhGOka54+NtWYsm8Wiy9u5Q1fJe264uxkcCw/IGy1BFjpO1eh445hlKlNYCdrhOPpivNHMfyWuXKrECTLa7IigNLcbM/Fl70mPbjk/B4qhDyQgLUfJd9sJ3CVHUczQn3pzNQg1DDkZT9aZWojwGOdy+opVDLL2Uol8zg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1tOB0O-00088Y-1R; Thu, 19 Dec 2024 08:31:32 +0100 Received: from dude05.red.stw.pengutronix.de ([2a0a:edc0:0:1101:1d::54]) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1tOB0L-004APw-2C; Thu, 19 Dec 2024 08:31:30 +0100 Received: from localhost ([::1] helo=dude05.red.stw.pengutronix.de) by dude05.red.stw.pengutronix.de with esmtp (Exim 4.96) (envelope-from ) id 1tOB0M-00GkbH-0s; Thu, 19 Dec 2024 08:31:30 +0100 From: Ahmad Fatoum Date: Thu, 19 Dec 2024 08:31:30 +0100 Subject: [PATCH 09/11] dt-bindings: thermal: give OS some leeway in absence of critical-action Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20241219-hw_protection-reboot-v1-9-263a0c1df802@pengutronix.de> References: <20241219-hw_protection-reboot-v1-0-263a0c1df802@pengutronix.de> In-Reply-To: <20241219-hw_protection-reboot-v1-0-263a0c1df802@pengutronix.de> To: Daniel Lezcano , Fabio Estevam , "Rafael J. Wysocki" , Zhang Rui , Lukasz Luba , Jonathan Corbet , Serge Hallyn , Liam Girdwood , Mark Brown , Matti Vaittinen , Benson Leung , Tzung-Bi Shih , Guenter Roeck , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-doc@vger.kernel.org, linux-security-module@vger.kernel.org, chrome-platform@lists.linux.dev, devicetree@vger.kernel.org, kernel@pengutronix.de, Ahmad Fatoum X-Mailer: b4 0.14.2 X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: a.fatoum@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-security-module@vger.kernel.org An operating system may allow its user to configure the action to be undertaken on critical overtemperature events. However, the bindings currently mandate an absence of the critical-action property to be equal to critical-action = "shutdown", which would mean any differing user configuration would violate the bindings. Resolve this by documenting the absence of the property to mean that the OS gets to decide. Signed-off-by: Ahmad Fatoum --- Documentation/devicetree/bindings/thermal/thermal-zones.yaml | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/Documentation/devicetree/bindings/thermal/thermal-zones.yaml b/Documentation/devicetree/bindings/thermal/thermal-zones.yaml index 0f435be1dbd8cfb4502be9d198ed6d51058f453b..0de0a9757ccc201ebbb0c8c8efb9f8da662f8e9c 100644 --- a/Documentation/devicetree/bindings/thermal/thermal-zones.yaml +++ b/Documentation/devicetree/bindings/thermal/thermal-zones.yaml @@ -82,9 +82,8 @@ patternProperties: $ref: /schemas/types.yaml#/definitions/string description: | The action the OS should perform after the critical temperature is reached. - By default the system will shutdown as a safe action to prevent damage - to the hardware, if the property is not set. - The shutdown action should be always the default and preferred one. + If the property is not set, it is up to the system to select the correct + action. The recommended and preferred default is shutdown. Choose 'reboot' with care, as the hardware may be in thermal stress, thus leading to infinite reboots that may cause damage to the hardware. Make sure the firmware/bootloader will act as the last resort and take From patchwork Thu Dec 19 07:31:31 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ahmad Fatoum X-Patchwork-Id: 13914683 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 691E7217F51 for ; Thu, 19 Dec 2024 07:50:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734594647; cv=none; b=i1dL/vk/UCDmBQavTjj9ZpxLb6Z7RZUYPNxGLdjHcSQN06E2IRvFc9ePOKVf5kpSoJl7qqnQIfenuhQ4dLHviTfuF7D+Fw03t5jzmLenRoQmPUNHhOmJ6pRHle5IvGzXJf+apsib4VbCPl5jCTGSztQxrbR/CQ932WvTHXp3AEA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734594647; c=relaxed/simple; bh=LN/2GKVWP8SVrflImM2f/d6NIlKudTEI+VcMQwEcCKY=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=YGdtQSPVeIStIK1Ol652x6sihdl7e14U50l8V5xnPaU77KhD1sZdJubhZ+EF/qbPLGjntFuffPG3W5zx2EnPO1xIkeCPNw3IcFpOTJqLAtsFTSU9PNr6ak0mIBQd6DCMOXtFGI81fDzDO7nSAWMFVG6QKdgRAydKxWX2SfYpc5g= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1tOBId-0003kW-Pr; Thu, 19 Dec 2024 08:50:23 +0100 Received: from dude05.red.stw.pengutronix.de ([2a0a:edc0:0:1101:1d::54]) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1tOBIc-004AWn-17; Thu, 19 Dec 2024 08:50:23 +0100 Received: from localhost ([::1] helo=dude05.red.stw.pengutronix.de) by dude05.red.stw.pengutronix.de with esmtp (Exim 4.96) (envelope-from ) id 1tOB0M-00GkbH-0t; Thu, 19 Dec 2024 08:31:30 +0100 From: Ahmad Fatoum Date: Thu, 19 Dec 2024 08:31:31 +0100 Subject: [PATCH 10/11] thermal: core: allow user configuration of hardware protection action Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20241219-hw_protection-reboot-v1-10-263a0c1df802@pengutronix.de> References: <20241219-hw_protection-reboot-v1-0-263a0c1df802@pengutronix.de> In-Reply-To: <20241219-hw_protection-reboot-v1-0-263a0c1df802@pengutronix.de> To: Daniel Lezcano , Fabio Estevam , "Rafael J. Wysocki" , Zhang Rui , Lukasz Luba , Jonathan Corbet , Serge Hallyn , Liam Girdwood , Mark Brown , Matti Vaittinen , Benson Leung , Tzung-Bi Shih , Guenter Roeck , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-doc@vger.kernel.org, linux-security-module@vger.kernel.org, chrome-platform@lists.linux.dev, devicetree@vger.kernel.org, kernel@pengutronix.de, Ahmad Fatoum X-Mailer: b4 0.14.2 X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: a.fatoum@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-security-module@vger.kernel.org In the general case, we don't know which of system shutdown or reboot is the better action to take to protect hardware in an emergency situation. We thus allow the policy to come from the device-tree in the form of an optional critical-action OF property, but so far there was no way for the end user to configure this. With recent addition of the hw_protection parameter, the user can now choose a default action for the case, where the driver isn't fully sure what's the better course of action. Let's make use of this by passing HWPROT_ACT_DEFAULT in absence of the critical-action OF property. As HWPROT_ACT_DEFAULT is shutdown by default, this introduces no functional change for users, unless they start using the new parameter. Signed-off-by: Ahmad Fatoum --- drivers/thermal/thermal_core.c | 17 ++++++++++------- drivers/thermal/thermal_core.h | 1 + drivers/thermal/thermal_of.c | 7 +++++-- 3 files changed, 16 insertions(+), 9 deletions(-) diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c index 19a3894ad752a91ef621794abbeec9abfb2323ec..abe990b7b40b0c7fa5034093b961e239840a18c1 100644 --- a/drivers/thermal/thermal_core.c +++ b/drivers/thermal/thermal_core.c @@ -369,7 +369,8 @@ void thermal_governor_update_tz(struct thermal_zone_device *tz, tz->governor->update_tz(tz, reason); } -static void thermal_zone_device_halt(struct thermal_zone_device *tz, bool shutdown) +static void thermal_zone_device_halt(struct thermal_zone_device *tz, + enum hw_protection_action action) { /* * poweroff_delay_ms must be a carefully profiled positive value. @@ -380,21 +381,23 @@ static void thermal_zone_device_halt(struct thermal_zone_device *tz, bool shutdo dev_emerg(&tz->device, "%s: critical temperature reached\n", tz->type); - if (shutdown) - hw_protection_shutdown(msg, poweroff_delay_ms); - else - hw_protection_reboot(msg, poweroff_delay_ms); + __hw_protection_trigger(msg, poweroff_delay_ms, action); } void thermal_zone_device_critical(struct thermal_zone_device *tz) { - thermal_zone_device_halt(tz, true); + thermal_zone_device_halt(tz, HWPROT_ACT_DEFAULT); } EXPORT_SYMBOL(thermal_zone_device_critical); +void thermal_zone_device_critical_shutdown(struct thermal_zone_device *tz) +{ + thermal_zone_device_halt(tz, HWPROT_ACT_SHUTDOWN); +} + void thermal_zone_device_critical_reboot(struct thermal_zone_device *tz) { - thermal_zone_device_halt(tz, false); + thermal_zone_device_halt(tz, HWPROT_ACT_REBOOT); } static void handle_critical_trips(struct thermal_zone_device *tz, diff --git a/drivers/thermal/thermal_core.h b/drivers/thermal/thermal_core.h index be271e7c8f4141146a03efecc82fc4036ec12df6..7d6637126007168ac05010af0f16a4c8012a0d77 100644 --- a/drivers/thermal/thermal_core.h +++ b/drivers/thermal/thermal_core.h @@ -262,6 +262,7 @@ int thermal_build_list_of_policies(char *buf); void __thermal_zone_device_update(struct thermal_zone_device *tz, enum thermal_notify_event event); void thermal_zone_device_critical_reboot(struct thermal_zone_device *tz); +void thermal_zone_device_critical_shutdown(struct thermal_zone_device *tz); void thermal_governor_update_tz(struct thermal_zone_device *tz, enum thermal_notify_event reason); diff --git a/drivers/thermal/thermal_of.c b/drivers/thermal/thermal_of.c index fab11b98ca4952d23d0232998433bd0650b53d24..c574e775d686599deddd08f932a5a6dd781d342e 100644 --- a/drivers/thermal/thermal_of.c +++ b/drivers/thermal/thermal_of.c @@ -396,9 +396,12 @@ static struct thermal_zone_device *thermal_of_zone_register(struct device_node * of_ops.should_bind = thermal_of_should_bind; ret = of_property_read_string(np, "critical-action", &action); - if (!ret) - if (!of_ops.critical && !strcasecmp(action, "reboot")) + if (!ret && !of_ops.critical) { + if (!strcasecmp(action, "reboot")) of_ops.critical = thermal_zone_device_critical_reboot; + else if (!strcasecmp(action, "shutdown")) + of_ops.critical = thermal_zone_device_critical_shutdown; + } tz = thermal_zone_device_register_with_trips(np->name, trips, ntrips, data, &of_ops, &tzp, From patchwork Thu Dec 19 07:31:32 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ahmad Fatoum X-Patchwork-Id: 13914682 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AF3112163A9 for ; Thu, 19 Dec 2024 07:50:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734594646; cv=none; b=T7hv7xvZwlICYAdzwa8IoJmL82GnEb9Us//yQQLpLsCMnXkdSiP0+aJRLDmNpRKxTU2UVwh/kCQwb9mTmiUFZXVI5ntmEvjfMp+ld8tqEYrcgitfmM+8bSD4yG9s68W0iw/5xgErwOlccMveeVu22enEK33W0ZQ7KsfQqQ1G7tA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; 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Thu, 19 Dec 2024 08:50:22 +0100 Received: from localhost ([::1] helo=dude05.red.stw.pengutronix.de) by dude05.red.stw.pengutronix.de with esmtp (Exim 4.96) (envelope-from ) id 1tOB0M-00GkbH-0u; Thu, 19 Dec 2024 08:31:30 +0100 From: Ahmad Fatoum Date: Thu, 19 Dec 2024 08:31:32 +0100 Subject: [PATCH 11/11] reboot: retire hw_protection_reboot and hw_protection_shutdown helpers Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20241219-hw_protection-reboot-v1-11-263a0c1df802@pengutronix.de> References: <20241219-hw_protection-reboot-v1-0-263a0c1df802@pengutronix.de> In-Reply-To: <20241219-hw_protection-reboot-v1-0-263a0c1df802@pengutronix.de> To: Daniel Lezcano , Fabio Estevam , "Rafael J. Wysocki" , Zhang Rui , Lukasz Luba , Jonathan Corbet , Serge Hallyn , Liam Girdwood , Mark Brown , Matti Vaittinen , Benson Leung , Tzung-Bi Shih , Guenter Roeck , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-doc@vger.kernel.org, linux-security-module@vger.kernel.org, chrome-platform@lists.linux.dev, devicetree@vger.kernel.org, kernel@pengutronix.de, Ahmad Fatoum X-Mailer: b4 0.14.2 X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: a.fatoum@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-security-module@vger.kernel.org The hw_protection_reboot and hw_protection_shutdown functions mix mechanism with policy: They let the driver requesting an emergency action for hardware protection also decide how to deal with it. This is inadequate in the general case as a driver reporting e.g. an imminent power failure can't know whether a shutdown or a reboot would be more appropriate for a given hardware platform. With the addition of the hw_protection parameter, it's now possible to configure at runtime the default emergency action and drivers are expected to use hw_protection_trigger to have this parameter dictate policy. As no current users of either hw_protection_shutdown or hw_protection_shutdown helpers remain, remove them, as not to tempt driver authors to call them. Existing users now either defer to hw_protection_trigger or call __hw_protection_trigger with a suitable argument directly when they have inside knowledge on whether a reboot or shutdown would be more appropriate. Signed-off-by: Ahmad Fatoum --- include/linux/reboot.h | 10 ---------- 1 file changed, 10 deletions(-) diff --git a/include/linux/reboot.h b/include/linux/reboot.h index 281696f509932e444eadd453fb0233aa7a07fbce..5c709463a7f85189e169bbaeb8bb7b115b20c996 100644 --- a/include/linux/reboot.h +++ b/include/linux/reboot.h @@ -200,16 +200,6 @@ static inline void hw_protection_trigger(const char *reason, int ms_until_forced __hw_protection_trigger(reason, ms_until_forced, HWPROT_ACT_DEFAULT); } -static inline void hw_protection_reboot(const char *reason, int ms_until_forced) -{ - __hw_protection_trigger(reason, ms_until_forced, HWPROT_ACT_REBOOT); -} - -static inline void hw_protection_shutdown(const char *reason, int ms_until_forced) -{ - __hw_protection_trigger(reason, ms_until_forced, HWPROT_ACT_SHUTDOWN); -} - /* * Emergency restart, callable from an interrupt handler. */