linux-kernel - [PATCH] rtc: rtc-cmos: Fix wake alarm breakage

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <5887691.lOV4Wx5bFT@kreacher>
Date:   Tue, 18 Oct 2022 18:09:31 +0200
From:   "Rafael J. Wysocki" <rjw@...ysocki.net>
To:     Alexandre Belloni <alexandre.belloni@...tlin.com>
Cc:     Alessandro Zummo <a.zummo@...ertech.it>,
        Mario Limonciello <mario.limonciello@....com>,
        linux-rtc@...r.kernel.org, Bjorn Helgaas <helgaas@...nel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Linux ACPI <linux-acpi@...r.kernel.org>,
        Linux PM <linux-pm@...r.kernel.org>,
        Mel Gorman <mgorman@...hsingularity.net>,
        Zhang Rui <rui.zhang@...el.com>,
        Todd Brandt <todd.e.brandt@...ux.intel.com>
Subject: [PATCH] rtc: rtc-cmos: Fix wake alarm breakage

From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>

Commit 4919d3eb2ec0 ("rtc: cmos: Fix event handler registration
ordering issue") overlooked the fact that cmos_do_probe() depended
on the preparations carried out by cmos_wake_setup() and the wake
alarm stopped working after the ordering of them had been changed.

Address this by partially reverting commit 4919d3eb2ec0 so that
cmos_wake_setup() is called before cmos_do_probe() again and moving
the rtc_wake_setup() invocation from cmos_wake_setup() directly to the
callers of cmos_do_probe() where it will happen after a successful
completion of the latter.

Fixes: 4919d3eb2ec0 ("rtc: cmos: Fix event handler registration ordering issue")
Reported-by: Zhang Rui <rui.zhang@...el.com>
Reported-by: Todd Brandt <todd.e.brandt@...ux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---

@Bjorn: This is the minimum fix.  Folding cmos_wake_setup() into cmos_do_probe()
requires changes that are a bit intrusive for post-rc1, but I will do that later.

---
 drivers/rtc/rtc-cmos.c |   11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

Index: linux-pm/drivers/rtc/rtc-cmos.c
===================================================================
--- linux-pm.orig/drivers/rtc/rtc-cmos.c
+++ linux-pm/drivers/rtc/rtc-cmos.c
@@ -1233,6 +1233,9 @@ static u32 rtc_handler(void *context)
 
 static inline void rtc_wake_setup(struct device *dev)
 {
+	if (acpi_disabled)
+		return;
+
 	acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, dev);
 	/*
 	 * After the RTC handler is installed, the Fixed_RTC event should
@@ -1286,7 +1289,6 @@ static void cmos_wake_setup(struct devic
 
 	use_acpi_alarm_quirks();
 
-	rtc_wake_setup(dev);
 	acpi_rtc_info.wake_on = rtc_wake_on;
 	acpi_rtc_info.wake_off = rtc_wake_off;
 
@@ -1354,6 +1356,8 @@ static int cmos_pnp_probe(struct pnp_dev
 {
 	int irq, ret;
 
+	cmos_wake_setup(&pnp->dev);
+
 	if (pnp_port_start(pnp, 0) == 0x70 && !pnp_irq_valid(pnp, 0)) {
 		irq = 0;
 #ifdef CONFIG_X86
@@ -1372,7 +1376,7 @@ static int cmos_pnp_probe(struct pnp_dev
 	if (ret)
 		return ret;
 
-	cmos_wake_setup(&pnp->dev);
+	rtc_wake_setup(&pnp->dev);
 
 	return 0;
 }
@@ -1461,6 +1465,7 @@ static int __init cmos_platform_probe(st
 	int irq, ret;
 
 	cmos_of_init(pdev);
+	cmos_wake_setup(&pdev->dev);
 
 	if (RTC_IOMAPPED)
 		resource = platform_get_resource(pdev, IORESOURCE_IO, 0);
@@ -1474,7 +1479,7 @@ static int __init cmos_platform_probe(st
 	if (ret)
 		return ret;
 
-	cmos_wake_setup(&pdev->dev);
+	rtc_wake_setup(&pdev->dev);
 
 	return 0;
 }