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  PHC 
Open Source and information security mailing list archives
 
Hash Suite for Android: free password hash cracker in your pocket
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Sun, 1 Mar 2009 23:26:46 +0100
From:	"Rafael J. Wysocki" <rjw@...k.pl>
To:	LKML <linux-kernel@...r.kernel.org>
Cc:	Linus Torvalds <torvalds@...ux-foundation.org>,
	Ingo Molnar <mingo@...e.hu>,
	"Eric W. Biederman" <ebiederm@...ssion.com>,
	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	Jeremy Fitzhardinge <jeremy@...p.org>,
	pm list <linux-pm@...ts.linux-foundation.org>,
	Len Brown <lenb@...nel.org>,
	Jesse Barnes <jbarnes@...tuousgeek.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Arve Hjønnevåg <arve@...roid.com>,
	Alan Stern <stern@...land.harvard.edu>,
	Johannes Berg <johannes@...solutions.net>
Subject: [RFC][PATCH 3/4] PM: Change hibernation code ordering

From: Rafael J. Wysocki <rjw@...k.pl>

Change the ordering of the hibernation core code so that the platform
"prepare" callbacks are executed and the nonboot CPUs are disabled
after calling device drivers' "late suspend" methods.

This change (along with the previous analogous change of the suspend
core code) will allow us to rework the PCI PM core so that the power
state of devices is changed in the "late" phase of suspend (and
analogously in the "early" phase of resume), which in turn will allow
us to avoid the race condition where a device using shared interrupts
is put into a low power state with interrupts enabled and then an
interrupt (for another device) comes in and confuses its driver.

Signed-off-by: Rafael J. Wysocki <rjw@...k.pl>
---
 kernel/power/disk.c |  109 +++++++++++++++++++++++++++++-----------------------
 1 file changed, 61 insertions(+), 48 deletions(-)

Index: linux-2.6/kernel/power/disk.c
===================================================================
--- linux-2.6.orig/kernel/power/disk.c
+++ linux-2.6/kernel/power/disk.c
@@ -228,13 +228,22 @@ static int create_image(int platform_mod
 		goto Unlock;
 	}
 
+	error = platform_pre_snapshot(platform_mode);
+	if (error || hibernation_test(TEST_PLATFORM))
+		goto Platform_finish;
+
+	error = disable_nonboot_cpus();
+	if (error || hibernation_test(TEST_CPUS)
+	    || hibernation_testmode(HIBERNATION_TEST))
+		goto Enable_cpus;
+
 	local_irq_disable();
 
 	sysdev_suspend(PMSG_FREEZE);
 	if (error) {
 		printk(KERN_ERR "PM: Some devices failed to power down, "
 			"aborting hibernation\n");
-		goto Power_up_devices;
+		goto Enable_irqs;
 	}
 
 	if (hibernation_test(TEST_CORE))
@@ -250,15 +259,22 @@ static int create_image(int platform_mod
 	restore_processor_state();
 	if (!in_suspend)
 		platform_leave(platform_mode);
+
  Power_up:
 	sysdev_resume();
 	/* NOTE:  device_power_up() is just a resume() for devices
 	 * that suspended with irqs off ... no overall powerup.
 	 */
 
- Power_up_devices:
+ Enable_irqs:
 	local_irq_enable();
 
+ Enable_cpus:
+	enable_nonboot_cpus();
+
+ Platform_finish:
+	platform_finish(platform_mode);
+
 	device_power_up(in_suspend ?
 		(error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
 
@@ -298,25 +314,9 @@ int hibernation_snapshot(int platform_mo
 	if (hibernation_test(TEST_DEVICES))
 		goto Recover_platform;
 
-	error = platform_pre_snapshot(platform_mode);
-	if (error || hibernation_test(TEST_PLATFORM))
-		goto Finish;
-
-	error = disable_nonboot_cpus();
-	if (!error) {
-		if (hibernation_test(TEST_CPUS))
-			goto Enable_cpus;
-
-		if (hibernation_testmode(HIBERNATION_TEST))
-			goto Enable_cpus;
+	error = create_image(platform_mode);
+	/* Control returns here after successful restore */
 
-		error = create_image(platform_mode);
-		/* Control returns here after successful restore */
-	}
- Enable_cpus:
-	enable_nonboot_cpus();
- Finish:
-	platform_finish(platform_mode);
  Resume_devices:
 	device_resume(in_suspend ?
 		(error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
@@ -338,7 +338,7 @@ int hibernation_snapshot(int platform_mo
  *	kernel.
  */
 
-static int resume_target_kernel(void)
+static int resume_target_kernel(bool platform_mode)
 {
 	int error;
 
@@ -351,9 +351,20 @@ static int resume_target_kernel(void)
 		goto Unlock;
 	}
 
+	error = platform_pre_restore(platform_mode);
+	if (error)
+		goto Cleanup;
+
+	error = disable_nonboot_cpus();
+	if (error)
+		goto Enable_cpus;
+
 	local_irq_disable();
 
-	sysdev_suspend(PMSG_QUIESCE);
+	error = sysdev_suspend(PMSG_QUIESCE);
+	if (error)
+		goto Enable_irqs;
+
 	/* We'll ignore saved state, but this gets preempt count (etc) right */
 	save_processor_state();
 	error = restore_highmem();
@@ -379,8 +390,15 @@ static int resume_target_kernel(void)
 
 	sysdev_resume();
 
+ Enable_irqs:
 	local_irq_enable();
 
+ Enable_cpus:
+	enable_nonboot_cpus();
+
+ Cleanup:
+	platform_restore_cleanup(platform_mode);
+
 	device_power_up(PMSG_RECOVER);
 
  Unlock:
@@ -405,19 +423,10 @@ int hibernation_restore(int platform_mod
 	pm_prepare_console();
 	suspend_console();
 	error = device_suspend(PMSG_QUIESCE);
-	if (error)
-		goto Finish;
-
-	error = platform_pre_restore(platform_mode);
 	if (!error) {
-		error = disable_nonboot_cpus();
-		if (!error)
-			error = resume_target_kernel();
-		enable_nonboot_cpus();
+		error = resume_target_kernel(platform_mode);
+		device_resume(PMSG_RECOVER);
 	}
-	platform_restore_cleanup(platform_mode);
-	device_resume(PMSG_RECOVER);
- Finish:
 	resume_console();
 	pm_restore_console();
 	return error;
@@ -453,34 +462,38 @@ int hibernation_platform_enter(void)
 		goto Resume_devices;
 	}
 
+	device_pm_lock();
+
+	error = device_power_down(PMSG_HIBERNATE);
+	if (error)
+		goto Unlock;
+
 	error = hibernation_ops->prepare();
 	if (error)
-		goto Resume_devices;
+		goto Platofrm_finish;
 
 	error = disable_nonboot_cpus();
 	if (error)
-		goto Finish;
-
-	device_pm_lock();
-
-	error = device_power_down(PMSG_HIBERNATE);
-	if (!error) {
-		local_irq_disable();
-		sysdev_suspend(PMSG_HIBERNATE);
-		hibernation_ops->enter();
-		/* We should never get here */
-		while (1);
-	}
+		goto Platofrm_finish;
 
-	device_pm_unlock();
+	local_irq_disable();
+	sysdev_suspend(PMSG_HIBERNATE);
+	hibernation_ops->enter();
+	/* We should never get here */
+	while (1);
 
 	/*
 	 * We don't need to reenable the nonboot CPUs or resume consoles, since
 	 * the system is going to be halted anyway.
 	 */
- Finish:
+ Platofrm_finish:
 	hibernation_ops->finish();
 
+	device_power_up(PMSG_RESTORE);
+
+ Unlock:
+	device_pm_unlock();
+
  Resume_devices:
 	entering_platform_hibernation = false;
 	device_resume(PMSG_RESTORE);
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists