linux/kernel/power, branch v2.6.14.1

[PATCH] x86_64: Set up safe page tables during resume

2005-10-10T15:36:46Z

The following patch makes swsusp avoid the possible temporary corruption of page translation tables during resume on x86-64. This is achieved by creating a copy of the relevant page tables that will not be modified by swsusp and can be safely used by it on resume. The problem is that during resume on x86-64 swsusp may temporarily corrupt the page tables used for the direct mapping of RAM. If that happens, a page fault occurs and cannot be handled properly, which leads to the solid hang of the affected system. This leads to the loss of the system's state from before suspend and may result in the loss of data or the corruption of filesystems, so it is a serious issue. Also, it appears to happen quite often (for me, as often as 50% of the time). The problem is related to the fact that (at least) one of the PMD entries used in the direct memory mapping (starting at PAGE_OFFSET) points to a page table the physical address of which is much greater than the physical address of the PMD entry itself. Moreover, unfortunately, the physical address of the page table before suspend (i.e. the one stored in the suspend image) happens to be different to the physical address of the corresponding page table used during resume (i.e. the one that is valid right before swsusp_arch_resume() in arch/x86_64/kernel/suspend_asm.S is executed). Thus while the image is restored, the "offending" PMD entry gets overwritten, so it does not point to the right physical address any more (i.e. there's no page table at the address pointed to by it, because it points to the address the page table has been at during suspend). Consequently, if the PMD entry is used later on, and it _is_ used in the process of copying the image pages, a page fault occurs, but it cannot be handled in the normal way and the system hangs. In principle we can call create_resume_mapping() from swsusp_arch_resume() (ie. from suspend_asm.S), but then the memory allocations in create_resume_mapping(), resume_pud_mapping(), and resume_pmd_mapping() must be made carefully so that we use _only_ NosaveFree pages in them (the other pages are overwritten by the loop in swsusp_arch_resume()). Additionally, we are in atomic context at that time, so we cannot use GFP_KERNEL. Moreover, if one of the allocations fails, we should free all of the allocated pages, so we need to trace them somehow. All of this is done in the appended patch, except that the functions populating the page tables are located in arch/x86_64/kernel/suspend.c rather than in init.c. It may be done in a more elegan way in the future, with the help of some swsusp patches that are in the works now. [AK: move some externs into headers, renamed a function] Signed-off-by: Rafael J. Wysocki Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds

[PATCH] swsusp: avoid problems if there are too many pages to save

2005-09-28T14:46:41Z

The following patch makes swsusp avoid problems during resume if there are too many pages to save on suspend. It adds a constant that allows us to verify if we are going to save too many pages and implements the check (this is done as early as we can tell that the check will trigger, which is in swsusp_alloc()). Signed-off-by: Rafael J. Wysocki Acked-by: Pavel Machek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] swsusp: prevent possible memory leak

2005-09-28T14:46:40Z

Prevent swsusp from leaking some memory in case of an error in read_pagedir(). It also prevents the BUG_ON() from triggering if there's an error while reading swap. Signed-off-by: Rafael J. Wysocki Acked-by: Pavel Machek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] swsusp: remove wrong code from data_free

2005-09-28T14:46:40Z

The following patch removes some wrong code from the data_free() function in swsusp. This function could only be called if there's an error while writing the suspend image to swap, so it is not triggered easily. However, if triggered, it would probably corrupt some memory. Signed-off-by: Rafael J. Wysocki Acked-by: Pavel Machek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] swsusp: fix comments

2005-09-23T05:17:36Z

Fix comments in swsusp. Signed-off-by: Pavel Machek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] swsusp: do not trigger BUG_ON() if there is not enough memory

2005-09-23T05:17:35Z

The following patch makes swsusp avoid triggering the BUG_ON() in swsusp_suspend() if there is not enough memory for suspend. Signed-off-by: Rafael J. Wysocki Cc: Pavel Machek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] SOFTWARE_SUSPEND needs HOTPLUG_CPU on SMP

2005-09-23T05:17:34Z

Signed-off-by: Randy Dunlap Acked-by: Pavel Machek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] suspend: cleanup calling of power off methods.

2005-09-23T05:17:33Z

In the lead up to 2.6.13 I fixed a large number of reboot problems by making the calling conventions consistent. Despite checking and double checking my work it appears I missed an obvious one. The S4 suspend code for PM_DISK_PLATFORM was also calling device_shutdown without setting system_state, and was not calling the appropriate reboot_notifier. This patch fixes the bug by replacing the call of device_suspend with kernel_poweroff_prepare. Various forms of this failure have been fixed and tracked for a while. Thanks for tracking this down go to: Alexey Starikovskiy, Meelis Roos , Nigel Cunningham , Pierre Ossman History of this bug is at: http://bugme.osdl.org/show_bug.cgi?id=4320 Signed-off-by: Eric W. Biederman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge linux-2.6 with linux-acpi-2.6

2005-09-08T05:45:47Z

[PATCH] introduce and use kzalloc

2005-09-07T23:57:45Z

This patch introduces a kzalloc wrapper and converts kernel/ to use it. It saves a little program text. Signed-off-by: Pekka Enberg Signed-off-by: Adrian Bunk Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds