user/sven/linux.git/kernel/power/power.h, branch v4.11.3

arch: Rename CONFIG_DEBUG_RODATA and CONFIG_DEBUG_MODULE_RONX

2017-02-07T20:32:52Z

Both of these options are poorly named. The features they provide are necessary for system security and should not be considered debug only. Change the names to CONFIG_STRICT_KERNEL_RWX and CONFIG_STRICT_MODULE_RWX to better describe what these options do. Signed-off-by: Laura Abbott Acked-by: Jessica Yu Signed-off-by: Kees Cook

PM / sleep: System sleep state selection interface rework

2016-11-21T21:45:40Z

There are systems in which the platform doesn't support any special sleep states, so suspend-to-idle (PM_SUSPEND_FREEZE) is the only available system sleep state. However, some user space frameworks only use the "mem" and (sometimes) "standby" sleep state labels, so the users of those systems need to modify user space in order to be able to use system suspend at all and that may be a pain in practice. Commit 0399d4db3edf (PM / sleep: Introduce command line argument for sleep state enumeration) attempted to address this problem by adding a command line argument to change the meaning of the "mem" string in /sys/power/state to make it trigger suspend-to-idle (instead of suspend-to-RAM). However, there also are systems in which the platform does support special sleep states, but suspend-to-idle is the preferred one anyway (it even may save more energy than the platform-provided sleep states in some cases) and the above commit doesn't help in those cases. For this reason, rework the system sleep state selection interface again (but preserve backwards compatibiliby). Namely, add a new sysfs file, /sys/power/mem_sleep, that will control the system suspend mode triggered by writing "mem" to /sys/power/state (in analogy with what /sys/power/disk does for hibernation). Make it select suspend-to-RAM ("deep" sleep) by default (if supported) and fall back to suspend-to-idle ("s2idle") otherwise and add a new command line argument, mem_sleep_default, allowing that default to be overridden if need be. At the same time, drop the relative_sleep_states command line argument that doesn't make sense any more. Signed-off-by: Rafael J. Wysocki Tested-by: Mario Limonciello

PM / Hibernate: allow hibernation with PAGE_POISONING_ZERO

2016-09-13T00:35:27Z

PAGE_POISONING_ZERO disables zeroing new pages on alloc, they are poisoned (zeroed) as they become available. In the hibernate use case, free pages will appear in the system without being cleared, left there by the loading kernel. This patch will make sure free pages are cleared on resume when PAGE_POISONING_ZERO is enabled. We free the pages just after resume because we can't do it later: going through any device resume code might allocate some memory and invalidate the free pages bitmap. Thus we don't need to disable hibernation when PAGE_POISONING_ZERO is enabled. Signed-off-by: Anisse Astier Reviewed-by: Kees Cook Acked-by: Pavel Machek Signed-off-by: Rafael J. Wysocki

x86 / hibernate: Use hlt_play_dead() when resuming from hibernation

2016-07-15T20:42:48Z

On Intel hardware, native_play_dead() uses mwait_play_dead() by default and only falls back to the other methods if that fails. That also happens during resume from hibernation, when the restore (boot) kernel runs disable_nonboot_cpus() to take all of the CPUs except for the boot one offline. However, that is problematic, because the address passed to __monitor() in mwait_play_dead() is likely to be written to in the last phase of hibernate image restoration and that causes the "dead" CPU to start executing instructions again. Unfortunately, the page containing the address in that CPU's instruction pointer may not be valid any more at that point. First, that page may have been overwritten with image kernel memory contents already, so the instructions the CPU attempts to execute may simply be invalid. Second, the page tables previously used by that CPU may have been overwritten by image kernel memory contents, so the address in its instruction pointer is impossible to resolve then. A report from Varun Koyyalagunta and investigation carried out by Chen Yu show that the latter sometimes happens in practice. To prevent it from happening, temporarily change the smp_ops.play_dead pointer during resume from hibernation so that it points to a special "play dead" routine which uses hlt_play_dead() and avoids the inadvertent "revivals" of "dead" CPUs this way. A slightly unpleasant consequence of this change is that if the system is hibernated with one or more CPUs offline, it will generally draw more power after resume than it did before hibernation, because the physical state entered by CPUs via hlt_play_dead() is higher-power than the mwait_play_dead() one in the majority of cases. It is possible to work around this, but it is unclear how much of a problem that's going to be in practice, so the workaround will be implemented later if it turns out to be necessary. Link: https://bugzilla.kernel.org/show_bug.cgi?id=106371 Reported-by: Varun Koyyalagunta Original-by: Chen Yu Tested-by: Chen Yu Signed-off-by: Rafael J. Wysocki Acked-by: Ingo Molnar

PM / hibernate: Image data protection during restoration

2016-07-10T00:12:10Z

Make it possible to protect all pages holding image data during hibernate image restoration by setting them read-only (so as to catch attempts to write to those pages after image data have been stored in them). This adds overhead to image restoration code (it may cause large page mappings to be split as a result of page flags changes) and the errors it protects against should never happen in theory, so the feature is only active after passing hibernate=protect_image to the command line of the restore kernel. Also it only is built if CONFIG_DEBUG_RODATA is set. Signed-off-by: Rafael J. Wysocki

PM / sleep: make PM notifiers called symmetrically

2016-06-27T22:38:55Z

This makes pm notifier PREPARE/POST symmetrical: if PREPARE fails, we will only undo what ever happened on PREPARE. It fixes the unbalanced CPU hotplug enable in CPU PM notifier. Signed-off-by: Lianwei Wang Signed-off-by: Rafael J. Wysocki

PM / sleep: Add support for read-only sysfs attributes

2016-01-04T21:28:59Z

Some sysfs attributes in /sys/power/ should really be read-only, so add support for that, convert those attributes to read-only and drop the stub .show() routines from them. Original-by: Sergey Senozhatsky Signed-off-by: Rafael J. Wysocki

suspend: simplify block I/O handling

2015-05-19T15:19:59Z

Stop abusing struct page functionality and the swap end_io handler, and instead add a modified version of the blk-lib.c bio_batch helpers. Also move the block I/O code into swap.c as they are directly tied into each other. Signed-off-by: Christoph Hellwig Tested-by: Pavel Machek Tested-by: Ming Lin Acked-by: Pavel Machek Acked-by: Rafael J. Wysocki Signed-off-by: Jens Axboe

PM / Hibernate: Migrate to ktime_t

2014-11-03T00:02:55Z

This patch migrates swsusp_show_speed and its callers to using ktime_t instead of 'struct timeval' which suffers from the y2038 problem. Changes to swsusp_show_speed: - use ktime_t for start and stop times - pass start and stop times by value Calling functions affected: - load_image - load_image_lzo - save_image - save_image_lzo - hibernate_preallocate_memory Design decisions: - use ktime_t to preserve same granularity of reporting as before - use centisecs logic as before to avoid 'div by zero' issues caused by using seconds and nanoseconds directly - use monotonic time (ktime_get()) since we only care about elapsed time. Signed-off-by: Tina Ruchandani Suggested-by: Arnd Bergmann Reviewed-by: Arnd Bergmann Acked-by: Pavel Machek Signed-off-by: Rafael J. Wysocki

PM / sleep: Fix test_suspend= command line option

2014-09-02T23:21:03Z

After commit d431cbc53cb7 (PM / sleep: Simplify sleep states sysfs interface code) the pm_states[] array is not populated initially, which causes setup_test_suspend() to always fail and the suspend testing during boot doesn't work any more. Fix the problem by using pm_labels[] instead of pm_states[] in setup_test_suspend() and storing a pointer to the label of the sleep state to test rather than the number representing it, because the connection between the state numbers and labels is only established by suspend_set_ops(). Fixes: d431cbc53cb7 (PM / sleep: Simplify sleep states sysfs interface code) Reported-by: Srinivas Pandruvada Signed-off-by: Rafael J. Wysocki