user/sven/linux.git/kernel/power/power.h, branch v5.4.262

PM: hibernate: powerpc: Expose pfn_is_nosave() prototype

2019-06-14T08:48:56Z

The declaration for pfn_is_nosave is only available in kernel/power/power.h. Since this function can be override in arch, expose it globally. Having a prototype will make sure to avoid warning (sometime treated as error with W=1) such as: arch/powerpc/kernel/suspend.c:18:5: error: no previous prototype for 'pfn_is_nosave' [-Werror=missing-prototypes] This moves the declaration into a globally visible header file and add missing include to avoid a warning on powerpc. Also remove the duplicated prototypes since not required anymore. Signed-off-by: Mathieu Malaterre Acked-by: Michael Ellerman (powerpc) Signed-off-by: Rafael J. Wysocki

x86/power: Fix swsusp_arch_resume prototype

2018-02-02T22:33:50Z

The declaration for swsusp_arch_resume marks it as 'asmlinkage', but the definition in x86-32 does not, and it fails to include the header with the declaration. This leads to a warning when building with link-time-optimizations: kernel/power/power.h:108:23: error: type of 'swsusp_arch_resume' does not match original declaration [-Werror=lto-type-mismatch] extern asmlinkage int swsusp_arch_resume(void); ^ arch/x86/power/hibernate_32.c:148:0: note: 'swsusp_arch_resume' was previously declared here int swsusp_arch_resume(void) This moves the declaration into a globally visible header file and fixes up both x86 definitions to match it. Signed-off-by: Arnd Bergmann Signed-off-by: Thomas Gleixner Cc: Len Brown Cc: Andi Kleen Cc: Nicolas Pitre Cc: linux-pm@vger.kernel.org Cc: "Rafael J. Wysocki" Cc: Pavel Machek Cc: Bart Van Assche Link: https://lkml.kernel.org/r/20180202145634.200291-2-arnd@arndb.de

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55Z

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

ACPI / PM: Prefer suspend-to-idle over S3 on some systems

2017-08-04T23:51:26Z

Modify the ACPI system sleep support setup code to select suspend-to-idle as the default system sleep state if (1) the ACPI_FADT_LOW_POWER_S0 flag is set in the FADT and (2) the Low Power Idle S0 _DSM interface has been discovered and (3) the default sleep state was not selected from the kernel command line. The main motivation for this change is that systems where the (1) and (2) conditions are met typically ship with OSes that don't exercise the S3 path in the platform firmware which remains untested and turns out to be non-functional at least in some cases. Signed-off-by: Rafael J. Wysocki Tested-by: Mario Limonciello

PM / sleep: Put pm_test under CONFIG_PM_SLEEP_DEBUG

2017-07-24T21:55:27Z

The pm_test sysfs attribute is under CONFIG_PM_DEBUG, but it doesn't make sense to provide it if CONFIG_PM_SLEEP is unset, so put it under CONFIG_PM_SLEEP_DEBUG instead. Signed-off-by: Rafael J. Wysocki

PM / s2idle: Rearrange the main suspend-to-idle loop

2017-07-24T21:53:44Z

As a preparation for subsequent changes, rearrange the core suspend-to-idle code by moving the initial invocation of dpm_suspend_noirq() into s2idle_loop(). This also causes debug messages from that code to appear in a less confusing order. Signed-off-by: Rafael J. Wysocki

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