user/sven/linux.git/kernel/reboot.c, branch v5.15.19

reboot: Add hardware protection power-off

2021-06-21T12:08:36Z

There can be few cases when we need to shut-down the system in order to protect the hardware. Currently this is done at least by the thermal core when temperature raises over certain limit. Some PMICs can also generate interrupts for example for over-current or over-voltage, voltage drops, short-circuit, ... etc. On some systems these are a sign of hardware failure and only thing to do is try to protect the rest of the hardware by shutting down the system. Add shut-down logic which can be used by all subsystems instead of implementing the shutdown in each subsystem. The logic is stolen from thermal_core with difference of using atomic_t instead of a mutex in order to allow calls directly from IRQ context and changing the WARN() to pr_emerg() as discussed here: https://lore.kernel.org/lkml/YJuPwAZroVZ%2Fw633@alley/ and here: https://lore.kernel.org/linux-iommu/20210331093104.383705-4-geert+renesas@glider.be/ Signed-off-by: Matti Vaittinen Acked-by: Daniel Lezcano Link: https://lore.kernel.org/r/e83ec1ca9408f90c857ea9dcdc57b14d9037b03f.1622628333.git.matti.vaittinen@fi.rohmeurope.com Signed-off-by: Mark Brown

Revert "PM: ACPI: reboot: Use S5 for reboot"

2021-03-18T15:58:02Z

This reverts commit d60cd06331a3566d3305b3c7b566e79edf4e2095. This patch causes a panic when rebooting my Dell Poweredge r440. I do not have the full panic log as it's lost at that stage of the reboot and I do not have a serial console. Reverting this patch makes my system able to reboot again. Signed-off-by: Josef Bacik Signed-off-by: Rafael J. Wysocki

reboot: hide from sysfs not applicable settings

2020-12-16T06:46:19Z

Not all the reboot settings from both the kernel command line or sysfs interface are available to all platforms. Filter out reboot_type and reboot_force which are x86 only, and also remove reboot_cpu on kernels without SMP support. This saves some space, and avoid confusing the user with settings which will have no effect. Link: https://lkml.kernel.org/r/20201130173717.198952-3-mcroce@linux.microsoft.com Signed-off-by: Matteo Croce Reviewed-by: Petr Mladek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

reboot: allow to override reboot type if quirks are found

2020-12-16T06:46:19Z

Patch series "reboot: sysfs improvements". Some improvements to the sysfs reboot interface: hide not working settings and support machines with known reboot quirks. This patch (of 2): On some machines a quirk can force a specific reboot type. Quirks are found during a DMI scan, the list of machines which need special reboot handling is defined in reboot_dmi_table. The kernel command line reboot= option overrides this via a global variable `reboot_default`, so that the reboot type requested in the command line is really performed. This was not true when setting the reboot type via the new sysfs interface. Fix this by setting reboot_default upon the first change, like reboot_setup() does for the command line. Link: https://lkml.kernel.org/r/20201130173717.198952-1-mcroce@linux.microsoft.com Link: https://lkml.kernel.org/r/20201130173717.198952-2-mcroce@linux.microsoft.com Signed-off-by: Matteo Croce Reviewed-by: Petr Mladek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

reboot: remove cf9_safe from allowed types and rename cf9_force

2020-12-16T06:46:19Z

BOOT_CF9_SAFE_STR is an internal value used only by the x86 code and it's not possible to set it from userspace. Remove it, and rename 'cf9_force' to 'pci', so to make it coherent with the kernel command line reboot= option. Tested with this script: cd /sys/kernel/reboot/ for i in cold warm hard soft gpio; do echo $i >mode read j type read j cpu read j force read j Cc: Arnd Bergmann Cc: Guenter Roeck Cc: Kees Cook Cc: Mike Rapoport Cc: Nathan Chancellor Cc: Pavel Tatashin Cc: Petr Mladek Cc: Tyler Hicks Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

reboot: allow to specify reboot mode via sysfs

2020-12-16T06:46:19Z

The kernel cmdline reboot= option offers some sort of control on how the reboot is issued. We don't always know in advance what type of reboot to perform. Sometimes a warm reboot is preferred to persist certain memory regions across the reboot. Others a cold one is needed to apply a future system update that makes a memory memory model change, like changing the base page size or resizing a persistent memory region. Or simply we want to enable reboot_force because we noticed that something bad happened. Add handles in sysfs to allow setting these reboot options, so they can be changed when the system is booted, other than at boot time. The handlers are under /kernel/reboot, can be read to get the current configuration and written to alter it. # cd /sys/kernel/reboot/ # grep . * cpu:0 force:0 mode:cold type:acpi # echo 2 >cpu # echo yes >force # echo soft >mode # echo bios >type # grep . * cpu:2 force:1 mode:soft type:bios Before setting anything, check for CAP_SYS_BOOT capability, so it's possible to allow an unpriviledged process to change these settings simply by relaxing the handles permissions, without opening them to the world. [natechancellor@gmail.com: fix variable assignments in type_store] Link: https://lkml.kernel.org/r/20201112035023.974748-1-natechancellor@gmail.com Link: https://github.com/ClangBuiltLinux/linux/issues/1197 Link: https://lkml.kernel.org/r/20201110202746.9690-1-mcroce@linux.microsoft.com Signed-off-by: Matteo Croce Signed-off-by: Nathan Chancellor Reviewed-by: Petr Mladek Cc: Mike Rapoport Cc: Guenter Roeck Cc: Arnd Bergmann Cc: Pavel Tatashin Cc: Kees Cook Cc: Tyler Hicks Cc: Nathan Chancellor Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

reboot: refactor and comment the cpu selection code

2020-12-16T06:46:19Z

Small improvements to the code, without changing the way it works: - use a local variable, to avoid a small time lapse where reboot_cpu can have an invalid value - comment the code which is not easy to understand at a glance - merge two identical code blocks into one - replace pointer arithmetics with equivalent array syntax Link: https://lkml.kernel.org/r/20201103214025.116799-4-mcroce@linux.microsoft.com Signed-off-by: Matteo Croce Cc: Arnd Bergmann Cc: Fabian Frederick Cc: Greg Kroah-Hartman Cc: Guenter Roeck Cc: Kees Cook Cc: Mike Rapoport Cc: Pavel Tatashin Cc: Petr Mladek Cc: Robin Holt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branches 'pm-sleep', 'pm-acpi', 'pm-domains' and 'powercap'

2020-12-15T14:26:14Z

* pm-sleep: PM: sleep: Add dev_wakeup_path() helper PM / suspend: fix kernel-doc markup PM: sleep: Print driver flags for all devices during suspend/resume * pm-acpi: PM: ACPI: Refresh wakeup device power configuration every time PM: ACPI: PCI: Drop acpi_pm_set_bridge_wakeup() PM: ACPI: reboot: Use S5 for reboot * pm-domains: PM: domains: create debugfs nodes when adding power domains PM: domains: replace -ENOTSUPP with -EOPNOTSUPP * powercap: powercap: Adjust printing the constraint name with new line powercap: RAPL: Add AMD Fam19h RAPL support powercap: Add AMD Fam17h RAPL support powercap/intel_rapl_msr: Convert rapl_msr_priv into pointer x86/msr-index: sort AMD RAPL MSRs by address

reboot: fix overflow parsing reboot cpu number

2020-11-14T19:26:03Z

Limit the CPU number to num_possible_cpus(), because setting it to a value lower than INT_MAX but higher than NR_CPUS produces the following error on reboot and shutdown: BUG: unable to handle page fault for address: ffffffff90ab1bb0 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 1c09067 P4D 1c09067 PUD 1c0a063 PMD 0 Oops: 0000 [#1] SMP CPU: 1 PID: 1 Comm: systemd-shutdow Not tainted 5.9.0-rc8-kvm #110 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 RIP: 0010:migrate_to_reboot_cpu+0xe/0x60 Code: ea ea 00 48 89 fa 48 c7 c7 30 57 f1 81 e9 fa ef ff ff 66 2e 0f 1f 84 00 00 00 00 00 53 8b 1d d5 ea ea 00 e8 14 33 fe ff 89 da <48> 0f a3 15 ea fc bd 00 48 89 d0 73 29 89 c2 c1 e8 06 65 48 8b 3c RSP: 0018:ffffc90000013e08 EFLAGS: 00010246 RAX: ffff88801f0a0000 RBX: 0000000077359400 RCX: 0000000000000000 RDX: 0000000077359400 RSI: 0000000000000002 RDI: ffffffff81c199e0 RBP: ffffffff81c1e3c0 R08: ffff88801f41f000 R09: ffffffff81c1e348 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 00007f32bedf8830 R14: 00000000fee1dead R15: 0000000000000000 FS: 00007f32bedf8980(0000) GS:ffff88801f480000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffff90ab1bb0 CR3: 000000001d057000 CR4: 00000000000006a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __do_sys_reboot.cold+0x34/0x5b do_syscall_64+0x2d/0x40 Fixes: 1b3a5d02ee07 ("reboot: move arch/x86 reboot= handling to generic kernel") Signed-off-by: Matteo Croce Signed-off-by: Andrew Morton Cc: Arnd Bergmann Cc: Fabian Frederick Cc: Greg Kroah-Hartman Cc: Guenter Roeck Cc: Kees Cook Cc: Mike Rapoport Cc: Pavel Tatashin Cc: Petr Mladek Cc: Robin Holt Cc: Link: https://lkml.kernel.org/r/20201103214025.116799-3-mcroce@linux.microsoft.com Signed-off-by: Linus Torvalds

Revert "kernel/reboot.c: convert simple_strtoul to kstrtoint"

2020-11-14T19:26:03Z

Patch series "fix parsing of reboot= cmdline", v3. The parsing of the reboot= cmdline has two major errors: - a missing bound check can crash the system on reboot - parsing of the cpu number only works if specified last Fix both. This patch (of 2): This reverts commit 616feab753972b97. kstrtoint() and simple_strtoul() have a subtle difference which makes them non interchangeable: if a non digit character is found amid the parsing, the former will return an error, while the latter will just stop parsing, e.g. simple_strtoul("123xyx") = 123. The kernel cmdline reboot= argument allows to specify the CPU used for rebooting, with the syntax `s####` among the other flags, e.g. "reboot=warm,s31,force", so if this flag is not the last given, it's silently ignored as well as the subsequent ones. Fixes: 616feab75397 ("kernel/reboot.c: convert simple_strtoul to kstrtoint") Signed-off-by: Matteo Croce Signed-off-by: Andrew Morton Cc: Guenter Roeck Cc: Petr Mladek Cc: Arnd Bergmann Cc: Mike Rapoport Cc: Kees Cook Cc: Pavel Tatashin Cc: Robin Holt Cc: Fabian Frederick Cc: Greg Kroah-Hartman Cc: Link: https://lkml.kernel.org/r/20201103214025.116799-2-mcroce@linux.microsoft.com Signed-off-by: Linus Torvalds