Commit graph

11 commits

Author SHA1 Message Date
Pingfan Liu
55f2503c3b PM / reboot: Eliminate race between reboot and suspend
At present, "systemctl suspend" and "shutdown" can run in parrallel. A
system can suspend after devices_shutdown(), and resume. Then the shutdown
task goes on to power off. This causes many devices are not really shut
off. Hence replacing reboot_mutex with system_transition_mutex (renamed
from pm_mutex) to achieve the exclusion. The renaming of pm_mutex as
system_transition_mutex can be better to reflect the purpose of the mutex.

Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-08-06 12:35:20 +02:00
Andrey Smirnov
2d8364bae4 kernel/reboot.c: add devm_register_reboot_notifier()
Add devm_* wrapper around register_reboot_notifier to simplify device
specific reboot notifier registration/unregistration.

[akpm@linux-foundation.org: move `struct device' forward decl to top-of-file]
Link: http://lkml.kernel.org/r/20170320171753.1705-1-andrew.smirnov@gmail.com
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17 16:10:04 -08:00
Dave Young
2965faa5e0 kexec: split kexec_load syscall from kexec core code
There are two kexec load syscalls, kexec_load another and kexec_file_load.
 kexec_file_load has been splited as kernel/kexec_file.c.  In this patch I
split kexec_load syscall code to kernel/kexec.c.

And add a new kconfig option KEXEC_CORE, so we can disable kexec_load and
use kexec_file_load only, or vice verse.

The original requirement is from Ted Ts'o, he want kexec kernel signature
being checked with CONFIG_KEXEC_VERIFY_SIG enabled.  But kexec-tools use
kexec_load syscall can bypass the checking.

Vivek Goyal proposed to create a common kconfig option so user can compile
in only one syscall for loading kexec kernel.  KEXEC/KEXEC_FILE selects
KEXEC_CORE so that old config files still work.

Because there's general code need CONFIG_KEXEC_CORE, so I updated all the
architecture Kconfig with a new option KEXEC_CORE, and let KEXEC selects
KEXEC_CORE in arch Kconfig.  Also updated general kernel code with to
kexec_load syscall.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Dave Young <dyoung@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Petr Tesarik <ptesarik@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-10 13:29:01 -07:00
Joel Stanley
7a54f46b30 kernel/reboot.c: add orderly_reboot for graceful reboot
The kernel has orderly_poweroff which allows the kernel to initiate a
graceful shutdown of userspace, by running /sbin/poweroff.  This adds
orderly_reboot that will cause userspace to shut itself down by calling
/sbin/reboot.

This will be used for shutdown initiated by a system controller on
platforms that do not use ACPI.

orderly_reboot() should be used when the system wants to allow userspace
to gracefully shut itself down.  For cases where the system may imminently
catch on fire, the existing emergency_restart() provides an immediate
reboot without involving userspace.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Kerr <jk@ozlabs.org>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15 16:35:23 -07:00
Guenter Roeck
b63adb9795 kernel: add support for kernel restart handler call chain
Various drivers implement architecture and/or device specific means to
restart (reset) the system.  Various mechanisms have been implemented to
support those schemes.  The best known mechanism is arm_pm_restart, which
is a function pointer to be set either from platform specific code or from
drivers.  Another mechanism is to use hardware watchdogs to issue a reset;
this mechanism is used if there is no other method available to reset a
board or system.  Two examples are alim7101_wdt, which currently uses the
reboot notifier to trigger a reset, and moxart_wdt, which registers the
arm_pm_restart function.

The existing mechanisms have a number of drawbacks.  Typically only one
scheme to restart the system is supported (at least if arm_pm_restart is
used).  At least in theory there can be multiple means to restart the
system, some of which may be less desirable (for example one mechanism may
only reset the CPU, while another may reset the entire system).  Using
arm_pm_restart can also be racy if the function pointer is set from a
driver, as the driver may be in the process of being unloaded when
arm_pm_restart is called.  Using the reboot notifier is always racy, as it
is unknown if and when other functions using the reboot notifier have
completed execution by the time the watchdog fires.

Introduce a system restart handler call chain to solve the described
problems.  This call chain is expected to be executed from the
architecture specific machine_restart() function.  Drivers providing
system restart functionality (such as the watchdog drivers mentioned
above) are expected to register with this call chain.  By using the
priority field in the notifier block, callers can control restart handler
execution sequence and thus ensure that the restart handler with the
optimal restart capabilities for a given system is called first.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Wim Van Sebroeck <wim@iguana.be>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jonas Jensen <jonas.jensen@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2014-09-26 00:00:06 -07:00
Fabian Frederick
616feab753 kernel/reboot.c: convert simple_strtoul to kstrtoint
Replace obsolete function.
kstrtoint is used as reboot_cpu is an integer.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:15 -07:00
Vivek Goyal
c97102ba96 kexec: migrate to reboot cpu
Commit 1b3a5d02ee ("reboot: move arch/x86 reboot= handling to generic
kernel") moved reboot= handling to generic code.  In the process it also
removed the code in native_machine_shutdown() which are moving reboot
process to reboot_cpu/cpu0.

I guess that thought must have been that all reboot paths are calling
migrate_to_reboot_cpu(), so we don't need this special handling.  But
kexec reboot path (kernel_kexec()) is not calling
migrate_to_reboot_cpu() so above change broke kexec.  Now reboot can
happen on non-boot cpu and when INIT is sent in second kerneo to bring
up BP, it brings down the machine.

So start calling migrate_to_reboot_cpu() in kexec reboot path to avoid
this problem.

Bisected by WANG Chao.

Reported-by: Matthew Whitehead <mwhitehe@redhat.com>
Reported-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Tested-by: Baoquan He <bhe@redhat.com>
Tested-by: WANG Chao <chaowang@redhat.com>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-12-18 19:04:50 -08:00
Chuansheng Liu
e2f0b88e84 kernel/reboot.c: re-enable the function of variable reboot_default
Commit 1b3a5d02ee ("reboot: move arch/x86 reboot= handling to generic
kernel") did some cleanup for reboot= command line, but it made the
reboot_default inoperative.

The default value of variable reboot_default should be 1, and if command
line reboot= is not set, system will use the default reboot mode.

[akpm@linux-foundation.org: fix comment layout]
Signed-off-by: Li Fei <fei.li@intel.com>
Signed-off-by: liu chuansheng <chuansheng.liu@intel.com>
Acked-by: Robin Holt <robinmholt@linux.com>
Cc: <stable@vger.kernel.org>	[3.11.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24 17:00:26 -07:00
Robin Holt
1b3a5d02ee reboot: move arch/x86 reboot= handling to generic kernel
Merge together the unicore32, arm, and x86 reboot= command line
parameter handling.

Signed-off-by: Robin Holt <holt@sgi.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Russ Anderson <rja@sgi.com>
Cc: Robin Holt <holt@sgi.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 10:33:29 -07:00
Robin Holt
972ee83df8 reboot: checkpatch.pl the new kernel/reboot.c file
Get the new file to pass scripts/checkpatch.pl

Signed-off-by: Robin Holt <holt@sgi.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Russ Anderson <rja@sgi.com>
Cc: Robin Holt <holt@sgi.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 10:33:29 -07:00
Robin Holt
15d94b8256 reboot: move shutdown/reboot related functions to kernel/reboot.c
This patch is preparatory.  It moves reboot related syscall, etc
functions from kernel/sys.c to kernel/reboot.c.

Signed-off-by: Robin Holt <holt@sgi.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Russ Anderson <rja@sgi.com>
Cc: Robin Holt <holt@sgi.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 10:33:29 -07:00