From 06d177662fb86b80c7fc2290667b9a14cb0bd925 Mon Sep 17 00:00:00 2001 From: tangmeng Date: Thu, 17 Feb 2022 12:23:21 +0800 Subject: kernel/reboot: move reboot sysctls to its own file kernel/sysctl.c is a kitchen sink where everyone leaves their dirty dishes, this makes it very difficult to maintain. To help with this maintenance let's start by moving sysctls to places where they actually belong. The proc sysctl maintainers do not want to know what sysctl knobs you wish to add for your own piece of code, we just care about the core logic. All filesystem syctls now get reviewed by fs folks. This commit follows the commit of fs, move the poweroff_cmd and ctrl-alt-del sysctls to its own file, kernel/reboot.c. Signed-off-by: tangmeng Signed-off-by: Luis Chamberlain --- kernel/reboot.c | 34 ++++++++++++++++++++++++++++++++-- 1 file changed, 32 insertions(+), 2 deletions(-) (limited to 'kernel/reboot.c') diff --git a/kernel/reboot.c b/kernel/reboot.c index 6bcc5d6a6572..ed4e6dfb7d44 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -23,7 +23,7 @@ * this indicates whether you can reboot with ctrl-alt-del: the default is yes */ -int C_A_D = 1; +static int C_A_D = 1; struct pid *cad_pid; EXPORT_SYMBOL(cad_pid); @@ -417,9 +417,37 @@ void ctrl_alt_del(void) kill_cad_pid(SIGINT, 1); } -char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff"; +#define POWEROFF_CMD_PATH_LEN 256 +static char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff"; static const char reboot_cmd[] = "/sbin/reboot"; +#ifdef CONFIG_SYSCTL +static struct ctl_table kern_reboot_table[] = { + { + .procname = "poweroff_cmd", + .data = &poweroff_cmd, + .maxlen = POWEROFF_CMD_PATH_LEN, + .mode = 0644, + .proc_handler = proc_dostring, + }, + { + .procname = "ctrl-alt-del", + .data = &C_A_D, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { } +}; + +static void __init kernel_reboot_sysctls_init(void) +{ + register_sysctl_init("kernel", kern_reboot_table); +} +#else +#define kernel_reboot_sysctls_init() do { } while (0) +#endif /* CONFIG_SYSCTL */ + static int run_cmd(const char *cmd) { char **argv; @@ -886,6 +914,8 @@ static int __init reboot_ksysfs_init(void) return ret; } + kernel_reboot_sysctls_init(); + return 0; } late_initcall(reboot_ksysfs_init); -- cgit v1.2.3 From 2bb2b7b57f81255c13f4395ea911d6bdc70c9fe2 Mon Sep 17 00:00:00 2001 From: John Ogness Date: Thu, 21 Apr 2022 23:28:47 +0206 Subject: printk: add functions to prefer direct printing Once kthread printing is available, console printing will no longer occur in the context of the printk caller. However, there are some special contexts where it is desirable for the printk caller to directly print out kernel messages. Using pr_flush() to wait for threaded printers is only possible if the caller is in a sleepable context and the kthreads are active. That is not always the case. Introduce printk_prefer_direct_enter() and printk_prefer_direct_exit() functions to explicitly (and globally) activate/deactivate preferred direct console printing. The term "direct console printing" refers to printing to all enabled consoles from the context of the printk caller. The term "prefer" is used because this type of printing is only best effort. If the console is currently locked or other printers are already actively printing, the printk caller will need to rely on the other contexts to handle the printing. This preferred direct printing is how all printing has been handled until now (unless it was explicitly deferred). When kthread printing is introduced, there may be some unanticipated problems due to kthreads being unable to flush important messages. In order to minimize such risks, preferred direct printing is activated for the primary important messages when the system experiences general types of major errors. These are: - emergency reboot/shutdown - cpu and rcu stalls - hard and soft lockups - hung tasks - warn - sysrq Note that since kthread printing does not yet exist, no behavior changes result from this commit. This is only implementing the counter and marking the various places where preferred direct printing is active. Signed-off-by: John Ogness Reviewed-by: Petr Mladek Acked-by: Paul E. McKenney # for RCU Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20220421212250.565456-13-john.ogness@linutronix.de --- kernel/reboot.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'kernel/reboot.c') diff --git a/kernel/reboot.c b/kernel/reboot.c index 6bcc5d6a6572..4177645e74d6 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -447,9 +447,11 @@ static int __orderly_reboot(void) ret = run_cmd(reboot_cmd); if (ret) { + printk_prefer_direct_enter(); pr_warn("Failed to start orderly reboot: forcing the issue\n"); emergency_sync(); kernel_restart(NULL); + printk_prefer_direct_exit(); } return ret; @@ -462,6 +464,7 @@ static int __orderly_poweroff(bool force) ret = run_cmd(poweroff_cmd); if (ret && force) { + printk_prefer_direct_enter(); pr_warn("Failed to start orderly shutdown: forcing the issue\n"); /* @@ -471,6 +474,7 @@ static int __orderly_poweroff(bool force) */ emergency_sync(); kernel_power_off(); + printk_prefer_direct_exit(); } return ret; @@ -528,6 +532,8 @@ EXPORT_SYMBOL_GPL(orderly_reboot); */ static void hw_failure_emergency_poweroff_func(struct work_struct *work) { + printk_prefer_direct_enter(); + /* * We have reached here after the emergency shutdown waiting period has * expired. This means orderly_poweroff has not been able to shut off @@ -544,6 +550,8 @@ static void hw_failure_emergency_poweroff_func(struct work_struct *work) */ pr_emerg("Hardware protection shutdown failed. Trying emergency restart\n"); emergency_restart(); + + printk_prefer_direct_exit(); } static DECLARE_DELAYED_WORK(hw_failure_emergency_poweroff_work, @@ -582,11 +590,13 @@ void hw_protection_shutdown(const char *reason, int ms_until_forced) { static atomic_t allow_proceed = ATOMIC_INIT(1); + printk_prefer_direct_enter(); + pr_emerg("HARDWARE PROTECTION shutdown (%s)\n", reason); /* Shutdown should be initiated only once. */ if (!atomic_dec_and_test(&allow_proceed)) - return; + goto out; /* * Queue a backup emergency shutdown in the event of @@ -594,6 +604,8 @@ void hw_protection_shutdown(const char *reason, int ms_until_forced) */ hw_failure_emergency_poweroff(ms_until_forced); orderly_poweroff(true); +out: + printk_prefer_direct_exit(); } EXPORT_SYMBOL_GPL(hw_protection_shutdown); -- cgit v1.2.3 From 764aaf44cd64dd1f760268ee0b22d2dc53cd5bc0 Mon Sep 17 00:00:00 2001 From: YueHaibing Date: Wed, 27 Apr 2022 20:54:01 +0800 Subject: reboot: Fix build warning without CONFIG_SYSCTL MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If CONFIG_SYSCTL is n, build warn: kernel/reboot.c:443:20: error: ‘kernel_reboot_sysctls_init’ defined but not used [-Werror=unused-function] static void __init kernel_reboot_sysctls_init(void) ^~~~~~~~~~~~~~~~~~~~~~~~~~ Move kernel_reboot_sysctls_init() to #ifdef block to fix this. Fixes: 06d177662fb8 ("kernel/reboot: move reboot sysctls to its own file") Signed-off-by: YueHaibing Signed-off-by: Luis Chamberlain --- kernel/reboot.c | 54 +++++++++++++++++++++++++++--------------------------- 1 file changed, 27 insertions(+), 27 deletions(-) (limited to 'kernel/reboot.c') diff --git a/kernel/reboot.c b/kernel/reboot.c index ed4e6dfb7d44..ecbf09ea03c5 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -421,33 +421,6 @@ void ctrl_alt_del(void) static char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff"; static const char reboot_cmd[] = "/sbin/reboot"; -#ifdef CONFIG_SYSCTL -static struct ctl_table kern_reboot_table[] = { - { - .procname = "poweroff_cmd", - .data = &poweroff_cmd, - .maxlen = POWEROFF_CMD_PATH_LEN, - .mode = 0644, - .proc_handler = proc_dostring, - }, - { - .procname = "ctrl-alt-del", - .data = &C_A_D, - .maxlen = sizeof(int), - .mode = 0644, - .proc_handler = proc_dointvec, - }, - { } -}; - -static void __init kernel_reboot_sysctls_init(void) -{ - register_sysctl_init("kernel", kern_reboot_table); -} -#else -#define kernel_reboot_sysctls_init() do { } while (0) -#endif /* CONFIG_SYSCTL */ - static int run_cmd(const char *cmd) { char **argv; @@ -895,6 +868,33 @@ static struct attribute *reboot_attrs[] = { NULL, }; +#ifdef CONFIG_SYSCTL +static struct ctl_table kern_reboot_table[] = { + { + .procname = "poweroff_cmd", + .data = &poweroff_cmd, + .maxlen = POWEROFF_CMD_PATH_LEN, + .mode = 0644, + .proc_handler = proc_dostring, + }, + { + .procname = "ctrl-alt-del", + .data = &C_A_D, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { } +}; + +static void __init kernel_reboot_sysctls_init(void) +{ + register_sysctl_init("kernel", kern_reboot_table); +} +#else +#define kernel_reboot_sysctls_init() do { } while (0) +#endif /* CONFIG_SYSCTL */ + static const struct attribute_group reboot_attr_group = { .attrs = reboot_attrs, }; -- cgit v1.2.3 From 232edc2f72f5beda3586360de6254d443820050a Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Tue, 10 May 2022 02:32:11 +0300 Subject: kernel/reboot: Introduce sys-off handler API In order to support power-off chaining we need to get rid of the global pm_* variables, replacing them with the new kernel API functions that support chaining. Introduce new generic sys-off handler API that brings the following features: 1. Power-off and restart handlers are registered using same API function that supports chaining, hence all power-off and restart modes will support chaining using this unified function. 2. Prevents notifier priority collisions by disallowing registration of multiple handlers at the non-default priority level. 3. Supports passing opaque user argument to callback, which allows us to remove global variables from drivers. This patch adds support of the following sys-off modes: - SYS_OFF_MODE_POWER_OFF_PREPARE that replaces global pm_power_off_prepare variable and provides chaining support for power-off-prepare handlers. - SYS_OFF_MODE_POWER_OFF that replaces global pm_power_off variable and provides chaining support for power-off handlers. - SYS_OFF_MODE_RESTART that provides a better restart API, removing a need from drivers to have a global scratch variable by utilizing the opaque callback argument. Signed-off-by: Dmitry Osipenko Signed-off-by: Rafael J. Wysocki --- kernel/reboot.c | 182 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 182 insertions(+) (limited to 'kernel/reboot.c') diff --git a/kernel/reboot.c b/kernel/reboot.c index 6bcc5d6a6572..3e6867ee61e0 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -48,6 +48,15 @@ int reboot_cpu; enum reboot_type reboot_type = BOOT_ACPI; int reboot_force; +struct sys_off_handler { + struct notifier_block nb; + int (*sys_off_cb)(struct sys_off_data *data); + void *cb_data; + enum sys_off_mode mode; + bool blocking; + void *list; +}; + /* * If set, this is used for preparing the system to power off. */ @@ -281,6 +290,179 @@ void kernel_halt(void) } EXPORT_SYMBOL_GPL(kernel_halt); +/* + * Notifier list for kernel code which wants to be called + * to prepare system for power off. + */ +static BLOCKING_NOTIFIER_HEAD(power_off_prep_handler_list); + +/* + * Notifier list for kernel code which wants to be called + * to power off system. + */ +static ATOMIC_NOTIFIER_HEAD(power_off_handler_list); + +static int sys_off_notify(struct notifier_block *nb, + unsigned long mode, void *cmd) +{ + struct sys_off_handler *handler; + struct sys_off_data data = {}; + + handler = container_of(nb, struct sys_off_handler, nb); + data.cb_data = handler->cb_data; + data.mode = mode; + data.cmd = cmd; + + return handler->sys_off_cb(&data); +} + +/** + * register_sys_off_handler - Register sys-off handler + * @mode: Sys-off mode + * @priority: Handler priority + * @callback: Callback function + * @cb_data: Callback argument + * + * Registers system power-off or restart handler that will be invoked + * at the step corresponding to the given sys-off mode. Handler's callback + * should return NOTIFY_DONE to permit execution of the next handler in + * the call chain or NOTIFY_STOP to break the chain (in error case for + * example). + * + * Multiple handlers can be registered at the default priority level. + * + * Only one handler can be registered at the non-default priority level, + * otherwise ERR_PTR(-EBUSY) is returned. + * + * Returns a new instance of struct sys_off_handler on success, or + * an ERR_PTR()-encoded error code otherwise. + */ +struct sys_off_handler * +register_sys_off_handler(enum sys_off_mode mode, + int priority, + int (*callback)(struct sys_off_data *data), + void *cb_data) +{ + struct sys_off_handler *handler; + int err; + + handler = kzalloc(sizeof(*handler), GFP_KERNEL); + if (!handler) + return ERR_PTR(-ENOMEM); + + switch (mode) { + case SYS_OFF_MODE_POWER_OFF_PREPARE: + handler->list = &power_off_prep_handler_list; + handler->blocking = true; + break; + + case SYS_OFF_MODE_POWER_OFF: + handler->list = &power_off_handler_list; + break; + + case SYS_OFF_MODE_RESTART: + handler->list = &restart_handler_list; + break; + + default: + kfree(handler); + return ERR_PTR(-EINVAL); + } + + handler->nb.notifier_call = sys_off_notify; + handler->nb.priority = priority; + handler->sys_off_cb = callback; + handler->cb_data = cb_data; + handler->mode = mode; + + if (handler->blocking) { + if (priority == SYS_OFF_PRIO_DEFAULT) + err = blocking_notifier_chain_register(handler->list, + &handler->nb); + else + err = blocking_notifier_chain_register_unique_prio(handler->list, + &handler->nb); + } else { + if (priority == SYS_OFF_PRIO_DEFAULT) + err = atomic_notifier_chain_register(handler->list, + &handler->nb); + else + err = atomic_notifier_chain_register_unique_prio(handler->list, + &handler->nb); + } + + if (err) { + kfree(handler); + return ERR_PTR(err); + } + + return handler; +} +EXPORT_SYMBOL_GPL(register_sys_off_handler); + +/** + * unregister_sys_off_handler - Unregister sys-off handler + * @handler: Sys-off handler + * + * Unregisters given sys-off handler. + */ +void unregister_sys_off_handler(struct sys_off_handler *handler) +{ + int err; + + if (!handler) + return; + + if (handler->blocking) + err = blocking_notifier_chain_unregister(handler->list, + &handler->nb); + else + err = atomic_notifier_chain_unregister(handler->list, + &handler->nb); + + /* sanity check, shall never happen */ + WARN_ON(err); + + kfree(handler); +} +EXPORT_SYMBOL_GPL(unregister_sys_off_handler); + +static void devm_unregister_sys_off_handler(void *data) +{ + struct sys_off_handler *handler = data; + + unregister_sys_off_handler(handler); +} + +/** + * devm_register_sys_off_handler - Register sys-off handler + * @dev: Device that registers handler + * @mode: Sys-off mode + * @priority: Handler priority + * @callback: Callback function + * @cb_data: Callback argument + * + * Registers resource-managed sys-off handler. + * + * Returns zero on success, or error code on failure. + */ +int devm_register_sys_off_handler(struct device *dev, + enum sys_off_mode mode, + int priority, + int (*callback)(struct sys_off_data *data), + void *cb_data) +{ + struct sys_off_handler *handler; + + handler = register_sys_off_handler(mode, priority, callback, cb_data); + if (IS_ERR(handler)) + return PTR_ERR(handler); + + return devm_add_action_or_reset(dev, devm_unregister_sys_off_handler, + handler); +} +EXPORT_SYMBOL_GPL(devm_register_sys_off_handler); + /** * kernel_power_off - power_off the system * -- cgit v1.2.3 From 7b9a3de9ffe76e4a965bafe26c91d9c6351e1e18 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Tue, 10 May 2022 02:32:12 +0300 Subject: kernel/reboot: Wrap legacy power-off callbacks into sys-off handlers Wrap legacy power-off callbacks into sys-off handlers in order to support co-existence of both legacy and new callbacks while we're in process of upgrading legacy callbacks to the new API. Signed-off-by: Dmitry Osipenko Signed-off-by: Rafael J. Wysocki --- kernel/reboot.c | 44 ++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 42 insertions(+), 2 deletions(-) (limited to 'kernel/reboot.c') diff --git a/kernel/reboot.c b/kernel/reboot.c index 3e6867ee61e0..96f681f7b20c 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -463,6 +463,47 @@ int devm_register_sys_off_handler(struct device *dev, } EXPORT_SYMBOL_GPL(devm_register_sys_off_handler); +static int legacy_pm_power_off_prepare(struct sys_off_data *data) +{ + if (pm_power_off_prepare) + pm_power_off_prepare(); + + return NOTIFY_DONE; +} + +static int legacy_pm_power_off(struct sys_off_data *data) +{ + if (pm_power_off) + pm_power_off(); + + return NOTIFY_DONE; +} + +/* + * Register sys-off handlers for legacy PM callbacks. This allows legacy + * PM callbacks co-exist with the new sys-off API. + * + * TODO: Remove legacy handlers once all legacy PM users will be switched + * to the sys-off based APIs. + */ +static int __init legacy_pm_init(void) +{ + register_sys_off_handler(SYS_OFF_MODE_POWER_OFF_PREPARE, + SYS_OFF_PRIO_DEFAULT, + legacy_pm_power_off_prepare, NULL); + + register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, SYS_OFF_PRIO_DEFAULT, + legacy_pm_power_off, NULL); + + return 0; +} +core_initcall(legacy_pm_init); + +static void do_kernel_power_off_prepare(void) +{ + blocking_notifier_call_chain(&power_off_prep_handler_list, 0, NULL); +} + /** * kernel_power_off - power_off the system * @@ -471,8 +512,7 @@ EXPORT_SYMBOL_GPL(devm_register_sys_off_handler); void kernel_power_off(void) { kernel_shutdown_prepare(SYSTEM_POWER_OFF); - if (pm_power_off_prepare) - pm_power_off_prepare(); + do_kernel_power_off_prepare(); migrate_to_reboot_cpu(); syscore_shutdown(); pr_emerg("Power down\n"); -- cgit v1.2.3 From 2b6aa7332f8020dfdaffe340ff038aac4df35238 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Tue, 10 May 2022 02:32:13 +0300 Subject: kernel/reboot: Add do_kernel_power_off() Add do_kernel_power_off() helper that will remove open-coded pm_power_off invocations from the architecture code. This is the first step on the way to remove the global pm_power_off variable, which will allow us to implement consistent power-off chaining support. Signed-off-by: Dmitry Osipenko Signed-off-by: Rafael J. Wysocki --- kernel/reboot.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'kernel/reboot.c') diff --git a/kernel/reboot.c b/kernel/reboot.c index 96f681f7b20c..892d25aa12df 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -504,6 +504,19 @@ static void do_kernel_power_off_prepare(void) blocking_notifier_call_chain(&power_off_prep_handler_list, 0, NULL); } +/** + * do_kernel_power_off - Execute kernel power-off handler call chain + * + * Expected to be called as last step of the power-off sequence. + * + * Powers off the system immediately if a power-off handler function has + * been registered. Otherwise does nothing. + */ +void do_kernel_power_off(void) +{ + atomic_notifier_call_chain(&power_off_handler_list, 0, NULL); +} + /** * kernel_power_off - power_off the system * -- cgit v1.2.3 From 5d34b41aa420c3908793b43419a1097362ca2668 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Tue, 10 May 2022 02:32:14 +0300 Subject: kernel/reboot: Add stub for pm_power_off Add weak stub for the global pm_power_off callback variable. This will allow us to remove pm_power_off definitions from arch/ code and transition to the new sys-off based API that will replace the global variable. Signed-off-by: Dmitry Osipenko Signed-off-by: Rafael J. Wysocki --- kernel/reboot.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'kernel/reboot.c') diff --git a/kernel/reboot.c b/kernel/reboot.c index 892d25aa12df..7723aff4d09b 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -57,6 +57,12 @@ struct sys_off_handler { void *list; }; +/* + * Temporary stub that prevents linkage failure while we're in process + * of removing all uses of legacy pm_power_off() around the kernel. + */ +void __weak (*pm_power_off)(void); + /* * If set, this is used for preparing the system to power off. */ -- cgit v1.2.3 From 0e2110d2e910e44cc7cf23fce14613e232602602 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Tue, 10 May 2022 02:32:15 +0300 Subject: kernel/reboot: Add kernel_can_power_off() Add kernel_can_power_off() helper that replaces open-coded checks of the global pm_power_off variable. This is a necessary step towards supporting chained power-off handlers. Signed-off-by: Dmitry Osipenko Signed-off-by: Rafael J. Wysocki --- kernel/reboot.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'kernel/reboot.c') diff --git a/kernel/reboot.c b/kernel/reboot.c index 7723aff4d09b..fb3f49350927 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -523,6 +523,18 @@ void do_kernel_power_off(void) atomic_notifier_call_chain(&power_off_handler_list, 0, NULL); } +/** + * kernel_can_power_off - check whether system can be powered off + * + * Returns true if power-off handler is registered and system can be + * powered off, false otherwise. + */ +bool kernel_can_power_off(void) +{ + return !atomic_notifier_call_chain_is_empty(&power_off_handler_list); +} +EXPORT_SYMBOL_GPL(kernel_can_power_off); + /** * kernel_power_off - power_off the system * @@ -581,7 +593,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, /* Instead of trying to make the power_off code look like * halt when pm_power_off is not set do it the easy way. */ - if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off) + if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !kernel_can_power_off()) cmd = LINUX_REBOOT_CMD_HALT; mutex_lock(&system_transition_mutex); -- cgit v1.2.3 From fb61375ecfba49e153af561402f49f6fe3bebd39 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Tue, 10 May 2022 02:32:16 +0300 Subject: kernel/reboot: Add register_platform_power_off() Add platform-level registration helpers that will ease transition of the arch/platform power-off callbacks to the new sys-off based API, allowing us to remove the global pm_power_off variable in the future. Signed-off-by: Dmitry Osipenko Signed-off-by: Rafael J. Wysocki --- kernel/reboot.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) (limited to 'kernel/reboot.c') diff --git a/kernel/reboot.c b/kernel/reboot.c index fb3f49350927..673d3f54dcad 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -469,6 +469,61 @@ int devm_register_sys_off_handler(struct device *dev, } EXPORT_SYMBOL_GPL(devm_register_sys_off_handler); +static struct sys_off_handler *platform_power_off_handler; + +static int platform_power_off_notify(struct sys_off_data *data) +{ + void (*platform_power_power_off_cb)(void) = data->cb_data; + + platform_power_power_off_cb(); + + return NOTIFY_DONE; +} + +/** + * register_platform_power_off - Register platform-level power-off callback + * @power_off: Power-off callback + * + * Registers power-off callback that will be called as last step + * of the power-off sequence. This callback is expected to be invoked + * for the last resort. Only one platform power-off callback is allowed + * to be registered at a time. + * + * Returns zero on success, or error code on failure. + */ +int register_platform_power_off(void (*power_off)(void)) +{ + struct sys_off_handler *handler; + + handler = register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, + SYS_OFF_PRIO_PLATFORM, + platform_power_off_notify, + power_off); + if (IS_ERR(handler)) + return PTR_ERR(handler); + + platform_power_off_handler = handler; + + return 0; +} +EXPORT_SYMBOL_GPL(register_platform_power_off); + +/** + * unregister_platform_power_off - Unregister platform-level power-off callback + * @power_off: Power-off callback + * + * Unregisters previously registered platform power-off callback. + */ +void unregister_platform_power_off(void (*power_off)(void)) +{ + if (platform_power_off_handler && + platform_power_off_handler->cb_data == power_off) { + unregister_sys_off_handler(platform_power_off_handler); + platform_power_off_handler = NULL; + } +} +EXPORT_SYMBOL_GPL(unregister_platform_power_off); + static int legacy_pm_power_off_prepare(struct sys_off_data *data) { if (pm_power_off_prepare) -- cgit v1.2.3 From 5b71808eb7c97815fc3b9c386ca0ef6daf2dc053 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Tue, 10 May 2022 02:32:32 +0300 Subject: reboot: Remove pm_power_off_prepare() All pm_power_off_prepare() users were converted to sys-off handler API. Remove the obsolete global callback variable. Signed-off-by: Dmitry Osipenko Signed-off-by: Rafael J. Wysocki --- kernel/reboot.c | 19 ------------------- 1 file changed, 19 deletions(-) (limited to 'kernel/reboot.c') diff --git a/kernel/reboot.c b/kernel/reboot.c index 673d3f54dcad..88c835167d9e 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -63,13 +63,6 @@ struct sys_off_handler { */ void __weak (*pm_power_off)(void); -/* - * If set, this is used for preparing the system to power off. - */ - -void (*pm_power_off_prepare)(void); -EXPORT_SYMBOL_GPL(pm_power_off_prepare); - /** * emergency_restart - reboot the system * @@ -524,14 +517,6 @@ void unregister_platform_power_off(void (*power_off)(void)) } EXPORT_SYMBOL_GPL(unregister_platform_power_off); -static int legacy_pm_power_off_prepare(struct sys_off_data *data) -{ - if (pm_power_off_prepare) - pm_power_off_prepare(); - - return NOTIFY_DONE; -} - static int legacy_pm_power_off(struct sys_off_data *data) { if (pm_power_off) @@ -549,10 +534,6 @@ static int legacy_pm_power_off(struct sys_off_data *data) */ static int __init legacy_pm_init(void) { - register_sys_off_handler(SYS_OFF_MODE_POWER_OFF_PREPARE, - SYS_OFF_PRIO_DEFAULT, - legacy_pm_power_off_prepare, NULL); - register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, SYS_OFF_PRIO_DEFAULT, legacy_pm_power_off, NULL); -- cgit v1.2.3 From d2c5415327171e6c1bca2dc4d8a77f450ecf7150 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Tue, 10 May 2022 02:32:34 +0300 Subject: kernel/reboot: Add devm_register_power_off_handler() Add devm_register_power_off_handler() helper that registers sys-off handler using power-off mode and with a default priority. Most drivers will want to register power-off handler with a default priority, so this helper will reduce the boilerplate code and make code easier to read and follow. Signed-off-by: Dmitry Osipenko Signed-off-by: Rafael J. Wysocki --- kernel/reboot.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'kernel/reboot.c') diff --git a/kernel/reboot.c b/kernel/reboot.c index 88c835167d9e..4dbb6e29247a 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -462,6 +462,28 @@ int devm_register_sys_off_handler(struct device *dev, } EXPORT_SYMBOL_GPL(devm_register_sys_off_handler); +/** + * devm_register_power_off_handler - Register power-off handler + * @dev: Device that registers callback + * @callback: Callback function + * @cb_data: Callback's argument + * + * Registers resource-managed sys-off handler with a default priority + * and using power-off mode. + * + * Returns zero on success, or error code on failure. + */ +int devm_register_power_off_handler(struct device *dev, + int (*callback)(struct sys_off_data *data), + void *cb_data) +{ + return devm_register_sys_off_handler(dev, + SYS_OFF_MODE_POWER_OFF, + SYS_OFF_PRIO_DEFAULT, + callback, cb_data); +} +EXPORT_SYMBOL_GPL(devm_register_power_off_handler); + static struct sys_off_handler *platform_power_off_handler; static int platform_power_off_notify(struct sys_off_data *data) -- cgit v1.2.3 From 6779db970bd287bb35b28bd5dc256fd7aef19d1c Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Tue, 10 May 2022 02:32:35 +0300 Subject: kernel/reboot: Add devm_register_restart_handler() Add devm_register_restart_handler() helper that registers sys-off handler using restart mode and with a default priority. Most drivers will want to register restart handler with a default priority, so this helper will reduce the boilerplate code and make code easier to read and follow. Signed-off-by: Dmitry Osipenko Signed-off-by: Rafael J. Wysocki --- kernel/reboot.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'kernel/reboot.c') diff --git a/kernel/reboot.c b/kernel/reboot.c index 4dbb6e29247a..bdb635842ec8 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -484,6 +484,28 @@ int devm_register_power_off_handler(struct device *dev, } EXPORT_SYMBOL_GPL(devm_register_power_off_handler); +/** + * devm_register_restart_handler - Register restart handler + * @dev: Device that registers callback + * @callback: Callback function + * @cb_data: Callback's argument + * + * Registers resource-managed sys-off handler with a default priority + * and using restart mode. + * + * Returns zero on success, or error code on failure. + */ +int devm_register_restart_handler(struct device *dev, + int (*callback)(struct sys_off_data *data), + void *cb_data) +{ + return devm_register_sys_off_handler(dev, + SYS_OFF_MODE_RESTART, + SYS_OFF_PRIO_DEFAULT, + callback, cb_data); +} +EXPORT_SYMBOL_GPL(devm_register_restart_handler); + static struct sys_off_handler *platform_power_off_handler; static int platform_power_off_notify(struct sys_off_data *data) -- cgit v1.2.3 From da007f171fc9dd993d03a360b515cac1c87921bb Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Wed, 25 May 2022 00:21:18 +0300 Subject: kernel/reboot: Change registration order of legacy power-off handler We're unconditionally registering sys-off handler for the legacy pm_power_off() callback, this causes problem for platforms that don't use power-off handlers at all and should be halted. Now reboot syscall assumes that there is a power-off handler installed and tries to power off system instead of halting it. To fix the trouble, move the handler's registration to the reboot syscall and check the pm_power_off() presence. Fixes: 0e2110d2e910 ("kernel/reboot: Add kernel_can_power_off()") Reported-by: Geert Uytterhoeven Tested-by: Geert Uytterhoeven Signed-off-by: Dmitry Osipenko Signed-off-by: Rafael J. Wysocki --- kernel/reboot.c | 33 +++++++++++++++++---------------- 1 file changed, 17 insertions(+), 16 deletions(-) (limited to 'kernel/reboot.c') diff --git a/kernel/reboot.c b/kernel/reboot.c index bdb635842ec8..d4aa372c0cdc 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -569,22 +569,6 @@ static int legacy_pm_power_off(struct sys_off_data *data) return NOTIFY_DONE; } -/* - * Register sys-off handlers for legacy PM callbacks. This allows legacy - * PM callbacks co-exist with the new sys-off API. - * - * TODO: Remove legacy handlers once all legacy PM users will be switched - * to the sys-off based APIs. - */ -static int __init legacy_pm_init(void) -{ - register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, SYS_OFF_PRIO_DEFAULT, - legacy_pm_power_off, NULL); - - return 0; -} -core_initcall(legacy_pm_init); - static void do_kernel_power_off_prepare(void) { blocking_notifier_call_chain(&power_off_prep_handler_list, 0, NULL); @@ -646,6 +630,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, void __user *, arg) { struct pid_namespace *pid_ns = task_active_pid_ns(current); + struct sys_off_handler *sys_off = NULL; char buffer[256]; int ret = 0; @@ -670,6 +655,21 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, if (ret) return ret; + /* + * Register sys-off handlers for legacy PM callback. This allows + * legacy PM callbacks temporary co-exist with the new sys-off API. + * + * TODO: Remove legacy handlers once all legacy PM users will be + * switched to the sys-off based APIs. + */ + if (pm_power_off) { + sys_off = register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, + SYS_OFF_PRIO_DEFAULT, + legacy_pm_power_off, NULL); + if (IS_ERR(sys_off)) + return PTR_ERR(sys_off); + } + /* Instead of trying to make the power_off code look like * halt when pm_power_off is not set do it the easy way. */ @@ -727,6 +727,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, break; } mutex_unlock(&system_transition_mutex); + unregister_sys_off_handler(sys_off); return ret; } -- cgit v1.2.3 From 587b9bfe0668bc997e51af9526a0c7c084d4660f Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Wed, 1 Jun 2022 01:11:02 +0300 Subject: kernel/reboot: Use static handler for register_platform_power_off() The register_platform_power_off() fails on m68k platform due to the memory allocation error that happens at a very early boot time when memory allocator isn't available yet. Fix it by using a static sys-off handler for the platform-level power-off handlers. Fixes: f0f7e5265b3b ("m68k: Switch to new sys-off handler API") Reported-by: Geert Uytterhoeven Signed-off-by: Dmitry Osipenko Reviewed-by: Geert Uytterhoeven Tested-by: Geert Uytterhoeven Signed-off-by: Rafael J. Wysocki --- kernel/reboot.c | 43 +++++++++++++++++++++++++++++++++++++------ 1 file changed, 37 insertions(+), 6 deletions(-) (limited to 'kernel/reboot.c') diff --git a/kernel/reboot.c b/kernel/reboot.c index a091145ee710..3b19b123efec 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -315,6 +315,37 @@ static int sys_off_notify(struct notifier_block *nb, return handler->sys_off_cb(&data); } +static struct sys_off_handler platform_sys_off_handler; + +static struct sys_off_handler *alloc_sys_off_handler(int priority) +{ + struct sys_off_handler *handler; + + /* + * Platforms like m68k can't allocate sys_off handler dynamically + * at the early boot time because memory allocator isn't available yet. + */ + if (priority == SYS_OFF_PRIO_PLATFORM) { + handler = &platform_sys_off_handler; + if (handler->cb_data) + return ERR_PTR(-EBUSY); + } else { + handler = kzalloc(sizeof(*handler), GFP_KERNEL); + if (!handler) + return ERR_PTR(-ENOMEM); + } + + return handler; +} + +static void free_sys_off_handler(struct sys_off_handler *handler) +{ + if (handler == &platform_sys_off_handler) + memset(handler, 0, sizeof(*handler)); + else + kfree(handler); +} + /** * register_sys_off_handler - Register sys-off handler * @mode: Sys-off mode @@ -345,9 +376,9 @@ register_sys_off_handler(enum sys_off_mode mode, struct sys_off_handler *handler; int err; - handler = kzalloc(sizeof(*handler), GFP_KERNEL); - if (!handler) - return ERR_PTR(-ENOMEM); + handler = alloc_sys_off_handler(priority); + if (IS_ERR(handler)) + return handler; switch (mode) { case SYS_OFF_MODE_POWER_OFF_PREPARE: @@ -364,7 +395,7 @@ register_sys_off_handler(enum sys_off_mode mode, break; default: - kfree(handler); + free_sys_off_handler(handler); return ERR_PTR(-EINVAL); } @@ -391,7 +422,7 @@ register_sys_off_handler(enum sys_off_mode mode, } if (err) { - kfree(handler); + free_sys_off_handler(handler); return ERR_PTR(err); } @@ -422,7 +453,7 @@ void unregister_sys_off_handler(struct sys_off_handler *handler) /* sanity check, shall never happen */ WARN_ON(err); - kfree(handler); + free_sys_off_handler(handler); } EXPORT_SYMBOL_GPL(unregister_sys_off_handler); -- cgit v1.2.3 From 2b8c612c6102f751e6e3e1bd425f64e9d3d3f638 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Mon, 6 Jun 2022 19:56:40 +0300 Subject: kernel/reboot: Fix powering off using a non-syscall code paths There are other methods of powering off machine than the reboot syscall. Previously we missed to cover those methods and it created power-off regression for some machines, like the PowerPC e500. Fix this problem by moving the legacy sys-off handler registration to the latest phase of power-off process and making the kernel_can_power_off() check the legacy pm_power_off presence. Tested-by: Michael Ellerman # ppce500 Reported-by: Michael Ellerman # ppce500 Fixes: da007f171fc9 ("kernel/reboot: Change registration order of legacy power-off handler") Signed-off-by: Dmitry Osipenko Signed-off-by: Rafael J. Wysocki --- kernel/reboot.c | 46 ++++++++++++++++++++++++++-------------------- 1 file changed, 26 insertions(+), 20 deletions(-) (limited to 'kernel/reboot.c') diff --git a/kernel/reboot.c b/kernel/reboot.c index 3b19b123efec..b5a71d1ff603 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -320,6 +320,7 @@ static struct sys_off_handler platform_sys_off_handler; static struct sys_off_handler *alloc_sys_off_handler(int priority) { struct sys_off_handler *handler; + gfp_t flags; /* * Platforms like m68k can't allocate sys_off handler dynamically @@ -330,7 +331,12 @@ static struct sys_off_handler *alloc_sys_off_handler(int priority) if (handler->cb_data) return ERR_PTR(-EBUSY); } else { - handler = kzalloc(sizeof(*handler), GFP_KERNEL); + if (system_state > SYSTEM_RUNNING) + flags = GFP_ATOMIC; + else + flags = GFP_KERNEL; + + handler = kzalloc(sizeof(*handler), flags); if (!handler) return ERR_PTR(-ENOMEM); } @@ -440,7 +446,7 @@ void unregister_sys_off_handler(struct sys_off_handler *handler) { int err; - if (!handler) + if (IS_ERR_OR_NULL(handler)) return; if (handler->blocking) @@ -615,7 +621,23 @@ static void do_kernel_power_off_prepare(void) */ void do_kernel_power_off(void) { + struct sys_off_handler *sys_off = NULL; + + /* + * Register sys-off handlers for legacy PM callback. This allows + * legacy PM callbacks temporary co-exist with the new sys-off API. + * + * TODO: Remove legacy handlers once all legacy PM users will be + * switched to the sys-off based APIs. + */ + if (pm_power_off) + sys_off = register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, + SYS_OFF_PRIO_DEFAULT, + legacy_pm_power_off, NULL); + atomic_notifier_call_chain(&power_off_handler_list, 0, NULL); + + unregister_sys_off_handler(sys_off); } /** @@ -626,7 +648,8 @@ void do_kernel_power_off(void) */ bool kernel_can_power_off(void) { - return !atomic_notifier_call_chain_is_empty(&power_off_handler_list); + return !atomic_notifier_call_chain_is_empty(&power_off_handler_list) || + pm_power_off; } EXPORT_SYMBOL_GPL(kernel_can_power_off); @@ -661,7 +684,6 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, void __user *, arg) { struct pid_namespace *pid_ns = task_active_pid_ns(current); - struct sys_off_handler *sys_off = NULL; char buffer[256]; int ret = 0; @@ -686,21 +708,6 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, if (ret) return ret; - /* - * Register sys-off handlers for legacy PM callback. This allows - * legacy PM callbacks temporary co-exist with the new sys-off API. - * - * TODO: Remove legacy handlers once all legacy PM users will be - * switched to the sys-off based APIs. - */ - if (pm_power_off) { - sys_off = register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, - SYS_OFF_PRIO_DEFAULT, - legacy_pm_power_off, NULL); - if (IS_ERR(sys_off)) - return PTR_ERR(sys_off); - } - /* Instead of trying to make the power_off code look like * halt when pm_power_off is not set do it the easy way. */ @@ -758,7 +765,6 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, break; } mutex_unlock(&system_transition_mutex); - unregister_sys_off_handler(sys_off); return ret; } -- cgit v1.2.3 From b87f02307d3cfbda768520f0687c51ca77e14fc3 Mon Sep 17 00:00:00 2001 From: Petr Mladek Date: Wed, 15 Jun 2022 18:28:05 +0200 Subject: printk: Wait for the global console lock when the system is going down There are reports that the console kthreads block the global console lock when the system is going down, for example, reboot, panic. First part of the solution was to block kthreads in these problematic system states so they stopped handling newly added messages. Second part of the solution is to wait when for the kthreads when they are actively printing. It solves the problem when a message was printed before the system entered the problematic state and the kthreads managed to step in. A busy waiting has to be used because panic() can be called in any context and in an unknown state of the scheduler. There must be a timeout because the kthread might get stuck or sleeping and never release the lock. The timeout 10s is an arbitrary value inspired by the softlockup timeout. Link: https://lore.kernel.org/r/20220610205038.GA3050413@paulmck-ThinkPad-P17-Gen-1 Link: https://lore.kernel.org/r/CAMdYzYpF4FNTBPZsEFeWRuEwSies36QM_As8osPWZSr2q-viEA@mail.gmail.com Signed-off-by: Petr Mladek Tested-by: Paul E. McKenney Link: https://lore.kernel.org/r/20220615162805.27962-3-pmladek@suse.com --- kernel/reboot.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel/reboot.c') diff --git a/kernel/reboot.c b/kernel/reboot.c index 4177645e74d6..310363685502 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -74,6 +74,7 @@ void kernel_restart_prepare(char *cmd) { blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); system_state = SYSTEM_RESTART; + try_block_console_kthreads(10000); usermodehelper_disable(); device_shutdown(); } @@ -262,6 +263,7 @@ static void kernel_shutdown_prepare(enum system_states state) blocking_notifier_call_chain(&reboot_notifier_list, (state == SYSTEM_HALT) ? SYS_HALT : SYS_POWER_OFF, NULL); system_state = state; + try_block_console_kthreads(10000); usermodehelper_disable(); device_shutdown(); } -- cgit v1.2.3 From 20fb0c8272bbb102d15bdd11aa64f828619dd7cc Mon Sep 17 00:00:00 2001 From: Petr Mladek Date: Thu, 23 Jun 2022 16:51:52 +0200 Subject: Revert "printk: Wait for the global console lock when the system is going down" This reverts commit b87f02307d3cfbda768520f0687c51ca77e14fc3. The testing of 5.19 release candidates revealed missing synchronization between early and regular console functionality. It would be possible to start the console kthreads later as a workaround. But it is clear that console lock serialized console drivers between each other. It opens a big area of possible problems that were not considered by people involved in the development and review. printk() is crucial for debugging kernel issues and console output is very important part of it. The number of consoles is huge and a proper review would take some time. As a result it need to be reverted for 5.19. Link: https://lore.kernel.org/r/YrBdjVwBOVgLfHyb@alley Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20220623145157.21938-2-pmladek@suse.com --- kernel/reboot.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'kernel/reboot.c') diff --git a/kernel/reboot.c b/kernel/reboot.c index 310363685502..4177645e74d6 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -74,7 +74,6 @@ void kernel_restart_prepare(char *cmd) { blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); system_state = SYSTEM_RESTART; - try_block_console_kthreads(10000); usermodehelper_disable(); device_shutdown(); } @@ -263,7 +262,6 @@ static void kernel_shutdown_prepare(enum system_states state) blocking_notifier_call_chain(&reboot_notifier_list, (state == SYSTEM_HALT) ? SYS_HALT : SYS_POWER_OFF, NULL); system_state = state; - try_block_console_kthreads(10000); usermodehelper_disable(); device_shutdown(); } -- cgit v1.2.3 From 07a22b61946f0b80065b0ddcc703b715f84355f5 Mon Sep 17 00:00:00 2001 From: Petr Mladek Date: Thu, 23 Jun 2022 16:51:57 +0200 Subject: Revert "printk: add functions to prefer direct printing" This reverts commit 2bb2b7b57f81255c13f4395ea911d6bdc70c9fe2. The testing of 5.19 release candidates revealed missing synchronization between early and regular console functionality. It would be possible to start the console kthreads later as a workaround. But it is clear that console lock serialized console drivers between each other. It opens a big area of possible problems that were not considered by people involved in the development and review. printk() is crucial for debugging kernel issues and console output is very important part of it. The number of consoles is huge and a proper review would take some time. As a result it need to be reverted for 5.19. Link: https://lore.kernel.org/r/YrBdjVwBOVgLfHyb@alley Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20220623145157.21938-7-pmladek@suse.com --- kernel/reboot.c | 14 +------------- 1 file changed, 1 insertion(+), 13 deletions(-) (limited to 'kernel/reboot.c') diff --git a/kernel/reboot.c b/kernel/reboot.c index 4177645e74d6..6bcc5d6a6572 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -447,11 +447,9 @@ static int __orderly_reboot(void) ret = run_cmd(reboot_cmd); if (ret) { - printk_prefer_direct_enter(); pr_warn("Failed to start orderly reboot: forcing the issue\n"); emergency_sync(); kernel_restart(NULL); - printk_prefer_direct_exit(); } return ret; @@ -464,7 +462,6 @@ static int __orderly_poweroff(bool force) ret = run_cmd(poweroff_cmd); if (ret && force) { - printk_prefer_direct_enter(); pr_warn("Failed to start orderly shutdown: forcing the issue\n"); /* @@ -474,7 +471,6 @@ static int __orderly_poweroff(bool force) */ emergency_sync(); kernel_power_off(); - printk_prefer_direct_exit(); } return ret; @@ -532,8 +528,6 @@ EXPORT_SYMBOL_GPL(orderly_reboot); */ static void hw_failure_emergency_poweroff_func(struct work_struct *work) { - printk_prefer_direct_enter(); - /* * We have reached here after the emergency shutdown waiting period has * expired. This means orderly_poweroff has not been able to shut off @@ -550,8 +544,6 @@ static void hw_failure_emergency_poweroff_func(struct work_struct *work) */ pr_emerg("Hardware protection shutdown failed. Trying emergency restart\n"); emergency_restart(); - - printk_prefer_direct_exit(); } static DECLARE_DELAYED_WORK(hw_failure_emergency_poweroff_work, @@ -590,13 +582,11 @@ void hw_protection_shutdown(const char *reason, int ms_until_forced) { static atomic_t allow_proceed = ATOMIC_INIT(1); - printk_prefer_direct_enter(); - pr_emerg("HARDWARE PROTECTION shutdown (%s)\n", reason); /* Shutdown should be initiated only once. */ if (!atomic_dec_and_test(&allow_proceed)) - goto out; + return; /* * Queue a backup emergency shutdown in the event of @@ -604,8 +594,6 @@ void hw_protection_shutdown(const char *reason, int ms_until_forced) */ hw_failure_emergency_poweroff(ms_until_forced); orderly_poweroff(true); -out: - printk_prefer_direct_exit(); } EXPORT_SYMBOL_GPL(hw_protection_shutdown); -- cgit v1.2.3