diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-kernel-reboot | 8 | ||||
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 6 | ||||
| -rw-r--r-- | include/linux/reboot.h | 22 | ||||
| -rw-r--r-- | include/uapi/linux/capability.h | 1 | ||||
| -rw-r--r-- | kernel/reboot.c | 48 |
5 files changed, 84 insertions, 1 deletions
diff --git a/Documentation/ABI/testing/sysfs-kernel-reboot b/Documentation/ABI/testing/sysfs-kernel-reboot index 837330fb2511..e117aba46be0 100644 --- a/Documentation/ABI/testing/sysfs-kernel-reboot +++ b/Documentation/ABI/testing/sysfs-kernel-reboot @@ -30,3 +30,11 @@ KernelVersion: 5.11 Contact: Matteo Croce <mcroce@microsoft.com> Description: Don't wait for any other CPUs on reboot and avoid anything that could hang. + +What: /sys/kernel/reboot/hw_protection +Date: April 2025 +KernelVersion: 6.15 +Contact: Ahmad Fatoum <a.fatoum@pengutronix.de> +Description: Hardware protection action taken on critical events like + overtemperature or imminent voltage loss. + Valid values are: reboot shutdown diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index fb8752b42ec8..b2f04967876f 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1933,6 +1933,12 @@ which allow the hypervisor to 'idle' the guest on lock contention. + hw_protection= [HW] + Format: reboot | shutdown + + Hardware protection action taken on critical events like + overtemperature or imminent voltage loss. + i2c_bus= [HW] Override the default board specific I2C bus speed or register an additional I2C bus that is not registered from board initialization code. diff --git a/include/linux/reboot.h b/include/linux/reboot.h index 53c64e31b3cf..79e02876f2ba 100644 --- a/include/linux/reboot.h +++ b/include/linux/reboot.h @@ -181,16 +181,36 @@ extern void orderly_reboot(void); /** * enum hw_protection_action - Hardware protection action * + * @HWPROT_ACT_DEFAULT: + * The default action should be taken. This is HWPROT_ACT_SHUTDOWN + * by default, but can be overridden. * @HWPROT_ACT_SHUTDOWN: * The system should be shut down (powered off) for HW protection. * @HWPROT_ACT_REBOOT: * The system should be rebooted for HW protection. */ -enum hw_protection_action { HWPROT_ACT_SHUTDOWN, HWPROT_ACT_REBOOT }; +enum hw_protection_action { HWPROT_ACT_DEFAULT, HWPROT_ACT_SHUTDOWN, HWPROT_ACT_REBOOT }; void __hw_protection_trigger(const char *reason, int ms_until_forced, enum hw_protection_action action); +/** + * hw_protection_trigger - Trigger default emergency system hardware protection action + * + * @reason: Reason of emergency shutdown or reboot to be printed. + * @ms_until_forced: Time to wait for orderly shutdown or reboot before + * triggering it. Negative value disables the forced + * shutdown or reboot. + * + * Initiate an emergency system shutdown or reboot in order to protect + * hardware from further damage. The exact action taken is controllable at + * runtime and defaults to shutdown. + */ +static inline void hw_protection_trigger(const char *reason, int ms_until_forced) +{ + __hw_protection_trigger(reason, ms_until_forced, HWPROT_ACT_DEFAULT); +} + static inline void hw_protection_reboot(const char *reason, int ms_until_forced) { __hw_protection_trigger(reason, ms_until_forced, HWPROT_ACT_REBOOT); diff --git a/include/uapi/linux/capability.h b/include/uapi/linux/capability.h index 5bb906098697..2e21b5594f81 100644 --- a/include/uapi/linux/capability.h +++ b/include/uapi/linux/capability.h @@ -275,6 +275,7 @@ struct vfs_ns_cap_data { /* Allow setting encryption key on loopback filesystem */ /* Allow setting zone reclaim policy */ /* Allow everything under CAP_BPF and CAP_PERFMON for backward compatibility */ +/* Allow setting hardware protection emergency action */ #define CAP_SYS_ADMIN 21 diff --git a/kernel/reboot.c b/kernel/reboot.c index faf1ff422634..2d6a06fe6c66 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -36,6 +36,8 @@ enum reboot_mode reboot_mode DEFAULT_REBOOT_MODE; EXPORT_SYMBOL_GPL(reboot_mode); enum reboot_mode panic_reboot_mode = REBOOT_UNDEFINED; +static enum hw_protection_action hw_protection_action = HWPROT_ACT_SHUTDOWN; + /* * This variable is used privately to keep track of whether or not * reboot_type is still set to its default value (i.e., reboot= hasn't @@ -1027,6 +1029,9 @@ void __hw_protection_trigger(const char *reason, int ms_until_forced, { static atomic_t allow_proceed = ATOMIC_INIT(1); + if (action == HWPROT_ACT_DEFAULT) + action = hw_protection_action; + pr_emerg("HARDWARE PROTECTION %s (%s)\n", hw_protection_action_str(action), reason); @@ -1046,6 +1051,48 @@ void __hw_protection_trigger(const char *reason, int ms_until_forced, } EXPORT_SYMBOL_GPL(__hw_protection_trigger); +static bool hw_protection_action_parse(const char *str, + enum hw_protection_action *action) +{ + if (sysfs_streq(str, "shutdown")) + *action = HWPROT_ACT_SHUTDOWN; + else if (sysfs_streq(str, "reboot")) + *action = HWPROT_ACT_REBOOT; + else + return false; + + return true; +} + +static int __init hw_protection_setup(char *str) +{ + hw_protection_action_parse(str, &hw_protection_action); + return 1; +} +__setup("hw_protection=", hw_protection_setup); + +#ifdef CONFIG_SYSFS +static ssize_t hw_protection_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%s\n", + hw_protection_action_str(hw_protection_action)); +} +static ssize_t hw_protection_store(struct kobject *kobj, + struct kobj_attribute *attr, const char *buf, + size_t count) +{ + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + if (!hw_protection_action_parse(buf, &hw_protection_action)) + return -EINVAL; + + return count; +} +static struct kobj_attribute hw_protection_attr = __ATTR_RW(hw_protection); +#endif + static int __init reboot_setup(char *str) { for (;;) { @@ -1305,6 +1352,7 @@ static struct kobj_attribute reboot_cpu_attr = __ATTR_RW(cpu); #endif static struct attribute *reboot_attrs[] = { + &hw_protection_attr.attr, &reboot_mode_attr.attr, #ifdef CONFIG_X86 &reboot_force_attr.attr, |