Merge tag 'mm-nonmm-stable-2025-03-30-18-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:

 - The series "powerpc/crash: use generic crashkernel reservation" from
   Sourabh Jain changes powerpc's kexec code to use more of the generic
   layers.

 - The series "get_maintainer: report subsystem status separately" from
   Vlastimil Babka makes some long-requested improvements to the
   get_maintainer output.

 - The series "ucount: Simplify refcounting with rcuref_t" from
   Sebastian Siewior cleans up and optimizing the refcounting in the
   ucount code.

 - The series "reboot: support runtime configuration of emergency
   hw_protection action" from Ahmad Fatoum improves the ability for a
   driver to perform an emergency system shutdown or reboot.

 - The series "Converge on using secs_to_jiffies() part two" from Easwar
   Hariharan performs further migrations from msecs_to_jiffies() to
   secs_to_jiffies().

 - The series "lib/interval_tree: add some test cases and cleanup" from
   Wei Yang permits more userspace testing of kernel library code, adds
   some more tests and performs some cleanups.

 - The series "hung_task: Dump the blocking task stacktrace" from Masami
   Hiramatsu arranges for the hung_task detector to dump the stack of
   the blocking task and not just that of the blocked task.

 - The series "resource: Split and use DEFINE_RES*() macros" from Andy
   Shevchenko provides some cleanups to the resource definition macros.

 - Plus the usual shower of singleton patches - please see the
   individual changelogs for details.

* tag 'mm-nonmm-stable-2025-03-30-18-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (77 commits)
  mailmap: consolidate email addresses of Alexander Sverdlin
  fs/procfs: fix the comment above proc_pid_wchan()
  relay: use kasprintf() instead of fixed buffer formatting
  resource: replace open coded variant of DEFINE_RES()
  resource: replace open coded variants of DEFINE_RES_*_NAMED()
  resource: replace open coded variant of DEFINE_RES_NAMED_DESC()
  resource: split DEFINE_RES_NAMED_DESC() out of DEFINE_RES_NAMED()
  samples: add hung_task detector mutex blocking sample
  hung_task: show the blocker task if the task is hung on mutex
  kexec_core: accept unaccepted kexec segments' destination addresses
  watchdog/perf: optimize bytes copied and remove manual NUL-termination
  lib/interval_tree: fix the comment of interval_tree_span_iter_next_gap()
  lib/interval_tree: skip the check before go to the right subtree
  lib/interval_tree: add test case for span iteration
  lib/interval_tree: add test case for interval_tree_iter_xxx() helpers
  lib/rbtree: add random seed
  lib/rbtree: split tests
  lib/rbtree: enable userland test suite for rbtree related data structure
  checkpatch: describe --min-conf-desc-length
  scripts/gdb/symbols: determine KASLR offset on s390
  ...

1 files changed, 109 insertions, 31 deletions

diff --git a/kernel/reboot.c b/kernel/reboot.c
index 41ab9e1ba357..ec087827c85c 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
@@ -229,6 +231,9 @@ EXPORT_SYMBOL(unregister_restart_handler);
 /**
  *	do_kernel_restart - Execute kernel restart handler call chain
  *
+ *	@cmd: pointer to buffer containing command to execute for restart
+ *		or %NULL
+ *
  *	Calls functions registered with register_restart_handler.
  *
  *	Expected to be called from machine_restart as last step of the restart
@@ -933,61 +938,86 @@ void orderly_reboot(void)
 }
 EXPORT_SYMBOL_GPL(orderly_reboot);
 
+static const char *hw_protection_action_str(enum hw_protection_action action)
+{
+	switch (action) {
+	case HWPROT_ACT_SHUTDOWN:
+		return "shutdown";
+	case HWPROT_ACT_REBOOT:
+		return "reboot";
+	default:
+		return "undefined";
+	}
+}
+
+static enum hw_protection_action hw_failure_emergency_action;
+
 /**
- * hw_failure_emergency_poweroff_func - emergency poweroff work after a known delay
- * @work: work_struct associated with the emergency poweroff function
+ * hw_failure_emergency_action_func - emergency action work after a known delay
+ * @work: work_struct associated with the emergency action function
  *
  * This function is called in very critical situations to force
- * a kernel poweroff after a configurable timeout value.
+ * a kernel poweroff or reboot after a configurable timeout value.
  */
-static void hw_failure_emergency_poweroff_func(struct work_struct *work)
+static void hw_failure_emergency_action_func(struct work_struct *work)
 {
+	const char *action_str = hw_protection_action_str(hw_failure_emergency_action);
+
+	pr_emerg("Hardware protection timed-out. Trying forced %s\n",
+		 action_str);
+
 	/*
-	 * We have reached here after the emergency shutdown waiting period has
-	 * expired. This means orderly_poweroff has not been able to shut off
-	 * the system for some reason.
+	 * We have reached here after the emergency action waiting period has
+	 * expired. This means orderly_poweroff/reboot has not been able to
+	 * shut off the system for some reason.
 	 *
-	 * Try to shut down the system immediately using kernel_power_off
-	 * if populated
+	 * Try to shut off the system immediately if possible
 	 */
-	pr_emerg("Hardware protection timed-out. Trying forced poweroff\n");
-	kernel_power_off();
+
+	if (hw_failure_emergency_action == HWPROT_ACT_REBOOT)
+		kernel_restart(NULL);
+	else
+		kernel_power_off();
 
 	/*
 	 * Worst of the worst case trigger emergency restart
 	 */
-	pr_emerg("Hardware protection shutdown failed. Trying emergency restart\n");
+	pr_emerg("Hardware protection %s failed. Trying emergency restart\n",
+		 action_str);
 	emergency_restart();
 }
 
-static DECLARE_DELAYED_WORK(hw_failure_emergency_poweroff_work,
-			    hw_failure_emergency_poweroff_func);
+static DECLARE_DELAYED_WORK(hw_failure_emergency_action_work,
+			    hw_failure_emergency_action_func);
 
 /**
- * hw_failure_emergency_poweroff - Trigger an emergency system poweroff
+ * hw_failure_emergency_schedule - Schedule an emergency system shutdown or reboot
+ *
+ * @action:		The hardware protection action to be taken
+ * @action_delay_ms:	Time in milliseconds to elapse before triggering action
  *
  * This may be called from any critical situation to trigger a system shutdown
- * after a given period of time. If time is negative this is not scheduled.
+ * or reboot after a given period of time.
+ * If time is negative this is not scheduled.
  */
-static void hw_failure_emergency_poweroff(int poweroff_delay_ms)
+static void hw_failure_emergency_schedule(enum hw_protection_action action,
+					  int action_delay_ms)
 {
-	if (poweroff_delay_ms <= 0)
+	if (action_delay_ms <= 0)
 		return;
-	schedule_delayed_work(&hw_failure_emergency_poweroff_work,
-			      msecs_to_jiffies(poweroff_delay_ms));
+	hw_failure_emergency_action = action;
+	schedule_delayed_work(&hw_failure_emergency_action_work,
+			      msecs_to_jiffies(action_delay_ms));
 }
 
 /**
- * __hw_protection_shutdown - Trigger an emergency system shutdown or reboot
+ * __hw_protection_trigger - Trigger an emergency system shutdown or reboot
  *
  * @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.
- * @shutdown:		If true, indicates that a shutdown will happen
- *			after the critical tempeature is reached.
- *			If false, indicates that a reboot will happen
- *			after the critical tempeature is reached.
+ * @action:		The hardware protection action to be taken.
  *
  * Initiate an emergency system shutdown or reboot in order to protect
  * hardware from further damage. Usage examples include a thermal protection.
@@ -995,11 +1025,16 @@ static void hw_failure_emergency_poweroff(int poweroff_delay_ms)
  * pending even if the previous request has given a large timeout for forced
  * shutdown/reboot.
  */
-void __hw_protection_shutdown(const char *reason, int ms_until_forced, bool shutdown)
+void __hw_protection_trigger(const char *reason, int ms_until_forced,
+			     enum hw_protection_action action)
 {
 	static atomic_t allow_proceed = ATOMIC_INIT(1);
 
-	pr_emerg("HARDWARE PROTECTION shutdown (%s)\n", reason);
+	if (action == HWPROT_ACT_DEFAULT)
+		action = hw_protection_action;
+
+	pr_emerg("HARDWARE PROTECTION %s (%s)\n",
+		 hw_protection_action_str(action), reason);
 
 	/* Shutdown should be initiated only once. */
 	if (!atomic_dec_and_test(&allow_proceed))
@@ -1009,13 +1044,55 @@ void __hw_protection_shutdown(const char *reason, int ms_until_forced, bool shut
 	 * Queue a backup emergency shutdown in the event of
 	 * orderly_poweroff failure
 	 */
-	hw_failure_emergency_poweroff(ms_until_forced);
-	if (shutdown)
+	hw_failure_emergency_schedule(action, ms_until_forced);
+	if (action == HWPROT_ACT_REBOOT)
+		orderly_reboot();
+	else
 		orderly_poweroff(true);
+}
+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
-		orderly_reboot();
+		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;
 }
-EXPORT_SYMBOL_GPL(__hw_protection_shutdown);
+static struct kobj_attribute hw_protection_attr = __ATTR_RW(hw_protection);
+#endif
 
 static int __init reboot_setup(char *str)
 {
@@ -1276,6 +1353,7 @@ 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,