Fix CPU hotplug callbacks to disable interrupts on UP kernels.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'smp-urgent-2025-12-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull CPU hotplug fix from Ingo Molnar:

 - Fix CPU hotplug callbacks to disable interrupts on UP kernels

* tag 'smp-urgent-2025-12-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  cpu: Make atomic hotplug callbacks run with interrupts disabled on UP

Documentation/translations/zh_CN/core-api/irq/irq-domain.rst

@@ -109,10 +109,6 @@ irq_domain维护着从hwirq号到Linux IRQ的radix的树状映射。 当一个hw
 如果hwirq号可以非常大，树状映射是一个很好的选择，因为它不需要分配一个和最大hwirq
 号一样大的表。 缺点是，hwirq到IRQ号的查找取决于表中有多少条目。
 
-irq_domain_add_tree()和irq_domain_create_tree()在功能上是等价的，除了第一
-个参数不同——前者接受一个Open Firmware特定的 'struct device_node' ，而后者接受
-一个更通用的抽象 'struct fwnode_handle' 。
-
 很少有驱动应该需要这个映射。
 
 无映射

arch/x86/events/amd/uncore.c

@@ -656,14 +656,11 @@ static int amd_uncore_df_event_init(struct perf_event *event)
 	struct hw_perf_event *hwc = &event->hw;
 	int ret = amd_uncore_event_init(event);
 
-	if (ret || pmu_version < 2)
-		return ret;
-
 	hwc->config = event->attr.config &
 		      (pmu_version >= 2 ? AMD64_PERFMON_V2_RAW_EVENT_MASK_NB :
 					  AMD64_RAW_EVENT_MASK_NB);
 
-	return 0;
+	return ret;
 }
 
 static int amd_uncore_df_add(struct perf_event *event, int flags)

arch/x86/events/intel/core.c

@@ -3378,6 +3378,9 @@ static int handle_pmi_common(struct pt_regs *regs, u64 status)
 
 		if (!test_bit(bit, cpuc->active_mask))
 			continue;
+		/* Event may have already been cleared: */
+		if (!event)
+			continue;
 
 		/*
 		 * There may be unprocessed PEBS records in the PEBS buffer,

drivers/irqchip/irq-mchp-eic.c

@@ -170,7 +170,7 @@ static int mchp_eic_domain_alloc(struct irq_domain *domain, unsigned int virq,
 
 	ret = irq_domain_translate_twocell(domain, fwspec, &hwirq, &type);
 	if (ret || hwirq >= MCHP_EIC_NIRQ)
-		return ret;
+		return ret ?: -EINVAL;
 
 	switch (type) {
 	case IRQ_TYPE_EDGE_RISING:

include/linux/irqdomain.h

@@ -730,22 +730,6 @@ static inline void msi_device_domain_free_wired(struct irq_domain *domain, unsig
 }
 #endif
 
-static inline struct irq_domain *irq_domain_add_tree(struct device_node *of_node,
-						     const struct irq_domain_ops *ops,
-						     void *host_data)
-{
-	struct irq_domain_info info = {
-		.fwnode		= of_fwnode_handle(of_node),
-		.hwirq_max	= ~0U,
-		.ops		= ops,
-		.host_data	= host_data,
-	};
-	struct irq_domain *d;
-
-	d = irq_domain_instantiate(&info);
-	return IS_ERR(d) ? NULL : d;
-}
-
 static inline struct irq_domain *irq_domain_add_linear(struct device_node *of_node,
 						       unsigned int size,
 						       const struct irq_domain_ops *ops,

include/linux/rseq_entry.h

@@ -596,7 +596,7 @@ static __always_inline void rseq_exit_to_user_mode_legacy(void)
 
 void __rseq_debug_syscall_return(struct pt_regs *regs);
 
-static inline void rseq_debug_syscall_return(struct pt_regs *regs)
+static __always_inline void rseq_debug_syscall_return(struct pt_regs *regs)
 {
 	if (static_branch_unlikely(&rseq_debug_enabled))
 		__rseq_debug_syscall_return(regs);

kernel/cpu.c

@@ -249,6 +249,14 @@ err:
 	return ret;
 }
 
+/*
+ * The former STARTING/DYING states, ran with IRQs disabled and must not fail.
+ */
+static bool cpuhp_is_atomic_state(enum cpuhp_state state)
+{
+	return CPUHP_AP_IDLE_DEAD <= state && state < CPUHP_AP_ONLINE;
+}
+
 #ifdef CONFIG_SMP
 static bool cpuhp_is_ap_state(enum cpuhp_state state)
 {
@@ -271,14 +279,6 @@ static inline void complete_ap_thread(struct cpuhp_cpu_state *st, bool bringup)
 	complete(done);
 }
 
-/*
- * The former STARTING/DYING states, ran with IRQs disabled and must not fail.
- */
-static bool cpuhp_is_atomic_state(enum cpuhp_state state)
-{
-	return CPUHP_AP_IDLE_DEAD <= state && state < CPUHP_AP_ONLINE;
-}
-
 /* Synchronization state management */
 enum cpuhp_sync_state {
 	SYNC_STATE_DEAD,
@@ -2364,7 +2364,14 @@ static int cpuhp_issue_call(int cpu, enum cpuhp_state state, bool bringup,
 	else
 		ret = cpuhp_invoke_callback(cpu, state, bringup, node, NULL);
 #else
-	ret = cpuhp_invoke_callback(cpu, state, bringup, node, NULL);
+	if (cpuhp_is_atomic_state(state)) {
+		guard(irqsave)();
+		ret = cpuhp_invoke_callback(cpu, state, bringup, node, NULL);
+		/* STARTING/DYING must not fail! */
+		WARN_ON_ONCE(ret);
+	} else {
+		ret = cpuhp_invoke_callback(cpu, state, bringup, node, NULL);
+	}
 #endif
 	BUG_ON(ret && !bringup);
 	return ret;

kernel/events/core.c

@@ -2317,8 +2317,6 @@ out:
 	perf_event__header_size(leader);
 }
 
-static void sync_child_event(struct perf_event *child_event);
-
 static void perf_child_detach(struct perf_event *event)
 {
 	struct perf_event *parent_event = event->parent;
@@ -2337,7 +2335,6 @@ static void perf_child_detach(struct perf_event *event)
 	lockdep_assert_held(&parent_event->child_mutex);
 	 */
 
-	sync_child_event(event);
 	list_del_init(&event->child_list);
 }
 
@@ -4588,6 +4585,7 @@ out:
 static void perf_remove_from_owner(struct perf_event *event);
 static void perf_event_exit_event(struct perf_event *event,
 				  struct perf_event_context *ctx,
+				  struct task_struct *task,
 				  bool revoke);
 
 /*
@@ -4615,7 +4613,7 @@ static void perf_event_remove_on_exec(struct perf_event_context *ctx)
 
 		modified = true;
 
-		perf_event_exit_event(event, ctx, false);
+		perf_event_exit_event(event, ctx, ctx->task, false);
 	}
 
 	raw_spin_lock_irqsave(&ctx->lock, flags);
@@ -12518,7 +12516,7 @@ static void __pmu_detach_event(struct pmu *pmu, struct perf_event *event,
 	/*
 	 * De-schedule the event and mark it REVOKED.
 	 */
-	perf_event_exit_event(event, ctx, true);
+	perf_event_exit_event(event, ctx, ctx->task, true);
 
 	/*
 	 * All _free_event() bits that rely on event->pmu:
@@ -14075,14 +14073,13 @@ void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu)
 }
 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context);
 
-static void sync_child_event(struct perf_event *child_event)
+static void sync_child_event(struct perf_event *child_event,
+			     struct task_struct *task)
 {
 	struct perf_event *parent_event = child_event->parent;
 	u64 child_val;
 
 	if (child_event->attr.inherit_stat) {
-		struct task_struct *task = child_event->ctx->task;
-
 		if (task && task != TASK_TOMBSTONE)
 			perf_event_read_event(child_event, task);
 	}
@@ -14101,7 +14098,9 @@ static void sync_child_event(struct perf_event *child_event)
 
 static void
 perf_event_exit_event(struct perf_event *event,
-		      struct perf_event_context *ctx, bool revoke)
+		      struct perf_event_context *ctx,
+		      struct task_struct *task,
+		      bool revoke)
 {
 	struct perf_event *parent_event = event->parent;
 	unsigned long detach_flags = DETACH_EXIT;
@@ -14124,6 +14123,9 @@ perf_event_exit_event(struct perf_event *event,
 		mutex_lock(&parent_event->child_mutex);
 		/* PERF_ATTACH_ITRACE might be set concurrently */
 		attach_state = READ_ONCE(event->attach_state);
+
+		if (attach_state & PERF_ATTACH_CHILD)
+			sync_child_event(event, task);
 	}
 
 	if (revoke)
@@ -14215,7 +14217,7 @@ static void perf_event_exit_task_context(struct task_struct *task, bool exit)
 		perf_event_task(task, ctx, 0);
 
 	list_for_each_entry_safe(child_event, next, &ctx->event_list, event_entry)
-		perf_event_exit_event(child_event, ctx, false);
+		perf_event_exit_event(child_event, ctx, exit ? task : NULL, false);
 
 	mutex_unlock(&ctx->mutex);
 

kernel/events/uprobes.c

@@ -79,7 +79,7 @@ struct uprobe {
 	 * The generic code assumes that it has two members of unknown type
 	 * owned by the arch-specific code:
 	 *
-	 * 	insn -	copy_insn() saves the original instruction here for
+	 *	insn -	copy_insn() saves the original instruction here for
 	 *		arch_uprobe_analyze_insn().
 	 *
 	 *	ixol -	potentially modified instruction to execute out of
@@ -107,8 +107,8 @@ static LIST_HEAD(delayed_uprobe_list);
  * allocated.
  */
 struct xol_area {
-	wait_queue_head_t 		wq;		/* if all slots are busy */
-	unsigned long 			*bitmap;	/* 0 = free slot */
+	wait_queue_head_t		wq;		/* if all slots are busy */
+	unsigned long			*bitmap;	/* 0 = free slot */
 
 	struct page			*page;
 	/*
@@ -116,7 +116,7 @@ struct xol_area {
 	 * itself.  The probed process or a naughty kernel module could make
 	 * the vma go away, and we must handle that reasonably gracefully.
 	 */
-	unsigned long 			vaddr;		/* Page(s) of instruction slots */
+	unsigned long			vaddr;		/* Page(s) of instruction slots */
 };
 
 static void uprobe_warn(struct task_struct *t, const char *msg)

kernel/irq/manage.c

@@ -2470,6 +2470,9 @@ int setup_percpu_irq(unsigned int irq, struct irqaction *act)
 	if (retval < 0)
 		return retval;
 
+	if (!act->affinity)
+		act->affinity = cpu_online_mask;
+
 	retval = __setup_irq(irq, desc, act);
 
 	if (retval)

lib/bug.c

@@ -173,6 +173,9 @@ struct bug_entry *find_bug(unsigned long bugaddr)
 	return module_find_bug(bugaddr);
 }
 
+__diag_push();
+__diag_ignore(GCC, all, "-Wsuggest-attribute=format",
+	      "Not a valid __printf() conversion candidate.");
 static void __warn_printf(const char *fmt, struct pt_regs *regs)
 {
 	if (!fmt)
@@ -192,6 +195,7 @@ static void __warn_printf(const char *fmt, struct pt_regs *regs)
 
 	printk("%s", fmt);
 }
+__diag_pop();
 
 static enum bug_trap_type __report_bug(struct bug_entry *bug, unsigned long bugaddr, struct pt_regs *regs)
 {
@@ -262,7 +266,7 @@ enum bug_trap_type report_bug_entry(struct bug_entry *bug, struct pt_regs *regs)
 	bool rcu = false;
 
 	rcu = warn_rcu_enter();
-	ret = __report_bug(bug, 0, regs);
+	ret = __report_bug(bug, bug_addr(bug), regs);
 	warn_rcu_exit(rcu);
 
 	return ret;