1 files changed, 32 insertions, 85 deletions

diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c
index 977d8b43a0d..4d1c746892e 100644
--- a/arch/x86/kernel/irq_64.c
+++ b/arch/x86/kernel/irq_64.c
@@ -26,6 +26,8 @@ EXPORT_PER_CPU_SYMBOL(irq_stat);
 DEFINE_PER_CPU(struct pt_regs *, irq_regs);
 EXPORT_PER_CPU_SYMBOL(irq_regs);
 
+int sysctl_panic_on_stackoverflow;
+
 /*
  * Probabilistic stack overflow check:
  *
@@ -36,15 +38,39 @@ EXPORT_PER_CPU_SYMBOL(irq_regs);
 static inline void stack_overflow_check(struct pt_regs *regs)
 {
 #ifdef CONFIG_DEBUG_STACKOVERFLOW
+#define STACK_TOP_MARGIN	128
+	struct orig_ist *oist;
+	u64 irq_stack_top, irq_stack_bottom;
+	u64 estack_top, estack_bottom;
 	u64 curbase = (u64)task_stack_page(current);
 
-	WARN_ONCE(regs->sp >= curbase &&
-		  regs->sp <= curbase + THREAD_SIZE &&
-		  regs->sp <  curbase + sizeof(struct thread_info) +
-					sizeof(struct pt_regs) + 128,
+	if (user_mode_vm(regs))
+		return;
+
+	if (regs->sp >= curbase + sizeof(struct thread_info) +
+				  sizeof(struct pt_regs) + STACK_TOP_MARGIN &&
+	    regs->sp <= curbase + THREAD_SIZE)
+		return;
+
+	irq_stack_top = (u64)__get_cpu_var(irq_stack_union.irq_stack) +
+			STACK_TOP_MARGIN;
+	irq_stack_bottom = (u64)__get_cpu_var(irq_stack_ptr);
+	if (regs->sp >= irq_stack_top && regs->sp <= irq_stack_bottom)
+		return;
+
+	oist = &__get_cpu_var(orig_ist);
+	estack_top = (u64)oist->ist[0] - EXCEPTION_STKSZ + STACK_TOP_MARGIN;
+	estack_bottom = (u64)oist->ist[N_EXCEPTION_STACKS - 1];
+	if (regs->sp >= estack_top && regs->sp <= estack_bottom)
+		return;
+
+	WARN_ONCE(1, "do_IRQ(): %s has overflown the kernel stack (cur:%Lx,sp:%lx,irq stk top-bottom:%Lx-%Lx,exception stk top-bottom:%Lx-%Lx)\n",
+		current->comm, curbase, regs->sp,
+		irq_stack_top, irq_stack_bottom,
+		estack_top, estack_bottom);
 
-		  "do_IRQ: %s near stack overflow (cur:%Lx,sp:%lx)\n",
-			current->comm, curbase, regs->sp);
+	if (sysctl_panic_on_stackoverflow)
+		panic("low stack detected by irq handler - check messages\n");
 #endif
 }
 
@@ -61,82 +87,3 @@ bool handle_irq(unsigned irq, struct pt_regs *regs)
 	generic_handle_irq_desc(irq, desc);
 	return true;
 }
-
-#ifdef CONFIG_HOTPLUG_CPU
-/* A cpu has been removed from cpu_online_mask.  Reset irq affinities. */
-void fixup_irqs(void)
-{
-	unsigned int irq;
-	static int warned;
-	struct irq_desc *desc;
-
-	for_each_irq_desc(irq, desc) {
-		int break_affinity = 0;
-		int set_affinity = 1;
-		const struct cpumask *affinity;
-
-		if (!desc)
-			continue;
-		if (irq == 2)
-			continue;
-
-		/* interrupt's are disabled at this point */
-		spin_lock(&desc->lock);
-
-		affinity = desc->affinity;
-		if (!irq_has_action(irq) ||
-		    cpumask_equal(affinity, cpu_online_mask)) {
-			spin_unlock(&desc->lock);
-			continue;
-		}
-
-		if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
-			break_affinity = 1;
-			affinity = cpu_all_mask;
-		}
-
-		if (desc->chip->mask)
-			desc->chip->mask(irq);
-
-		if (desc->chip->set_affinity)
-			desc->chip->set_affinity(irq, affinity);
-		else if (!(warned++))
-			set_affinity = 0;
-
-		if (desc->chip->unmask)
-			desc->chip->unmask(irq);
-
-		spin_unlock(&desc->lock);
-
-		if (break_affinity && set_affinity)
-			printk("Broke affinity for irq %i\n", irq);
-		else if (!set_affinity)
-			printk("Cannot set affinity for irq %i\n", irq);
-	}
-
-	/* That doesn't seem sufficient.  Give it 1ms. */
-	local_irq_enable();
-	mdelay(1);
-	local_irq_disable();
-}
-#endif
-
-extern void call_softirq(void);
-
-asmlinkage void do_softirq(void)
-{
-	__u32 pending;
-	unsigned long flags;
-
-	if (in_interrupt())
-		return;
-
-	local_irq_save(flags);
-	pending = local_softirq_pending();
-	/* Switch to interrupt stack */
-	if (pending) {
-		call_softirq();
-		WARN_ON_ONCE(softirq_count());
-	}
-	local_irq_restore(flags);
-}