Merge tag 'usb-3.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb

[firefly-linux-kernel-4.4.55.git] / kernel / softirq.c

diff --git a/kernel/softirq.c b/kernel/softirq.c
index be3d3514c325f8aad38d62f65d2aee0393a70585..d7d498d8cc4f8185954a220c66071cbc5761b917 100644 (file)
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -328,10 +328,19 @@ void irq_enter(void)
 
 static inline void invoke_softirq(void)
 {
-       if (!force_irqthreads)
-               __do_softirq();
-       else
+       if (!force_irqthreads) {
+               /*
+                * We can safely execute softirq on the current stack if
+                * it is the irq stack, because it should be near empty
+                * at this stage. But we have no way to know if the arch
+                * calls irq_exit() on the irq stack. So call softirq
+                * in its own stack to prevent from any overrun on top
+                * of a potentially deep task stack.
+                */
+               do_softirq();
+       } else {
                wakeup_softirqd();
+       }
 }
 
 static inline void tick_irq_exit(void)
@@ -876,7 +885,6 @@ int __init __weak early_irq_init(void)
        return 0;
 }
 
-#ifdef CONFIG_GENERIC_HARDIRQS
 int __init __weak arch_probe_nr_irqs(void)
 {
        return NR_IRQS_LEGACY;
@@ -886,4 +894,3 @@ int __init __weak arch_early_irq_init(void)
 {
        return 0;
 }
-#endif