X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=kernel%2Fsoftirq.c;h=dcab1d3fb53d284cc42da1e36c6e5d001cd5baa9;hb=37bf06375c90a42fe07b9bebdb07bc316ae5a0ce;hp=3e88612fc87e382b65663a3ffd6f13d0c27f2fb7;hpb=6bfa687c19b7ab8adee03f0d43c197c2945dd869;p=firefly-linux-kernel-4.4.55.git

diff --git a/kernel/softirq.c b/kernel/softirq.c
index 3e88612fc87e..dcab1d3fb53d 100644
--- 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)