[tip: irq/core] softirq: Add debug check to __raise_softirq_irqoff()

[tip-bot2 for Jiafei Pan]

The following commit has been merged into the irq/core branch of tip:

Commit-ID:     cdabce2e3dff7e4bcef73473987618569d178af3
Gitweb:        https://git.kernel.org/tip/cdabce2e3dff7e4bcef73473987618569d178af3
Author:        Jiafei Pan <Jiafei.Pan@xxxxxxx>
AuthorDate:    Fri, 14 Aug 2020 12:55:22 +08:00
Committer:     Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Wed, 16 Sep 2020 15:18:56 +02:00

softirq: Add debug check to __raise_softirq_irqoff()

__raise_softirq_irqoff() must be called with interrupts disabled to protect
the per CPU softirq pending state update against an interrupt and soft
interrupt handling on return from interrupt.

Add a lockdep assertion to validate the calling convention.

[ tglx: Massaged changelog ]

Signed-off-by: Jiafei Pan <Jiafei.Pan@xxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200814045522.45719-1-Jiafei.Pan@xxxxxxx

---
 kernel/softirq.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/softirq.c b/kernel/softirq.c
index bf88d7f..09229ad 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -481,6 +481,7 @@ void raise_softirq(unsigned int nr)
 
 void __raise_softirq_irqoff(unsigned int nr)
 {
+	lockdep_assert_irqs_disabled();
 	trace_softirq_raise(nr);
 	or_softirq_pending(1UL << nr);
 }