Commit 80f8b450 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'irq-urgent-2024-05-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull irq fix from Ingo Molnar:
 "Fix suspicious RCU usage in __do_softirq()"

* tag 'irq-urgent-2024-05-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  softirq: Fix suspicious RCU usage in __do_softirq()
parents b9158815 1dd1eff1

kernel/softirq.c

+8 −4
Original line number Diff line number Diff line
@@ -508,7 +508,7 @@ static inline bool lockdep_softirq_start(void) { return false; } 
static inline void lockdep_softirq_end(bool in_hardirq) { }

#endif



asmlinkage __visible void __softirq_entry __do_softirq(void)

static void handle_softirqs(bool ksirqd)

{

	unsigned long end = jiffies + MAX_SOFTIRQ_TIME;

	unsigned long old_flags = current->flags;
@@ -563,8 +563,7 @@ asmlinkage __visible void __softirq_entry __do_softirq(void) 
		pending >>= softirq_bit;

	}



	if (!IS_ENABLED(CONFIG_PREEMPT_RT) &&

	    __this_cpu_read(ksoftirqd) == current)

	if (!IS_ENABLED(CONFIG_PREEMPT_RT) && ksirqd)

		rcu_softirq_qs();



	local_irq_disable();
@@ -584,6 +583,11 @@ asmlinkage __visible void __softirq_entry __do_softirq(void) 
	current_restore_flags(old_flags, PF_MEMALLOC);

}



asmlinkage __visible void __softirq_entry __do_softirq(void)

{

	handle_softirqs(false);

}



/**

 * irq_enter_rcu - Enter an interrupt context with RCU watching

 */
@@ -921,7 +925,7 @@ static void run_ksoftirqd(unsigned int cpu) 
		 * We can safely run softirq on inline stack, as we are not deep

		 * in the task stack here.

		 */

		__do_softirq();

		handle_softirqs(true);

		ksoftirqd_run_end();

		cond_resched();

		return;