Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | From | Thomas Gleixner <> | Subject | Re: [syzbot] [kernel?] WARNING: suspicious RCU usage in __do_softirq | Date | Mon, 22 Apr 2024 23:15:28 +0200 |
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On Fri, Apr 19 2024 at 13:50, Z qiang wrote: >> On Thu, Apr 18, 2024 at 05:49:38PM +0800, Z qiang wrote: > static __init int spawn_ksoftirqd(void) > { > + int cpu; > + > + for_each_possible_cpu(cpu) > + per_cpu(ksoftirqd_work, cpu) = false;
First of all that initialization is pointless, but why making all of this complex as hell?
Thanks,
tglx --- diff --git a/kernel/softirq.c b/kernel/softirq.c index b315b21fb28c..e991d735be0d 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -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 kirqd) { 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) && kirqd) 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;
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