diff options
| -rw-r--r-- | kernel/irq_work.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/kernel/irq_work.c b/kernel/irq_work.c index 57be1a6cd8d..64eddd59ed8 100644 --- a/kernel/irq_work.c +++ b/kernel/irq_work.c @@ -34,15 +34,21 @@ static DEFINE_PER_CPU(struct llist_head, irq_work_list); */ static bool irq_work_claim(struct irq_work *work) { - unsigned long flags, nflags; + unsigned long flags, oflags, nflags; + /* + * Start with our best wish as a premise but only trust any + * flag value after cmpxchg() result. + */ + flags = work->flags & ~IRQ_WORK_PENDING; for (;;) { - flags = work->flags; - if (flags & IRQ_WORK_PENDING) - return false; nflags = flags | IRQ_WORK_FLAGS; - if (cmpxchg(&work->flags, flags, nflags) == flags) + oflags = cmpxchg(&work->flags, flags, nflags); + if (oflags == flags) break; + if (oflags & IRQ_WORK_PENDING) + return false; + flags = oflags; cpu_relax(); } |