____napi_schedule() needs to be invoked with disabled interrupts due to __raise_softirq_irqoff (in order not to corrupt the per-CPU list). ____napi_schedule() needs also to be invoked from an interrupt context so that the raised-softirq is processed while the interrupt context is left. Add lockdep asserts for both conditions. While this is the second time the irq/softirq check is needed, provide a generic lockdep_assert_softirq_will_run() which is used by both caller.
Unified · Split
| @@ -329,6 +329,12 @@ extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie); · 328 unmodified lines | ||
| 329 | 329 | |
| 330 | 330 | #define lockdep_assert_none_held_once() \ |
| 331 | 331 | lockdep_assert_once(!current->lockdep_depth) |
| 332 | +/* | |
| 333 | + * Ensure that softirq is handled within the callchain and not delayed and | |
| 334 | + * handled by chance. | |
| 335 | + */ | |
| 336 | +#define lockdep_assert_softirq_will_run() \ | |
| 337 | + lockdep_assert_once(hardirq_count() | softirq_count()) | |
| 332 | 338 | |
| 333 | 339 | #define lockdep_recursing(tsk) ((tsk)->lockdep_recursion) |
| 334 | 340 | |
| @@ -414,6 +420,7 @@ extern int lockdep_is_held(const void *); · 79 unmodified lines | ||
| 414 | 420 | #define lockdep_assert_held_read(l) do { (void)(l); } while (0) |
| 415 | 421 | #define lockdep_assert_held_once(l) do { (void)(l); } while (0) |
| 416 | 422 | #define lockdep_assert_none_held_once() do { } while (0) |
| 423 | +#define lockdep_assert_softirq_will_run() do { } while (0) | |
| 417 | 424 | |
| 418 | 425 | #define lockdep_recursing(tsk) (0) |
| 419 | 426 | |
| @@ -4265,6 +4265,9 @@ static inline void ____napi_schedule(struct softnet_data *sd, · 4264 unmodified lines | ||
| 4265 | 4265 | { |
| 4266 | 4266 | struct task_struct *thread; |
| 4267 | 4267 | |
| 4268 | + lockdep_assert_softirq_will_run(); | |
| 4269 | + lockdep_assert_irqs_disabled(); | |
| 4270 | + | |
| 4268 | 4271 | if (test_bit(NAPI_STATE_THREADED, &napi->state)) { |
| 4269 | 4272 | /* Paired with smp_mb__before_atomic() in |
| 4270 | 4273 | * napi_enable()/dev_set_threaded(). |
| @@ -4872,7 +4875,7 @@ int __netif_rx(struct sk_buff *skb) · 601 unmodified lines | ||
| 4872 | 4875 | { |
| 4873 | 4876 | int ret; |
| 4874 | 4877 | |
| 4875 | − lockdep_assert_once(hardirq_count() | softirq_count()); | |
| 4878 | + lockdep_assert_softirq_will_run(); | |
| 4876 | 4879 | |
| 4877 | 4880 | trace_netif_rx_entry(skb); |
| 4878 | 4881 | ret = netif_rx_internal(skb); |