The current semantic for napi_consume_skb() is that caller need
to provide non-zero budget when calling from NAPI context, and
breaking this semantic will cause hard to debug problem, because
_kfree_skb_defer() need to run in atomic context in order to push
the skb to the particular cpu' napi_alloc_cache atomically.
So add the lockdep_assert_in_softirq() to assert when the running
context is not in_softirq, in_softirq means softirq is serving or
BH is disabled. Because the softirq context can be interrupted by
hard IRQ or NMI context, so lockdep_assert_in_softirq() need to
assert about hard IRQ or NMI context too.
Suggested-by: Jakub Kicinski <k...@kernel.org>
Signed-off-by: Yunsheng Lin <linyunsh...@huawei.com>
---
include/linux/lockdep.h | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index f559487..f5e3d81 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -594,6 +594,12 @@ do {
\
this_cpu_read(hardirqs_enabled))); \
} while (0)
+#define lockdep_assert_in_softirq() \
+do { \
+ WARN_ON_ONCE(__lockdep_enabled && \
+ (!in_softirq() || in_irq() || in_nmi())); \
+} while (0)
+
#else
# define might_lock(lock) do { } while (0)
# define might_lock_read(lock) do { } while (0)
@@ -605,6 +611,7 @@ do {
\
# define lockdep_assert_preemption_enabled() do { } while (0)
# define lockdep_assert_preemption_disabled() do { } while (0)
+# define lockdep_assert_in_softirq() do { } while (0)
#endif
#ifdef CONFIG_PROVE_RAW_LOCK_NESTING
--
2.8.1
