Doing arithmetic with the NULL pointer is undefined.
Caught by UBSan:
../app/test/test_tailq.c:111:9: runtime error:
member access within null pointer of type 'struct rte_tailq_head'
Fixes: f6b4f6c9c123 ("tailq: use a single cast macro")
Cc: sta...@dpdk.org
Signed-off-by: David Marchand <david.march...@redhat.com>
---
Changes since v3:
- left the cast macro untouched and fixed the lookup macro instead,
---
lib/eal/include/rte_tailq.h | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/lib/eal/include/rte_tailq.h b/lib/eal/include/rte_tailq.h
index 89f7ef2134..e7caed6812 100644
--- a/lib/eal/include/rte_tailq.h
+++ b/lib/eal/include/rte_tailq.h
@@ -69,11 +69,12 @@ struct rte_tailq_elem {
* @return
* The return value from rte_eal_tailq_lookup, typecast to the appropriate
* structure pointer type.
- * NULL on error, since the tailq_head is the first
- * element in the rte_tailq_head structure.
+ * NULL on error.
*/
-#define RTE_TAILQ_LOOKUP(name, struct_name) \
- RTE_TAILQ_CAST(rte_eal_tailq_lookup(name), struct_name)
+#define RTE_TAILQ_LOOKUP(name, struct_name) __extension__ ({ \
+ struct rte_tailq_head *head = rte_eal_tailq_lookup(name); \
+ head == NULL ? NULL : RTE_TAILQ_CAST(head, struct_name); \
+})
/**
* Dump tail queues to a file.
--
2.50.0
