| From f860e1baa816d3be4ec0d14210b59f0f9c499dd6 Mon Sep 17 00:00:00 2001 |
| From: "Gustavo A. R. Silva" <gustavo@embeddedor.com> |
| Date: Fri, 29 Mar 2019 10:27:26 -0500 |
| Subject: cxgb3/l2t: Fix undefined behaviour |
| |
| [ Upstream commit 76497732932f15e7323dc805e8ea8dc11bb587cf ] |
| |
| The use of zero-sized array causes undefined behaviour when it is not |
| the last member in a structure. As it happens to be in this case. |
| |
| Also, the current code makes use of a language extension to the C90 |
| standard, but the preferred mechanism to declare variable-length |
| types such as this one is a flexible array member, introduced in |
| C99: |
| |
| struct foo { |
| int stuff; |
| struct boo array[]; |
| }; |
| |
| By making use of the mechanism above, we will get a compiler warning |
| in case the flexible array does not occur last. Which is beneficial |
| to cultivate a high-quality code. |
| |
| Fixes: e48f129c2f20 ("[SCSI] cxgb3i: convert cdev->l2opt to use rcu to prevent NULL dereference") |
| Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/net/ethernet/chelsio/cxgb3/l2t.h | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| diff --git a/drivers/net/ethernet/chelsio/cxgb3/l2t.h b/drivers/net/ethernet/chelsio/cxgb3/l2t.h |
| index c2fd323c40782..ea75f275023ff 100644 |
| --- a/drivers/net/ethernet/chelsio/cxgb3/l2t.h |
| +++ b/drivers/net/ethernet/chelsio/cxgb3/l2t.h |
| @@ -75,8 +75,8 @@ struct l2t_data { |
| struct l2t_entry *rover; /* starting point for next allocation */ |
| atomic_t nfree; /* number of free entries */ |
| rwlock_t lock; |
| - struct l2t_entry l2tab[0]; |
| struct rcu_head rcu_head; /* to handle rcu cleanup */ |
| + struct l2t_entry l2tab[]; |
| }; |
| |
| typedef void (*arp_failure_handler_func)(struct t3cdev * dev, |
| -- |
| 2.20.1 |
| |
