diff options
| author | Jason Gunthorpe <jgg@mellanox.com> | 2020-02-27 16:36:51 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-04-13 10:45:13 +0200 |
| commit | ee433d1cdee016c73707b4636c9dd4424aaaad53 (patch) | |
| tree | 8e66d06862bf74ddbac581c4595148175790d069 | |
| parent | abc4ea7f1345398261295345fd9b30243e4f4f8e (diff) | |
RDMA/cma: Teach lockdep about the order of rtnl and lock
commit 32ac9e4399b12d3e54d312a0e0e30ed5cd19bd4e upstream.
This lock ordering only happens when bonding is enabled and a certain
bonding related event fires. However, since it can happen this is a global
restriction on lock ordering.
Teach lockdep about the order directly and unconditionally so bugs here
are found quickly.
See https://syzkaller.appspot.com/bug?extid=55de90ab5f44172b0c90
Link: https://lore.kernel.org/r/20200227203651.GA27185@ziepe.ca
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/infiniband/core/cma.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c index e16872e0724f..d9e384478baa 100644 --- a/drivers/infiniband/core/cma.c +++ b/drivers/infiniband/core/cma.c @@ -4635,6 +4635,19 @@ static int __init cma_init(void) { int ret; + /* + * There is a rare lock ordering dependency in cma_netdev_callback() + * that only happens when bonding is enabled. Teach lockdep that rtnl + * must never be nested under lock so it can find these without having + * to test with bonding. + */ + if (IS_ENABLED(CONFIG_LOCKDEP)) { + rtnl_lock(); + mutex_lock(&lock); + mutex_unlock(&lock); + rtnl_unlock(); + } + cma_wq = alloc_ordered_workqueue("rdma_cm", WQ_MEM_RECLAIM); if (!cma_wq) return -ENOMEM; |