16c09b1c76
Order of initialization in rds_tcp_init needs to be done so
that resources are set up and destroyed in the correct synchronization
sequence with both the data path, as well as netns create/destroy
path. Specifically,
- we must call register_pernet_subsys and get the rds_tcp_netid
before calling register_netdevice_notifier, otherwise we risk
the sequence
1. register_netdevice_notifier sets up netdev notifier callback
2. rds_tcp_dev_event -> rds_tcp_kill_sock uses netid 0, and finds
the wrong rtn, resulting in a panic with string that is of the form:
BUG: unable to handle kernel NULL pointer dereference at 000000000000000d
IP: rds_tcp_kill_sock+0x3a/0x1d0 [rds_tcp]
:
- the rds_tcp_incoming_slab kmem_cache must be initialized before the
datapath starts up. The latter can happen any time after the
pernet_subsys registration of rds_tcp_net_ops, whose -> init
function sets up the listen socket. If the rds_tcp_incoming_slab has
not been set up at that time, a panic of the form below may be
encountered
BUG: unable to handle kernel NULL pointer dereference at 0000000000000014
IP: kmem_cache_alloc+0x90/0x1c0
:
rds_tcp_data_recv+0x1e7/0x370 [rds_tcp]
tcp_read_sock+0x96/0x1c0
rds_tcp_recv_path+0x65/0x80 [rds_tcp]
:
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.