Commit Graph

7 Commits

Author SHA1 Message Date
Tom Parkin 7b7c0719cd l2tp: avoid deadlock in l2tp stats update
l2tp's u64_stats writers were incorrectly synchronised, making it possible to
deadlock a 64bit machine running a 32bit kernel simply by sending the l2tp
code netlink commands while passing data through l2tp sessions.

Previous discussion on netdev determined that alternative solutions such as
spinlock writer synchronisation or per-cpu data would bring unjustified
overhead, given that most users interested in high volume traffic will likely
be running 64bit kernels on 64bit hardware.

As such, this patch replaces l2tp's use of u64_stats with atomic_long_t,
thereby avoiding the deadlock.

Ref:
http://marc.info/?l=linux-netdev&m=134029167910731&w=2
http://marc.info/?l=linux-netdev&m=134079868111131&w=2

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-20 12:10:39 -04:00
Joe Perches a4ca44fa57 net: l2tp: Standardize logging styles
Use more current logging styles.

Add pr_fmt to prefix output appropriately.
Convert printks to pr_<level>.
Convert PRINTK macros to new l2tp_<level> macros.
Neaten some <foo>_refcount debugging macros.
Use print_hex_dump_bytes instead of hand-coded loops.
Coalesce formats and align arguments.

Some KERN_DEBUG output is not now emitted unless
dynamic_debugging is enabled.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-17 04:34:38 -04:00
Chris Elston 2121c3f571 l2tp: show IPv6 addresses in l2tp debugfs file
If an L2TP tunnel uses IPv6, make sure the l2tp debugfs file shows the
IPv6 address correctly.

Signed-off-by: Chris Elston <celston@katalix.com>
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-01 09:30:55 -04:00
Al Viro b8f07a0631 fix return values of l2tp_dfs_seq_open()
More fallout from struct net lifetime rules review: PTR_ERR() is *already*
negative and failing ->open() should return negatives on failure.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-06-05 14:11:09 -07:00
Dr. David Alan Gilbert 6f9b901823 l2tp: kzalloc with swapped params in l2tp_dfs_seq_open
'sparse' spotted that the parameters to kzalloc in l2tp_dfs_seq_open
were swapped.

Tested on current git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
at 1792f17b72  build, boots and I can see that directory,
but there again I could see /sys/kernel/debug/l2tp with it swapped; I don't have
any l2tp in use.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-01 06:56:02 -07:00
Joe Perches a4fbf8415c net/l2tp/l2tp_debugfs.c: Convert NIPQUAD to %pI4
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-15 15:37:13 -07:00
James Chapman 0ad6614048 l2tp: Add debugfs files for dumping l2tp debug info
The existing pppol2tp driver exports debug info to
/proc/net/pppol2tp. Rather than adding info to that file for the new
functionality added in this patch series, we add new files in debugfs,
leaving the old /proc file for backwards compatibility (L2TPv2 only).

Currently only one file is provided: l2tp/tunnels, which lists
internal debug info for all l2tp tunnels and sessions. More files may
be added later. The info is for debug and problem analysis only -
userspace apps should use netlink to obtain status about l2tp tunnels
and sessions.

Although debugfs does not support net namespaces, the tunnels and
sessions dumped in l2tp/tunnels are only those in the net namespace of
the process reading the file.

Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03 14:56:07 -07:00