Commit Graph

253 Commits

Author SHA1 Message Date
Linus Torvalds a0e881b7c1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull second vfs pile from Al Viro:
 "The stuff in there: fsfreeze deadlock fixes by Jan (essentially, the
  deadlock reproduced by xfstests 068), symlink and hardlink restriction
  patches, plus assorted cleanups and fixes.

  Note that another fsfreeze deadlock (emergency thaw one) is *not*
  dealt with - the series by Fernando conflicts a lot with Jan's, breaks
  userland ABI (FIFREEZE semantics gets changed) and trades the deadlock
  for massive vfsmount leak; this is going to be handled next cycle.
  There probably will be another pull request, but that stuff won't be
  in it."

Fix up trivial conflicts due to unrelated changes next to each other in
drivers/{staging/gdm72xx/usb_boot.c, usb/gadget/storage_common.c}

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (54 commits)
  delousing target_core_file a bit
  Documentation: Correct s_umount state for freeze_fs/unfreeze_fs
  fs: Remove old freezing mechanism
  ext2: Implement freezing
  btrfs: Convert to new freezing mechanism
  nilfs2: Convert to new freezing mechanism
  ntfs: Convert to new freezing mechanism
  fuse: Convert to new freezing mechanism
  gfs2: Convert to new freezing mechanism
  ocfs2: Convert to new freezing mechanism
  xfs: Convert to new freezing code
  ext4: Convert to new freezing mechanism
  fs: Protect write paths by sb_start_write - sb_end_write
  fs: Skip atime update on frozen filesystem
  fs: Add freezing handling to mnt_want_write() / mnt_drop_write()
  fs: Improve filesystem freezing handling
  switch the protection of percpu_counter list to spinlock
  nfsd: Push mnt_want_write() outside of i_mutex
  btrfs: Push mnt_want_write() outside of i_mutex
  fat: Push mnt_want_write() outside of i_mutex
  ...
2012-08-01 10:26:23 -07:00
Al Viro faf0201029 clean unix_bind() up a bit
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-29 21:24:15 +04:00
Al Viro a8104a9fcd pull mnt_want_write()/mnt_drop_write() into kern_path_create()/done_path_create() resp.
One side effect - attempt to create a cross-device link on a read-only fs fails
with EROFS instead of EXDEV now.  Makes more sense, POSIX allows, etc.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-29 21:24:15 +04:00
Al Viro 921a1650de new helper: done_path_create()
releases what needs to be released after {kern,user}_path_create()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-29 21:24:13 +04:00
Andrey Vagin 51d7cccf07 net: make sock diag per-namespace
Before this patch sock_diag works for init_net only and dumps
information about sockets from all namespaces.

This patch expands sock_diag for all name-spaces.
It creates a netlink kernel socket for each netns and filters
data during dumping.

v2: filter accoding with netns in all places
    remove an unused variable.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Pavel Emelyanov <xemul@parallels.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Andrew Vagin <avagin@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-16 22:31:34 -07:00
Thomas Graf 4245375db8 unix_diag: Do not use RTA_PUT() macros
Also, no need to trim on nlmsg_put() failure, nothing has been added
yet.  We also want to use nlmsg_end(), nlmsg_new() and nlmsg_free().

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-27 15:36:43 -07:00
David S. Miller b61bb01974 unix_diag: Move away from NLMSG_PUT().
And use nlmsg_data() while we're here too and remove useless
casts.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-26 21:41:00 -07:00
Eric Dumazet 8b51b064a6 af_unix: remove unix_iter_state
As pointed out by Michael Tokarev , struct unix_iter_state is no longer
needed.

Suggested-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-09 19:06:21 -07:00
Eric Dumazet 7123aaa3a1 af_unix: speedup /proc/net/unix
/proc/net/unix has quadratic behavior, and can hold unix_table_lock for
a while if high number of unix sockets are alive. (90 ms for 200k
sockets...)

We already have a hash table, so its quite easy to use it.

Problem is unbound sockets are still hashed in a single hash slot
(unix_socket_table[UNIX_HASH_TABLE])

This patch also spreads unbound sockets to 256 hash slots, to speedup
both /proc/net/unix and unix_diag.

Time to read /proc/net/unix with 200k unix sockets :
(time dd if=/proc/net/unix of=/dev/null bs=4k)

before : 520 secs
after : 2 secs

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-08 14:27:23 -07:00
Shan Wei 8dcf01fc00 net: sock_diag_handler structs can be const
read only, so change it to const.

Signed-off-by: Shan Wei <davidshan@tencent.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-25 20:46:59 -04:00
Eric W. Biederman ec8f23ce0f net: Convert all sysctl registrations to register_net_sysctl
This results in code with less boiler plate that is a bit easier
to read.

Additionally stops us from using compatibility code in the sysctl
core, hastening the day when the compatibility code can be removed.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-20 21:22:30 -04:00
Eric W. Biederman 5dd3df105b net: Move all of the network sysctls without a namespace into init_net.
This makes it clearer which sysctls are relative to your current network
namespace.

This makes it a little less error prone by not exposing sysctls for the
initial network namespace in other namespaces.

This is the same way we handle all of our other network interfaces to
userspace and I can't honestly remember why we didn't do this for
sysctls right from the start.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-20 21:21:17 -04:00
Eric Dumazet 95c9617472 net: cleanup unsigned to unsigned int
Use of "unsigned int" is preferred to bare "unsigned" in net tree.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-15 12:44:40 -04:00
Eric Dumazet eb6a24816b af_unix: reduce high order page allocations
unix_dgram_sendmsg() currently builds linear skbs, and this can stress
page allocator with high order page allocations. When memory gets
fragmented, this can eventually fail.

We can try to use order-2 allocations for skb head (SKB_MAX_ALLOC) plus
up to 16 page fragments to lower pressure on buddy allocator.

This patch has no effect on messages of less than 16064 bytes.
(on 64bit arches with PAGE_SIZE=4096)

For bigger messages (from 16065 to 81600 bytes), this patch brings
reliability at the expense of performance penalty because of extra pages
allocations.

netperf -t DG_STREAM -T 0,2 -- -m 16064 -s 200000
->4086040 Messages / 10s

netperf -t DG_STREAM -T 0,2 -- -m 16068 -s 200000
->3901747 Messages / 10s

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-03 16:43:18 -04:00
Hans Verkuil 626cf23660 poll: add poll_requested_events() and poll_does_not_wait() functions
In some cases the poll() implementation in a driver has to do different
things depending on the events the caller wants to poll for.  An example
is when a driver needs to start a DMA engine if the caller polls for
POLLIN, but doesn't want to do that if POLLIN is not requested but instead
only POLLOUT or POLLPRI is requested.  This is something that can happen
in the video4linux subsystem among others.

Unfortunately, the current epoll/poll/select implementation doesn't
provide that information reliably.  The poll_table_struct does have it: it
has a key field with the event mask.  But once a poll() call matches one
or more bits of that mask any following poll() calls are passed a NULL
poll_table pointer.

Also, the eventpoll implementation always left the key field at ~0 instead
of using the requested events mask.

This was changed in eventpoll.c so the key field now contains the actual
events that should be polled for as set by the caller.

The solution to the NULL poll_table pointer is to set the qproc field to
NULL in poll_table once poll() matches the events, not the poll_table
pointer itself.  That way drivers can obtain the mask through a new
poll_requested_events inline.

The poll_table_struct can still be NULL since some kernel code calls it
internally (netfs_state_poll() in ./drivers/staging/pohmelfs/netfs.h).  In
that case poll_requested_events() returns ~0 (i.e.  all events).

Very rarely drivers might want to know whether poll_wait will actually
wait.  If another earlier file descriptor in the set already matched the
events the caller wanted to wait for, then the kernel will return from the
select() call without waiting.  This might be useful information in order
to avoid doing expensive work.

A new helper function poll_does_not_wait() is added that drivers can use
to detect this situation.  This is now used in sock_poll_wait() in
include/net/sock.h.  This was the only place in the kernel that needed
this information.

Drivers should no longer access any of the poll_table internals, but use
the poll_requested_events() and poll_does_not_wait() access functions
instead.  In order to enforce that the poll_table fields are now prepended
with an underscore and a comment was added warning against using them
directly.

This required a change in unix_dgram_poll() in unix/af_unix.c which used
the key field to get the requested events.  It's been replaced by a call
to poll_requested_events().

For qproc it was especially important to change its name since the
behavior of that field changes with this patch since this function pointer
can now be NULL when that wasn't possible in the past.

Any driver accessing the qproc or key fields directly will now fail to compile.

Some notes regarding the correctness of this patch: the driver's poll()
function is called with a 'struct poll_table_struct *wait' argument.  This
pointer may or may not be NULL, drivers can never rely on it being one or
the other as that depends on whether or not an earlier file descriptor in
the select()'s fdset matched the requested events.

There are only three things a driver can do with the wait argument:

1) obtain the key field:

	events = wait ? wait->key : ~0;

   This will still work although it should be replaced with the new
   poll_requested_events() function (which does exactly the same).
   This will now even work better, since wait is no longer set to NULL
   unnecessarily.

2) use the qproc callback. This could be deadly since qproc can now be
   NULL. Renaming qproc should prevent this from happening. There are no
   kernel drivers that actually access this callback directly, BTW.

3) test whether wait == NULL to determine whether poll would return without
   waiting. This is no longer sufficient as the correct test is now
   wait == NULL || wait->_qproc == NULL.

   However, the worst that can happen here is a slight performance hit in
   the case where wait != NULL and wait->_qproc == NULL. In that case the
   driver will assume that poll_wait() will actually add the fd to the set
   of waiting file descriptors. Of course, poll_wait() will not do that
   since it tests for wait->_qproc. This will not break anything, though.

   There is only one place in the whole kernel where this happens
   (sock_poll_wait() in include/net/sock.h) and that code will be replaced
   by a call to poll_does_not_wait() in the next patch.

   Note that even if wait->_qproc != NULL drivers cannot rely on poll_wait()
   actually waiting. The next file descriptor from the set might match the
   event mask and thus any possible waits will never happen.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Jonathan Corbet <corbet@lwn.net>
Reviewed-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23 16:58:38 -07:00
Linus Torvalds e2a0883e40 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs pile 1 from Al Viro:
 "This is _not_ all; in particular, Miklos' and Jan's stuff is not there
  yet."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (64 commits)
  ext4: initialization of ext4_li_mtx needs to be done earlier
  debugfs-related mode_t whack-a-mole
  hfsplus: add an ioctl to bless files
  hfsplus: change finder_info to u32
  hfsplus: initialise userflags
  qnx4: new helper - try_extent()
  qnx4: get rid of qnx4_bread/qnx4_getblk
  take removal of PF_FORKNOEXEC to flush_old_exec()
  trim includes in inode.c
  um: uml_dup_mmap() relies on ->mmap_sem being held, but activate_mm() doesn't hold it
  um: embed ->stub_pages[] into mmu_context
  gadgetfs: list_for_each_safe() misuse
  ocfs2: fix leaks on failure exits in module_init
  ecryptfs: make register_filesystem() the last potential failure exit
  ntfs: forgets to unregister sysctls on register_filesystem() failure
  logfs: missing cleanup on register_filesystem() failure
  jfs: mising cleanup on register_filesystem() failure
  make configfs_pin_fs() return root dentry on success
  configfs: configfs_create_dir() has parent dentry in dentry->d_parent
  configfs: sanitize configfs_create()
  ...
2012-03-21 13:36:41 -07:00
Al Viro 68ac1234fb switch touch_atime to struct path
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20 21:29:41 -04:00
Al Viro 40ffe67d2e switch unix_sock to struct path
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20 21:29:41 -04:00
Pablo Neira Ayuso 80d326fab5 netlink: add netlink_dump_control structure for netlink_dump_start()
Davem considers that the argument list of this interface is getting
out of control. This patch tries to address this issue following
his proposal:

struct netlink_dump_control c = { .dump = dump, .done = done, ... };

netlink_dump_start(..., &c);

Suggested by David S. Miller.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-26 14:10:06 -05:00
Eric Dumazet 9f6f9af769 af_unix: MSG_TRUNC support for dgram sockets
Piergiorgio Beruto expressed the need to fetch size of first datagram in
queue for AF_UNIX sockets and suggested a patch against SIOCINQ ioctl.

I suggested instead to implement MSG_TRUNC support as a recv() input
flag, as already done for RAW, UDP & NETLINK sockets.

len = recv(fd, &byte, 1, MSG_PEEK | MSG_TRUNC);

MSG_TRUNC asks recv() to return the real length of the packet, even when
is was longer than the passed buffer.

There is risk that a userland application used MSG_TRUNC by accident
(since it had no effect on af_unix sockets) and this might break after
this patch.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Tested-by: Piergiorgio Beruto <piergiorgio.beruto@gmail.com>
CC: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-22 14:47:02 -05:00
Pavel Emelyanov fc0d753641 unix: Support peeking offset for stream sockets
The same here -- we can protect the sk_peek_off manipulations with
the unix_sk->readlock mutex.

The peeking of data from a stream socket is done in the datagram style,
i.e. even if there's enough room for more data in the user buffer, only
the head skb's data is copied in there. This feature is preserved when
peeking data from a given offset -- the data is read till the nearest
skb's boundary.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-21 15:03:58 -05:00
Pavel Emelyanov f55bb7f9cb unix: Support peeking offset for datagram and seqpacket sockets
The sk_peek_off manipulations are protected with the unix_sk->readlock mutex.
This mutex is enough since all we need is to syncronize setting the offset
vs reading the queue head. The latter is fully covered with the mentioned lock.

The recently added __skb_recv_datagram's offset is used to pick the skb to
read the data from.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-21 15:03:58 -05:00
Eric Dumazet 6f01fd6e6f af_unix: fix EPOLLET regression for stream sockets
Commit 0884d7aa24 (AF_UNIX: Fix poll blocking problem when reading from
a stream socket) added a regression for epoll() in Edge Triggered mode
(EPOLLET)

Appropriate fix is to use skb_peek()/skb_unlink() instead of
skb_dequeue(), and only call skb_unlink() when skb is fully consumed.

This remove the need to requeue a partial skb into sk_receive_queue head
and the extra sk->sk_data_ready() calls that added the regression.

This is safe because once skb is given to sk_receive_queue, it is not
modified by a writer, and readers are serialized by u->readlock mutex.

This also reduce number of spinlock acquisition for small reads or
MSG_PEEK users so should improve overall performance.

Reported-by: Nick Mathewson <nickm@freehaven.net>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Alexey Moiseytsev <himeraster@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-01-30 12:45:07 -05:00
Linus Torvalds 38e5781bbf Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  igmp: Avoid zero delay when receiving odd mixture of IGMP queries
  netdev: make net_device_ops const
  bcm63xx: make ethtool_ops const
  usbnet: make ethtool_ops const
  net: Fix build with INET disabled.
  net: introduce netif_addr_lock_nested() and call if when appropriate
  net: correct lock name in dev_[uc/mc]_sync documentations.
  net: sk_update_clone is only used in net/core/sock.c
  8139cp: fix missing napi_gro_flush.
  pktgen: set correct max and min in pktgen_setup_inject()
  smsc911x: Unconditionally include linux/smscphy.h in smsc911x.h
  asix: fix infinite loop in rx_fixup()
  net: Default UDP and UNIX diag to 'n'.
  r6040: fix typo in use of MCR0 register bits
  net: fix sock_clone reference mismatch with tcp memcontrol
2012-01-09 14:46:52 -08:00
Linus Torvalds 972b2c7199 Merge branch 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
* 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (165 commits)
  reiserfs: Properly display mount options in /proc/mounts
  vfs: prevent remount read-only if pending removes
  vfs: count unlinked inodes
  vfs: protect remounting superblock read-only
  vfs: keep list of mounts for each superblock
  vfs: switch ->show_options() to struct dentry *
  vfs: switch ->show_path() to struct dentry *
  vfs: switch ->show_devname() to struct dentry *
  vfs: switch ->show_stats to struct dentry *
  switch security_path_chmod() to struct path *
  vfs: prefer ->dentry->d_sb to ->mnt->mnt_sb
  vfs: trim includes a bit
  switch mnt_namespace ->root to struct mount
  vfs: take /proc/*/mounts and friends to fs/proc_namespace.c
  vfs: opencode mntget() mnt_set_mountpoint()
  vfs: spread struct mount - remaining argument of next_mnt()
  vfs: move fsnotify junk to struct mount
  vfs: move mnt_devname
  vfs: move mnt_list to struct mount
  vfs: switch pnode.h macros to struct mount *
  ...
2012-01-08 12:19:57 -08:00
David S. Miller 6d62a66e42 net: Default UDP and UNIX diag to 'n'.
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-01-07 12:13:06 -08:00
Al Viro 04fc66e789 switch ->path_mknod() to umode_t
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:55:19 -05:00
Pavel Emelyanov c9da99e647 unix_diag: Fixup RQLEN extension report
While it's not too late fix the recently added RQLEN diag extension
to report rqlen and wqlen in the same way as TCP does.

I.e. for listening sockets the ack backlog length (which is the input
queue length for socket) in rqlen and the max ack backlog length in
wqlen, and what the CINQ/OUTQ ioctls do for established.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-30 16:46:02 -05:00
Pavel Emelyanov 885ee74d5d af_unix: Move CINQ/COUTQ code to helpers
Currently tcp diag reports rqlen and wqlen values similar to how
the CINQ/COUTQ iotcls do. To make unix diag report these values
in the same way move the respective code into helpers.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-30 16:45:45 -05:00
Pavel Emelyanov 257b529876 unix_diag: Add the MEMINFO extension
[ Fix indentation of sock_diag*() calls. -DaveM ]

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-30 16:44:24 -05:00
David S. Miller e09e9d189b unix: If we happen to find peer NULL when diag dumping, write zero.
Otherwise we leave uninitialized kernel memory in there.

Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-26 14:41:55 -05:00
Pavel Emelyanov 3b0723c12e unix_diag: Fix incoming connections nla length
The NLA_PUT macro should accept the actual attribute length, not
the amount of elements in array :(

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-26 14:08:47 -05:00
Cyrill Gorcunov 2ea744a583 net: unix -- Add missing module.h inclusion
Otherwise getting

 | net/unix/diag.c:312:16: error: expected declaration specifiers or ‘...’ before string constant
 | net/unix/diag.c:313:1: error: expected declaration specifiers or ‘...’ before string constant

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-20 13:29:43 -05:00
Pavel Emelyanov 5d531aaa64 unix_diag: Write it into kbuild
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-16 13:48:29 -05:00
Pavel Emelyanov cbf391958a unix_diag: Receive queue lenght NLA
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-16 13:48:29 -05:00
Pavel Emelyanov 2aac7a2cb0 unix_diag: Pending connections IDs NLA
When establishing a unix connection on stream sockets the
server end receives an skb with socket in its receive queue.

Report who is waiting for these ends to be accepted for
listening sockets via NLA.

There's a lokcing issue with this -- the unix sk state lock is
required to access the peer, and it is taken under the listening
sk's queue lock. Strictly speaking the queue lock should be taken
inside the state lock, but since in this case these two sockets
are different it shouldn't lead to deadlock.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-16 13:48:28 -05:00
Pavel Emelyanov ac02be8d96 unix_diag: Unix peer inode NLA
Report the peer socket inode ID as NLA. With this it's finally
possible to find out the other end of an interesting unix connection.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-16 13:48:28 -05:00
Pavel Emelyanov 5f7b056946 unix_diag: Unix inode info NLA
Actually, the socket path if it's not anonymous doesn't give
a clue to which file the socket is bound to. Even if the path
is absolute, it can be unlinked and then new socket can be
bound to it.

With this NLA it's possible to check which file a particular
socket is really bound to.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-16 13:48:28 -05:00
Pavel Emelyanov f5248b48a6 unix_diag: Unix socket name NLA
Report the sun_path when requested as NLA. With leading '\0' if
present but without the leading AF_UNIX bits.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-16 13:48:28 -05:00
Pavel Emelyanov 5d3cae8bc3 unix_diag: Dumping exact socket core
The socket inode is used as a key for lookup. This is effectively
the only really unique ID of a unix socket, but using this for
search currently has one problem -- it is O(number of sockets) :(

Does it worth fixing this lookup or inventing some other ID for
unix sockets?

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-16 13:48:28 -05:00
Pavel Emelyanov 45a96b9be6 unix_diag: Dumping all sockets core
Walk the unix sockets table and fill the core response structure,
which includes type, state and inode.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-16 13:48:28 -05:00
Pavel Emelyanov 22931d3b90 unix_diag: Basic module skeleton
Includes basic module_init/_exit functionality, dump/get_exact stubs
and declares the basic API structures for request and response.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-16 13:48:27 -05:00
Pavel Emelyanov fa7ff56f75 af_unix: Export stuff required for diag module
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-16 13:48:27 -05:00
Alexey Moiseytsev 0884d7aa24 AF_UNIX: Fix poll blocking problem when reading from a stream socket
poll() call may be blocked by concurrent reading from the same stream
socket.

Signed-off-by: Alexey Moiseytsev <himeraster@gmail.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-26 16:34:22 -05:00
Eric Dumazet 16e5726269 af_unix: dont send SCM_CREDENTIALS by default
Since commit 7361c36c52 (af_unix: Allow credentials to work across
user and pid namespaces) af_unix performance dropped a lot.

This is because we now take a reference on pid and cred in each write(),
and release them in read(), usually done from another process,
eventually from another cpu. This triggers false sharing.

# Events: 154K cycles
#
# Overhead  Command       Shared Object        Symbol
# ........  .......  ..................  .........................
#
    10.40%  hackbench  [kernel.kallsyms]   [k] put_pid
     8.60%  hackbench  [kernel.kallsyms]   [k] unix_stream_recvmsg
     7.87%  hackbench  [kernel.kallsyms]   [k] unix_stream_sendmsg
     6.11%  hackbench  [kernel.kallsyms]   [k] do_raw_spin_lock
     4.95%  hackbench  [kernel.kallsyms]   [k] unix_scm_to_skb
     4.87%  hackbench  [kernel.kallsyms]   [k] pid_nr_ns
     4.34%  hackbench  [kernel.kallsyms]   [k] cred_to_ucred
     2.39%  hackbench  [kernel.kallsyms]   [k] unix_destruct_scm
     2.24%  hackbench  [kernel.kallsyms]   [k] sub_preempt_count
     1.75%  hackbench  [kernel.kallsyms]   [k] fget_light
     1.51%  hackbench  [kernel.kallsyms]   [k]
__mutex_lock_interruptible_slowpath
     1.42%  hackbench  [kernel.kallsyms]   [k] sock_alloc_send_pskb

This patch includes SCM_CREDENTIALS information in a af_unix message/skb
only if requested by the sender, [man 7 unix for details how to include
ancillary data using sendmsg() system call]

Note: This might break buggy applications that expected SCM_CREDENTIAL
from an unaware write() system call, and receiver not using SO_PASSCRED
socket option.

If SOCK_PASSCRED is set on source or destination socket, we still
include credentials for mere write() syscalls.

Performance boost in hackbench : more than 50% gain on a 16 thread
machine (2 quad-core cpus, 2 threads per core)

hackbench 20 thread 2000

4.228 sec instead of 9.102 sec

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-09-28 13:29:50 -04:00
David S. Miller f78a5fda91 Revert "Scm: Remove unnecessary pid & credential references in Unix socket's send and receive path"
This reverts commit 0856a30409.

As requested by Eric Dumazet, it has various ref-counting
problems and has introduced regressions.  Eric will add
a more suitable version of this performance fix.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-09-16 19:34:00 -04:00
Tim Chen 0856a30409 Scm: Remove unnecessary pid & credential references in Unix socket's send and receive path
Patch series 109f6e39..7361c36c back in 2.6.36 added functionality to
allow credentials to work across pid namespaces for packets sent via
UNIX sockets.  However, the atomic reference counts on pid and
credentials caused plenty of cache bouncing when there are numerous
threads of the same pid sharing a UNIX socket.  This patch mitigates the
problem by eliminating extraneous reference counts on pid and
credentials on both send and receive path of UNIX sockets. I found a 2x
improvement in hackbench's threaded case.

On the receive path in unix_dgram_recvmsg, currently there is an
increment of reference count on pid and credentials in scm_set_cred.
Then there are two decrement of the reference counts.  Once in scm_recv
and once when skb_free_datagram call skb->destructor function
unix_destruct_scm.  One pair of increment and decrement of ref count on
pid and credentials can be eliminated from the receive path.  Until we
destroy the skb, we already set a reference when we created the skb on
the send side.

On the send path, there are two increments of ref count on pid and
credentials, once in scm_send and once in unix_scm_to_skb.  Then there
is a decrement of the reference counts in scm_destroy's call to
scm_destroy_cred at the end of unix_dgram_sendmsg functions.   One pair
of increment and decrement of the reference counts can be removed so we
only need to increment the ref counts once.

By incorporating these changes, for hackbench running on a 4 socket
NHM-EX machine with 40 cores, the execution of hackbench on
50 groups of 20 threads sped up by factor of 2.

Hackbench command used for testing:
./hackbench 50 thread 2000

Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-24 19:41:13 -07:00
Al Viro dae6ad8f37 new helpers: kern_path_create/user_path_create
combination of kern_path_parent() and lookup_create().  Does *not*
expose struct nameidata to caller.  Syscalls converted to that...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:44:05 -04:00
Dan Rosenberg 71338aa7d0 net: convert %p usage to %pK
The %pK format specifier is designed to hide exposed kernel pointers,
specifically via /proc interfaces.  Exposing these pointers provides an
easy target for kernel write vulnerabilities, since they reveal the
locations of writable structures containing easily triggerable function
pointers.  The behavior of %pK depends on the kptr_restrict sysctl.

If kptr_restrict is set to 0, no deviation from the standard %p behavior
occurs.  If kptr_restrict is set to 1, the default, if the current user
(intended to be a reader via seq_printf(), etc.) does not have CAP_SYSLOG
(currently in the LSM tree), kernel pointers using %pK are printed as 0's.
 If kptr_restrict is set to 2, kernel pointers using %pK are printed as
0's regardless of privileges.  Replacing with 0's was chosen over the
default "(null)", which cannot be parsed by userland %p, which expects
"(nil)".

The supporting code for kptr_restrict and %pK are currently in the -mm
tree.  This patch converts users of %p in net/ to %pK.  Cases of printing
pointers to the syslog are not covered, since this would eliminate useful
information for postmortem debugging and the reading of the syslog is
already optionally protected by the dmesg_restrict sysctl.

Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Cc: James Morris <jmorris@namei.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Thomas Graf <tgraf@infradead.org>
Cc: Eugene Teo <eugeneteo@kernel.org>
Cc: Kees Cook <kees.cook@canonical.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David S. Miller <davem@davemloft.net>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Eric Paris <eparis@parisplace.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-24 01:13:12 -04:00
Eric W. Biederman a05d2ad1c1 af_unix: Only allow recv on connected seqpacket sockets.
This fixes the following oops discovered by Dan Aloni:
> Anyway, the following is the output of the Oops that I got on the
> Ubuntu kernel on which I first detected the problem
> (2.6.37-12-generic). The Oops that followed will be more useful, I
> guess.

>[ 5594.669852] BUG: unable to handle kernel NULL pointer dereference
> at           (null)
> [ 5594.681606] IP: [<ffffffff81550b7b>] unix_dgram_recvmsg+0x1fb/0x420
> [ 5594.687576] PGD 2a05d067 PUD 2b951067 PMD 0
> [ 5594.693720] Oops: 0002 [#1] SMP
> [ 5594.699888] last sysfs file:

The bug was that unix domain sockets use a pseduo packet for
connecting and accept uses that psudo packet to get the socket.
In the buggy seqpacket case we were allowing unconnected
sockets to call recvmsg and try to receive the pseudo packet.

That is always wrong and as of commit 7361c36c5 the pseudo
packet had become enough different from a normal packet
that the kernel started oopsing.

Do for seqpacket_recv what was done for seqpacket_send in 2.5
and only allow it on connected seqpacket sockets.

Cc: stable@kernel.org
Tested-by: Dan Aloni <dan@aloni.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-01 23:16:28 -07:00
Lucas De Marchi 25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Linus Torvalds 7a6362800c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1480 commits)
  bonding: enable netpoll without checking link status
  xfrm: Refcount destination entry on xfrm_lookup
  net: introduce rx_handler results and logic around that
  bonding: get rid of IFF_SLAVE_INACTIVE netdev->priv_flag
  bonding: wrap slave state work
  net: get rid of multiple bond-related netdevice->priv_flags
  bonding: register slave pointer for rx_handler
  be2net: Bump up the version number
  be2net: Copyright notice change. Update to Emulex instead of ServerEngines
  e1000e: fix kconfig for crc32 dependency
  netfilter ebtables: fix xt_AUDIT to work with ebtables
  xen network backend driver
  bonding: Improve syslog message at device creation time
  bonding: Call netif_carrier_off after register_netdevice
  bonding: Incorrect TX queue offset
  net_sched: fix ip_tos2prio
  xfrm: fix __xfrm_route_forward()
  be2net: Fix UDP packet detected status in RX compl
  Phonet: fix aligned-mode pipe socket buffer header reserve
  netxen: support for GbE port settings
  ...

Fix up conflicts in drivers/staging/brcm80211/brcmsmac/wl_mac80211.c
with the staging updates.
2011-03-16 16:29:25 -07:00
Linus Torvalds 422e6c4bc4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (57 commits)
  tidy the trailing symlinks traversal up
  Turn resolution of trailing symlinks iterative everywhere
  simplify link_path_walk() tail
  Make trailing symlink resolution in path_lookupat() iterative
  update nd->inode in __do_follow_link() instead of after do_follow_link()
  pull handling of one pathname component into a helper
  fs: allow AT_EMPTY_PATH in linkat(), limit that to CAP_DAC_READ_SEARCH
  Allow passing O_PATH descriptors via SCM_RIGHTS datagrams
  readlinkat(), fchownat() and fstatat() with empty relative pathnames
  Allow O_PATH for symlinks
  New kind of open files - "location only".
  ext4: Copy fs UUID to superblock
  ext3: Copy fs UUID to superblock.
  vfs: Export file system uuid via /proc/<pid>/mountinfo
  unistd.h: Add new syscalls numbers to asm-generic
  x86: Add new syscalls for x86_64
  x86: Add new syscalls for x86_32
  fs: Remove i_nlink check from file system link callback
  fs: Don't allow to create hardlink for deleted file
  vfs: Add open by file handle support
  ...
2011-03-15 15:48:13 -07:00
David S. Miller c337ffb68e Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2011-03-15 15:15:17 -07:00
Al Viro 326be7b484 Allow passing O_PATH descriptors via SCM_RIGHTS datagrams
Just need to make sure that AF_UNIX garbage collector won't
confuse O_PATHed socket on filesystem for real AF_UNIX opened
socket.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15 02:21:45 -04:00
Daniel Baluta e5537bfc98 af_unix: update locking comment
We latch our state using a spinlock not a r/w kind of lock.

Signed-off-by: Daniel Baluta <dbaluta@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-14 15:25:33 -07:00
Al Viro c9c6cac0c2 kill path_lookup()
all remaining callers pass LOOKUP_PARENT to it, so
flags argument can die; renamed to kern_path_parent()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-14 09:15:23 -04:00
David S. Miller 33175d84ee Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	drivers/net/bnx2x/bnx2x_cmn.c
2011-03-10 14:26:00 -08:00
Hagen Paul Pfeifer 6118e35a71 af_unix: remove unused struct sockaddr_un cruft
Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-07 15:51:14 -08:00
Rainer Weikusat b3ca9b02b0 net: fix multithreaded signal handling in unix recv routines
The unix_dgram_recvmsg and unix_stream_recvmsg routines in
net/af_unix.c utilize mutex_lock(&u->readlock) calls in order to
serialize read operations of multiple threads on a single socket. This
implies that, if all n threads of a process block in an AF_UNIX recv
call trying to read data from the same socket, one of these threads
will be sleeping in state TASK_INTERRUPTIBLE and all others in state
TASK_UNINTERRUPTIBLE. Provided that a particular signal is supposed to
be handled by a signal handler defined by the process and that none of
this threads is blocking the signal, the complete_signal routine in
kernel/signal.c will select the 'first' such thread it happens to
encounter when deciding which thread to notify that a signal is
supposed to be handled and if this is one of the TASK_UNINTERRUPTIBLE
threads, the signal won't be handled until the one thread not blocking
on the u->readlock mutex is woken up because some data to process has
arrived (if this ever happens). The included patch fixes this by
changing mutex_lock to mutex_lock_interruptible and handling possible
error returns in the same way interruptions are handled by the actual
receive-code.

Signed-off-by: Rainer Weikusat <rweikusat@mobileactivedefense.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-07 15:31:16 -08:00
Eric Dumazet eaefd1105b net: add __rcu annotations to sk_wq and wq
Add proper RCU annotations/verbs to sk_wq and wq members

Fix __sctp_write_space() sk_sleep() abuse (and sock->wq access)

Fix sunrpc sk_sleep() abuse too

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-22 10:19:31 -08:00
Alban Crequy 7180a03118 af_unix: coding style: remove one level of indentation in unix_shutdown()
Signed-off-by: Alban Crequy <alban.crequy@collabora.co.uk>
Reviewed-by: Ian Molton <ian.molton@collabora.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-19 23:31:11 -08:00
Alban Crequy d6ae3bae3d af_unix: implement socket filter
Linux Socket Filters can already be successfully attached and detached on unix
sockets with setsockopt(sockfd, SOL_SOCKET, SO_{ATTACH,DETACH}_FILTER, ...).
See: Documentation/networking/filter.txt

But the filter was never used in the unix socket code so it did not work. This
patch uses sk_filter() to filter buffers before delivery.

This short program demonstrates the problem on SOCK_DGRAM.

int main(void) {
  int i, j, ret;
  int sv[2];
  struct pollfd fds[2];
  char *message = "Hello world!";
  char buffer[64];
  struct sock_filter ins[32] = {{0,},};
  struct sock_fprog filter;

  socketpair(AF_UNIX, SOCK_DGRAM, 0, sv);

  for (i = 0 ; i < 2 ; i++) {
    fds[i].fd = sv[i];
    fds[i].events = POLLIN;
    fds[i].revents = 0;
  }

  for(j = 1 ; j < 13 ; j++) {

    /* Set a socket filter to truncate the message */
    memset(ins, 0, sizeof(ins));
    ins[0].code = BPF_RET|BPF_K;
    ins[0].k = j;
    filter.len = 1;
    filter.filter = ins;
    setsockopt(sv[1], SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter));

    /* send a message */
    send(sv[0], message, strlen(message) + 1, 0);

    /* The filter should let the message pass but truncated. */
    poll(fds, 2, 0);

    /* Receive the truncated message*/
    ret = recv(sv[1], buffer, 64, 0);
    printf("received %d bytes, expected %d\n", ret, j);
  }

    for (i = 0 ; i < 2 ; i++)
      close(sv[i]);

  return 0;
}

Signed-off-by: Alban Crequy <alban.crequy@collabora.co.uk>
Reviewed-by: Ian Molton <ian.molton@collabora.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-18 21:33:05 -08:00
David S. Miller 3610cda53f af_unix: Avoid socket->sk NULL OOPS in stream connect security hooks.
unix_release() can asynchornously set socket->sk to NULL, and
it does so without holding the unix_state_lock() on "other"
during stream connects.

However, the reverse mapping, sk->sk_socket, is only transitioned
to NULL under the unix_state_lock().

Therefore make the security hooks follow the reverse mapping instead
of the forward mapping.

Reported-by: Jeremy Fitzhardinge <jeremy@goop.org>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-05 15:38:53 -08:00
David S. Miller fe6c791570 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
	net/llc/af_llc.c
2010-12-08 13:47:38 -08:00
Eric Dumazet 25888e3031 af_unix: limit recursion level
Its easy to eat all kernel memory and trigger NMI watchdog, using an
exploit program that queues unix sockets on top of others.

lkml ref : http://lkml.org/lkml/2010/11/25/8

This mechanism is used in applications, one choice we have is to have a
recursion limit.

Other limits might be needed as well (if we queue other types of files),
since the passfd mechanism is currently limited by socket receive queue
sizes only.

Add a recursion_level to unix socket, allowing up to 4 levels.

Each time we send an unix socket through sendfd mechanism, we copy its
recursion level (plus one) to receiver. This recursion level is cleared
when socket receive queue is emptied.

Reported-by: Марк Коренберг <socketpair@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-29 09:45:15 -08:00
Eric Dumazet 9915672d41 af_unix: limit unix_tot_inflight
Vegard Nossum found a unix socket OOM was possible, posting an exploit
program.

My analysis is we can eat all LOWMEM memory before unix_gc() being
called from unix_release_sock(). Moreover, the thread blocked in
unix_gc() can consume huge amount of time to perform cleanup because of
huge working set.

One way to handle this is to have a sensible limit on unix_tot_inflight,
tested from wait_for_unix_gc() and to force a call to unix_gc() if this
limit is hit.

This solves the OOM and also reduce overall latencies, and should not
slowdown normal workloads.

Reported-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-24 09:15:27 -08:00
Eric Dumazet 973a34aa85 af_unix: optimize unix_dgram_poll()
unix_dgram_poll() is pretty expensive to check POLLOUT status, because
it has to lock the socket to get its peer, take a reference on the peer
to check its receive queue status, and queue another poll_wait on
peer_wait. This all can be avoided if the process calling
unix_dgram_poll() is not interested in POLLOUT status. It makes
unix_dgram_recvmsg() faster by not queueing irrelevant pollers in
peer_wait.

On a test program provided by Alan Crequy :

Before:

real    0m0.211s
user    0m0.000s
sys     0m0.208s

After:

real    0m0.044s
user    0m0.000s
sys     0m0.040s

Suggested-by: Davide Libenzi <davidel@xmailserver.org>
Reported-by: Alban Crequy <alban.crequy@collabora.co.uk>
Acked-by: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-08 13:50:09 -08:00
Eric Dumazet 5456f09aaf af_unix: fix unix_dgram_poll() behavior for EPOLLOUT event
Alban Crequy reported a problem with connected dgram af_unix sockets and
provided a test program. epoll() would miss to send an EPOLLOUT event
when a thread unqueues a packet from the other peer, making its receive
queue not full.

This is because unix_dgram_poll() fails to call sock_poll_wait(file,
&unix_sk(other)->peer_wait, wait);
if the socket is not writeable at the time epoll_ctl(ADD) is called.

We must call sock_poll_wait(), regardless of 'writable' status, so that
epoll can be notified later of states changes.

Misc: avoids testing twice (sk->sk_shutdown & RCV_SHUTDOWN)

Reported-by: Alban Crequy <alban.crequy@collabora.co.uk>
Cc: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-08 13:50:09 -08:00
Eric Dumazet 67426b756c af_unix: use keyed wakeups
Instead of wakeup all sleepers, use wake_up_interruptible_sync_poll() to
wakeup only ones interested into writing the socket.

This patch is a specialization of commit 37e5540b3c (epoll keyed
wakeups: make sockets use keyed wakeups).

On a test program provided by Alan Crequy :

Before:
real    0m3.101s
user    0m0.000s
sys     0m6.104s

After:

real	0m0.211s
user	0m0.000s
sys	0m0.208s

Reported-by: Alban Crequy <alban.crequy@collabora.co.uk>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-08 13:50:08 -08:00
Eric Dumazet 518de9b39e fs: allow for more than 2^31 files
Robin Holt tried to boot a 16TB system and found af_unix was overflowing
a 32bit value :

<quote>

We were seeing a failure which prevented boot.  The kernel was incapable
of creating either a named pipe or unix domain socket.  This comes down
to a common kernel function called unix_create1() which does:

        atomic_inc(&unix_nr_socks);
        if (atomic_read(&unix_nr_socks) > 2 * get_max_files())
                goto out;

The function get_max_files() is a simple return of files_stat.max_files.
files_stat.max_files is a signed integer and is computed in
fs/file_table.c's files_init().

        n = (mempages * (PAGE_SIZE / 1024)) / 10;
        files_stat.max_files = n;

In our case, mempages (total_ram_pages) is approx 3,758,096,384
(0xe0000000).  That leaves max_files at approximately 1,503,238,553.
This causes 2 * get_max_files() to integer overflow.

</quote>

Fix is to let /proc/sys/fs/file-nr & /proc/sys/fs/file-max use long
integers, and change af_unix to use an atomic_long_t instead of atomic_t.

get_max_files() is changed to return an unsigned long.  get_nr_files() is
changed to return a long.

unix_nr_socks is changed from atomic_t to atomic_long_t, while not
strictly needed to address Robin problem.

Before patch (on a 64bit kernel) :
# echo 2147483648 >/proc/sys/fs/file-max
# cat /proc/sys/fs/file-max
-18446744071562067968

After patch:
# echo 2147483648 >/proc/sys/fs/file-max
# cat /proc/sys/fs/file-max
2147483648
# cat /proc/sys/fs/file-nr
704     0       2147483648

Reported-by: Robin Holt <holt@sgi.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: David Miller <davem@davemloft.net>
Reviewed-by: Robin Holt <holt@sgi.com>
Tested-by: Robin Holt <holt@sgi.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:15 -07:00
Alban Crequy 3f66116e89 AF_UNIX: Implement SO_TIMESTAMP and SO_TIMETAMPNS on Unix sockets
Userspace applications can already request to receive timestamps with:
setsockopt(sockfd, SOL_SOCKET, SO_TIMESTAMP, ...)

Although setsockopt() returns zero (success), timestamps are not added to the
ancillary data. This patch fixes that on SOCK_DGRAM and SOCK_SEQPACKET Unix
sockets.

Signed-off-by: Alban Crequy <alban.crequy@collabora.co.uk>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-05 14:54:36 -07:00
David S. Miller e548833df8 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	net/mac80211/main.c
2010-09-09 22:27:33 -07:00
Tetsuo Handa 8df73ff90f UNIX: Do not loop forever at unix_autobind().
We assumed that unix_autobind() never fails if kzalloc() succeeded.
But unix_autobind() allows only 1048576 names. If /proc/sys/fs/file-max is
larger than 1048576 (e.g. systems with more than 10GB of RAM), a local user can
consume all names using fork()/socket()/bind().

If all names are in use, those who call bind() with addr_len == sizeof(short)
or connect()/sendmsg() with setsockopt(SO_PASSCRED) will continue

  while (1)
        yield();

loop at unix_autobind() till a name becomes available.
This patch adds a loop counter in order to give up after 1048576 attempts.

Calling yield() for once per 256 attempts may not be sufficient when many names
are already in use, for __unix_find_socket_byname() can take long time under
such circumstance. Therefore, this patch also adds cond_resched() call.

Note that currently a local user can consume 2GB of kernel memory if the user
is allowed to create and autobind 1048576 UNIX domain sockets. We should
consider adding some restriction for autobind operation.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-07 13:57:23 -07:00
Eric Dumazet db40980fcd net: poll() optimizations
No need to test twice sk->sk_shutdown & RCV_SHUTDOWN

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-06 18:48:45 -07:00
Neil Horman 70d4bf6d46 drop_monitor: convert some kfree_skb call sites to consume_skb
Convert a few calls from kfree_skb to consume_skb

Noticed while I was working on dropwatch that I was detecting lots of internal
skb drops in several places.  While some are legitimate, several were not,
freeing skbs that were at the end of their life, rather than being discarded due
to an error.  This patch converts those calls sites from using kfree_skb to
consume_skb, which quiets the in-kernel drop_monitor code from detecting them as
drops.  Tested successfully by myself

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-20 13:28:05 -07:00
Eric W. Biederman 6616f7888c af_unix: Allow connecting to sockets in other network namespaces.
Remove the restriction that only allows connecting to a unix domain
socket identified by unix path that is in the same network namespace.

Crossing network namespaces is always tricky and we did not support
this at first, because of a strict policy of don't mix the namespaces.
Later after Pavel proposed this we did not support this because no one
had performed the audit to make certain using unix domain sockets
across namespaces is safe.

What fundamentally makes connecting to af_unix sockets in other
namespaces is safe is that you have to have the proper permissions on
the unix domain socket inode that lives in the filesystem.  If you
want strict isolation you just don't create inodes where unfriendlys
can get at them, or with permissions that allow unfriendlys to open
them.  All nicely handled for us by the mount namespace and other
standard file system facilities.

I looked through unix domain sockets and they are a very controlled
environment so none of the work that goes on in dev_forward_skb to
make crossing namespaces safe appears needed, we are not loosing
controll of the skb and so do not need to set up the skb to look like
it is comming in fresh from the outside world.  Further the fields in
struct unix_skb_parms should not have any problems crossing network
namespaces.

Now that we handle SCM_CREDENTIALS in a way that gives useable values
across namespaces.  There does not appear to be any operational
problems with encouraging the use of unix domain sockets across
containers either.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-16 14:58:17 -07:00
Eric W. Biederman 7361c36c52 af_unix: Allow credentials to work across user and pid namespaces.
In unix_skb_parms store pointers to struct pid and struct cred instead
of raw uid, gid, and pid values, then translate the credentials on
reception into values that are meaningful in the receiving processes
namespaces.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-16 14:58:16 -07:00
Eric W. Biederman 109f6e39fa af_unix: Allow SO_PEERCRED to work across namespaces.
Use struct pid and struct cred to store the peer credentials on struct
sock.  This gives enough information to convert the peer credential
information to a value relative to whatever namespace the socket is in
at the time.

This removes nasty surprises when using SO_PEERCRED on socket
connetions where the processes on either side are in different pid and
user namespaces.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-16 14:55:55 -07:00
Ilpo Järvinen a2f3be17c0 unix/garbage: kill copy of the skb queue walker
Worse yet, it seems that its arguments were in reverse order. Also
remove one related helper which seems hardly worth keeping.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-03 15:39:58 -07:00
Eric Dumazet 4381548237 net: sock_def_readable() and friends RCU conversion
sk_callback_lock rwlock actually protects sk->sk_sleep pointer, so we
need two atomic operations (and associated dirtying) per incoming
packet.

RCU conversion is pretty much needed :

1) Add a new structure, called "struct socket_wq" to hold all fields
that will need rcu_read_lock() protection (currently: a
wait_queue_head_t and a struct fasync_struct pointer).

[Future patch will add a list anchor for wakeup coalescing]

2) Attach one of such structure to each "struct socket" created in
sock_alloc_inode().

3) Respect RCU grace period when freeing a "struct socket_wq"

4) Change sk_sleep pointer in "struct sock" by sk_wq, pointer to "struct
socket_wq"

5) Change sk_sleep() function to use new sk->sk_wq instead of
sk->sk_sleep

6) Change sk_has_sleeper() to wq_has_sleeper() that must be used inside
a rcu_read_lock() section.

7) Change all sk_has_sleeper() callers to :
  - Use rcu_read_lock() instead of read_lock(&sk->sk_callback_lock)
  - Use wq_has_sleeper() to eventually wakeup tasks.
  - Use rcu_read_unlock() instead of read_unlock(&sk->sk_callback_lock)

8) sock_wake_async() is modified to use rcu protection as well.

9) Exceptions :
  macvtap, drivers/net/tun.c, af_unix use integrated "struct socket_wq"
instead of dynamically allocated ones. They dont need rcu freeing.

Some cleanups or followups are probably needed, (possible
sk_callback_lock conversion to a spinlock for example...).

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-01 15:00:15 -07:00
Eric Dumazet aa39514516 net: sk_sleep() helper
Define a new function to return the waitqueue of a "struct sock".

static inline wait_queue_head_t *sk_sleep(struct sock *sk)
{
	return sk->sk_sleep;
}

Change all read occurrences of sk_sleep by a call to this function.

Needed for a future RCU conversion. sk_sleep wont be a field directly
available.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-20 16:37:13 -07:00
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Stephen Hemminger 663717f65c AF_UNIX: update locking comment
The lock used in unix_state_lock() is a spin_lock not reader-writer.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-18 14:12:06 -08:00
Alexey Dobriyan 2c8c1e7297 net: spread __net_init, __net_exit
__net_init/__net_exit are apparently not going away, so use them
to full extent.

In some cases __net_init was removed, because it was called from
__net_exit code.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-01-17 19:16:02 -08:00
Linus Torvalds d7fc02c7ba Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1815 commits)
  mac80211: fix reorder buffer release
  iwmc3200wifi: Enable wimax core through module parameter
  iwmc3200wifi: Add wifi-wimax coexistence mode as a module parameter
  iwmc3200wifi: Coex table command does not expect a response
  iwmc3200wifi: Update wiwi priority table
  iwlwifi: driver version track kernel version
  iwlwifi: indicate uCode type when fail dump error/event log
  iwl3945: remove duplicated event logging code
  b43: fix two warnings
  ipw2100: fix rebooting hang with driver loaded
  cfg80211: indent regulatory messages with spaces
  iwmc3200wifi: fix NULL pointer dereference in pmkid update
  mac80211: Fix TX status reporting for injected data frames
  ath9k: enable 2GHz band only if the device supports it
  airo: Fix integer overflow warning
  rt2x00: Fix padding bug on L2PAD devices.
  WE: Fix set events not propagated
  b43legacy: avoid PPC fault during resume
  b43: avoid PPC fault during resume
  tcp: fix a timewait refcnt race
  ...

Fix up conflicts due to sysctl cleanups (dead sysctl_check code and
CTL_UNNUMBERED removed) in
	kernel/sysctl_check.c
	net/ipv4/sysctl_net_ipv4.c
	net/ipv6/addrconf.c
	net/sctp/sysctl.c
2009-12-08 07:55:01 -08:00
Joe Perches f64f9e7192 net: Move && and || to end of previous line
Not including net/atm/

Compiled tested x86 allyesconfig only
Added a > 80 column line or two, which I ignored.
Existing checkpatch plaints willfully, cheerfully ignored.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-29 16:55:45 -08:00
Eric W. Biederman f8572d8f2a sysctl net: Remove unused binary sysctl code
Now that sys_sysctl is a compatiblity wrapper around /proc/sys
all sysctl strategy routines, and all ctl_name and strategy
entries in the sysctl tables are unused, and can be
revmoed.

In addition neigh_sysctl_register has been modified to no longer
take a strategy argument and it's callers have been modified not
to pass one.

Cc: "David Miller" <davem@davemloft.net>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: netdev@vger.kernel.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-11-12 02:05:06 -08:00
Cyrill Gorcunov 13cfa97bef net: netlink_getname, packet_getname -- use DECLARE_SOCKADDR guard
Use guard DECLARE_SOCKADDR in a few more places which allow
us to catch if the structure copied back is too big.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-10 20:54:41 -08:00
Eric Paris 3f378b6844 net: pass kern to net_proto_family create function
The generic __sock_create function has a kern argument which allows the
security system to make decisions based on if a socket is being created by
the kernel or by userspace.  This patch passes that flag to the
net_proto_family specific create function, so it can do the same thing.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-05 22:18:14 -08:00
David S. Miller cfadf853f6 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	drivers/net/sh_eth.c
2009-10-27 01:03:26 -07:00
Tomoki Sekiyama 77238f2b94 AF_UNIX: Fix deadlock on connecting to shutdown socket
I found a deadlock bug in UNIX domain socket, which makes able to DoS
attack against the local machine by non-root users.

How to reproduce:
1. Make a listening AF_UNIX/SOCK_STREAM socket with an abstruct
    namespace(*), and shutdown(2) it.
 2. Repeat connect(2)ing to the listening socket from the other sockets
    until the connection backlog is full-filled.
 3. connect(2) takes the CPU forever. If every core is taken, the
    system hangs.

PoC code: (Run as many times as cores on SMP machines.)

int main(void)
{
	int ret;
	int csd;
	int lsd;
	struct sockaddr_un sun;

	/* make an abstruct name address (*) */
	memset(&sun, 0, sizeof(sun));
	sun.sun_family = PF_UNIX;
	sprintf(&sun.sun_path[1], "%d", getpid());

	/* create the listening socket and shutdown */
	lsd = socket(AF_UNIX, SOCK_STREAM, 0);
	bind(lsd, (struct sockaddr *)&sun, sizeof(sun));
	listen(lsd, 1);
	shutdown(lsd, SHUT_RDWR);

	/* connect loop */
	alarm(15); /* forcely exit the loop after 15 sec */
	for (;;) {
		csd = socket(AF_UNIX, SOCK_STREAM, 0);
		ret = connect(csd, (struct sockaddr *)&sun, sizeof(sun));
		if (-1 == ret) {
			perror("connect()");
			break;
		}
		puts("Connection OK");
	}
	return 0;
}

(*) Make sun_path[0] = 0 to use the abstruct namespace.
    If a file-based socket is used, the system doesn't deadlock because
    of context switches in the file system layer.

Why this happens:
 Error checks between unix_socket_connect() and unix_wait_for_peer() are
 inconsistent. The former calls the latter to wait until the backlog is
 processed. Despite the latter returns without doing anything when the
 socket is shutdown, the former doesn't check the shutdown state and
 just retries calling the latter forever.

Patch:
 The patch below adds shutdown check into unix_socket_connect(), so
 connect(2) to the shutdown socket will return -ECONREFUSED.

Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com>
Signed-off-by: Masanori Yoshida <masanori.yoshida.tv@hitachi.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-18 23:17:37 -07:00
Stephen Hemminger ec1b4cf74c net: mark net_proto_ops as const
All usages of structure net_proto_ops should be declared const.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-07 01:10:46 -07:00
Miklos Szeredi 8ba69ba6a3 net: unix: fix sending fds in multiple buffers
Kalle Olavi Niemitalo reported that:

  "..., when one process calls sendmsg once to send 43804 bytes of
  data and one file descriptor, and another process then calls recvmsg
  three times to receive the 16032+16032+11740 bytes, each of those
  recvmsg calls returns the file descriptor in the ancillary data.  I
  confirmed this with strace.  The behaviour differs from Linux
  2.6.26, where reportedly only one of those recvmsg calls (I think
  the first one) returned the file descriptor."

This bug was introduced by a patch from me titled "net: unix: fix inflight
counting bug in garbage collector", commit 6209344f5.

And the reason is, quoting Kalle:

  "Before your patch, unix_attach_fds() would set scm->fp = NULL, so
  that if the loop in unix_stream_sendmsg() ran multiple iterations,
  it could not call unix_attach_fds() again.  But now,
  unix_attach_fds() leaves scm->fp unchanged, and I think this causes
  it to be called multiple times and duplicate the same file
  descriptors to each struct sk_buff."

Fix this by introducing a flag that is cleared at the start and set
when the fds attached to the first buffer.  The resulting code should
work equivalently to the one on 2.6.26.

Reported-by: Kalle Olavi Niemitalo <kon@iki.fi>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-11 11:31:45 -07:00
Jiri Olsa a57de0b433 net: adding memory barrier to the poll and receive callbacks
Adding memory barrier after the poll_wait function, paired with
receive callbacks. Adding fuctions sock_poll_wait and sk_has_sleeper
to wrap the memory barrier.

Without the memory barrier, following race can happen.
The race fires, when following code paths meet, and the tp->rcv_nxt
and __add_wait_queue updates stay in CPU caches.

CPU1                         CPU2

sys_select                   receive packet
  ...                        ...
  __add_wait_queue           update tp->rcv_nxt
  ...                        ...
  tp->rcv_nxt check          sock_def_readable
  ...                        {
  schedule                      ...
                                if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
                                        wake_up_interruptible(sk->sk_sleep)
                                ...
                             }

If there was no cache the code would work ok, since the wait_queue and
rcv_nxt are opposit to each other.

Meaning that once tp->rcv_nxt is updated by CPU2, the CPU1 either already
passed the tp->rcv_nxt check and sleeps, or will get the new value for
tp->rcv_nxt and will return with new data mask.
In both cases the process (CPU1) is being added to the wait queue, so the
waitqueue_active (CPU2) call cannot miss and will wake up CPU1.

The bad case is when the __add_wait_queue changes done by CPU1 stay in its
cache, and so does the tp->rcv_nxt update on CPU2 side.  The CPU1 will then
endup calling schedule and sleep forever if there are no more data on the
socket.

Calls to poll_wait in following modules were ommited:
	net/bluetooth/af_bluetooth.c
	net/irda/af_irda.c
	net/irda/irnet/irnet_ppp.c
	net/mac80211/rc80211_pid_debugfs.c
	net/phonet/socket.c
	net/rds/af_rds.c
	net/rfkill/core.c
	net/sunrpc/cache.c
	net/sunrpc/rpc_pipe.c
	net/tipc/socket.c

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-09 17:06:57 -07:00
Eric Dumazet 31e6d363ab net: correct off-by-one write allocations reports
commit 2b85a34e91
(net: No more expensive sock_hold()/sock_put() on each tx)
changed initial sk_wmem_alloc value.

We need to take into account this offset when reporting
sk_wmem_alloc to user, in PROC_FS files or various
ioctls (SIOCOUTQ/TIOCOUTQ)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-18 00:29:12 -07:00
Al Viro ce3b0f8d5c New helper - current_umask()
current->fs->umask is what most of fs_struct users are doing.
Put that into a helper function.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-31 23:00:26 -04:00
Wei Yongjun 40d44446cf unix: remove some pointless conditionals before kfree_skb()
Remove some pointless conditionals before kfree_skb().

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-26 23:07:34 -08:00
Kentaro Takeda be6d3e56a6 introduce new LSM hooks where vfsmount is available.
Add new LSM hooks for path-based checks.  Call them on directory-modifying
operations at the points where we still know the vfsmount involved.

Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-12-31 18:07:37 -05:00
Linus Torvalds 0191b625ca Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1429 commits)
  net: Allow dependancies of FDDI & Tokenring to be modular.
  igb: Fix build warning when DCA is disabled.
  net: Fix warning fallout from recent NAPI interface changes.
  gro: Fix potential use after free
  sfc: If AN is enabled, always read speed/duplex from the AN advertising bits
  sfc: When disabling the NIC, close the device rather than unregistering it
  sfc: SFT9001: Add cable diagnostics
  sfc: Add support for multiple PHY self-tests
  sfc: Merge top-level functions for self-tests
  sfc: Clean up PHY mode management in loopback self-test
  sfc: Fix unreliable link detection in some loopback modes
  sfc: Generate unique names for per-NIC workqueues
  802.3ad: use standard ethhdr instead of ad_header
  802.3ad: generalize out mac address initializer
  802.3ad: initialize ports LACPDU from const initializer
  802.3ad: remove typedef around ad_system
  802.3ad: turn ports is_individual into a bool
  802.3ad: turn ports is_enabled into a bool
  802.3ad: make ntt bool
  ixgbe: Fix set_ringparam in ixgbe to use the same memory pools.
  ...

Fixed trivial IPv4/6 address printing conflicts in fs/cifs/connect.c due
to the conversion to %pI (in this networking merge) and the addition of
doing IPv6 addresses (from the earlier merge of CIFS).
2008-12-28 12:49:40 -08:00