Input: don't modify the id of ioctl-provided ff effect on upload failure

If a new (id == -1) ff effect was uploaded from userspace,
ff-core.c::input_ff_upload() will have assigned a positive number to the
new effect id.  Currently, evdev.c::evdev_do_ioctl() will save this new id
to userspace, regardless of whether the upload succeeded or not.

On upload failure, this can be confusing because the dev->ff->effects[]
array will not contain an element at the index of that new effect id.

This patch fixes this by leaving the id unchanged after upload fails.

Note: Unfortunately applications should still expect changed effect id for
quite some time.

This has been discussed on:
http://www.mail-archive.com/linux-input@vger.kernel.org/msg08513.html
("ff-core effect id handling in case of a failed effect upload")

Suggested-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Elias Vanderstuyft <elias.vds@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Input: mousedev - fix race when creating mixed device

We should not be using static variable mousedev_mix in methods that can be
called before that singleton gets assigned. While at it let's add open and
close methods to mousedev structure so that we do not need to test if we
are dealing with multiplexor or normal device and simply call appropriate
method directly.

This fixes: https://bugzilla.kernel.org/show_bug.cgi?id=71551

Reported-by: GiulioDP <depasquale.giulio@gmail.com>
Tested-by: GiulioDP <depasquale.giulio@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
resizable namespace.c hashes

* switch allocation to alloc_large_system_hash()
* make sizes overridable by boot parameters (mhash_entries=, mphash_entries=)
* switch mountpoint_hashtable from list_head to hlist_head

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
keep shadowed vfsmounts together

preparation to switching mnt_hash to hlist

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
don't bother with propagate_mnt() unless the target is shared

If the dest_mnt is not shared, propagate_mnt() does nothing -
there's no mounts to propagate to and thus no copies to create.
Might as well don't bother calling it in that case.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
switch mnt_hash to hlist

fixes RCU bug - walking through hlist is safe in face of element moves,
since it's self-terminating.  Cyclic lists are not - if we end up jumping
to another hash chain, we'll loop infinitely without ever hitting the
original list head.

[fix for dumb braino folded]

Spotted by: Max Kellermann <mk@cm4all.com>
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
ext4: atomically set inode->i_flags in ext4_set_inode_flags()

Use cmpxchg() to atomically set i_flags instead of clearing out the
S_IMMUTABLE, S_APPEND, etc. flags and then setting them from the
EXT4_IMMUTABLE_FL, EXT4_APPEND_FL flags, since this opens up a race
where an immutable file has the immutable flag cleared for a brief
window of time.

Reported-by: John Sullivan <jsrhbz@kanargh.force9.co.uk>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
AUDIT: Allow login in non-init namespaces

It its possible to configure your PAM stack to refuse login if audit
messages (about the login) were unable to be sent.  This is common in
many distros and thus normal configuration of many containers.  The PAM
modules determine if audit is enabled/disabled in the kernel based on
the return value from sending an audit message on the netlink socket.
If userspace gets back ECONNREFUSED it believes audit is disabled in the
kernel.  If it gets any other error else it refuses to let the login
proceed.

Just about ever since the introduction of namespaces the kernel audit
subsystem has returned EPERM if the task sending a message was not in
the init user or pid namespace.  So many forms of containers have never
worked if audit was enabled in the kernel.

BUT if the container was not in net_init then the kernel network code
would send ECONNREFUSED (instead of the audit code sending EPERM).  Thus
by pure accident/dumb luck/bug if an admin configured the PAM stack to
reject all logins that didn't talk to audit, but then ran the login
untility in the non-init_net namespace, it would work!! Clearly this was
a bug, but it is a bug some people expected.

With the introduction of network namespace support in 3.14-rc1 the two
bugs stopped cancelling each other out.  Now, containers in the
non-init_net namespace refused to let users log in (just like PAM was
configfured!) Obviously some people were not happy that what used to let
users log in, now didn't!

This fix is kinda hacky.  We return ECONNREFUSED for all non-init
relevant namespaces.  That means that not only will the old broken
non-init_net setups continue to work, now the broken non-init_pid or
non-init_user setups will 'work'.  They don't really work, since audit
isn't logging things.  But it's what most users want.

In 3.15 we should have patches to support not only the non-init_net
(3.14) namespace but also the non-init_pid and non-init_user namespace.
So all will be right in the world.  This just opens the doors wide open
on 3.14 and hopefully makes users happy, if not the audit system...

Reported-by: Andre Tomt <andre@tomt.net>
Reported-by: Adam Richter <adam_richter2004@yahoo.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input

Pull input updates from Dmitry Torokhov:
 "Some more updates for the input subsystem.

  You will get a fix for race in mousedev that has been causing quite a
  few oopses lately and a small fixup for force feedback support in
  evdev"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: mousedev - fix race when creating mixed device
  Input: don't modify the id of ioctl-provided ff effect on upload failure
MAINTAINERS: resume as Documentation maintainer

I am the new kernel tree Documentation maintainer (except for parts that
are handled by other people, of course).

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Rob Landley <rob@landley.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs fixes from Al Viro:
 "Switch mnt_hash to hlist, turning the races between __lookup_mnt() and
  hash modifications into false negatives from __lookup_mnt() (instead
  of hangs)"

On the false negatives from __lookup_mnt():
 "The *only* thing we care about is not getting stuck in __lookup_mnt().
  If it misses an entry because something in front of it just got moved
  around, etc, we are fine.  We'll notice that mount_lock mismatch and
  that'll be it"

* 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  switch mnt_hash to hlist
  don't bother with propagate_mnt() unless the target is shared
  keep shadowed vfsmounts together
  resizable namespace.c hashes
Linux 3.14