This step prepares the application of proper controller locking: Push
all state changing work into the notify handler that are called by
capi_ctr_ready and capi_ctr_down, switch detach_capi_ctr to issue a
synchronous ctr_down. Also ensure that we do not go through any action
if the state did not change.
Signed-off-by: NJan Kiszka <jan.kiszka@web.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Turn the lock protecting registered capi drivers into a mutex and apply
it consistently.
Signed-off-by: NJan Kiszka <jan.kiszka@web.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

At least for our internal use, fix the misnomers that refer to a CAPI
controller as 'card'. No functional changes.
Signed-off-by: NJan Kiszka <jan.kiszka@web.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The CVS revisions dumped by all CAPI modules are meaningless today. And
that some CAPI module is loaded or removed does not necessarily deserve
a message. Just keep the message of the central module, capi.ko, drop
the rest.
Signed-off-by: NJan Kiszka <jan.kiszka@web.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Auto-mounting the capifs during module init prevents unloading its
module. Instead, pin the filesystem as long as some NCCI node exists.
Signed-off-by: NJan Kiszka <jan.kiszka@web.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

capifs_mnt->mnt_sb->s_root already contains what we need.
Signed-off-by: NJan Kiszka <jan.kiszka@web.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Instead of looking up the dentry of an NCCI node again in
capifs_free_ncci pass the pointer via the capifs user.

This patch also reduces the #ifdef mess in capi.c a bit as far as capifs
was causing it.
Signed-off-by: NJan Kiszka <jan.kiszka@web.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When something went wrong during capifs_new_ncci, the looked up dentry
was not properly released. Neither was the allocated inode. Refactor the
function to avoid leaks.
Signed-off-by: NJan Kiszka <jan.kiszka@web.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Convert code away from ->read_proc/->write_proc interfaces.  Switch to
proc_create()/proc_create_data() which make addition of proc entries
reliable wrt NULL ->proc_fops, NULL ->data and so on.

Problem with ->read_proc et al is described here commit
786d7e16 "Fix rmmod/read/write races in
/proc entries"

[akpm@linux-foundation.org: CONFIG_PROC_FS=n build fix]
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NKarsten Keil <keil@b1-systems.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

That is "success", "unknown", "through", "performance", "[re|un]mapping"
, "access", "default", "reasonable", "[con]currently", "temperature"
, "channel", "[un]used", "application", "example","hierarchy", "therefore"
, "[over|under]flow", "contiguous", "threshold", "enough" and others.
Signed-off-by: NAndré Goddard Rosa <andre.goddard@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Additionally, some excessive newlines removed.
Signed-off-by: NMichael Roth <mroth@nessie.de>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

After m68k's task_thread_info() doesn't refer to current,
it's possible to remove sched.h from interrupt.h and not break m68k!
Many thanks to Heiko Carstens for allowing this.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>

Being able to change the debugmode module parameter of capidrv on the
fly is quite useful for debugging and doesn't do any harm.
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In several places, capidrv sends a CAPI message to the ISDN
device and then updates its internal state accordingly.
If the response message from the device arrives before the
state is updated, it may be rejected or processed incorrectly.
Avoid these races by updating the state before emitting the
message.

Impact: bugfix
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Acked-by: NKarsten Keil <keil@b1-systems.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Info values in the 0x00xx range are defined in the CAPI standard
as "Informational, message processed successfully". Therefore a
CONNECT_B3_CONF message with an Info value in that range should
open an NCCI just as with Info==0.

Impact: minor bugfix
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Acked-by: NKarsten Keil <keil@b1-systems.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make all seq_operations structs const, to help mitigate against
revectoring user-triggerable function pointers.

This is derived from the grsecurity patch, although generated from scratch
because it's simpler than extracting the changes from there.
Signed-off-by: NJames Morris <jmorris@namei.org>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Acked-by: NCasey Schaufler <casey@schaufler-ca.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

The dereferencing of the private pointer cmsg->m in capi_cmsg2str() may
cause an Oops in case of an error, which is particularly inconvenient
as that function is typically used to format an error message. Add a
NULL pointer check to avoid this.

Impact: error handling improvement
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add kerneldoc comments for the exported funtions in capiutil.c.

Impact: documentation
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Change the name of the Kernel CAPI exported function capi_ctr_reseted()
to something representing its purpose better.

Impact: renaming, no functional change
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

we don't want to deal with half-updated config
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Put generic_show_options read access to s_options under rcu_read_lock,
split save_mount_options() into "we are setting it the first time"
(uses in foo_fill_super()) and "we are relacing and freeing the old one",
synchronize_rcu() before kfree() in the latter.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

isdn: document Kernel CAPI driver interface

Create a file Documentation/isdn/INTERFACE.CAPI describing the
interface between the kernel CAPI subsystem and ISDN device drivers,
analogous to the existing Documentation/isdn/INTERFACE for the old
isdn4linux subsystem. Also add kerneldoc comments to the exported
functions in drivers/isdn/capi/kcapi.c.

Impact: Documentation
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NKarsten Keil <keil@b1-systems.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

struct tty_operations::proc_fops took it's place and there is one less
create_proc_read_entry() user now!
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Impact: Attribute functions with __acquires(...) resp. __releases(...).

Fix this sparse warnings:
  drivers/isdn/capi/kcapi_proc.c:241:13: warning: context imbalance in 'capi_driver_start' - wrong count at exit
  drivers/isdn/capi/kcapi_proc.c:252:13: warning: context imbalance in 'capi_driver_stop' - unexpected unlock
Signed-off-by: NHannes Eder <hannes@hanneseder.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove some pointless conditionals before kfree_skb().
Signed-off-by: NWei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

... and don't bother in callers.  Don't bother with zeroing i_blocks,
while we are at it - it's already been zeroed.

i_mode is not worth the effort; it has no common default value.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Correct two typos.
Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Acked-by: NKarsten Keil <kkeil@suse.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.

Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().

Change some task->e?[ug]id to task_e?[ug]id().  In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Reviewed-by: NJames Morris <jmorris@namei.org>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Acked-by: NKarsten Keil <kkeil@suse.de>
Cc: isdn4linux@listserv.isdn4linux.de
Signed-off-by: NJames Morris <jmorris@namei.org>

Now that device_create() has been audited, rename things back to the
original call to be sane.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Today's linux-next build (x86_64 allmodconfig) failed like this:

/drivers/char/tty_ioctl.c: In function 'change_termios':
drivers/isdn/capi/capi.c:1234: error: implicit declaration of function 'n_tty_ioctl'
drivers/isdn/gigaset/ser-gigaset.c: In function 'gigaset_tty_ioctl':
drivers/isdn/gigaset/ser-gigaset.c:648: error: implicit declaration of function 'n_tty_ioctl'

Introduced by commit 686b5e4aea05a80e370dc931b7f4a8d03c80da54
("tty-move-canon-specials").  I added the following patch (which may not
be correct).
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

After calling capi_ctr_get, error handling code should call capi_ctr_put.

The semantic match that finds this problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@r@
expression x,E;
statement S;
position p1,p2,p3;
@@

(
if ((x = capi_ctr_get@p1(...)) == NULL || ...) S
|
x = capi_ctr_get@p1(...)
... when != x
if (x == NULL || ...) S
)
<...
if@p3 (...) { ... when != capi_ctr_put(x)
                  when != if (x) { ... capi_ctr_put(x); ...}
    return@p2 ...;
}
...>
(
return x;
|
return 0;
|
x = E
|
E = x
|
capi_ctr_put(x)
)

@exists@
position r.p1,r.p2,r.p3;
expression x;
int ret != 0;
statement S;
@@

* x = capi_ctr_get@p1(...)
  <...
* if@p3 (...)
  S
  ...>
* return@p2 \(NULL\|ret\);
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some hardware needs to do break handling itself and may have partial
support only. Make break_ctl return an error code. Add a tty driver flag
so you can indicate driver hardware side break support.
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

device_create() is race-prone, so use the race-free
device_create_drvdata() instead as device_create() is going away.

Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Move the line disciplines towards a conventional ->ops arrangement.  For
the moment the actual 'tty_ldisc' struct in the tty is kept as part of
the tty struct but this can then be changed if it turns out that when it
all settles down we want to refcount ldiscs separately to the tty.

Pull the ldisc code out of /proc and put it with our ldisc code.
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Put explicit lock_kernel() calls into capi_open()
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

cdebug_init() is called from kcapi_init() which is module
initialization function, so it must return negative values on errors.
Signed-off-by: NMarcin Slusarz <marcin.slusarz@gmail.com>
Acked-by: NKarsten Keil <kkeil@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NAlan Cox <alan@redhat.com>
Acked-by: NKarsten Keil <kkeil@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use proc_create()/proc_create_data() to make sure that ->proc_fops and ->data
be setup before gluing PDE to main tree.

Add correct ->owner to proc_fops to fix reading/module unloading race.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Acked-by: NKarsten Keil <kkeil@suse.de>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>