No need for irqsave acquisition of acklock, bh-safe is sufficient.
Moverover, move kfree out of the lock and do not take acklock at all
in capiminor_del_all_ack as we are the last user of the list here.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Introduce outlock as a spin lock that protects capiminor's outqueue,
outbytes and outskb (formerly known as ttyskb). outlock can be acquired
from soft-IRQ context via capinc_write, so make it bh-safe.
This finally removes the last reason for keeping the workaround lock
around (which was incomplete and partly broken anyway). And as we no
longer call handle_recv_skb in atomic context, gen_data_b3_resp_for can
use non-atomic allocation now.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The inbytes counter was only updated but never read.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The capiminor members datahandle and msgid are incremented outside any
lock, so better do this atomically.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This struct is describing a queue entry, not the queue itself.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Avoid re-queuing skbs unless the error detected in handle_recv_skb is
expected to be recoverable such as lacking memory, a full CAPI queue, a
full TTY input buffer, or a not yet existing TTY.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Sending a message down the CAPI stack may trigger the reception of an
answer, but this will go through capi_recv_message and call
handle_minor_recv from there. There is no need to walk the receive queue
on capinc_tty_write.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Not needed, tty->count keeps track of this information. At this chance,
drop traces of ancient attempts to debug this logic via _DEBUG_REFCOUNT.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use a plain spin lock for capiminors_lock, drop inconsistent irqsafe
acquisitions (it's only used in process context anyway).
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The nccip in capiminor used to serve as an indicator that the NCCI was
close. But we don't need this, we issue a hangup on capincci_free_minor.
So drop this legacy.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
capincci_free and, thus, capincci_free_minor runs in process context, so
we can issue the hangup of the associated TTY synchronously.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
tty_struct's driver_data cannot be NULL, no need to test for it.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use the reference management features of tty_port to look up and drop
again the tty_struct associated with a capiminor.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Properly associate/disassociate a capiminor object with its TTY via the
install/cleanup handlers instead of trying to guess first open and last
close.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Install a reference counter for capiminor objects. Acquire it when
obtaining a capiminor from the array during capinc_tty_open, drop it
when closing the tty again. Another reference is held for the hook-up
with capincci.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
No need to allocate a fixed major for this TTY, both capifs and udev
make this transparent to the user.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Register capiminors dynamically with the TTY core so that udev can make
them show up as the NCCIs appear or disappear. This removes the need to
check if the capiminor requested in capinc_tty_open actually exists.
And this completely obsoletes capifs which will be scheduled for removal
in a later patch.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Return proper error code if tty_register_driver fails. In contrast,
tty_unregister_driver cannot practically fail, so drop that error
handling. Finally, mark capinc_tty_init/exit with __init/__exit.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Using a plain array of pointers simplifies the management of capiminors.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Replace open-coded NCCI list management with standard mechanisms.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
capi_read still used interruptible_sleep_on, risking to miss a wakeup
this way. Convert it to wait_event_interruptible.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Both capincci_alloc and capiminor_alloc run in non-atomic context,
update their memory allocations accordingly.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rename 'ncci_list_mtx' to 'lock', expressing that it now protects a
larger set of capidev members: the NCCI list, ap.applid (ie. the
registration of the application), and modifications of userflags.
We do not need to protect each and every check for ap.applid because,
once an application is registered, it will stay for the whole lifetime
of the device.
Also, there is no need to apply the capidev mutex during release (if
there could be concurrent users, we would crash them anyway by freeing
the device at the end of capi_release).
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fold capidev_alloc and capidev_free into capi_open and capi_release -
there are no other users. Someone pushed a lock_kernel into capi_open.
Drop it, we don't need it. Also remove the useless test from open that
checks for private_data == NULL.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
No need for anything "harder" here (specifically no need for
irqsave...). Also, make the list removal the first operation of
capidev_free to avoid dumping half-released devices via /proc.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make the code a bit more readable be providing stub functions for the
!CONFIG_ISDN_CAPI_MIDDLEWARE case. Though a few lines are moved around,
this comes with no functional changes.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Drop the application rw-lock in favour of RCU. This synchronizes
capi20_release against capi_ctr_handle_message which may dereference an
application from (soft-)IRQ context. Any other access to the application
list is now protected by the capi_controller_lock as well. This also
allows to safely inspect applications for /proc dumping by holding
capi_controller_lock.
At this chance, drop some useless release_in_progress checks where we
obtained the application pointer from the list (which becomes NULL on
release_in_progress).
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch applies the mutex so far only protecting the controller list
to (almost) all accesses of controller data structures. It also reworks
waiting on state changes in old_capi_manufacturer so that it no longer
poll and holds a module reference to the controller owner while waiting
(the latter was partly done already). Modification and checking of the
blocked state remains racy by design, the caller is responsible for
dealing with this.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Another step towards proper locking: Rework the callback provided to
capidrv for controller state changes. This is so far attached to an
application, which would require us to hold the corresponding lock
across notification calls.
But there is no direct relation between a controller up/down event and
an application, so let's decouple them and provide a notifier call chain
for those events instead. This notifier chain is first of all used
internally. Here we request the highest priority to unsure that
housekeeping work is done before any other notifications. The chain is
exported via [un]register_capictr_notifier to our only user, capidrv, to
replace the racy and unfixable capi20_set_callback.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
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: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Turn the lock protecting registered capi drivers into a mutex and apply
it consistently.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David 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: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David 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: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David 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: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
capifs_mnt->mnt_sb->s_root already contains what we need.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David 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: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David 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: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David 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
786d7e1612 "Fix rmmod/read/write races in
/proc entries"
[akpm@linux-foundation.org: CONFIG_PROC_FS=n build fix]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: Karsten Keil <keil@b1-systems.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
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: Alexey 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: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David 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: Tilman Schmidt <tilman@imap.cc>
Acked-by: Karsten Keil <keil@b1-systems.de>
Signed-off-by: David 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: Tilman Schmidt <tilman@imap.cc>
Acked-by: Karsten Keil <keil@b1-systems.de>
Signed-off-by: David 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: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (34 commits)
trivial: fix typo in aic7xxx comment
trivial: fix comment typo in drivers/ata/pata_hpt37x.c
trivial: typo in kernel-parameters.txt
trivial: fix typo in tracing documentation
trivial: add __init/__exit macros in drivers/gpio/bt8xxgpio.c
trivial: add __init macro/ fix of __exit macro location in ipmi_poweroff.c
trivial: remove unnecessary semicolons
trivial: Fix duplicated word "options" in comment
trivial: kbuild: remove extraneous blank line after declaration of usage()
trivial: improve help text for mm debug config options
trivial: doc: hpfall: accept disk device to unload as argument
trivial: doc: hpfall: reduce risk that hpfall can do harm
trivial: SubmittingPatches: Fix reference to renumbered step
trivial: fix typos "man[ae]g?ment" -> "management"
trivial: media/video/cx88: add __init/__exit macros to cx88 drivers
trivial: fix typo in CONFIG_DEBUG_FS in gcov doc
trivial: fix missing printk space in amd_k7_smp_check
trivial: fix typo s/ketymap/keymap/ in comment
trivial: fix typo "to to" in multiple files
trivial: fix typos in comments s/DGBU/DBGU/
...
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: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add kerneldoc comments for the exported funtions in capiutil.c.
Impact: documentation
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
