Regression in 2.6.28-rc1: When I added the new state_mutex which
prevents corruption of raw1394's internal state when accessed by
multithreaded client applications, the following possible though
highly unlikely deadlock slipped in:
Thread A: Thread B:
- acquire mmap_sem - raw1394_write() or raw1394_ioctl()
- raw1394_mmap() - acquire state_mutex
- acquire state_mutex - copy_to/from_user(), possible page fault:
acquire mmap_sem
The simplest fix is to use mutex_trylock() instead of mutex_lock() in
raw1394_mmap(). This changes the behavior under contention in a way
which is visible to userspace clients. However, since multithreaded
access was entirely buggy before state_mutex was added and libraw1394's
documentation advised application programmers to use a handle only in a
single thread, this change in behaviour should not be an issue in
practice at all.
Since we have to use mutex_trylock() in raw1394_mmap() regardless
whether /dev/raw1394 was opened with O_NONBLOCK or not, we now use
mutex_trylock() unconditionally everywhere for state_mutex, just to have
consistent behavior.
Reported-by: Johannes Weiner <hannes@saeurebad.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
firewire: Add more documentation to firewire-cdev.h
firewire: fix ioctl() return code
firewire: fix setting tag and sy in iso transmission
firewire: fw-sbp2: fix another small generation access bug
firewire: fw-sbp2: enforce s/g segment size limit
firewire: fw_send_request_sync()
ieee1394: survive a few seconds connection loss
ieee1394: nodemgr clean up class iterators
ieee1394: dv1394, video1394: remove unnecessary expressions
ieee1394: raw1394: make write() thread-safe
ieee1394: raw1394: narrow down the state_mutex protected region
ieee1394: raw1394: replace BKL by local mutex, make ioctl() and mmap() thread-safe
ieee1394: sbp2: enforce s/g segment size limit
ieee1394: sbp2: check for DMA mapping failures
ieee1394: sbp2: stricter dma_sync
ieee1394: Use DIV_ROUND_UP
Now that device_create() has been audited, rename things back to the
original call to be sane.
Cc: Ben Collins <ben.collins@ubuntu.com>
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Application programs should use a libraw1394 handle only in a single
thread. The raw1394 driver was apparently relying on this, because it
did nothing to protect its fi->state variable from corruption due to
concurrent accesses.
We now serialize the fi->state accesses. This affects the write() path.
We re-use the state_mutex which was introduced to protect fi->iso_state
accesses in the ioctl() path. These paths and accesses are independent
of each other, hence separate mutexes could be used. But I don't see
much benefit in that.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Refactor the ioctl dispatcher in order to move a fraction of it out of
the section which is serialized by fi->state_mutex. This is not so much
about performance but more about self-documentation: The mutex_lock()/
mutex_unlock() calls are now closer to the data accesses which the mutex
protects, i.e. to the iso_state switch.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
This removes the last usage of the Big Kernel Lock from the ieee1394
stack, i.e. from raw1394's (unlocked_)ioctl and compat_ioctl.
The ioctl()s don't need to take the BKL, but they need to be serialized
per struct file *. In particular, accesses to ->iso_state need to be
serial. We simply use a blocking mutex for this purpose because
libraw1394 does not use O_NONBLOCK. In practice, there is no lock
contention anyway because most if not all libraw1394 clients use a
libraw1394 handle only in a single thread.
mmap() also accesses ->iso_state. Until now this was unprotected
against concurrent changes by ioctls. Fix this bug while we are at it.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
device_create() is race-prone, so use the race-free
device_create_drvdata() instead as device_create() is going away.
Cc: Ben Collins <ben.collins@ubuntu.com>
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Actually in this case wrap the function for now.
Signed-off-by: Alan Cox <alan@redhat.com>
Added raw1394_compat_ioctl hunk.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Currently the kernel will issue the following warning:
drivers/ieee1394/raw1394.c:2938: warning: 'raw1394_id_table' defined but not used
Add #ifdef MODULE guards around the declaration.
Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Ditto with dv1394_id_table and video1394_id_table.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
As it seems, some host controllers have issues that can cause them to
skip cycles now and then when using large packets. I suspect that this
is due to DMA not succeeding in time. If the transmit fifo can't contain
more than one packet (big packets), the DMA should provide a new packet
each cycle (125us). I am under the impression that my current PCI
express test system can't guarantee this.
In any case, the patch tries to provide a workaround as follows:
The DMA program descriptors are modified such that when an error occurs,
the DMA engine retries the descriptor the next cycle instead of
stalling. This way no data is lost. The side effect of this is that
packets are sent with one cycle delay. This however might not be that
much of a problem for certain protocols (e.g. AM824). If they use
padding packets for e.g. rate matching they can drop one of those to
resync the streams.
The amount of skips between two userspace wakeups is counted. This
number is then propagated to userspace through the upper 16 bits of the
'dropped' parameter. This allows unmodified userspace applications due
to the following:
1) libraw simply passes this dropped parameter to the user application
2) the meaning of the dropped parameter is: if it's nonzero, something
bad has happened. The actual value of the parameter at this moment does
not have a specific meaning.
A libraw client can then retrieve the number of skipped cycles and
account for them if needed.
Signed-off-by: Pieter Palmers <pieterp@joow.be>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Unless you're adding a kobject to the sysfs hierarchy, there is no
point setting its kobject name.
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
These drivers don't need to match any unit_directory type device.
They just need the id_table for module autoloading per module alias.
Not binding any of these drivers allows special-purpose drivers with
similar or same IDs to bind to devices. This currently only benefits
out-of-tree drivers; on the other hand it is in no way detrimental to
in-tree drivers.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Based on patch "the scheduled removal of RAW1394_REQ_ISO_{SEND,LISTEN}"
from Adrian Bunk, November 20 2006.
This patch also removes the underlying facilities in ohci1394 and
disables them in pcilynx. That is, hpsb_host_driver.devctl() and
hpsb_host_driver.transmit_packet() are no longer used for iso reception
and transmission.
Since video1394 and dv1394 only work with ohci1394 and raw1394's rawiso
interface has never been implemented in pcilynx, pcilynx is now no
longer useful for isochronous applications.
raw1394 will still handle the request types but will complete the
requests with errors that indicate API version conflicts.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Here is a straightforward conversion to "struct device". The "struct
class_device" will be removed from the kernel.
It seems to work fine for me with and without CONFIG_SYSFS_DEPRECATED
set.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
I was told that only i386 aligns 64 bit integers at 4 bytes boundaries
while all other architectures (32 bit architectures with 64 bit
siblings) align it on 8 bytes boundaries.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Pointed out by Arnd Bergmann: PPC32 aligns this at 64bit, IA32 packs
it. A kernel-wide available __compat_u64 which is 4-byte aligned on
AMD64 and IA64 would be nicer though.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Add compat_ioctl. Although all structures are more or less same,
raw1394_iso_packets got pointer inside, and raw1394_cycle_timer got unwanted
padding in the middle. I did not add any translation for ioctls passing array
of integers around as integers seem to have same size (32 bits) on all
architectures supported by Linux.
Signed-off-by: Petr Vandrovec <petr@vandrovec.name>
Acked-by: Dan Dennedy <dan@dennedy.org>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (split into 3 patches)
* write(fd, buf, 52) from 32bit app was returning 56. Most of callers did not
care, but some (arm registration) did, and anyway it looks bad if request for
writing 52 bytes returns 56. And returning sizeof anything in 'int' is not
good as well. So all functions now return '0' instead of
sizeof(struct raw1394_request) on success, and write() itself provides correct
return value (it just returns value it was asked to write on success as raw1394
does not do any partial writes at all).
* Related to this was problem that write() could have returned 0 when kernel
state would become corrupted and moved to different state than
opened/initialized/connected. Now it returns -EBADFD which seemed appropriate.
Signed-off-by: Petr Vandrovec <petr@vandrovec.name>
Acked-by: Dan Dennedy <dan@dennedy.org>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (split into 3 patches)
read() always failed with -EFAULT. This was happening due to
raw1394_compat_read copying data to wrong location - access_ok always
failed as 'r' is kernel address, not user. Whole function just tried to
copy data from 'r' to 'r', which is not good.
Signed-off-by: Petr Vandrovec <petr@vandrovec.name>
Acked-by: Dan Dennedy <dan@dennedy.org>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (split into 3 patches)
While playing with libiec61883 I've noticed that async_send is broken
because it was doing copy_from_user(...., packet->data_size) before
packet->data_size was set to any useful value. It got broken when
packet->allocated_data_size got introduced, as hpsb_alloc_packet does
not set packet->data_size anymore. (Regression in 2.6.22-rc1)
Signed-off-by: Petr Vandrovec <petr@vandrovec.name>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Remove includes of <linux/smp_lock.h> where it is not used/needed.
Suggested by Al Viro.
Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This considerably reduces the memory requirements for a packet and
eliminates ieee1394's dependency on CONFIG_NET.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
* 'for-linus' of ssh://master.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
ieee1394: fix another deadlock in nodemgr
ieee1394: cycle timer read extension for raw1394
This implements the simultaneous read of the isochronous cycle timer and
the system clock (in usecs). This allows to express the exact receive
time of an ISO packet as a system time with microsecond accuracy.
http://bugzilla.kernel.org/show_bug.cgi?id=7773
The counterpart patch for libraw1394 can be found at
http://thread.gmane.org/gmane.linux.kernel.firewire.devel/8934
Patch update (Stefan R.): Disable preemption and local interrupts.
Prevent integer overflow. Add paranoid error checks and kerneldoc to
hpsb_read_cycle_timer. Move it to other ieee1394_core high-level API
functions. Change comments. Adjust whitespace. Rename struct
_raw1394_cycle_timer.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: Pieter Palmers <pieterp@joow.be>
Acked-by: Dan Dennedy <dan@dennedy.org>
Many struct file_operations in the kernel can be "const". Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data. In addition it'll catch accidental writes at compile time to
these shared resources.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Unloading the low-level driver module of a FireWire host can lead to
all sorts of trouble if a raw1394 userspace client is using the host.
Just disallow it by incrementing the LLD's module reference count on
a RAW1394_REQ_SET_CARD write operation. Decrement it when the file
is closed.
This feature wouldn't be relevant if "modprobe -r video1394" or
"modprobe -r dv1394" didn't automatically unload ohci1394 too.
http://bugzilla.kernel.org/show_bug.cgi?id=7701
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Dan Dennedy <dan@dennedy.org>
This patch consolidates some bookkeeping for driver registering. It
closely models what pci_register_driver() does. The main addition is
that the owner of the driver is set, so we get a proper symlink
for /sys/bus/ieee1394/driver/*/module.
Also moves setting of name and bus type into nodemgr. Because of this,
we can remove the EXPORT_SYMBOL for ieee1394_bus_type, since it's now
only used in ieee1394.ko.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Known to be affected:
- libdc1394: prefers video1394 for now, old-style raw1394 support might
be dropped eventually
- OpenH323 PWLib, AVC video input module: uses libraw1394's old API
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
SLAB_KERNEL is an alias of GFP_KERNEL.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
SLAB_ATOMIC is an alias of GFP_ATOMIC
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Sleeping functions like copy_to_user were accessed inside spinlocks in
raw1394's arm_register, arm_unregister, arm_get_buf, arm_set_buf.
http://bugzilla.kernel.org/show_bug.cgi?id=7120
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Tested-by: David Trent <DTrent@piacton.com>
(cherry picked from e575953ec17c3f5c1e738847d2d16c241bb99783 commit)
A deactivated macro, defined as "#define foo(bar)", will result in
silent corruption if somebody forgets a semicolon after a call to foo.
Replace it by "#define foo(bar) do {} while (0)" which will reveal any
respective syntax errors.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
An already existing wait queue replaces raw1394's complete_sem which was
maintained in parallel to the wait queue. The role of the semaphore's
counter is taken over by a direct check of what was really counted: The
presence of items in the list of completed requests.
Notes:
- raw1394_release() sleeps uninterruptibly until all requests were
completed. This is the same behaviour as before the patch.
- The macros wait_event and wait_event_interruptible are called with a
condition argument which has a side effect, i.e. manipulation of the
requests list. This side effect happens only if the condition is
true. The patch relies on the fact that wait_event[_interruptible]
does not evaluate the condition again after it became true.
- The diffstat looks unfavorable with respect to added lines of code.
However 19 of them are comments, and some are due to separation of
existing code blocks into two small helper functions.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Ben Collins <bcollins@ubuntu.com>
Remove unnecessary includes, add missing includes.
Use forward type declarations for some structs.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Ben Collins <bcollins@ubuntu.com>
This patch converts the combination of list_del(A) and list_add(A, B) to
list_move(A, B) under drivers/.
Acked-by: Corey Minyard <minyard@mvista.com>
Cc: Ben Collins <bcollins@debian.org>
Acked-by: Roland Dreier <rolandd@cisco.com>
Cc: Alasdair Kergon <dm-devel@redhat.com>
Cc: Gerd Knorr <kraxel@bytesex.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frank Pavlic <fpavlic@de.ibm.com>
Acked-by: Matthew Wilcox <matthew@wil.cx>
Cc: Andrew Vasquez <linux-driver@qlogic.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Signed-off-by: Akinobu Mita <mita@miraclelinux.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Devfs has been disabled in the last kernel releases, so let's
remove it from ieee1394core, raw1394, video1394, dv1394.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Dan Dennedy <dan@dennedy.org>
Signed-off-by: Jody McIntyre <scjody@modernduck.com>
Not for the ioctls so far because I was too lazy.
Cc: bcollins@debian.org
Cc: dan@dennedy.org
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The coverity checker spotted that this was a NULL pointer dereference in
the "if (copy_from_user(...))" case since the next step is to
kfree(cache->filled_head).
There's no need to free cache at this point, and it's getting free'd
later.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Jody McIntyre <scjody@modernduck.com>
The previous patch adding the ability to nest struct class_device
changed the paramaters to the call class_device_create(). This patch
fixes up all in-kernel users of the function.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Changes all spinlocks that can be held during an irq handler to disable
interrupts while the lock is held. Changes spin_[un]lock_irq to use the
irqsave/irqrestore variants for robustness and readability.
In raw1394.c:handle_iso_listen(), don't grab host_info_lock at all -- we're
not accessing host_info_list or host_count, and holding this lock while
trying to tasklet_kill the iso tasklet this can cause an ABBA deadlock if
ohci:dma_rcv_tasklet is running and tries to grab host_info_lock in
raw1394.c:receive_iso. Test program attached reliably deadlocks all SMP
machines I have been able to test without this patch.
Signed-off-by: Andy Wingo <wingo@pobox.com>
Acked-by: Ben Collins <bcollins@ubuntu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- added typedef unsigned int __nocast gfp_t;
- replaced __nocast uses for gfp flags with gfp_t - it gives exactly
the same warnings as far as sparse is concerned, doesn't change
generated code (from gcc point of view we replaced unsigned int with
typedef) and documents what's going on far better.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
amdtp, dv1394, raw1394, video1394:
Delete legacy module aliases. The macros did not work and the aliases are not
needed nowadays.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Ben Collins <bcollins@debian.org>
Signed-off-by: Jody McIntyre <scjody@steamballoon.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
