<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/drivers/firewire/core-cdev.c, branch linux-2.6.35.y</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=linux-2.6.35.y</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=linux-2.6.35.y'/>
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<updated>2011-08-01T20:55:01+00:00</updated>
<entry>
<title>firewire: cdev: return -ENOTTY for unimplemented ioctls, not</title>
<updated>2011-08-01T20:55:01+00:00</updated>
<author>
<name>Stefan Richter</name>
<email>stefanr@s5r6.in-berlin.de</email>
</author>
<published>2011-07-09T14:42:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=5392dda6e2b429cdf8d72dcbe36481372e1caa14'/>
<id>urn:sha1:5392dda6e2b429cdf8d72dcbe36481372e1caa14</id>
<content type='text'>
[ upstream commit d873d794235efa590ab3c94d5ee22bb1fab19ac4 ]
 -EINVAL

On Jun 27 Linus Torvalds wrote:
&gt; The correct error code for "I don't understand this ioctl" is ENOTTY.
&gt; The naming may be odd, but you should think of that error value as a
&gt; "unrecognized ioctl number, you're feeding me random numbers that I
&gt; don't understand and I assume for historical reasons that you tried to
&gt; do some tty operation on me".
[...]
&gt; The EINVAL thing goes way back, and is a disaster. It predates Linux
&gt; itself, as far as I can tell. You'll find lots of man-pages that have
&gt; this line in it:
&gt;
&gt;   EINVAL Request or argp is not valid.
&gt;
&gt; and it shows up in POSIX etc. And sadly, it generally shows up
&gt; _before_ the line that says
&gt;
&gt;   ENOTTY The specified request does not apply to the kind of object
&gt; that the descriptor d references.
&gt;
&gt; so a lot of people get to the EINVAL, and never even notice the ENOTTY.
[...]
&gt; At least glibc (and hopefully other C libraries) use a _string_ that
&gt; makes much more sense: strerror(ENOTTY) is "Inappropriate ioctl for
&gt; device"

So let's correct this in the &lt;linux/firewire-cdev.h&gt; ABI while it is
still young, relative to distributor adoption.

Side note:  We return -ENOTTY not only on _IOC_TYPE or _IOC_NR mismatch,
but also on _IOC_SIZE mismatch.  An ioctl with an unsupported size of
argument structure can be seen as an unsupported version of that ioctl.

Signed-off-by: Stefan Richter &lt;stefanr@s5r6.in-berlin.de&gt;
Cc: &lt;stable@kernel.org&gt;
Signed-off-by: Andi Kleen &lt;ak@linux.intel.com&gt;

</content>
</entry>
<entry>
<title>firewire: cdev: prevent race between first get_info ioctl</title>
<updated>2011-08-01T20:55:01+00:00</updated>
<author>
<name>Stefan Richter</name>
<email>stefanr@s5r6.in-berlin.de</email>
</author>
<published>2011-07-09T14:43:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=c20974dfa539046b0cec0af14a2d707c39f33b2a'/>
<id>urn:sha1:c20974dfa539046b0cec0af14a2d707c39f33b2a</id>
<content type='text'>
[ upstream commit 93b37905f70083d6143f5f4dba0a45cc64379a62 ]
 and bus reset event queuing

Between open(2) of a /dev/fw* and the first FW_CDEV_IOC_GET_INFO
ioctl(2) on it, the kernel already queues FW_CDEV_EVENT_BUS_RESET events
to be read(2) by the client.  The get_info ioctl is practically always
issued right away after open, hence this condition only occurs if the
client opens during a bus reset, especially during a rapid series of bus
resets.

The problem with this condition is twofold:

  - These bus reset events carry the (as yet undocumented) @closure
    value of 0.  But it is not the kernel's place to choose closures;
    they are privat to the client.  E.g., this 0 value forced from the
    kernel makes it unsafe for clients to dereference it as a pointer to
    a closure object without NULL pointer check.

  - It is impossible for clients to determine the relative order of bus
    reset events from get_info ioctl(2) versus those from read(2),
    except in one way:  By comparison of closure values.  Again, such a
    procedure imposes complexity on clients and reduces freedom in use
    of the bus reset closure.

So, change the ABI to suppress queuing of bus reset events before the
first FW_CDEV_IOC_GET_INFO ioctl was issued by the client.

Note, this ABI change cannot be version-controlled.  The kernel cannot
distinguish old from new clients before the first FW_CDEV_IOC_GET_INFO
ioctl.

We will try to back-merge this change into currently maintained stable/
longterm series, and we only document the new behaviour.  The old
behavior is now considered a kernel bug, which it basically is.

Signed-off-by: Stefan Richter &lt;stefanr@s5r6.in-berlin.de&gt;
Cc: &lt;stable@kernel.org&gt;
Signed-off-by: Andi Kleen &lt;ak@linux.intel.com&gt;

</content>
</entry>
<entry>
<title>Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6</title>
<updated>2010-05-27T17:22:06+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2010-05-27T17:22:06+00:00</published>
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<id>urn:sha1:55ddf14b04bfe5afaab892a8fb12164b803f1dd5</id>
<content type='text'>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
  ieee1394: schedule for removal
  firewire: core: use separate timeout for each transaction
  firewire: core: Fix tlabel exhaustion problem
  firewire: core: make transaction label allocation more robust
  firewire: core: clean up config ROM related defined constants
  ieee1394: mark char device files as not seekable
  firewire: cdev: mark char device files as not seekable
  firewire: ohci: cleanups and fix for nonstandard build without debug facility
  firewire: ohci: wait for PHY register accesses to complete
  firewire: ohci: fix up configuration of TI chips
  firewire: ohci: enable 1394a enhancements
  firewire: ohci: do not clear PHY interrupt status inadvertently
  firewire: ohci: add a function for reading PHY registers

Trivial conflicts in Documentation/feature-removal-schedule.txt
</content>
</entry>
<entry>
<title>Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6</title>
<updated>2010-04-15T18:56:20+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2010-04-15T18:56:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=2fed94c032316d89422d4abfca2a882897489b94'/>
<id>urn:sha1:2fed94c032316d89422d4abfca2a882897489b94</id>
<content type='text'>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
  firewire: cdev: change license of exported header files to MIT license
  firewire: cdev: comment fixlet
  firewire: cdev: iso packet documentation
  firewire: cdev: fix information leak
  firewire: cdev: require quadlet-aligned headers for transmit packets
  firewire: cdev: disallow receive packets without header
</content>
</entry>
<entry>
<title>firewire: cdev: mark char device files as not seekable</title>
<updated>2010-04-10T14:51:14+00:00</updated>
<author>
<name>Stefan Richter</name>
<email>stefanr@s5r6.in-berlin.de</email>
</author>
<published>2010-04-10T15:38:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=3ac26b2ee30005930117fe6a180c139c5f300faf'/>
<id>urn:sha1:3ac26b2ee30005930117fe6a180c139c5f300faf</id>
<content type='text'>
The &lt;linux/firewire-cdev.h&gt; character device file ABI (i.e. /dev/fw*
character device file interface) does not make any use of lseek(),
pread(), pwrite() (or any kind of write() at all).

Use nonseekable_open() and, redundantly, set file_operations.llseek to
no_llseek to remove any doubt whether the BKL-grabbing default_llseek
handler is used.  (Also shuffle file_operations initialization according
to the order of handler definitions.)

Signed-off-by: Stefan Richter &lt;stefanr@s5r6.in-berlin.de&gt;
</content>
</entry>
<entry>
<title>firewire: cdev: fix information leak</title>
<updated>2010-04-10T14:51:13+00:00</updated>
<author>
<name>Stefan Richter</name>
<email>stefanr@s5r6.in-berlin.de</email>
</author>
<published>2010-04-07T06:30:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=9cac00b8f0079d5d3d54ec4dae453d58dec30e7c'/>
<id>urn:sha1:9cac00b8f0079d5d3d54ec4dae453d58dec30e7c</id>
<content type='text'>
A userspace client got to see uninitialized stack-allocated memory if it
specified an _IOC_READ type of ioctl and an argument size larger than
expected by firewire-core's ioctl handlers (but not larger than the
core's union ioctl_arg).

Fix this by clearing the requested buffer size to zero, but only at _IOR
ioctls.  This way, there is almost no runtime penalty to legitimate
ioctls.  The only legitimate _IOR is FW_CDEV_IOC_GET_CYCLE_TIMER with 12
or 16 bytes to memset.

[Another way to fix this would be strict checking of argument size (and
possibly direction) vs. command number.  However, we then need a lookup
table, and we need to allow for slight size deviations in case of 32bit
userland on 64bit kernel.]

Reported-by: Clemens Ladisch &lt;clemens@ladisch.de&gt;
Signed-off-by: Stefan Richter &lt;stefanr@s5r6.in-berlin.de&gt;
</content>
</entry>
<entry>
<title>firewire: cdev: require quadlet-aligned headers for transmit packets</title>
<updated>2010-04-10T14:51:13+00:00</updated>
<author>
<name>Clemens Ladisch</name>
<email>clemens@ladisch.de</email>
</author>
<published>2010-03-31T14:26:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=385ab5bcd4be586dffdba550b310308d89eade71'/>
<id>urn:sha1:385ab5bcd4be586dffdba550b310308d89eade71</id>
<content type='text'>
The definition of struct fw_cdev_iso_packet seems to imply that the
header_length must be quadlet-aligned, and in fact, specifying an
unaligned header has never really worked when using multiple packet
structures, because the position of the next control word is computed by
rounding the header_length _down_, so the last one to three bytes of the
header would overlap the next control word.

To avoid this problem, check that the header length is properly aligned.

Signed-off-by: Clemens Ladisch &lt;clemens@ladisch.de&gt;
Signed-off-by: Stefan Richter &lt;stefanr@s5r6.in-berlin.de&gt;
</content>
</entry>
<entry>
<title>firewire: cdev: disallow receive packets without header</title>
<updated>2010-04-10T14:51:13+00:00</updated>
<author>
<name>Clemens Ladisch</name>
<email>clemens@ladisch.de</email>
</author>
<published>2010-03-31T14:26:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=4ba1d9c0c22947a9207029e7184733252e6135f1'/>
<id>urn:sha1:4ba1d9c0c22947a9207029e7184733252e6135f1</id>
<content type='text'>
In receive contexts, reject packets with header_length==0.  This would
be an instruction to queue zero packets which would not make sense.

This prevents a division by zero in the OHCI driver.

Signed-off-by: Clemens Ladisch &lt;clemens@ladisch.de&gt;
Signed-off-by: Stefan Richter &lt;stefanr@s5r6.in-berlin.de&gt;
</content>
</entry>
<entry>
<title>include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h</title>
<updated>2010-03-30T13:02:32+00:00</updated>
<author>
<name>Tejun Heo</name>
<email>tj@kernel.org</email>
</author>
<published>2010-03-24T08:04:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=5a0e3ad6af8660be21ca98a971cd00f331318c05'/>
<id>urn:sha1:5a0e3ad6af8660be21ca98a971cd00f331318c05</id>
<content type='text'>
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 -&gt; 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 &lt;tj@kernel.org&gt;
Guess-its-ok-by: Christoph Lameter &lt;cl@linux-foundation.org&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Lee Schermerhorn &lt;Lee.Schermerhorn@hp.com&gt;
</content>
</entry>
<entry>
<title>firewire: core: combine a bit of repeated code</title>
<updated>2010-02-24T19:36:55+00:00</updated>
<author>
<name>Stefan Richter</name>
<email>stefanr@s5r6.in-berlin.de</email>
</author>
<published>2010-02-21T16:56:42+00:00</published>
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<id>urn:sha1:64582298b9c29535188380f488873e7d2196a2eb</id>
<content type='text'>
Signed-off-by: Stefan Richter &lt;stefanr@s5r6.in-berlin.de&gt;
</content>
</entry>
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