<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/usb/mon, branch v2.6.34.8</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>USB: resizing usbmon binary interface buffer causes protection faults</title>
<updated>2010-08-13T20:27:25+00:00</updated>
<author>
<name>Steven Robertson</name>
<email>steven@strobe.cc</email>
</author>
<published>2010-07-21T20:38:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=df9f1d0df4208a41410922114eb73cfeba254803'/>
<id>df9f1d0df4208a41410922114eb73cfeba254803</id>
<content type='text'>
commit 33d973ad88ceb83ed1449592b7574b5b5bb33ac6 upstream.

Enlarging the buffer size via the MON_IOCT_RING_SIZE ioctl causes
general protection faults. It appears the culprit is an incorrect
argument to mon_free_buff: instead of passing the size of the current
buffer being freed, the size of the new buffer is passed.

Use the correct size argument to mon_free_buff when changing the size of
the buffer.

Signed-off-by: Steven Robertson &lt;steven@strobe.cc&gt;
Acked-by: Pete Zaitcev &lt;zaitcev@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 33d973ad88ceb83ed1449592b7574b5b5bb33ac6 upstream.

Enlarging the buffer size via the MON_IOCT_RING_SIZE ioctl causes
general protection faults. It appears the culprit is an incorrect
argument to mon_free_buff: instead of passing the size of the current
buffer being freed, the size of the new buffer is passed.

Use the correct size argument to mon_free_buff when changing the size of
the buffer.

Signed-off-by: Steven Robertson &lt;steven@strobe.cc&gt;
Acked-by: Pete Zaitcev &lt;zaitcev@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>USB: fix usbmon and DMA mapping for scatter-gather URBs</title>
<updated>2010-07-05T18:22:07+00:00</updated>
<author>
<name>Alan Stern</name>
<email>stern@rowland.harvard.edu</email>
</author>
<published>2010-04-02T17:27:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4a8b98282f192abc27f1c18dc81ed2e59929e168'/>
<id>4a8b98282f192abc27f1c18dc81ed2e59929e168</id>
<content type='text'>
commit ff9c895f07d36193c75533bda8193bde8ca99d02 upstream.

This patch (as1368) fixes a rather obscure bug in usbmon: When tracing
URBs sent by the scatter-gather library, it accesses the data buffers
while they are still mapped for DMA.

The solution is to move the mapping and unmapping out of the s-g
library and into the usual place in hcd.c.  This requires the addition
of new URB flag bits to describe the kind of mapping needed, since we
have to call dma_map_sg() if the HCD supports native scatter-gather
operation and dma_map_page() if it doesn't.  The nice thing about
having the new flags is that they simplify the testing for unmapping.

The patch removes the only caller of usb_buffer_[un]map_sg(), so those
functions are #if'ed out.  A later patch will remove them entirely.

As a result of this change, urb-&gt;sg will be set in situations where
it wasn't set previously.  Hence the xhci and whci drivers are
adjusted to test urb-&gt;num_sgs instead, which retains its original
meaning and is nonzero only when the HCD has to handle a scatterlist.

Finally, even when a submission error occurs we don't want to hand
URBs to usbmon before they are unmapped.  The submission path is
rearranged so that map_urb_for_dma() is called only for non-root-hub
URBs and unmap_urb_for_dma() is called immediately after a submission
error.  This simplifies the error handling.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit ff9c895f07d36193c75533bda8193bde8ca99d02 upstream.

This patch (as1368) fixes a rather obscure bug in usbmon: When tracing
URBs sent by the scatter-gather library, it accesses the data buffers
while they are still mapped for DMA.

The solution is to move the mapping and unmapping out of the s-g
library and into the usual place in hcd.c.  This requires the addition
of new URB flag bits to describe the kind of mapping needed, since we
have to call dma_map_sg() if the HCD supports native scatter-gather
operation and dma_map_page() if it doesn't.  The nice thing about
having the new flags is that they simplify the testing for unmapping.

The patch removes the only caller of usb_buffer_[un]map_sg(), so those
functions are #if'ed out.  A later patch will remove them entirely.

As a result of this change, urb-&gt;sg will be set in situations where
it wasn't set previously.  Hence the xhci and whci drivers are
adjusted to test urb-&gt;num_sgs instead, which retains its original
meaning and is nonzero only when the HCD has to handle a scatterlist.

Finally, even when a submission error occurs we don't want to hand
URBs to usbmon before they are unmapped.  The submission path is
rearranged so that map_urb_for_dma() is called only for non-root-hub
URBs and unmap_urb_for_dma() is called immediately after a submission
error.  This simplifies the error handling.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</pre>
</div>
</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.toradex.cn/cgit/linux-toradex.git/commit/?id=5a0e3ad6af8660be21ca98a971cd00f331318c05'/>
<id>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>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: usbmon: mask seconds properly in text API</title>
<updated>2010-03-02T22:55:14+00:00</updated>
<author>
<name>Pete Zaitcev</name>
<email>zaitcev@redhat.com</email>
</author>
<published>2010-02-20T06:55:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=47cb17089c059d24e5da03f2b44ee3a089075b78'/>
<id>47cb17089c059d24e5da03f2b44ee3a089075b78</id>
<content type='text'>
The code does not implement the comment, so timestamps for long traces
become confusing instead of wrapping neatly as expected. This was actually
observed. Fortunately for API being in debugfs, we can just fix this instead
of staying bug-for-bug compatible. Double fortunately, the stable binary
API is not affected.

Signed-off-by: Pete Zaitcev &lt;zaitcev@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;


</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The code does not implement the comment, so timestamps for long traces
become confusing instead of wrapping neatly as expected. This was actually
observed. Fortunately for API being in debugfs, we can just fix this instead
of staying bug-for-bug compatible. Double fortunately, the stable binary
API is not affected.

Signed-off-by: Pete Zaitcev &lt;zaitcev@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;


</pre>
</div>
</content>
</entry>
<entry>
<title>usbmon: add bus number to text API</title>
<updated>2010-03-02T22:53:30+00:00</updated>
<author>
<name>Pete Zaitcev</name>
<email>zaitcev@redhat.com</email>
</author>
<published>2010-01-05T18:50:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2bc0d109326e9f2b25fa1dfcc9de2489e1e00e36'/>
<id>2bc0d109326e9f2b25fa1dfcc9de2489e1e00e36</id>
<content type='text'>
Due to a simple oversight when bus zero was added, the text API fails to
deliver the bus number in 'E' messages (which are equivalent of 'C'
messages, only for error case). This makes it harder, for instance,
use a search-and-highlight in a text editor. So fix it.

Also, Alan Stern requested adding timestamps to 'E' messages. This is
purely cosmetic, but makes it easier to read the trace. This is done
for both text and binary APIs.

Signed-off-by: Pete Zaitcev &lt;zaitcev@redhat.com&gt;
Cc: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;


</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Due to a simple oversight when bus zero was added, the text API fails to
deliver the bus number in 'E' messages (which are equivalent of 'C'
messages, only for error case). This makes it harder, for instance,
use a search-and-highlight in a text editor. So fix it.

Also, Alan Stern requested adding timestamps to 'E' messages. This is
purely cosmetic, but makes it easier to read the trace. This is done
for both text and binary APIs.

Signed-off-by: Pete Zaitcev &lt;zaitcev@redhat.com&gt;
Cc: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;


</pre>
</div>
</content>
</entry>
<entry>
<title>USB: add scatter-gather support to usbmon</title>
<updated>2009-12-11T19:55:20+00:00</updated>
<author>
<name>Alan Stern</name>
<email>stern@rowland.harvard.edu</email>
</author>
<published>2009-11-06T17:32:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b375e1169d8ecc9e9db3ecba8147d484b5510833'/>
<id>b375e1169d8ecc9e9db3ecba8147d484b5510833</id>
<content type='text'>
This patch (as1301) adds support to usbmon for scatter-gather URBs.
The text interface looks at only the first scatterlist element, since
it never copies more than 32 bytes of data anyway.  The binary
interface copies as much data as possible up to the first
non-addressable buffer.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
CC: Pete Zaitcev &lt;zaitcev@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch (as1301) adds support to usbmon for scatter-gather URBs.
The text interface looks at only the first scatterlist element, since
it never copies more than 32 bytes of data anyway.  The binary
interface copies as much data as possible up to the first
non-addressable buffer.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
CC: Pete Zaitcev &lt;zaitcev@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>USB: usbmon: fix bug in mon_buff_area_shrink</title>
<updated>2009-11-18T00:46:34+00:00</updated>
<author>
<name>Alan Stern</name>
<email>stern@rowland.harvard.edu</email>
</author>
<published>2009-11-04T16:35:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fca94748c5136ff390eadc443871b82f1f77dcd6'/>
<id>fca94748c5136ff390eadc443871b82f1f77dcd6</id>
<content type='text'>
This patch (as1299b) fixes a bug in an error-handling path of usbmon's
binary interface.  The storage area for URB data is divided into
fixed-size blocks.  If an URB's data can't be copied, the area
reserved for it should be decreased to the size of the truncated
information (rounded up to a block boundary).  Rounding up the amount
to be removed and subtracting it from the reserved size is definitely
the wrong thing to do.

Also, when the data for an isochronous URB can't be copied, we can
still copy the isoc packet descriptors.  In fact the current code does
copy the descriptors, but then sets the capture length to 0 so they
remain inaccessible.  The capture length should be reduced to the
length of the descriptors, not set to 0.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Acked-by: Pete Zaitcev &lt;zaitcev@redhat.com&gt;
CC: stable &lt;stable@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch (as1299b) fixes a bug in an error-handling path of usbmon's
binary interface.  The storage area for URB data is divided into
fixed-size blocks.  If an URB's data can't be copied, the area
reserved for it should be decreased to the size of the truncated
information (rounded up to a block boundary).  Rounding up the amount
to be removed and subtracting it from the reserved size is definitely
the wrong thing to do.

Also, when the data for an isochronous URB can't be copied, we can
still copy the isoc packet descriptors.  In fact the current code does
copy the descriptors, but then sets the capture length to 0 so they
remain inaccessible.  The capture length should be reduced to the
length of the descriptors, not set to 0.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Acked-by: Pete Zaitcev &lt;zaitcev@redhat.com&gt;
CC: stable &lt;stable@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>const: mark struct vm_struct_operations</title>
<updated>2009-09-27T18:39:25+00:00</updated>
<author>
<name>Alexey Dobriyan</name>
<email>adobriyan@gmail.com</email>
</author>
<published>2009-09-27T18:29:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f0f37e2f77731b3473fa6bd5ee53255d9a9cdb40'/>
<id>f0f37e2f77731b3473fa6bd5ee53255d9a9cdb40</id>
<content type='text'>
* mark struct vm_area_struct::vm_ops as const
* mark vm_ops in AGP code

But leave TTM code alone, something is fishy there with global vm_ops
being used.

Signed-off-by: Alexey Dobriyan &lt;adobriyan@gmail.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* mark struct vm_area_struct::vm_ops as const
* mark vm_ops in AGP code

But leave TTM code alone, something is fishy there with global vm_ops
being used.

Signed-off-by: Alexey Dobriyan &lt;adobriyan@gmail.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: usbmon: end ugly tricks with DMA peeking</title>
<updated>2009-09-23T13:46:19+00:00</updated>
<author>
<name>Pete Zaitcev</name>
<email>zaitcev@redhat.com</email>
</author>
<published>2009-06-11T14:53:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4e9e92003529e5c7bb11281f7c2c9b3fe8858403'/>
<id>4e9e92003529e5c7bb11281f7c2c9b3fe8858403</id>
<content type='text'>
This patch fixes crashes when usbmon attempts to access GART aperture.
The old code attempted to take a bus address and convert it into a
virtual address, which clearly was impossible on systems with actual
IOMMUs. Let us not persist in this foolishness, and use transfer_buffer
in all cases instead.

I think downsides are negligible. The ones I see are:
 - A driver may pass an address of one buffer down as transfer_buffer,
   and entirely different entity mapped for DMA, resulting in misleading
   output of usbmon. Note, however, that PIO based controllers would
   do transfer the same data that usbmon sees here.
 - Out of tree drivers may crash usbmon if they store garbage in
   transfer_buffer. I inspected the in-tree drivers, and clarified
   the documentation in comments.
 - Drivers that use get_user_pages will not be possible to monitor.
   I only found one driver with this problem (drivers/staging/rspiusb).
 - Same happens with with usb_storage transferring from highmem, but
   it works fine on 64-bit systems, so I think it's not a concern.
   At least we don't crash anymore.

Why didn't we do this in 2.6.10? That's because back in those days
it was popular not to fill in transfer_buffer, so almost all
traffic would be invisible (e.g. all of HID was like that).
But now, the tree is almost 100% PIO friendly, so we can do the
right thing at last.

Signed-off-by: Pete Zaitcev &lt;zaitcev@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch fixes crashes when usbmon attempts to access GART aperture.
The old code attempted to take a bus address and convert it into a
virtual address, which clearly was impossible on systems with actual
IOMMUs. Let us not persist in this foolishness, and use transfer_buffer
in all cases instead.

I think downsides are negligible. The ones I see are:
 - A driver may pass an address of one buffer down as transfer_buffer,
   and entirely different entity mapped for DMA, resulting in misleading
   output of usbmon. Note, however, that PIO based controllers would
   do transfer the same data that usbmon sees here.
 - Out of tree drivers may crash usbmon if they store garbage in
   transfer_buffer. I inspected the in-tree drivers, and clarified
   the documentation in comments.
 - Drivers that use get_user_pages will not be possible to monitor.
   I only found one driver with this problem (drivers/staging/rspiusb).
 - Same happens with with usb_storage transferring from highmem, but
   it works fine on 64-bit systems, so I think it's not a concern.
   At least we don't crash anymore.

Why didn't we do this in 2.6.10? That's because back in those days
it was popular not to fill in transfer_buffer, so almost all
traffic would be invisible (e.g. all of HID was like that).
But now, the tree is almost 100% PIO friendly, so we can do the
right thing at last.

Signed-off-by: Pete Zaitcev &lt;zaitcev@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>USB: usbmon: drop Kconfig defaults</title>
<updated>2009-09-23T13:46:19+00:00</updated>
<author>
<name>Pete Zaitcev</name>
<email>zaitcev@redhat.com</email>
</author>
<published>2009-06-10T21:21:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b07f4d016ed179bc4fb8046657a84d5dc0e94b42'/>
<id>b07f4d016ed179bc4fb8046657a84d5dc0e94b42</id>
<content type='text'>
These statements seem to be unnecessary. No idea why, but I built all
possible configurations and everything gets built just as before.

It's an old patch that popped from discussion with Paul in November 2008.
Obviously not a very high priority but better late than never.

Signed-off-by: Pete Zaitcev &lt;zaitcev@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
These statements seem to be unnecessary. No idea why, but I built all
possible configurations and everything gets built just as before.

It's an old patch that popped from discussion with Paul in November 2008.
Obviously not a very high priority but better late than never.

Signed-off-by: Pete Zaitcev &lt;zaitcev@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</pre>
</div>
</content>
</entry>
</feed>
