2008-11-06 09:16:27

by Bryan Wu

[permalink] [raw]
Subject: [PATCH] Video/UVC: Fix unaligned exceptions in uvc video driver.

From: Michael Hennerich <[email protected]>

buffer can be odd aligned on some NOMMU machine such as Blackfin

Signed-off-by: Michael Hennerich <[email protected]>
Signed-off-by: Bryan Wu <[email protected]>
---
drivers/media/video/uvc/uvc_driver.c | 37 +++++++++++++++++----------------
1 files changed, 19 insertions(+), 18 deletions(-)

diff --git a/drivers/media/video/uvc/uvc_driver.c b/drivers/media/video/uvc/uvc_driver.c
index d7ad060..9b4f469 100644
--- a/drivers/media/video/uvc/uvc_driver.c
+++ b/drivers/media/video/uvc/uvc_driver.c
@@ -31,6 +31,7 @@
#include <linux/videodev2.h>
#include <linux/vmalloc.h>
#include <linux/wait.h>
+#include <asm/unaligned.h>
#include <asm/atomic.h>

#include <media/v4l2-common.h>
@@ -432,20 +433,20 @@ static int uvc_parse_format(struct uvc_device *dev,

frame->bFrameIndex = buffer[3];
frame->bmCapabilities = buffer[4];
- frame->wWidth = le16_to_cpup((__le16 *)&buffer[5]);
- frame->wHeight = le16_to_cpup((__le16 *)&buffer[7]);
- frame->dwMinBitRate = le32_to_cpup((__le32 *)&buffer[9]);
- frame->dwMaxBitRate = le32_to_cpup((__le32 *)&buffer[13]);
+ frame->wWidth = le16_to_cpu(get_unaligned((__le16 *) &buffer[5]));
+ frame->wHeight = le16_to_cpu(get_unaligned((__le16 *) &buffer[7]));
+ frame->dwMinBitRate = le32_to_cpu(get_unaligned((__le32 *) &buffer[9]));
+ frame->dwMaxBitRate = le32_to_cpu(get_unaligned((__le32 *) &buffer[13]));
if (ftype != VS_FRAME_FRAME_BASED) {
frame->dwMaxVideoFrameBufferSize =
- le32_to_cpup((__le32 *)&buffer[17]);
+ le32_to_cpu(get_unaligned((__le32 *) &buffer[17]));
frame->dwDefaultFrameInterval =
- le32_to_cpup((__le32 *)&buffer[21]);
+ le32_to_cpu(get_unaligned((__le32 *) &buffer[21]));
frame->bFrameIntervalType = buffer[25];
} else {
frame->dwMaxVideoFrameBufferSize = 0;
frame->dwDefaultFrameInterval =
- le32_to_cpup((__le32 *)&buffer[17]);
+ le32_to_cpu(get_unaligned((__le32 *) &buffer[17]));
frame->bFrameIntervalType = buffer[21];
}
frame->dwFrameInterval = *intervals;
@@ -468,7 +469,7 @@ static int uvc_parse_format(struct uvc_device *dev,
* some other divisions by zero which could happen.
*/
for (i = 0; i < n; ++i) {
- interval = le32_to_cpup((__le32 *)&buffer[26+4*i]);
+ interval = le32_to_cpu(get_unaligned((__le32 *) &buffer[26+4*i]));
*(*intervals)++ = interval ? interval : 1;
}

@@ -814,7 +815,7 @@ static int uvc_parse_vendor_control(struct uvc_device *dev,
memcpy(unit->extension.guidExtensionCode, &buffer[4], 16);
unit->extension.bNumControls = buffer[20];
unit->extension.bNrInPins =
- le16_to_cpup((__le16 *)&buffer[21]);
+ le16_to_cpu(get_unaligned((__le16 *) &buffer[21]));
unit->extension.baSourceID = (__u8 *)unit + sizeof *unit;
memcpy(unit->extension.baSourceID, &buffer[22], p);
unit->extension.bControlSize = buffer[22+p];
@@ -858,8 +859,8 @@ static int uvc_parse_standard_control(struct uvc_device *dev,
return -EINVAL;
}

- dev->uvc_version = le16_to_cpup((__le16 *)&buffer[3]);
- dev->clock_frequency = le32_to_cpup((__le32 *)&buffer[7]);
+ dev->uvc_version = le16_to_cpu(get_unaligned((__le16 *) &buffer[3]));
+ dev->clock_frequency = le32_to_cpu(get_unaligned((__le32 *) &buffer[7]));

/* Parse all USB Video Streaming interfaces. */
for (i = 0; i < n; ++i) {
@@ -886,7 +887,7 @@ static int uvc_parse_standard_control(struct uvc_device *dev,
/* Make sure the terminal type MSB is not null, otherwise it
* could be confused with a unit.
*/
- type = le16_to_cpup((__le16 *)&buffer[4]);
+ type = le16_to_cpu(get_unaligned((__le16 *) &buffer[4]));
if ((type & 0xff00) == 0) {
uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
"interface %d INPUT_TERMINAL %d has invalid "
@@ -928,11 +929,11 @@ static int uvc_parse_standard_control(struct uvc_device *dev,
term->camera.bControlSize = n;
term->camera.bmControls = (__u8 *)term + sizeof *term;
term->camera.wObjectiveFocalLengthMin =
- le16_to_cpup((__le16 *)&buffer[8]);
+ le16_to_cpu(get_unaligned((__le16 *) &buffer[8]));
term->camera.wObjectiveFocalLengthMax =
- le16_to_cpup((__le16 *)&buffer[10]);
+ le16_to_cpu(get_unaligned((__le16 *) &buffer[10]));
term->camera.wOcularFocalLength =
- le16_to_cpup((__le16 *)&buffer[12]);
+ le16_to_cpu(get_unaligned((__le16 *) &buffer[12]));
memcpy(term->camera.bmControls, &buffer[15], n);
} else if (UVC_ENTITY_TYPE(term) == ITT_MEDIA_TRANSPORT_INPUT) {
term->media.bControlSize = n;
@@ -968,7 +969,7 @@ static int uvc_parse_standard_control(struct uvc_device *dev,
/* Make sure the terminal type MSB is not null, otherwise it
* could be confused with a unit.
*/
- type = le16_to_cpup((__le16 *)&buffer[4]);
+ type = le16_to_cpu(get_unaligned((__le16 *) &buffer[4]));
if ((type & 0xff00) == 0) {
uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
"interface %d OUTPUT_TERMINAL %d has invalid "
@@ -1042,7 +1043,7 @@ static int uvc_parse_standard_control(struct uvc_device *dev,
unit->type = buffer[2];
unit->processing.bSourceID = buffer[4];
unit->processing.wMaxMultiplier =
- le16_to_cpup((__le16 *)&buffer[5]);
+ le16_to_cpu(get_unaligned((__le16 *) &buffer[5]));
unit->processing.bControlSize = buffer[7];
unit->processing.bmControls = (__u8 *)unit + sizeof *unit;
memcpy(unit->processing.bmControls, &buffer[8], n);
@@ -1078,7 +1079,7 @@ static int uvc_parse_standard_control(struct uvc_device *dev,
memcpy(unit->extension.guidExtensionCode, &buffer[4], 16);
unit->extension.bNumControls = buffer[20];
unit->extension.bNrInPins =
- le16_to_cpup((__le16 *)&buffer[21]);
+ le16_to_cpu(get_unaligned((__le16 *) &buffer[21]));
unit->extension.baSourceID = (__u8 *)unit + sizeof *unit;
memcpy(unit->extension.baSourceID, &buffer[22], p);
unit->extension.bControlSize = buffer[22+p];
--
1.5.6.3


2008-11-09 12:55:10

by Laurent Pinchart

[permalink] [raw]
Subject: Re: [PATCH] Video/UVC: Fix unaligned exceptions in uvc video driver.

Hi Bryan, Michael,

Thanks for the patch.

On Thursday 06 November 2008, Bryan Wu wrote:
> From: Michael Hennerich <[email protected]>
>
> buffer can be odd aligned on some NOMMU machine such as Blackfin

The comment is a bit misleading. Buffers can be odd-aligned independently off
the machine type. The issue comes from machines that can't access unaligned
memory. Something like "Fix access to unaligned memory" would be better.

> Signed-off-by: Michael Hennerich <[email protected]>
> Signed-off-by: Bryan Wu <[email protected]>
> ---
> drivers/media/video/uvc/uvc_driver.c | 37
> +++++++++++++++++---------------- 1 files changed, 19 insertions(+), 18
> deletions(-)
>
> diff --git a/drivers/media/video/uvc/uvc_driver.c
> b/drivers/media/video/uvc/uvc_driver.c index d7ad060..9b4f469 100644
> --- a/drivers/media/video/uvc/uvc_driver.c
> +++ b/drivers/media/video/uvc/uvc_driver.c
> @@ -31,6 +31,7 @@
> #include <linux/videodev2.h>
> #include <linux/vmalloc.h>
> #include <linux/wait.h>
> +#include <asm/unaligned.h>
> #include <asm/atomic.h>
>
> #include <media/v4l2-common.h>
> @@ -432,20 +433,20 @@ static int uvc_parse_format(struct uvc_device *dev,
>
> frame->bFrameIndex = buffer[3];
> frame->bmCapabilities = buffer[4];
> - frame->wWidth = le16_to_cpup((__le16 *)&buffer[5]);
> - frame->wHeight = le16_to_cpup((__le16 *)&buffer[7]);
> - frame->dwMinBitRate = le32_to_cpup((__le32 *)&buffer[9]);
> - frame->dwMaxBitRate = le32_to_cpup((__le32 *)&buffer[13]);
> + frame->wWidth = le16_to_cpu(get_unaligned((__le16 *) &buffer[5]));

What about using get_unaligned_le16 and get_unaligned_le32 directly ? Lines
would be shorter and could be kept behind the 80 columns limit more easily.

Tell me if you want to resubmit or if I should make the modification myself
(including the patch description).

> + frame->wHeight = le16_to_cpu(get_unaligned((__le16 *) &buffer[7]));
> + frame->dwMinBitRate = le32_to_cpu(get_unaligned((__le32 *) &buffer[9]));
> + frame->dwMaxBitRate = le32_to_cpu(get_unaligned((__le32 *)
> &buffer[13])); if (ftype != VS_FRAME_FRAME_BASED) {
> frame->dwMaxVideoFrameBufferSize =
> - le32_to_cpup((__le32 *)&buffer[17]);
> + le32_to_cpu(get_unaligned((__le32 *) &buffer[17]));
> frame->dwDefaultFrameInterval =
> - le32_to_cpup((__le32 *)&buffer[21]);
> + le32_to_cpu(get_unaligned((__le32 *) &buffer[21]));
> frame->bFrameIntervalType = buffer[25];
> } else {
> frame->dwMaxVideoFrameBufferSize = 0;
> frame->dwDefaultFrameInterval =
> - le32_to_cpup((__le32 *)&buffer[17]);
> + le32_to_cpu(get_unaligned((__le32 *) &buffer[17]));
> frame->bFrameIntervalType = buffer[21];
> }
> frame->dwFrameInterval = *intervals;
> @@ -468,7 +469,7 @@ static int uvc_parse_format(struct uvc_device *dev,
> * some other divisions by zero which could happen.
> */
> for (i = 0; i < n; ++i) {
> - interval = le32_to_cpup((__le32 *)&buffer[26+4*i]);
> + interval = le32_to_cpu(get_unaligned((__le32 *) &buffer[26+4*i]));
> *(*intervals)++ = interval ? interval : 1;
> }
>
> @@ -814,7 +815,7 @@ static int uvc_parse_vendor_control(struct uvc_device
> *dev, memcpy(unit->extension.guidExtensionCode, &buffer[4], 16);
> unit->extension.bNumControls = buffer[20];
> unit->extension.bNrInPins =
> - le16_to_cpup((__le16 *)&buffer[21]);
> + le16_to_cpu(get_unaligned((__le16 *) &buffer[21]));
> unit->extension.baSourceID = (__u8 *)unit + sizeof *unit;
> memcpy(unit->extension.baSourceID, &buffer[22], p);
> unit->extension.bControlSize = buffer[22+p];
> @@ -858,8 +859,8 @@ static int uvc_parse_standard_control(struct uvc_device
> *dev, return -EINVAL;
> }
>
> - dev->uvc_version = le16_to_cpup((__le16 *)&buffer[3]);
> - dev->clock_frequency = le32_to_cpup((__le32 *)&buffer[7]);
> + dev->uvc_version = le16_to_cpu(get_unaligned((__le16 *) &buffer[3]));
> + dev->clock_frequency = le32_to_cpu(get_unaligned((__le32 *)
> &buffer[7]));
>
> /* Parse all USB Video Streaming interfaces. */
> for (i = 0; i < n; ++i) {
> @@ -886,7 +887,7 @@ static int uvc_parse_standard_control(struct uvc_device
> *dev, /* Make sure the terminal type MSB is not null, otherwise it
> * could be confused with a unit.
> */
> - type = le16_to_cpup((__le16 *)&buffer[4]);
> + type = le16_to_cpu(get_unaligned((__le16 *) &buffer[4]));
> if ((type & 0xff00) == 0) {
> uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
> "interface %d INPUT_TERMINAL %d has invalid "
> @@ -928,11 +929,11 @@ static int uvc_parse_standard_control(struct
> uvc_device *dev, term->camera.bControlSize = n;
> term->camera.bmControls = (__u8 *)term + sizeof *term;
> term->camera.wObjectiveFocalLengthMin =
> - le16_to_cpup((__le16 *)&buffer[8]);
> + le16_to_cpu(get_unaligned((__le16 *) &buffer[8]));
> term->camera.wObjectiveFocalLengthMax =
> - le16_to_cpup((__le16 *)&buffer[10]);
> + le16_to_cpu(get_unaligned((__le16 *) &buffer[10]));
> term->camera.wOcularFocalLength =
> - le16_to_cpup((__le16 *)&buffer[12]);
> + le16_to_cpu(get_unaligned((__le16 *) &buffer[12]));
> memcpy(term->camera.bmControls, &buffer[15], n);
> } else if (UVC_ENTITY_TYPE(term) == ITT_MEDIA_TRANSPORT_INPUT) {
> term->media.bControlSize = n;
> @@ -968,7 +969,7 @@ static int uvc_parse_standard_control(struct uvc_device
> *dev, /* Make sure the terminal type MSB is not null, otherwise it
> * could be confused with a unit.
> */
> - type = le16_to_cpup((__le16 *)&buffer[4]);
> + type = le16_to_cpu(get_unaligned((__le16 *) &buffer[4]));
> if ((type & 0xff00) == 0) {
> uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
> "interface %d OUTPUT_TERMINAL %d has invalid "
> @@ -1042,7 +1043,7 @@ static int uvc_parse_standard_control(struct
> uvc_device *dev, unit->type = buffer[2];
> unit->processing.bSourceID = buffer[4];
> unit->processing.wMaxMultiplier =
> - le16_to_cpup((__le16 *)&buffer[5]);
> + le16_to_cpu(get_unaligned((__le16 *) &buffer[5]));
> unit->processing.bControlSize = buffer[7];
> unit->processing.bmControls = (__u8 *)unit + sizeof *unit;
> memcpy(unit->processing.bmControls, &buffer[8], n);
> @@ -1078,7 +1079,7 @@ static int uvc_parse_standard_control(struct
> uvc_device *dev, memcpy(unit->extension.guidExtensionCode, &buffer[4], 16);
> unit->extension.bNumControls = buffer[20];
> unit->extension.bNrInPins =
> - le16_to_cpup((__le16 *)&buffer[21]);
> + le16_to_cpu(get_unaligned((__le16 *) &buffer[21]));
> unit->extension.baSourceID = (__u8 *)unit + sizeof *unit;
> memcpy(unit->extension.baSourceID, &buffer[22], p);
> unit->extension.bControlSize = buffer[22+p];

Cheers,

Laurent Pinchart

2008-11-10 02:07:47

by Bryan Wu

[permalink] [raw]
Subject: Re: [PATCH] Video/UVC: Fix unaligned exceptions in uvc video driver.

On Sun, Nov 9, 2008 at 8:55 PM, Laurent Pinchart
<[email protected]> wrote:
> Hi Bryan, Michael,
>
> Thanks for the patch.
>
> On Thursday 06 November 2008, Bryan Wu wrote:
>> From: Michael Hennerich <[email protected]>
>>
>> buffer can be odd aligned on some NOMMU machine such as Blackfin
>
> The comment is a bit misleading. Buffers can be odd-aligned independently off
> the machine type. The issue comes from machines that can't access unaligned
> memory. Something like "Fix access to unaligned memory" would be better.
>
>> Signed-off-by: Michael Hennerich <[email protected]>
>> Signed-off-by: Bryan Wu <[email protected]>
>> ---
>> drivers/media/video/uvc/uvc_driver.c | 37
>> +++++++++++++++++---------------- 1 files changed, 19 insertions(+), 18
>> deletions(-)
>>
>> diff --git a/drivers/media/video/uvc/uvc_driver.c
>> b/drivers/media/video/uvc/uvc_driver.c index d7ad060..9b4f469 100644
>> --- a/drivers/media/video/uvc/uvc_driver.c
>> +++ b/drivers/media/video/uvc/uvc_driver.c
>> @@ -31,6 +31,7 @@
>> #include <linux/videodev2.h>
>> #include <linux/vmalloc.h>
>> #include <linux/wait.h>
>> +#include <asm/unaligned.h>
>> #include <asm/atomic.h>
>>
>> #include <media/v4l2-common.h>
>> @@ -432,20 +433,20 @@ static int uvc_parse_format(struct uvc_device *dev,
>>
>> frame->bFrameIndex = buffer[3];
>> frame->bmCapabilities = buffer[4];
>> - frame->wWidth = le16_to_cpup((__le16 *)&buffer[5]);
>> - frame->wHeight = le16_to_cpup((__le16 *)&buffer[7]);
>> - frame->dwMinBitRate = le32_to_cpup((__le32 *)&buffer[9]);
>> - frame->dwMaxBitRate = le32_to_cpup((__le32 *)&buffer[13]);
>> + frame->wWidth = le16_to_cpu(get_unaligned((__le16 *) &buffer[5]));
>
> What about using get_unaligned_le16 and get_unaligned_le32 directly ? Lines
> would be shorter and could be kept behind the 80 columns limit more easily.
>
> Tell me if you want to resubmit or if I should make the modification myself
> (including the patch description).
>

I guess Michael will update this patch according to you review. Then
we will resubmit it.

Thanks a lot
-Bryan

2008-11-10 10:51:32

by Hennerich, Michael

[permalink] [raw]
Subject: RE: [PATCH] Video/UVC: Fix unaligned exceptions in uvc video driver.



>-----Original Message-----
>From: Laurent Pinchart [mailto:[email protected]]
>Sent: Sunday, November 09, 2008 1:55 PM
>To: Bryan Wu
>Cc: [email protected]; [email protected];
linux-
>[email protected]; Michael Hennerich
>Subject: Re: [PATCH] Video/UVC: Fix unaligned exceptions in uvc video
>driver.
>
>Hi Bryan, Michael,
>
>Thanks for the patch.
>
>On Thursday 06 November 2008, Bryan Wu wrote:
>> From: Michael Hennerich <[email protected]>
>>
>> buffer can be odd aligned on some NOMMU machine such as Blackfin
>
>The comment is a bit misleading. Buffers can be odd-aligned
independently
>off
>the machine type. The issue comes from machines that can't access
unaligned
>memory. Something like "Fix access to unaligned memory" would be
better.
>
>> Signed-off-by: Michael Hennerich <[email protected]>
>> Signed-off-by: Bryan Wu <[email protected]>
>> ---
>> drivers/media/video/uvc/uvc_driver.c | 37
>> +++++++++++++++++---------------- 1 files changed, 19 insertions(+),
18
>> deletions(-)
>>
>> diff --git a/drivers/media/video/uvc/uvc_driver.c
>> b/drivers/media/video/uvc/uvc_driver.c index d7ad060..9b4f469 100644
>> --- a/drivers/media/video/uvc/uvc_driver.c
>> +++ b/drivers/media/video/uvc/uvc_driver.c
>> @@ -31,6 +31,7 @@
>> #include <linux/videodev2.h>
>> #include <linux/vmalloc.h>
>> #include <linux/wait.h>
>> +#include <asm/unaligned.h>
>> #include <asm/atomic.h>
>>
>> #include <media/v4l2-common.h>
>> @@ -432,20 +433,20 @@ static int uvc_parse_format(struct uvc_device
*dev,
>>
>> frame->bFrameIndex = buffer[3];
>> frame->bmCapabilities = buffer[4];
>> - frame->wWidth = le16_to_cpup((__le16 *)&buffer[5]);
>> - frame->wHeight = le16_to_cpup((__le16 *)&buffer[7]);
>> - frame->dwMinBitRate = le32_to_cpup((__le32
*)&buffer[9]);
>> - frame->dwMaxBitRate = le32_to_cpup((__le32
*)&buffer[13]);
>> + frame->wWidth = le16_to_cpu(get_unaligned((__le16 *)
>&buffer[5]));
>
>What about using get_unaligned_le16 and get_unaligned_le32 directly ?
Lines
>would be shorter and could be kept behind the 80 columns limit more
easily.
>
>Tell me if you want to resubmit or if I should make the modification
myself
>(including the patch description).

Laurent,

Well - I just used the same style already used in various other places
in the uvc driver. - Just wanted to be consistent.

If you don't mind doing the changes (including the patch description),
please go ahead.

Thanks and best regards,
Michael

>
>> + frame->wHeight = le16_to_cpu(get_unaligned((__le16 *)
>&buffer[7]));
>> + frame->dwMinBitRate = le32_to_cpu(get_unaligned((__le32
*)
>&buffer[9]));
>> + frame->dwMaxBitRate = le32_to_cpu(get_unaligned((__le32
*)
>> &buffer[13])); if (ftype != VS_FRAME_FRAME_BASED) {
>> frame->dwMaxVideoFrameBufferSize =
>> - le32_to_cpup((__le32 *)&buffer[17]);
>> + le32_to_cpu(get_unaligned((__le32 *)
&buffer[17]));
>> frame->dwDefaultFrameInterval =
>> - le32_to_cpup((__le32 *)&buffer[21]);
>> + le32_to_cpu(get_unaligned((__le32 *)
&buffer[21]));
>> frame->bFrameIntervalType = buffer[25];
>> } else {
>> frame->dwMaxVideoFrameBufferSize = 0;
>> frame->dwDefaultFrameInterval =
>> - le32_to_cpup((__le32 *)&buffer[17]);
>> + le32_to_cpu(get_unaligned((__le32 *)
&buffer[17]));
>> frame->bFrameIntervalType = buffer[21];
>> }
>> frame->dwFrameInterval = *intervals;
>> @@ -468,7 +469,7 @@ static int uvc_parse_format(struct uvc_device
*dev,
>> * some other divisions by zero which could happen.
>> */
>> for (i = 0; i < n; ++i) {
>> - interval = le32_to_cpup((__le32
*)&buffer[26+4*i]);
>> + interval = le32_to_cpu(get_unaligned((__le32 *)
>&buffer[26+4*i]));
>> *(*intervals)++ = interval ? interval : 1;
>> }
>>
>> @@ -814,7 +815,7 @@ static int uvc_parse_vendor_control(struct
uvc_device
>> *dev, memcpy(unit->extension.guidExtensionCode, &buffer[4], 16);
>> unit->extension.bNumControls = buffer[20];
>> unit->extension.bNrInPins =
>> - le16_to_cpup((__le16 *)&buffer[21]);
>> + le16_to_cpu(get_unaligned((__le16 *)
&buffer[21]));
>> unit->extension.baSourceID = (__u8 *)unit + sizeof
*unit;
>> memcpy(unit->extension.baSourceID, &buffer[22], p);
>> unit->extension.bControlSize = buffer[22+p];
>> @@ -858,8 +859,8 @@ static int uvc_parse_standard_control(struct
>uvc_device
>> *dev, return -EINVAL;
>> }
>>
>> - dev->uvc_version = le16_to_cpup((__le16 *)&buffer[3]);
>> - dev->clock_frequency = le32_to_cpup((__le32
*)&buffer[7]);
>> + dev->uvc_version = le16_to_cpu(get_unaligned((__le16 *)
>&buffer[3]));
>> + dev->clock_frequency = le32_to_cpu(get_unaligned((__le32
*)
>> &buffer[7]));
>>
>> /* Parse all USB Video Streaming interfaces. */
>> for (i = 0; i < n; ++i) {
>> @@ -886,7 +887,7 @@ static int uvc_parse_standard_control(struct
>uvc_device
>> *dev, /* Make sure the terminal type MSB is not null, otherwise it
>> * could be confused with a unit.
>> */
>> - type = le16_to_cpup((__le16 *)&buffer[4]);
>> + type = le16_to_cpu(get_unaligned((__le16 *)
&buffer[4]));
>> if ((type & 0xff00) == 0) {
>> uvc_trace(UVC_TRACE_DESCR, "device %d
videocontrol "
>> "interface %d INPUT_TERMINAL %d has
invalid "
>> @@ -928,11 +929,11 @@ static int uvc_parse_standard_control(struct
>> uvc_device *dev, term->camera.bControlSize = n;
>> term->camera.bmControls = (__u8 *)term + sizeof
*term;
>> term->camera.wObjectiveFocalLengthMin =
>> - le16_to_cpup((__le16 *)&buffer[8]);
>> + le16_to_cpu(get_unaligned((__le16 *)
&buffer[8]));
>> term->camera.wObjectiveFocalLengthMax =
>> - le16_to_cpup((__le16 *)&buffer[10]);
>> + le16_to_cpu(get_unaligned((__le16 *)
&buffer[10]));
>> term->camera.wOcularFocalLength =
>> - le16_to_cpup((__le16 *)&buffer[12]);
>> + le16_to_cpu(get_unaligned((__le16 *)
&buffer[12]));
>> memcpy(term->camera.bmControls, &buffer[15], n);
>> } else if (UVC_ENTITY_TYPE(term) ==
ITT_MEDIA_TRANSPORT_INPUT)
>{
>> term->media.bControlSize = n;
>> @@ -968,7 +969,7 @@ static int uvc_parse_standard_control(struct
>uvc_device
>> *dev, /* Make sure the terminal type MSB is not null, otherwise it
>> * could be confused with a unit.
>> */
>> - type = le16_to_cpup((__le16 *)&buffer[4]);
>> + type = le16_to_cpu(get_unaligned((__le16 *)
&buffer[4]));
>> if ((type & 0xff00) == 0) {
>> uvc_trace(UVC_TRACE_DESCR, "device %d
videocontrol "
>> "interface %d OUTPUT_TERMINAL %d has
invalid "
>> @@ -1042,7 +1043,7 @@ static int uvc_parse_standard_control(struct
>> uvc_device *dev, unit->type = buffer[2];
>> unit->processing.bSourceID = buffer[4];
>> unit->processing.wMaxMultiplier =
>> - le16_to_cpup((__le16 *)&buffer[5]);
>> + le16_to_cpu(get_unaligned((__le16 *)
&buffer[5]));
>> unit->processing.bControlSize = buffer[7];
>> unit->processing.bmControls = (__u8 *)unit + sizeof
*unit;
>> memcpy(unit->processing.bmControls, &buffer[8], n);
>> @@ -1078,7 +1079,7 @@ static int uvc_parse_standard_control(struct
>> uvc_device *dev, memcpy(unit->extension.guidExtensionCode,
&buffer[4],
>16);
>> unit->extension.bNumControls = buffer[20];
>> unit->extension.bNrInPins =
>> - le16_to_cpup((__le16 *)&buffer[21]);
>> + le16_to_cpu(get_unaligned((__le16 *)
&buffer[21]));
>> unit->extension.baSourceID = (__u8 *)unit + sizeof
*unit;
>> memcpy(unit->extension.baSourceID, &buffer[22], p);
>> unit->extension.bControlSize = buffer[22+p];
>
>Cheers,
>
>Laurent Pinchart

2008-11-11 17:11:36

by Laurent Pinchart

[permalink] [raw]
Subject: Re: [PATCH] Video/UVC: Fix unaligned exceptions in uvc video driver.

On Monday 10 November 2008, Hennerich, Michael wrote:
> > -----Original Message-----
> > From: Laurent Pinchart [mailto:[email protected]]
> > Sent: Sunday, November 09, 2008 1:55 PM
> > To: Bryan Wu
> > Cc: [email protected]; [email protected];
> > [email protected]; Michael Hennerich
> > Subject: Re: [PATCH] Video/UVC: Fix unaligned exceptions in uvc video
> > driver.
> >
> > Hi Bryan, Michael,
> >
> > Thanks for the patch.
> >
> > On Thursday 06 November 2008, Bryan Wu wrote:
> > > From: Michael Hennerich <[email protected]>
> > >
> > > buffer can be odd aligned on some NOMMU machine such as Blackfin
> >
> > The comment is a bit misleading. Buffers can be odd-aligned independently
> > off the machine type. The issue comes from machines that can't access
> > unaligned memory. Something like "Fix access to unaligned memory" would be
> > better.
[snip]

> > What about using get_unaligned_le16 and get_unaligned_le32 directly ?
> > Lines would be shorter and could be kept behind the 80 columns limit more
> > easily.
> > Tell me if you want to resubmit or if I should make the modification
> > myself (including the patch description).
>
> Laurent,
>
> Well - I just used the same style already used in various other places
> in the uvc driver. - Just wanted to be consistent.

No worries. get_unaligned_le{16|32} has been introduced in the kernel recently
and I haven't updated the uvcvideo driver like I should have. I'll fix that.

> If you don't mind doing the changes (including the patch description),
> please go ahead.

Ok I'll fix and submit the patch.

Best regards,

Laurent Pinchart