diff mbox

v4l2-compat-ioctl32: fix struct v4l2_event32 alignment

Message ID 1440158630-29620-1-git-send-email-a.hajda@samsung.com (mailing list archive)
State Superseded, archived
Delegated to: Hans Verkuil
Headers

Commit Message

Andrzej Hajda Aug. 21, 2015, 12:03 p.m. UTC 
  Union v4l2_event::u is aligned to 8 bytes on arm32. On arm64 v4l2_event32::u
is aligned to 4 bytes. As a result structures v4l2_event and v4l2_event32 have
different sizes and VIDOC_DQEVENT ioctl does not work from arm32 apps running
on arm64 kernel. The patch fixes it. Using compat_s64 allows to retain 4 bytes
alignment on x86 architecture.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
---
Hi Hans,

Tested successfully on arm32 app / arm64 kernel.
Thanks for help.

Regards
Andrzej
---
 drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 1 +
 1 file changed, 1 insertion(+)

Comments

Hans Verkuil Aug. 21, 2015, 12:06 p.m. UTC | #1 
On 08/21/2015 02:03 PM, Andrzej Hajda wrote:
> Union v4l2_event::u is aligned to 8 bytes on arm32. On arm64 v4l2_event32::u
> is aligned to 4 bytes. As a result structures v4l2_event and v4l2_event32 have
> different sizes and VIDOC_DQEVENT ioctl does not work from arm32 apps running
> on arm64 kernel. The patch fixes it. Using compat_s64 allows to retain 4 bytes
> alignment on x86 architecture.

What about v4l2_standard32 and v4l2_ext_control32? I very strongly suspect that
those will break for arm32 apps on an arm64 as well.

I prefer a patch that fixes all three...

Regards,

	Hans

> 
> Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
> ---
> Hi Hans,
> 
> Tested successfully on arm32 app / arm64 kernel.
> Thanks for help.
> 
> Regards
> Andrzej
> ---
>  drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
> index af63543..52afffe 100644
> --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
> +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
> @@ -738,6 +738,7 @@ static int put_v4l2_ext_controls32(struct v4l2_ext_controls *kp, struct v4l2_ext
>  struct v4l2_event32 {
>  	__u32				type;
>  	union {
> +		compat_s64		value64;
>  		__u8			data[64];
>  	} u;
>  	__u32				pending;
> 

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diff mbox

Patch

diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
index af63543..52afffe 100644
--- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
+++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
@@ -738,6 +738,7 @@  static int put_v4l2_ext_controls32(struct v4l2_ext_controls *kp, struct v4l2_ext
 struct v4l2_event32 {
 	__u32				type;
 	union {
+		compat_s64		value64;
 		__u8			data[64];
 	} u;
 	__u32				pending;