From: Arnd Bergmann <arnd@arndb.de>
To: Ming Lei <ming.lei@canonical.com>
Cc: linux-arm-kernel@lists.infradead.org,
Mauro Carvalho Chehab <mchehab@infradead.org>,
Tony Lindgren <tony@atomide.com>, Greg KH <greg@kroah.com>,
linux-kernel@vger.kernel.org,
Sylwester Nawrocki <snjw23@gmail.com>,
Alan Cox <alan@lxorguk.ukuu.org.uk>,
linux-omap@vger.kernel.org
Subject: Re: [RFC PATCH v1 5/7] media: v4l2: introduce two IOCTLs for face detection
Date: Tue, 6 Dec 2011 12:55:55 +0000 [thread overview]
Message-ID: <201112061255.56136.arnd@arndb.de> (raw)
In-Reply-To: <CACVXFVMB+HuQDb+Pxo0d8x46P82-c-OPxaL0c661Wztyx3NWJA@mail.gmail.com>
On Tuesday 06 December 2011, Ming Lei wrote:
> diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h
> index 073eb4d..8aeaa1e 100644
> --- a/include/linux/videodev2.h
> +++ b/include/linux/videodev2.h
> @@ -2214,7 +2214,12 @@ struct v4l2_fd_result {
> __u32 buf_index;
> __u32 face_cnt;
> __u32 reserved[6];
> - struct v4l2_fd_detection *fd;
> +
> + /*make 64/32 compatible*/
> + union {
> + struct v4l2_fd_detection *fd;
> + __u64 dummy;
> + };
> };
>
That's not compatible, at least not on any big-endian architecture.
If you want to have an indirect pointer, you have to cast it to the
__u64 member in user space and back in kernel space.
Using an array added to the end of the v4l2_fd_result structure
rather than a pointer would really make this easier IMHO.
Arnd
WARNING: multiple messages have this Message-ID (diff)
From: arnd@arndb.de (Arnd Bergmann)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC PATCH v1 5/7] media: v4l2: introduce two IOCTLs for face detection
Date: Tue, 6 Dec 2011 12:55:55 +0000 [thread overview]
Message-ID: <201112061255.56136.arnd@arndb.de> (raw)
In-Reply-To: <CACVXFVMB+HuQDb+Pxo0d8x46P82-c-OPxaL0c661Wztyx3NWJA@mail.gmail.com>
On Tuesday 06 December 2011, Ming Lei wrote:
> diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h
> index 073eb4d..8aeaa1e 100644
> --- a/include/linux/videodev2.h
> +++ b/include/linux/videodev2.h
> @@ -2214,7 +2214,12 @@ struct v4l2_fd_result {
> __u32 buf_index;
> __u32 face_cnt;
> __u32 reserved[6];
> - struct v4l2_fd_detection *fd;
> +
> + /*make 64/32 compatible*/
> + union {
> + struct v4l2_fd_detection *fd;
> + __u64 dummy;
> + };
> };
>
That's not compatible, at least not on any big-endian architecture.
If you want to have an indirect pointer, you have to cast it to the
__u64 member in user space and back in kernel space.
Using an array added to the end of the v4l2_fd_result structure
rather than a pointer would really make this easier IMHO.
Arnd
next prev parent reply other threads:[~2011-12-06 12:56 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-02 9:12 [RFC PATCH v1 0/7] media&omap4: introduce face detection(FD) driver Ming Lei
2011-12-02 9:12 ` Ming Lei
2011-12-02 9:12 ` [RFC PATCH v1 1/7] omap4: introduce fdif(face detect module) hwmod Ming Lei
2011-12-02 9:12 ` Ming Lei
2011-12-13 2:42 ` Ming Lei
2011-12-13 2:42 ` Ming Lei
2011-12-02 9:12 ` [RFC PATCH v1 2/7] omap4: build fdif omap device from hwmod Ming Lei
2011-12-02 9:12 ` Ming Lei
2011-12-02 12:10 ` Sergei Shtylyov
2011-12-02 12:10 ` Sergei Shtylyov
2011-12-05 4:25 ` Ming Lei
2011-12-05 4:25 ` Ming Lei
2011-12-05 4:25 ` Ming Lei
2011-12-02 9:12 ` [RFC PATCH v1 3/7] media: videobuf2: move out of setting pgprot_noncached from vb2_mmap_pfn_range Ming Lei
2011-12-02 9:12 ` Ming Lei
2011-12-02 9:12 ` [RFC PATCH v1 4/7] media: videobuf2: introduce VIDEOBUF2_PAGE memops Ming Lei
2011-12-02 9:12 ` Ming Lei
2011-12-02 16:35 ` Aguirre, Sergio
2011-12-02 16:35 ` Aguirre, Sergio
2011-12-05 2:16 ` Ming Lei
2011-12-05 2:16 ` Ming Lei
2011-12-02 9:12 ` [RFC PATCH v1 5/7] media: v4l2: introduce two IOCTLs for face detection Ming Lei
2011-12-02 9:12 ` Ming Lei
2011-12-02 12:33 ` Arnd Bergmann
2011-12-02 12:33 ` Arnd Bergmann
2011-12-04 11:18 ` Ming Lei
2011-12-04 11:18 ` Ming Lei
2011-12-04 11:18 ` Ming Lei
2011-12-05 14:37 ` Arnd Bergmann
2011-12-05 14:37 ` Arnd Bergmann
2011-12-06 6:30 ` Ming Lei
2011-12-06 6:30 ` Ming Lei
2011-12-06 12:55 ` Arnd Bergmann [this message]
2011-12-06 12:55 ` Arnd Bergmann
2011-12-06 13:11 ` Ming Lei
2011-12-06 13:11 ` Ming Lei
2011-12-06 14:41 ` Arnd Bergmann
2011-12-06 14:41 ` Arnd Bergmann
2011-12-06 14:52 ` Ming Lei
2011-12-06 14:52 ` Ming Lei
2011-12-06 15:45 ` Ming Lei
2011-12-06 15:45 ` Ming Lei
2011-12-06 20:59 ` Arnd Bergmann
2011-12-06 20:59 ` Arnd Bergmann
2011-12-02 9:12 ` [RFC PATCH v1 6/7] media: video: introduce face detection driver module Ming Lei
2011-12-02 9:12 ` Ming Lei
2011-12-02 9:12 ` [RFC PATCH v1 7/7] media: video: introduce omap4 face detection module driver Ming Lei
2011-12-02 9:12 ` Ming Lei
2011-12-02 10:28 ` [RFC PATCH v1 0/7] media&omap4: introduce face detection(FD) driver Sylwester Nawrocki
2011-12-02 10:28 ` Sylwester Nawrocki
2011-12-02 14:59 ` Ming Lei
2011-12-02 14:59 ` Ming Lei
-- strict thread matches above, loose matches on Subject: below --
2011-12-02 15:02 Ming Lei
2011-12-02 15:02 ` [RFC PATCH v1 5/7] media: v4l2: introduce two IOCTLs for face detection Ming Lei
2011-12-02 15:02 ` Ming Lei
2011-12-05 22:15 ` Sylwester Nawrocki
2011-12-05 22:15 ` Sylwester Nawrocki
2011-12-08 3:42 ` Ming Lei
2011-12-08 3:42 ` Ming Lei
2011-12-08 22:27 ` Sylwester Nawrocki
2011-12-08 22:27 ` Sylwester Nawrocki
2011-12-09 4:34 ` Ming Lei
2011-12-09 4:34 ` Ming Lei
2011-12-11 17:27 ` Sylwester Nawrocki
2011-12-11 17:27 ` Sylwester Nawrocki
2011-12-14 15:34 ` Sakari Ailus
2011-12-14 15:57 ` Ming Lei
2011-12-21 19:32 ` Sylwester Nawrocki
2011-12-26 2:00 ` Ming Lei
2011-12-27 20:53 ` Sylwester Nawrocki
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