/*
 * ioctl32.c: Conversion between 32bit and 64bit native ioctls.
 *      Separated from fs stuff by Arnd Bergmann <arnd@arndb.de>
 *
 * Copyright (C) 1997-2000  Jakub Jelinek  (jakub@redhat.com)
 * Copyright (C) 1998  Eddie C. Dost  (ecd@skynet.be)
 * Copyright (C) 2001,2002  Andi Kleen, SuSE Labs
 * Copyright (C) 2003       Pavel Machek (pavel@ucw.cz)
 * Copyright (C) 2005       Philippe De Muyter (phdm@macqel.be)
 * Copyright (C) 2008       Hans Verkuil <hverkuil@xs4all.nl>
 *
 * These routines maintain argument size conversion between 32bit and 64bit
 * ioctls.
 */

#include <linux/compat.h>
#include <linux/module.h>
#include <linux/videodev2.h>
#include <linux/v4l2-subdev.h>
#include <media/v4l2-dev.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-ioctl.h>

/**
 * assign_in_user() - Copy from one __user var to another one
 *
 * @to: __user var where data will be stored
 * @from: __user var where data will be retrieved.
 *
 * As this code very often needs to allocate userspace memory, it is easier
 * to have a macro that will do both get_user() and put_user() at once.
 *
 * This function complements the macros defined at asm-generic/uaccess.h.
 * It uses the same argument order as copy_in_user()
 */
#define assign_in_user(to, from)                                        \
({                                                                      \
        typeof(*from) __assign_tmp;                                     \
                                                                        \
        get_user(__assign_tmp, from) || put_user(__assign_tmp, to);     \
})

/**
 * get_user_cast() - Stores at a kernelspace local var the contents from a
 *              pointer with userspace data that is not tagged with __user.
 *
 * @__x: var where data will be stored
 * @__ptr: var where data will be retrieved.
 *
 * Sometimes we need to declare a pointer without __user because it
 * comes from a pointer struct field that will be retrieved from userspace
 * by the 64-bit native ioctl handler. This function ensures that the
 * @__ptr will be cast to __user before calling get_user() in order to
 * avoid warnings with static code analyzers like smatch.
 */
#define get_user_cast(__x, __ptr)                                       \
({                                                                      \
        get_user(__x, (typeof(*__ptr) __user *)(__ptr));                \
})

/**
 * put_user_force() - Stores the contents of a kernelspace local var
 *                    into a userspace pointer, removing any __user cast.
 *
 * @__x: var where data will be stored
 * @__ptr: var where data will be retrieved.
 *
 * Sometimes we need to remove the __user attribute from some data,
 * by passing the __force macro. This function ensures that the
 * @__ptr will be cast with __force before calling put_user(), in order to
 * avoid warnings with static code analyzers like smatch.
 */
#define put_user_force(__x, __ptr)                                      \
({                                                                      \
        put_user((typeof(*__x) __force *)(__x), __ptr);                 \
})

/**
 * assign_in_user_cast() - Copy from one __user var to another one
 *
 * @to: __user var where data will be stored
 * @from: var where data will be retrieved that needs to be cast to __user.
 *
 * As this code very often needs to allocate userspace memory, it is easier
 * to have a macro that will do both get_user_cast() and put_user() at once.
 *
 * This function should be used instead of assign_in_user() when the @from
 * variable was not declared as __user. See get_user_cast() for more details.
 *
 * This function complements the macros defined at asm-generic/uaccess.h.
 * It uses the same argument order as copy_in_user()
 */
#define assign_in_user_cast(to, from)                                   \
({                                                                      \
        typeof(*from) __assign_tmp;                                     \
                                                                        \
        get_user_cast(__assign_tmp, from) || put_user(__assign_tmp, to);\
})

/**
 * native_ioctl - Ancillary function that calls the native 64 bits ioctl
 * handler.
 *
 * @file: pointer to &struct file with the file handler
 * @cmd: ioctl to be called
 * @arg: arguments passed from/to the ioctl handler
 *
 * This function calls the native ioctl handler at v4l2-dev, e. g. v4l2_ioctl()
 */
static long native_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
        long ret = -ENOIOCTLCMD;

        if (file->f_op->unlocked_ioctl)
                ret = file->f_op->unlocked_ioctl(file, cmd, arg);

        return ret;
}


/*
 * Per-ioctl data copy handlers.
 *
 * Those come in pairs, with a get_v4l2_foo() and a put_v4l2_foo() routine,
 * where "v4l2_foo" is the name of the V4L2 struct.
 *
 * They basically get two __user pointers, one with a 32-bits struct that
 * came from the userspace call and a 64-bits struct, also allocated as
 * userspace, but filled internally by do_video_ioctl().
 *
 * For ioctls that have pointers inside it, the functions will also
 * receive an ancillary buffer with extra space, used to pass extra
 * data to the routine.
 */

struct v4l2_clip32 {
        struct v4l2_rect        c;
        compat_caddr_t          next;
};

struct v4l2_window32 {
        struct v4l2_rect        w;
        __u32                   field;  /* enum v4l2_field */
        __u32                   chromakey;
        compat_caddr_t          clips; /* actually struct v4l2_clip32 * */
        __u32                   clipcount;
        compat_caddr_t          bitmap;
        __u8                    global_alpha;
};

static int get_v4l2_window32(struct v4l2_window __user *p64,
                             struct v4l2_window32 __user *p32,
                             void __user *aux_buf, u32 aux_space)
{
        struct v4l2_clip32 __user *uclips;
        struct v4l2_clip __user *kclips;
        compat_caddr_t p;
        u32 clipcount;

        if (!access_ok(p32, sizeof(*p32)) ||
            copy_in_user(&p64->w, &p32->w, sizeof(p32->w)) ||
            assign_in_user(&p64->field, &p32->field) ||
            assign_in_user(&p64->chromakey, &p32->chromakey) ||
            assign_in_user(&p64->global_alpha, &p32->global_alpha) ||
            get_user(clipcount, &p32->clipcount) ||
            put_user(clipcount, &p64->clipcount))
                return -EFAULT;
        if (clipcount > 2048)
                return -EINVAL;
        if (!clipcount)
                return put_user(NULL, &p64->clips);

        if (get_user(p, &p32->clips))
                return -EFAULT;
        uclips = compat_ptr(p);
        if (aux_space < clipcount * sizeof(*kclips))
                return -EFAULT;
        kclips = aux_buf;
        if (put_user(kclips, &p64->clips))
                return -EFAULT;

        while (clipcount--) {
                if (copy_in_user(&kclips->c, &uclips->c, sizeof(uclips->c)))
                        return -EFAULT;
                if (put_user(clipcount ? kclips + 1 : NULL, &kclips->next))
                        return -EFAULT;
                uclips++;
                kclips++;
        }
        return 0;
}

static int put_v4l2_window32(struct v4l2_window __user *p64,
                             struct v4l2_window32 __user *p32)
{
        struct v4l2_clip __user *kclips;
        struct v4l2_clip32 __user *uclips;
        compat_caddr_t p;
        u32 clipcount;

        if (copy_in_user(&p32->w, &p64->w, sizeof(p64->w)) ||
            assign_in_user(&p32->field, &p64->field) ||
            assign_in_user(&p32->chromakey, &p64->chromakey) ||
            assign_in_user(&p32->global_alpha, &p64->global_alpha) ||
            get_user(clipcount, &p64->clipcount) ||
            put_user(clipcount, &p32->clipcount))
                return -EFAULT;
        if (!clipcount)
                return 0;

        if (get_user(kclips, &p64->clips))
                return -EFAULT;
        if (get_user(p, &p32->clips))
                return -EFAULT;
        uclips = compat_ptr(p);
        while (clipcount--) {
                if (copy_in_user(&uclips->c, &kclips->c, sizeof(uclips->c)))
                        return -EFAULT;
                uclips++;
                kclips++;
        }
        return 0;
}

struct v4l2_format32 {
        __u32   type;   /* enum v4l2_buf_type */
        union {
                struct v4l2_pix_format  pix;
                struct v4l2_pix_format_mplane   pix_mp;
                struct v4l2_window32    win;
                struct v4l2_vbi_format  vbi;
                struct v4l2_sliced_vbi_format   sliced;
                struct v4l2_sdr_format  sdr;
                struct v4l2_meta_format meta;
                __u8    raw_data[200];        /* user-defined */
        } fmt;
};

/**
 * struct v4l2_create_buffers32 - VIDIOC_CREATE_BUFS32 argument
 * @index:      on return, index of the first created buffer
 * @count:      entry: number of requested buffers,
 *              return: number of created buffers
 * @memory:     buffer memory type
 * @format:     frame format, for which buffers are requested
 * @reserved:   future extensions
 */
struct v4l2_create_buffers32 {
        __u32                   index;
        __u32                   count;
        __u32                   memory; /* enum v4l2_memory */
        struct v4l2_format32    format;
        __u32                   reserved[8];
};

static int __bufsize_v4l2_format(struct v4l2_format32 __user *p32, u32 *size)
{
        u32 type;

        if (get_user(type, &p32->type))
                return -EFAULT;

        switch (type) {
        case V4L2_BUF_TYPE_VIDEO_OVERLAY:
        case V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY: {
                u32 clipcount;

                if (get_user(clipcount, &p32->fmt.win.clipcount))
                        return -EFAULT;
                if (clipcount > 2048)
                        return -EINVAL;
                *size = clipcount * sizeof(struct v4l2_clip);
                return 0;
        }
        default:
                *size = 0;
                return 0;
        }
}

static int bufsize_v4l2_format(struct v4l2_format32 __user *p32, u32 *size)
{
        if (!access_ok(p32, sizeof(*p32)))
                return -EFAULT;
        return __bufsize_v4l2_format(p32, size);
}

static int __get_v4l2_format32(struct v4l2_format __user *p64,
                               struct v4l2_format32 __user *p32,
                               void __user *aux_buf, u32 aux_space)
{
        u32 type;

        if (get_user(type, &p32->type) || put_user(type, &p64->type))
                return -EFAULT;

        switch (type) {
        case V4L2_BUF_TYPE_VIDEO_CAPTURE:
        case V4L2_BUF_TYPE_VIDEO_OUTPUT:
                return copy_in_user(&p64->fmt.pix, &p32->fmt.pix,
                                    sizeof(p64->fmt.pix)) ? -EFAULT : 0;
        case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
        case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE:
                return copy_in_user(&p64->fmt.pix_mp, &p32->fmt.pix_mp,
                                    sizeof(p64->fmt.pix_mp)) ? -EFAULT : 0;
        case V4L2_BUF_TYPE_VIDEO_OVERLAY:
        case V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY:
                return get_v4l2_window32(&p64->fmt.win, &p32->fmt.win,
                                         aux_buf, aux_space);
        case V4L2_BUF_TYPE_VBI_CAPTURE:
        case V4L2_BUF_TYPE_VBI_OUTPUT:
                return copy_in_user(&p64->fmt.vbi, &p32->fmt.vbi,
                                    sizeof(p64->fmt.vbi)) ? -EFAULT : 0;
        case V4L2_BUF_TYPE_SLICED_VBI_CAPTURE:
        case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
                return copy_in_user(&p64->fmt.sliced, &p32->fmt.sliced,
                                    sizeof(p64->fmt.sliced)) ? -EFAULT : 0;
        case V4L2_BUF_TYPE_SDR_CAPTURE:
        case V4L2_BUF_TYPE_SDR_OUTPUT:
                return copy_in_user(&p64->fmt.sdr, &p32->fmt.sdr,
                                    sizeof(p64->fmt.sdr)) ? -EFAULT : 0;
        case V4L2_BUF_TYPE_META_CAPTURE:
        case V4L2_BUF_TYPE_META_OUTPUT:
                return copy_in_user(&p64->fmt.meta, &p32->fmt.meta,
                                    sizeof(p64->fmt.meta)) ? -EFAULT : 0;
        default:
                return -EINVAL;
        }
}

static int get_v4l2_format32(struct v4l2_format __user *p64,
                             struct v4l2_format32 __user *p32,
                             void __user *aux_buf, u32 aux_space)
{
        if (!access_ok(p32, sizeof(*p32)))
                return -EFAULT;
        return __get_v4l2_format32(p64, p32, aux_buf, aux_space);
}

static int bufsize_v4l2_create(struct v4l2_create_buffers32 __user *p32,
                               u32 *size)
{
        if (!access_ok(p32, sizeof(*p32)))
                return -EFAULT;
        return __bufsize_v4l2_format(&p32->format, size);
}

static int get_v4l2_create32(struct v4l2_create_buffers __user *p64,
                             struct v4l2_create_buffers32 __user *p32,
                             void __user *aux_buf, u32 aux_space)
{
        if (!access_ok(p32, sizeof(*p32)) ||
            copy_in_user(p64, p32,
                         offsetof(struct v4l2_create_buffers32, format)))
                return -EFAULT;
        return __get_v4l2_format32(&p64->format, &p32->format,
                                   aux_buf, aux_space);
}

static int __put_v4l2_format32(struct v4l2_format __user *p64,
                               struct v4l2_format32 __user *p32)
{
        u32 type;

        if (get_user(type, &p64->type))
                return -EFAULT;

        switch (type) {
        case V4L2_BUF_TYPE_VIDEO_CAPTURE:
        case V4L2_BUF_TYPE_VIDEO_OUTPUT:
                return copy_in_user(&p32->fmt.pix, &p64->fmt.pix,
                                    sizeof(p64->fmt.pix)) ? -EFAULT : 0;
        case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
        case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE:
                return copy_in_user(&p32->fmt.pix_mp, &p64->fmt.pix_mp,
                                    sizeof(p64->fmt.pix_mp)) ? -EFAULT : 0;
        case V4L2_BUF_TYPE_VIDEO_OVERLAY:
        case V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY:
                return put_v4l2_window32(&p64->fmt.win, &p32->fmt.win);
        case V4L2_BUF_TYPE_VBI_CAPTURE:
        case V4L2_BUF_TYPE_VBI_OUTPUT:
                return copy_in_user(&p32->fmt.vbi, &p64->fmt.vbi,
                                    sizeof(p64->fmt.vbi)) ? -EFAULT : 0;
        case V4L2_BUF_TYPE_SLICED_VBI_CAPTURE:
        case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
                return copy_in_user(&p32->fmt.sliced, &p64->fmt.sliced,
                                    sizeof(p64->fmt.sliced)) ? -EFAULT : 0;
        case V4L2_BUF_TYPE_SDR_CAPTURE:
        case V4L2_BUF_TYPE_SDR_OUTPUT:
                return copy_in_user(&p32->fmt.sdr, &p64->fmt.sdr,
                                    sizeof(p64->fmt.sdr)) ? -EFAULT : 0;
        case V4L2_BUF_TYPE_META_CAPTURE:
        case V4L2_BUF_TYPE_META_OUTPUT:
                return copy_in_user(&p32->fmt.meta, &p64->fmt.meta,
                                    sizeof(p64->fmt.meta)) ? -EFAULT : 0;
        default:
                return -EINVAL;
        }
}

static int put_v4l2_format32(struct v4l2_format __user *p64,
                             struct v4l2_format32 __user *p32)
{
        if (!access_ok(p32, sizeof(*p32)))
                return -EFAULT;
        return __put_v4l2_format32(p64, p32);
}

static int put_v4l2_create32(struct v4l2_create_buffers __user *p64,
                             struct v4l2_create_buffers32 __user *p32)
{
        if (!access_ok(p32, sizeof(*p32)) ||
            copy_in_user(p32, p64,
                         offsetof(struct v4l2_create_buffers32, format)) ||
            copy_in_user(p32->reserved, p64->reserved, sizeof(p64->reserved)))
                return -EFAULT;
        return __put_v4l2_format32(&p64->format, &p32->format);
}

struct v4l2_standard32 {
        __u32                index;
        compat_u64           id;
        __u8                 name[24];
        struct v4l2_fract    frameperiod; /* Frames, not fields */
        __u32                framelines;
        __u32                reserved[4];
};

static int get_v4l2_standard32(struct v4l2_standard __user *p64,
                               struct v4l2_standard32 __user *p32)
{
        /* other fields are not set by the user, nor used by the driver */
        if (!access_ok(p32, sizeof(*p32)) ||
            assign_in_user(&p64->index, &p32->index))
                return -EFAULT;
        return 0;
}

static int put_v4l2_standard32(struct v4l2_standard __user *p64,
                               struct v4l2_standard32 __user *p32)
{
        if (!access_ok(p32, sizeof(*p32)) ||
            assign_in_user(&p32->index, &p64->index) ||
            assign_in_user(&p32->id, &p64->id) ||
            copy_in_user(p32->name, p64->name, sizeof(p32->name)) ||
            copy_in_user(&p32->frameperiod, &p64->frameperiod,
                         sizeof(p32->frameperiod)) ||
            assign_in_user(&p32->framelines, &p64->framelines) ||
            copy_in_user(p32->reserved, p64->reserved, sizeof(p32->reserved)))
                return -EFAULT;
        return 0;
}

struct v4l2_plane32 {
        __u32                   bytesused;
        __u32                   length;
        union {
                __u32           mem_offset;
                compat_long_t   userptr;
                __s32           fd;
        } m;
        __u32                   data_offset;
        __u32                   reserved[11];
};

struct v4l2_buffer32 {
        __u32                   index;
        __u32                   type;   /* enum v4l2_buf_type */
        __u32                   bytesused;
        __u32                   flags;
        __u32                   field;  /* enum v4l2_field */
        struct compat_timeval   timestamp;
        struct v4l2_timecode    timecode;
        __u32                   sequence;

        /* memory location */
        __u32                   memory; /* enum v4l2_memory */
        union {
                __u32           offset;
                compat_long_t   userptr;
                compat_caddr_t  planes;
                __s32           fd;
        } m;
        __u32                   length;
        __u32                   reserved2;
        __u32                   reserved;
};

static int get_v4l2_plane32(struct v4l2_plane __user *p64,
                            struct v4l2_plane32 __user *p32,
                            enum v4l2_memory memory)
{
        compat_ulong_t p;

        if (copy_in_user(p64, p32, 2 * sizeof(__u32)) ||
            copy_in_user(&p64->data_offset, &p32->data_offset,
                         sizeof(p64->data_offset)))
                return -EFAULT;

        switch (memory) {
        case V4L2_MEMORY_MMAP:
        case V4L2_MEMORY_OVERLAY:
                if (copy_in_user(&p64->m.mem_offset, &p32->m.mem_offset,
                                 sizeof(p32->m.mem_offset)))
                        return -EFAULT;
                break;
        case V4L2_MEMORY_USERPTR:
                if (get_user(p, &p32->m.userptr) ||
                    put_user((unsigned long)compat_ptr(p), &p64->m.userptr))
                        return -EFAULT;
                break;
        case V4L2_MEMORY_DMABUF:
                if (copy_in_user(&p64->m.fd, &p32->m.fd, sizeof(p32->m.fd)))
                        return -EFAULT;
                break;
        }

        return 0;
}

static int put_v4l2_plane32(struct v4l2_plane __user *p64,
                            struct v4l2_plane32 __user *p32,
                            enum v4l2_memory memory)
{
        unsigned long p;

        if (copy_in_user(p32, p64, 2 * sizeof(__u32)) ||
            copy_in_user(&p32->data_offset, &p64->data_offset,
                         sizeof(p64->data_offset)))
                return -EFAULT;

        switch (memory) {
        case V4L2_MEMORY_MMAP:
        case V4L2_MEMORY_OVERLAY:
                if (copy_in_user(&p32->m.mem_offset, &p64->m.mem_offset,
                                 sizeof(p64->m.mem_offset)))
                        return -EFAULT;
                break;
        case V4L2_MEMORY_USERPTR:
                if (get_user(p, &p64->m.userptr) ||
                    put_user((compat_ulong_t)ptr_to_compat((void __user *)p),
                             &p32->m.userptr))
                        return -EFAULT;
                break;
        case V4L2_MEMORY_DMABUF:
                if (copy_in_user(&p32->m.fd, &p64->m.fd, sizeof(p64->m.fd)))
                        return -EFAULT;
                break;
        }

        return 0;
}

static int bufsize_v4l2_buffer(struct v4l2_buffer32 __user *p32, u32 *size)
{
        u32 type;
        u32 length;

        if (!access_ok(p32, sizeof(*p32)) ||
            get_user(type, &p32->type) ||
            get_user(length, &p32->length))
                return -EFAULT;

        if (V4L2_TYPE_IS_MULTIPLANAR(type)) {
                if (length > VIDEO_MAX_PLANES)
                        return -EINVAL;

                /*
                 * We don't really care if userspace decides to kill itself
                 * by passing a very big length value
                 */
                *size = length * sizeof(struct v4l2_plane);
        } else {
                *size = 0;
        }
        return 0;
}

static int get_v4l2_buffer32(struct v4l2_buffer __user *p64,
                             struct v4l2_buffer32 __user *p32,
                             void __user *aux_buf, u32 aux_space)
{
        u32 type;
        u32 length;
        enum v4l2_memory memory;
        struct v4l2_plane32 __user *uplane32;
        struct v4l2_plane __user *uplane;
        compat_caddr_t p;
        int ret;

        if (!access_ok(p32, sizeof(*p32)) ||
            assign_in_user(&p64->index, &p32->index) ||
            get_user(type, &p32->type) ||
            put_user(type, &p64->type) ||
            assign_in_user(&p64->flags, &p32->flags) ||
            get_user(memory, &p32->memory) ||
            put_user(memory, &p64->memory) ||
            get_user(length, &p32->length) ||
            put_user(length, &p64->length))
                return -EFAULT;

        if (V4L2_TYPE_IS_OUTPUT(type))
                if (assign_in_user(&p64->bytesused, &p32->bytesused) ||
                    assign_in_user(&p64->field, &p32->field) ||
                    assign_in_user(&p64->timestamp.tv_sec,
                                   &p32->timestamp.tv_sec) ||
                    assign_in_user(&p64->timestamp.tv_usec,
                                   &p32->timestamp.tv_usec))
                        return -EFAULT;

        if (V4L2_TYPE_IS_MULTIPLANAR(type)) {
                u32 num_planes = length;

                if (num_planes == 0) {
                        /*
                         * num_planes == 0 is legal, e.g. when userspace doesn't
                         * need planes array on DQBUF
                         */
                        return put_user(NULL, &p64->m.planes);
                }
                if (num_planes > VIDEO_MAX_PLANES)
                        return -EINVAL;

                if (get_user(p, &p32->m.planes))
                        return -EFAULT;

                uplane32 = compat_ptr(p);
                if (!access_ok(uplane32,
                               num_planes * sizeof(*uplane32)))
                        return -EFAULT;

                /*
                 * We don't really care if userspace decides to kill itself
                 * by passing a very big num_planes value
                 */
                if (aux_space < num_planes * sizeof(*uplane))
                        return -EFAULT;

                uplane = aux_buf;
                if (put_user_force(uplane, &p64->m.planes))
                        return -EFAULT;

                while (num_planes--) {
                        ret = get_v4l2_plane32(uplane, uplane32, memory);
                        if (ret)
                                return ret;
                        uplane++;
                        uplane32++;
                }
        } else {
                switch (memory) {
                case V4L2_MEMORY_MMAP:
                case V4L2_MEMORY_OVERLAY:
                        if (assign_in_user(&p64->m.offset, &p32->m.offset))
                                return -EFAULT;
                        break;
                case V4L2_MEMORY_USERPTR: {
                        compat_ulong_t userptr;

                        if (get_user(userptr, &p32->m.userptr) ||
                            put_user((unsigned long)compat_ptr(userptr),
                                     &p64->m.userptr))
                                return -EFAULT;
                        break;
                }
                case V4L2_MEMORY_DMABUF:
                        if (assign_in_user(&p64->m.fd, &p32->m.fd))
                                return -EFAULT;
                        break;
                }
        }

        return 0;
}

static int put_v4l2_buffer32(struct v4l2_buffer __user *p64,
                             struct v4l2_buffer32 __user *p32)
{
        u32 type;
        u32 length;
        enum v4l2_memory memory;
        struct v4l2_plane32 __user *uplane32;
        struct v4l2_plane *uplane;
        compat_caddr_t p;
        int ret;

        if (!access_ok(p32, sizeof(*p32)) ||
            assign_in_user(&p32->index, &p64->index) ||
            get_user(type, &p64->type) ||
            put_user(type, &p32->type) ||
            assign_in_user(&p32->flags, &p64->flags) ||
            get_user(memory, &p64->memory) ||
            put_user(memory, &p32->memory))
                return -EFAULT;

        if (assign_in_user(&p32->bytesused, &p64->bytesused) ||
            assign_in_user(&p32->field, &p64->field) ||
            assign_in_user(&p32->timestamp.tv_sec, &p64->timestamp.tv_sec) ||
            assign_in_user(&p32->timestamp.tv_usec, &p64->timestamp.tv_usec) ||
            copy_in_user(&p32->timecode, &p64->timecode, sizeof(p64->timecode)) ||
            assign_in_user(&p32->sequence, &p64->sequence) ||
            assign_in_user(&p32->reserved2, &p64->reserved2) ||
            assign_in_user(&p32->reserved, &p64->reserved) ||
            get_user(length, &p64->length) ||
            put_user(length, &p32->length))
                return -EFAULT;

        if (V4L2_TYPE_IS_MULTIPLANAR(type)) {
                u32 num_planes = length;

                if (num_planes == 0)
                        return 0;
                /* We need to define uplane without __user, even though
                 * it does point to data in userspace here. The reason is
                 * that v4l2-ioctl.c copies it from userspace to kernelspace,
                 * so its definition in videodev2.h doesn't have a
                 * __user markup. Defining uplane with __user causes
                 * smatch warnings, so instead declare it without __user
                 * and cast it as a userspace pointer to put_v4l2_plane32().
                 */
                if (get_user(uplane, &p64->m.planes))
                        return -EFAULT;
                if (get_user(p, &p32->m.planes))
                        return -EFAULT;
                uplane32 = compat_ptr(p);

                while (num_planes--) {
                        ret = put_v4l2_plane32((void __user *)uplane,
                                               uplane32, memory);
                        if (ret)
                                return ret;
                        ++uplane;
                        ++uplane32;
                }
        } else {
                switch (memory) {
                case V4L2_MEMORY_MMAP:
                case V4L2_MEMORY_OVERLAY:
                        if (assign_in_user(&p32->m.offset, &p64->m.offset))
                                return -EFAULT;
                        break;
                case V4L2_MEMORY_USERPTR:
                        if (assign_in_user(&p32->m.userptr, &p64->m.userptr))
                                return -EFAULT;
                        break;
                case V4L2_MEMORY_DMABUF:
                        if (assign_in_user(&p32->m.fd, &p64->m.fd))
                                return -EFAULT;
                        break;
                }
        }

        return 0;
}

struct v4l2_framebuffer32 {
        __u32                   capability;
        __u32                   flags;
        compat_caddr_t          base;
        struct {
                __u32           width;
                __u32           height;
                __u32           pixelformat;
                __u32           field;
                __u32           bytesperline;
                __u32           sizeimage;
                __u32           colorspace;
                __u32           priv;
        } fmt;
};

static int get_v4l2_framebuffer32(struct v4l2_framebuffer __user *p64,
                                  struct v4l2_framebuffer32 __user *p32)
{
        compat_caddr_t tmp;

        if (!access_ok(p32, sizeof(*p32)) ||
            get_user(tmp, &p32->base) ||
            put_user_force(compat_ptr(tmp), &p64->base) ||
            assign_in_user(&p64->capability, &p32->capability) ||
            assign_in_user(&p64->flags, &p32->flags) ||
            copy_in_user(&p64->fmt, &p32->fmt, sizeof(p64->fmt)))
                return -EFAULT;
        return 0;
}

static int put_v4l2_framebuffer32(struct v4l2_framebuffer __user *p64,
                                  struct v4l2_framebuffer32 __user *p32)
{
        void *base;

        if (!access_ok(p32, sizeof(*p32)) ||
            get_user(base, &p64->base) ||
            put_user(ptr_to_compat((void __user *)base), &p32->base) ||
            assign_in_user(&p32->capability, &p64->capability) ||
            assign_in_user(&p32->flags, &p64->flags) ||
            copy_in_user(&p32->fmt, &p64->fmt, sizeof(p64->fmt)))
                return -EFAULT;
        return 0;
}

struct v4l2_input32 {
        __u32        index;             /*  Which input */
        __u8         name[32];          /*  Label */
        __u32        type;              /*  Type of input */
        __u32        audioset;          /*  Associated audios (bitfield) */
        __u32        tuner;             /*  Associated tuner */
        compat_u64   std;
        __u32        status;
        __u32        capabilities;
        __u32        reserved[3];
};

/*
 * The 64-bit v4l2_input struct has extra padding at the end of the struct.
 * Otherwise it is identical to the 32-bit version.
 */
static inline int get_v4l2_input32(struct v4l2_input __user *p64,
                                   struct v4l2_input32 __user *p32)
{
        if (copy_in_user(p64, p32, sizeof(*p32)))
                return -EFAULT;
        return 0;
}

static inline int put_v4l2_input32(struct v4l2_input __user *p64,
                                   struct v4l2_input32 __user *p32)
{
        if (copy_in_user(p32, p64, sizeof(*p32)))
                return -EFAULT;
        return 0;
}

struct v4l2_ext_controls32 {
        __u32 which;
        __u32 count;
        __u32 error_idx;
        __s32 request_fd;
        __u32 reserved[1];
        compat_caddr_t controls; /* actually struct v4l2_ext_control32 * */
};

struct v4l2_ext_control32 {
        __u32 id;
        __u32 size;
        __u32 reserved2[1];
        union {
                __s32 value;
                __s64 value64;
                compat_caddr_t string; /* actually char * */
        };
} __attribute__ ((packed));

/* Return true if this control is a pointer type. */
static inline bool ctrl_is_pointer(struct file *file, u32 id)
{
        struct video_device *vdev = video_devdata(file);
        struct v4l2_fh *fh = NULL;
        struct v4l2_ctrl_handler *hdl = NULL;
        struct v4l2_query_ext_ctrl qec = { id };
        const struct v4l2_ioctl_ops *ops = vdev->ioctl_ops;

        if (test_bit(V4L2_FL_USES_V4L2_FH, &vdev->flags))
                fh = file->private_data;

        if (fh && fh->ctrl_handler)
                hdl = fh->ctrl_handler;
        else if (vdev->ctrl_handler)
                hdl = vdev->ctrl_handler;

        if (hdl) {
                struct v4l2_ctrl *ctrl = v4l2_ctrl_find(hdl, id);

                return ctrl && ctrl->is_ptr;
        }

        if (!ops || !ops->vidioc_query_ext_ctrl)
                return false;

        return !ops->vidioc_query_ext_ctrl(file, fh, &qec) &&
                (qec.flags & V4L2_CTRL_FLAG_HAS_PAYLOAD);
}

static int bufsize_v4l2_ext_controls(struct v4l2_ext_controls32 __user *p32,
                                     u32 *size)
{
        u32 count;

        if (!access_ok(p32, sizeof(*p32)) ||
            get_user(count, &p32->count))
                return -EFAULT;
        if (count > V4L2_CID_MAX_CTRLS)
                return -EINVAL;
        *size = count * sizeof(struct v4l2_ext_control);
        return 0;
}

static int get_v4l2_ext_controls32(struct file *file,
                                   struct v4l2_ext_controls __user *p64,
                                   struct v4l2_ext_controls32 __user *p32,
                                   void __user *aux_buf, u32 aux_space)
{
        struct v4l2_ext_control32 __user *ucontrols;
        struct v4l2_ext_control __user *kcontrols;
        u32 count;
        u32 n;
        compat_caddr_t p;

        if (!access_ok(p32, sizeof(*p32)) ||
            assign_in_user(&p64->which, &p32->which) ||
            get_user(count, &p32->count) ||
            put_user(count, &p64->count) ||
            assign_in_user(&p64->error_idx, &p32->error_idx) ||
            assign_in_user(&p64->request_fd, &p32->request_fd) ||
            copy_in_user(p64->reserved, p32->reserved, sizeof(p64->reserved)))
                return -EFAULT;

        if (count == 0)
                return put_user(NULL, &p64->controls);
        if (count > V4L2_CID_MAX_CTRLS)
                return -EINVAL;
        if (get_user(p, &p32->controls))
                return -EFAULT;
        ucontrols = compat_ptr(p);
        if (!access_ok(ucontrols, count * sizeof(*ucontrols)))
                return -EFAULT;
        if (aux_space < count * sizeof(*kcontrols))
                return -EFAULT;
        kcontrols = aux_buf;
        if (put_user_force(kcontrols, &p64->controls))
                return -EFAULT;

        for (n = 0; n < count; n++) {
                u32 id;

                if (copy_in_user(kcontrols, ucontrols, sizeof(*ucontrols)))
                        return -EFAULT;

                if (get_user(id, &kcontrols->id))
                        return -EFAULT;

                if (ctrl_is_pointer(file, id)) {
                        void __user *s;

                        if (get_user(p, &ucontrols->string))
                                return -EFAULT;
                        s = compat_ptr(p);
                        if (put_user(s, &kcontrols->string))
                                return -EFAULT;
                }
                ucontrols++;
                kcontrols++;
        }
        return 0;
}

static int put_v4l2_ext_controls32(struct file *file,
                                   struct v4l2_ext_controls __user *p64,
                                   struct v4l2_ext_controls32 __user *p32)
{
        struct v4l2_ext_control32 __user *ucontrols;
        struct v4l2_ext_control *kcontrols;
        u32 count;
        u32 n;
        compat_caddr_t p;

        /*
         * We need to define kcontrols without __user, even though it does
         * point to data in userspace here. The reason is that v4l2-ioctl.c
         * copies it from userspace to kernelspace, so its definition in
         * videodev2.h doesn't have a __user markup. Defining kcontrols
         * with __user causes smatch warnings, so instead declare it
         * without __user and cast it as a userspace pointer where needed.
         */
        if (!access_ok(p32, sizeof(*p32)) ||
            assign_in_user(&p32->which, &p64->which) ||
            get_user(count, &p64->count) ||
            put_user(count, &p32->count) ||
            assign_in_user(&p32->error_idx, &p64->error_idx) ||
            assign_in_user(&p32->request_fd, &p64->request_fd) ||
            copy_in_user(p32->reserved, p64->reserved, sizeof(p32->reserved)) ||
            get_user(kcontrols, &p64->controls))
                return -EFAULT;

        if (!count || count > (U32_MAX/sizeof(*ucontrols)))
                return 0;
        if (get_user(p, &p32->controls))
                return -EFAULT;
        ucontrols = compat_ptr(p);
        if (!access_ok(ucontrols, count * sizeof(*ucontrols)))
                return -EFAULT;

        for (n = 0; n < count; n++) {
                unsigned int size = sizeof(*ucontrols);
                u32 id;

                if (get_user_cast(id, &kcontrols->id) ||
                    put_user(id, &ucontrols->id) ||
                    assign_in_user_cast(&ucontrols->size, &kcontrols->size) ||

                    copy_in_user(&ucontrols->reserved2,
                                 (void __user *)&kcontrols->reserved2,
                                 sizeof(ucontrols->reserved2)))
                        return -EFAULT;

                /*
                 * Do not modify the pointer when copying a pointer control.
                 * The contents of the pointer was changed, not the pointer
                 * itself.
                 */
                if (ctrl_is_pointer(file, id))
                        size -= sizeof(ucontrols->value64);

                if (copy_in_user(ucontrols,
                                 (void __user *)kcontrols, size))
                        return -EFAULT;

                ucontrols++;
                kcontrols++;
        }
        return 0;
}

struct v4l2_event32 {
        __u32                           type;
        union {
                compat_s64              value64;
                __u8                    data[64];
        } u;
        __u32                           pending;
        __u32                           sequence;
        struct compat_timespec          timestamp;
        __u32                           id;
        __u32                           reserved[8];
};

static int put_v4l2_event32(struct v4l2_event __user *p64,
                            struct v4l2_event32 __user *p32)
{
        if (!access_ok(p32, sizeof(*p32)) ||
            assign_in_user(&p32->type, &p64->type) ||
            copy_in_user(&p32->u, &p64->u, sizeof(p64->u)) ||
            assign_in_user(&p32->pending, &p64->pending) ||
            assign_in_user(&p32->sequence, &p64->sequence) ||
            assign_in_user(&p32->timestamp.tv_sec, &p64->timestamp.tv_sec) ||
            assign_in_user(&p32->timestamp.tv_nsec, &p64->timestamp.tv_nsec) ||
            assign_in_user(&p32->id, &p64->id) ||
            copy_in_user(p32->reserved, p64->reserved, sizeof(p32->reserved)))
                return -EFAULT;
        return 0;
}

struct v4l2_edid32 {
        __u32 pad;
        __u32 start_block;
        __u32 blocks;
        __u32 reserved[5];
        compat_caddr_t edid;
};

static int get_v4l2_edid32(struct v4l2_edid __user *p64,
                           struct v4l2_edid32 __user *p32)
{
        compat_uptr_t tmp;

        if (!access_ok(p32, sizeof(*p32)) ||
            assign_in_user(&p64->pad, &p32->pad) ||
            assign_in_user(&p64->start_block, &p32->start_block) ||
            assign_in_user_cast(&p64->blocks, &p32->blocks) ||
            get_user(tmp, &p32->edid) ||
            put_user_force(compat_ptr(tmp), &p64->edid) ||
            copy_in_user(p64->reserved, p32->reserved, sizeof(p64->reserved)))
                return -EFAULT;
        return 0;
}

static int put_v4l2_edid32(struct v4l2_edid __user *p64,
                           struct v4l2_edid32 __user *p32)
{
        void *edid;

        if (!access_ok(p32, sizeof(*p32)) ||
            assign_in_user(&p32->pad, &p64->pad) ||
            assign_in_user(&p32->start_block, &p64->start_block) ||
            assign_in_user(&p32->blocks, &p64->blocks) ||
            get_user(edid, &p64->edid) ||
            put_user(ptr_to_compat((void __user *)edid), &p32->edid) ||
            copy_in_user(p32->reserved, p64->reserved, sizeof(p32->reserved)))
                return -EFAULT;
        return 0;
}

/*
 * List of ioctls that require 32-bits/64-bits conversion
 *
 * The V4L2 ioctls that aren't listed there don't have pointer arguments
 * and the struct size is identical for both 32 and 64 bits versions, so
 * they don't need translations.
 */

#define VIDIOC_G_FMT32          _IOWR('V',  4, struct v4l2_format32)
#define VIDIOC_S_FMT32          _IOWR('V',  5, struct v4l2_format32)
#define VIDIOC_QUERYBUF32       _IOWR('V',  9, struct v4l2_buffer32)
#define VIDIOC_G_FBUF32         _IOR ('V', 10, struct v4l2_framebuffer32)
#define VIDIOC_S_FBUF32         _IOW ('V', 11, struct v4l2_framebuffer32)
#define VIDIOC_QBUF32           _IOWR('V', 15, struct v4l2_buffer32)
#define VIDIOC_DQBUF32          _IOWR('V', 17, struct v4l2_buffer32)
#define VIDIOC_ENUMSTD32        _IOWR('V', 25, struct v4l2_standard32)
#define VIDIOC_ENUMINPUT32      _IOWR('V', 26, struct v4l2_input32)
#define VIDIOC_G_EDID32         _IOWR('V', 40, struct v4l2_edid32)
#define VIDIOC_S_EDID32         _IOWR('V', 41, struct v4l2_edid32)
#define VIDIOC_TRY_FMT32        _IOWR('V', 64, struct v4l2_format32)
#define VIDIOC_G_EXT_CTRLS32    _IOWR('V', 71, struct v4l2_ext_controls32)
#define VIDIOC_S_EXT_CTRLS32    _IOWR('V', 72, struct v4l2_ext_controls32)
#define VIDIOC_TRY_EXT_CTRLS32  _IOWR('V', 73, struct v4l2_ext_controls32)
#define VIDIOC_DQEVENT32        _IOR ('V', 89, struct v4l2_event32)
#define VIDIOC_CREATE_BUFS32    _IOWR('V', 92, struct v4l2_create_buffers32)
#define VIDIOC_PREPARE_BUF32    _IOWR('V', 93, struct v4l2_buffer32)

#define VIDIOC_OVERLAY32        _IOW ('V', 14, s32)
#define VIDIOC_STREAMON32       _IOW ('V', 18, s32)
#define VIDIOC_STREAMOFF32      _IOW ('V', 19, s32)
#define VIDIOC_G_INPUT32        _IOR ('V', 38, s32)
#define VIDIOC_S_INPUT32        _IOWR('V', 39, s32)
#define VIDIOC_G_OUTPUT32       _IOR ('V', 46, s32)
#define VIDIOC_S_OUTPUT32       _IOWR('V', 47, s32)

/**
 * alloc_userspace() - Allocates a 64-bits userspace pointer compatible
 *      for calling the native 64-bits version of an ioctl.
 *
 * @size:       size of the structure itself to be allocated.
 * @aux_space:  extra size needed to store "extra" data, e.g. space for
 *              other __user data that is pointed to fields inside the
 *              structure.
 * @new_p64:    pointer to a pointer to be filled with the allocated struct.
 *
 * Return:
 *
 * if it can't allocate memory, either -ENOMEM or -EFAULT will be returned.
 * Zero otherwise.
 */
static int alloc_userspace(unsigned int size, u32 aux_space,
                           void __user **new_p64)
{
        *new_p64 = compat_alloc_user_space(size + aux_space);
        if (!*new_p64)
                return -ENOMEM;
        if (clear_user(*new_p64, size))
                return -EFAULT;
        return 0;
}

/**
 * do_video_ioctl() - Ancillary function with handles a compat32 ioctl call
 *
 * @file: pointer to &struct file with the file handler
 * @cmd: ioctl to be called
 * @arg: arguments passed from/to the ioctl handler
 *
 * This function is called when a 32 bits application calls a V4L2 ioctl
 * and the Kernel is compiled with 64 bits.
 *
 * This function is called by v4l2_compat_ioctl32() when the function is
 * not private to some specific driver.
 *
 * It converts a 32-bits struct into a 64 bits one, calls the native 64-bits
 * ioctl handler and fills back the 32-bits struct with the results of the
 * native call.
 */
static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
        void __user *p32 = compat_ptr(arg);
        void __user *new_p64 = NULL;
        void __user *aux_buf;
        u32 aux_space;
        int compatible_arg = 1;
        long err = 0;

        /*
         * 1. When struct size is different, converts the command.
         */
        switch (cmd) {
        case VIDIOC_G_FMT32: cmd = VIDIOC_G_FMT; break;
        case VIDIOC_S_FMT32: cmd = VIDIOC_S_FMT; break;
        case VIDIOC_QUERYBUF32: cmd = VIDIOC_QUERYBUF; break;
        case VIDIOC_G_FBUF32: cmd = VIDIOC_G_FBUF; break;
        case VIDIOC_S_FBUF32: cmd = VIDIOC_S_FBUF; break;
        case VIDIOC_QBUF32: cmd = VIDIOC_QBUF; break;
        case VIDIOC_DQBUF32: cmd = VIDIOC_DQBUF; break;
        case VIDIOC_ENUMSTD32: cmd = VIDIOC_ENUMSTD; break;
        case VIDIOC_ENUMINPUT32: cmd = VIDIOC_ENUMINPUT; break;
        case VIDIOC_TRY_FMT32: cmd = VIDIOC_TRY_FMT; break;
        case VIDIOC_G_EXT_CTRLS32: cmd = VIDIOC_G_EXT_CTRLS; break;
        case VIDIOC_S_EXT_CTRLS32: cmd = VIDIOC_S_EXT_CTRLS; break;
        case VIDIOC_TRY_EXT_CTRLS32: cmd = VIDIOC_TRY_EXT_CTRLS; break;
        case VIDIOC_DQEVENT32: cmd = VIDIOC_DQEVENT; break;
        case VIDIOC_OVERLAY32: cmd = VIDIOC_OVERLAY; break;
        case VIDIOC_STREAMON32: cmd = VIDIOC_STREAMON; break;
        case VIDIOC_STREAMOFF32: cmd = VIDIOC_STREAMOFF; break;
        case VIDIOC_G_INPUT32: cmd = VIDIOC_G_INPUT; break;
        case VIDIOC_S_INPUT32: cmd = VIDIOC_S_INPUT; break;
        case VIDIOC_G_OUTPUT32: cmd = VIDIOC_G_OUTPUT; break;
        case VIDIOC_S_OUTPUT32: cmd = VIDIOC_S_OUTPUT; break;
        case VIDIOC_CREATE_BUFS32: cmd = VIDIOC_CREATE_BUFS; break;
        case VIDIOC_PREPARE_BUF32: cmd = VIDIOC_PREPARE_BUF; break;
        case VIDIOC_G_EDID32: cmd = VIDIOC_G_EDID; break;
        case VIDIOC_S_EDID32: cmd = VIDIOC_S_EDID; break;
        }

        /*
         * 2. Allocates a 64-bits userspace pointer to store the
         * values of the ioctl and copy data from the 32-bits __user
         * argument into it.
         */
        switch (cmd) {
        case VIDIOC_OVERLAY:
        case VIDIOC_STREAMON:
        case VIDIOC_STREAMOFF:
        case VIDIOC_S_INPUT:
        case VIDIOC_S_OUTPUT:
                err = alloc_userspace(sizeof(unsigned int), 0, &new_p64);
                if (!err && assign_in_user((unsigned int __user *)new_p64,
                                           (compat_uint_t __user *)p32))
                        err = -EFAULT;
                compatible_arg = 0;
                break;

        case VIDIOC_G_INPUT:
        case VIDIOC_G_OUTPUT:
                err = alloc_userspace(sizeof(unsigned int), 0, &new_p64);
                compatible_arg = 0;
                break;

        case VIDIOC_G_EDID:
        case VIDIOC_S_EDID:
                err = alloc_userspace(sizeof(struct v4l2_edid), 0, &new_p64);
                if (!err)
                        err = get_v4l2_edid32(new_p64, p32);
                compatible_arg = 0;
                break;

        case VIDIOC_G_FMT:
        case VIDIOC_S_FMT:
        case VIDIOC_TRY_FMT:
                err = bufsize_v4l2_format(p32, &aux_space);
                if (!err)
                        err = alloc_userspace(sizeof(struct v4l2_format),
                                              aux_space, &new_p64);
                if (!err) {
                        aux_buf = new_p64 + sizeof(struct v4l2_format);
                        err = get_v4l2_format32(new_p64, p32,
                                                aux_buf, aux_space);
                }
                compatible_arg = 0;
                break;

        case VIDIOC_CREATE_BUFS:
                err = bufsize_v4l2_create(p32, &aux_space);
                if (!err)
                        err = alloc_userspace(sizeof(struct v4l2_create_buffers),
                                              aux_space, &new_p64);
                if (!err) {
                        aux_buf = new_p64 + sizeof(struct v4l2_create_buffers);
                        err = get_v4l2_create32(new_p64, p32,
                                                aux_buf, aux_space);
                }
                compatible_arg = 0;
                break;

        case VIDIOC_PREPARE_BUF:
        case VIDIOC_QUERYBUF:
        case VIDIOC_QBUF:
        case VIDIOC_DQBUF:
                err = bufsize_v4l2_buffer(p32, &aux_space);
                if (!err)
                        err = alloc_userspace(sizeof(struct v4l2_buffer),
                                              aux_space, &new_p64);
                if (!err) {
                        aux_buf = new_p64 + sizeof(struct v4l2_buffer);
                        err = get_v4l2_buffer32(new_p64, p32,
                                                aux_buf, aux_space);
                }
                compatible_arg = 0;
                break;

        case VIDIOC_S_FBUF:
                err = alloc_userspace(sizeof(struct v4l2_framebuffer), 0,
                                      &new_p64);
                if (!err)
                        err = get_v4l2_framebuffer32(new_p64, p32);
                compatible_arg = 0;
                break;

        case VIDIOC_G_FBUF:
                err = alloc_userspace(sizeof(struct v4l2_framebuffer), 0,
                                      &new_p64);
                compatible_arg = 0;
                break;

        case VIDIOC_ENUMSTD:
                err = alloc_userspace(sizeof(struct v4l2_standard), 0,
                                      &new_p64);
                if (!err)
                        err = get_v4l2_standard32(new_p64, p32);
                compatible_arg = 0;
                break;

        case VIDIOC_ENUMINPUT:
                err = alloc_userspace(sizeof(struct v4l2_input), 0, &new_p64);
                if (!err)
                        err = get_v4l2_input32(new_p64, p32);
                compatible_arg = 0;
                break;

        case VIDIOC_G_EXT_CTRLS:
        case VIDIOC_S_EXT_CTRLS:
        case VIDIOC_TRY_EXT_CTRLS:
                err = bufsize_v4l2_ext_controls(p32, &aux_space);
                if (!err)
                        err = alloc_userspace(sizeof(struct v4l2_ext_controls),
                                              aux_space, &new_p64);
                if (!err) {
                        aux_buf = new_p64 + sizeof(struct v4l2_ext_controls);
                        err = get_v4l2_ext_controls32(file, new_p64, p32,
                                                      aux_buf, aux_space);
                }
                compatible_arg = 0;
                break;
        case VIDIOC_DQEVENT:
                err = alloc_userspace(sizeof(struct v4l2_event), 0, &new_p64);
                compatible_arg = 0;
                break;
        }
        if (err)
                return err;

        /*
         * 3. Calls the native 64-bits ioctl handler.
         *
         * For the functions where a conversion was not needed,
         * compatible_arg is true, and it will call it with the arguments
         * provided by userspace and stored at @p32 var.
         *
         * Otherwise, it will pass the newly allocated @new_p64 argument.
         */
        if (compatible_arg)
                err = native_ioctl(file, cmd, (unsigned long)p32);
        else
                err = native_ioctl(file, cmd, (unsigned long)new_p64);

        if (err == -ENOTTY)
                return err;

        /*
         * 4. Special case: even after an error we need to put the
         * results back for some ioctls.
         *
         * In the case of EXT_CTRLS, the error_idx will contain information
         * on which control failed.
         *
         * In the case of S_EDID, the driver can return E2BIG and set
         * the blocks to maximum allowed value.
         */
        switch (cmd) {
        case VIDIOC_G_EXT_CTRLS:
        case VIDIOC_S_EXT_CTRLS:
        case VIDIOC_TRY_EXT_CTRLS:
                if (put_v4l2_ext_controls32(file, new_p64, p32))
                        err = -EFAULT;
                break;
        case VIDIOC_S_EDID:
                if (put_v4l2_edid32(new_p64, p32))
                        err = -EFAULT;
                break;
        }
        if (err)
                return err;

        /*
         * 5. Copy the data returned at the 64 bits userspace pointer to
         * the original 32 bits structure.
         */
        switch (cmd) {
        case VIDIOC_S_INPUT:
        case VIDIOC_S_OUTPUT:
        case VIDIOC_G_INPUT:
        case VIDIOC_G_OUTPUT:
                if (assign_in_user((compat_uint_t __user *)p32,
                                   ((unsigned int __user *)new_p64)))
                        err = -EFAULT;
                break;

        case VIDIOC_G_FBUF:
                err = put_v4l2_framebuffer32(new_p64, p32);
                break;

        case VIDIOC_DQEVENT:
                err = put_v4l2_event32(new_p64, p32);
                break;

        case VIDIOC_G_EDID:
                err = put_v4l2_edid32(new_p64, p32);
                break;

        case VIDIOC_G_FMT:
        case VIDIOC_S_FMT:
        case VIDIOC_TRY_FMT:
                err = put_v4l2_format32(new_p64, p32);
                break;

        case VIDIOC_CREATE_BUFS:
                err = put_v4l2_create32(new_p64, p32);
                break;

        case VIDIOC_PREPARE_BUF:
        case VIDIOC_QUERYBUF:
        case VIDIOC_QBUF:
        case VIDIOC_DQBUF:
                err = put_v4l2_buffer32(new_p64, p32);
                break;

        case VIDIOC_ENUMSTD:
                err = put_v4l2_standard32(new_p64, p32);
                break;

        case VIDIOC_ENUMINPUT:
                err = put_v4l2_input32(new_p64, p32);
                break;
        }
        return err;
}

/**
 * v4l2_compat_ioctl32() - Handles a compat32 ioctl call
 *
 * @file: pointer to &struct file with the file handler
 * @cmd: ioctl to be called
 * @arg: arguments passed from/to the ioctl handler
 *
 * This function is meant to be used as .compat_ioctl fops at v4l2-dev.c
 * in order to deal with 32-bit calls on a 64-bits Kernel.
 *
 * This function calls do_video_ioctl() for non-private V4L2 ioctls.
 * If the function is a private one it calls vdev->fops->compat_ioctl32
 * instead.
 */
long v4l2_compat_ioctl32(struct file *file, unsigned int cmd, unsigned long arg)
{
        struct video_device *vdev = video_devdata(file);
        long ret = -ENOIOCTLCMD;

        if (!file->f_op->unlocked_ioctl)
                return ret;

        if (_IOC_TYPE(cmd) == 'V' && _IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
                ret = do_video_ioctl(file, cmd, arg);
        else if (vdev->fops->compat_ioctl32)
                ret = vdev->fops->compat_ioctl32(file, cmd, arg);

        if (ret == -ENOIOCTLCMD)
                pr_debug("compat_ioctl32: unknown ioctl '%c', dir=%d, #%d (0x%08x)\n",
                         _IOC_TYPE(cmd), _IOC_DIR(cmd), _IOC_NR(cmd), cmd);
        return ret;
}
EXPORT_SYMBOL_GPL(v4l2_compat_ioctl32);