pcm_compat.c

linux 内核源代码

struct snd_xferi32 {
	s32 result;
	u32 buf;
	u32 frames;
};

static int snd_pcm_ioctl_xferi_compat(struct snd_pcm_substream *substream,
				      int dir, struct snd_xferi32 __user *data32)
{
	compat_caddr_t buf;
	u32 frames;
	int err;

	if (! substream->runtime)
		return -ENOTTY;
	if (substream->stream != dir)
		return -EINVAL;
	if (substream->runtime->status->state == SNDRV_PCM_STATE_OPEN)
		return -EBADFD;

	if (get_user(buf, &data32->buf) ||
	    get_user(frames, &data32->frames))
		return -EFAULT;

	if (dir == SNDRV_PCM_STREAM_PLAYBACK)
		err = snd_pcm_lib_write(substream, compat_ptr(buf), frames);
	else
		err = snd_pcm_lib_read(substream, compat_ptr(buf), frames);
	if (err < 0)
		return err;
	/* copy the result */
	if (put_user(err, &data32->result))
		return -EFAULT;
	return 0;
}


/* snd_xfern needs remapping of bufs */
struct snd_xfern32 {
	s32 result;
	u32 bufs;  /* this is void **; */
	u32 frames;
};

/*
 * xfern ioctl nees to copy (up to) 128 pointers on stack.
 * although we may pass the copied pointers through f_op->ioctl, but the ioctl
 * handler there expands again the same 128 pointers on stack, so it is better
 * to handle the function (calling pcm_readv/writev) directly in this handler.
 */
static int snd_pcm_ioctl_xfern_compat(struct snd_pcm_substream *substream,
				      int dir, struct snd_xfern32 __user *data32)
{
	compat_caddr_t buf;
	compat_caddr_t __user *bufptr;
	u32 frames;
	void __user **bufs;
	int err, ch, i;

	if (! substream->runtime)
		return -ENOTTY;
	if (substream->stream != dir)
		return -EINVAL;

	if ((ch = substream->runtime->channels) > 128)
		return -EINVAL;
	if (get_user(buf, &data32->bufs) ||
	    get_user(frames, &data32->frames))
		return -EFAULT;
	bufptr = compat_ptr(buf);
	bufs = kmalloc(sizeof(void __user *) * ch, GFP_KERNEL);
	if (bufs == NULL)
		return -ENOMEM;
	for (i = 0; i < ch; i++) {
		u32 ptr;
		if (get_user(ptr, bufptr)) {
			kfree(bufs);
			return -EFAULT;
		}
		bufs[ch] = compat_ptr(ptr);
		bufptr++;
	}
	if (dir == SNDRV_PCM_STREAM_PLAYBACK)
		err = snd_pcm_lib_writev(substream, bufs, frames);
	else
		err = snd_pcm_lib_readv(substream, bufs, frames);
	if (err >= 0) {
		if (put_user(err, &data32->result))
			err = -EFAULT;
	}
	kfree(bufs);
	return err;
}


struct snd_pcm_mmap_status32 {
	s32 state;
	s32 pad1;
	u32 hw_ptr;
	struct compat_timespec tstamp;
	s32 suspended_state;
} __attribute__((packed));

struct snd_pcm_mmap_control32 {
	u32 appl_ptr;
	u32 avail_min;
};

struct snd_pcm_sync_ptr32 {
	u32 flags;
	union {
		struct snd_pcm_mmap_status32 status;
		unsigned char reserved[64];
	} s;
	union {
		struct snd_pcm_mmap_control32 control;
		unsigned char reserved[64];
	} c;
} __attribute__((packed));

static int snd_pcm_ioctl_sync_ptr_compat(struct snd_pcm_substream *substream,
					 struct snd_pcm_sync_ptr32 __user *src)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	volatile struct snd_pcm_mmap_status *status;
	volatile struct snd_pcm_mmap_control *control;
	u32 sflags;
	struct snd_pcm_mmap_control scontrol;
	struct snd_pcm_mmap_status sstatus;
	snd_pcm_uframes_t boundary;
	int err;

	snd_assert(runtime, return -EINVAL);

	if (get_user(sflags, &src->flags) ||
	    get_user(scontrol.appl_ptr, &src->c.control.appl_ptr) ||
	    get_user(scontrol.avail_min, &src->c.control.avail_min))
		return -EFAULT;
	if (sflags & SNDRV_PCM_SYNC_PTR_HWSYNC) {
		err = snd_pcm_hwsync(substream);
		if (err < 0)
			return err;
	}
	status = runtime->status;
	control = runtime->control;
	boundary = recalculate_boundary(runtime);
	if (! boundary)
		boundary = 0x7fffffff;
	snd_pcm_stream_lock_irq(substream);
	/* FIXME: we should consider the boundary for the sync from app */
	if (!(sflags & SNDRV_PCM_SYNC_PTR_APPL))
		control->appl_ptr = scontrol.appl_ptr;
	else
		scontrol.appl_ptr = control->appl_ptr % boundary;
	if (!(sflags & SNDRV_PCM_SYNC_PTR_AVAIL_MIN))
		control->avail_min = scontrol.avail_min;
	else
		scontrol.avail_min = control->avail_min;
	sstatus.state = status->state;
	sstatus.hw_ptr = status->hw_ptr % boundary;
	sstatus.tstamp = status->tstamp;
	sstatus.suspended_state = status->suspended_state;
	snd_pcm_stream_unlock_irq(substream);
	if (put_user(sstatus.state, &src->s.status.state) ||
	    put_user(sstatus.hw_ptr, &src->s.status.hw_ptr) ||
	    put_user(sstatus.tstamp.tv_sec, &src->s.status.tstamp.tv_sec) ||
	    put_user(sstatus.tstamp.tv_nsec, &src->s.status.tstamp.tv_nsec) ||
	    put_user(sstatus.suspended_state, &src->s.status.suspended_state) ||
	    put_user(scontrol.appl_ptr, &src->c.control.appl_ptr) ||
	    put_user(scontrol.avail_min, &src->c.control.avail_min))
		return -EFAULT;

	return 0;
}


/*
 */
enum {
	SNDRV_PCM_IOCTL_HW_REFINE32 = _IOWR('A', 0x10, struct snd_pcm_hw_params32),
	SNDRV_PCM_IOCTL_HW_PARAMS32 = _IOWR('A', 0x11, struct snd_pcm_hw_params32),
	SNDRV_PCM_IOCTL_SW_PARAMS32 = _IOWR('A', 0x13, struct snd_pcm_sw_params32),
	SNDRV_PCM_IOCTL_STATUS32 = _IOR('A', 0x20, struct snd_pcm_status32),
	SNDRV_PCM_IOCTL_DELAY32 = _IOR('A', 0x21, s32),
	SNDRV_PCM_IOCTL_CHANNEL_INFO32 = _IOR('A', 0x32, struct snd_pcm_channel_info32),
	SNDRV_PCM_IOCTL_REWIND32 = _IOW('A', 0x46, u32),
	SNDRV_PCM_IOCTL_FORWARD32 = _IOW('A', 0x49, u32),
	SNDRV_PCM_IOCTL_WRITEI_FRAMES32 = _IOW('A', 0x50, struct snd_xferi32),
	SNDRV_PCM_IOCTL_READI_FRAMES32 = _IOR('A', 0x51, struct snd_xferi32),
	SNDRV_PCM_IOCTL_WRITEN_FRAMES32 = _IOW('A', 0x52, struct snd_xfern32),
	SNDRV_PCM_IOCTL_READN_FRAMES32 = _IOR('A', 0x53, struct snd_xfern32),
	SNDRV_PCM_IOCTL_SYNC_PTR32 = _IOWR('A', 0x23, struct snd_pcm_sync_ptr32),

};

static long snd_pcm_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg)
{
	struct snd_pcm_file *pcm_file;
	struct snd_pcm_substream *substream;
	void __user *argp = compat_ptr(arg);

	pcm_file = file->private_data;
	if (! pcm_file)
		return -ENOTTY;
	substream = pcm_file->substream;
	if (! substream)
		return -ENOTTY;

	/*
	 * When PCM is used on 32bit mode, we need to disable
	 * mmap of PCM status/control records because of the size
	 * incompatibility.
	 */
	pcm_file->no_compat_mmap = 1;

	switch (cmd) {
	case SNDRV_PCM_IOCTL_PVERSION:
	case SNDRV_PCM_IOCTL_INFO:
	case SNDRV_PCM_IOCTL_TSTAMP:
	case SNDRV_PCM_IOCTL_HWSYNC:
	case SNDRV_PCM_IOCTL_PREPARE:
	case SNDRV_PCM_IOCTL_RESET:
	case SNDRV_PCM_IOCTL_START:
	case SNDRV_PCM_IOCTL_DROP:
	case SNDRV_PCM_IOCTL_DRAIN:
	case SNDRV_PCM_IOCTL_PAUSE:
	case SNDRV_PCM_IOCTL_HW_FREE:
	case SNDRV_PCM_IOCTL_RESUME:
	case SNDRV_PCM_IOCTL_XRUN:
	case SNDRV_PCM_IOCTL_LINK:
	case SNDRV_PCM_IOCTL_UNLINK:
		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
			return snd_pcm_playback_ioctl1(file, substream, cmd, argp);
		else
			return snd_pcm_capture_ioctl1(file, substream, cmd, argp);
	case SNDRV_PCM_IOCTL_HW_REFINE32:
		return snd_pcm_ioctl_hw_params_compat(substream, 1, argp);
	case SNDRV_PCM_IOCTL_HW_PARAMS32:
		return snd_pcm_ioctl_hw_params_compat(substream, 0, argp);
	case SNDRV_PCM_IOCTL_SW_PARAMS32:
		return snd_pcm_ioctl_sw_params_compat(substream, argp);
	case SNDRV_PCM_IOCTL_STATUS32:
		return snd_pcm_status_user_compat(substream, argp);
	case SNDRV_PCM_IOCTL_SYNC_PTR32:
		return snd_pcm_ioctl_sync_ptr_compat(substream, argp);
	case SNDRV_PCM_IOCTL_CHANNEL_INFO32:
		return snd_pcm_ioctl_channel_info_compat(substream, argp);
	case SNDRV_PCM_IOCTL_WRITEI_FRAMES32:
		return snd_pcm_ioctl_xferi_compat(substream, SNDRV_PCM_STREAM_PLAYBACK, argp);
	case SNDRV_PCM_IOCTL_READI_FRAMES32:
		return snd_pcm_ioctl_xferi_compat(substream, SNDRV_PCM_STREAM_CAPTURE, argp);
	case SNDRV_PCM_IOCTL_WRITEN_FRAMES32:
		return snd_pcm_ioctl_xfern_compat(substream, SNDRV_PCM_STREAM_PLAYBACK, argp);
	case SNDRV_PCM_IOCTL_READN_FRAMES32:
		return snd_pcm_ioctl_xfern_compat(substream, SNDRV_PCM_STREAM_CAPTURE, argp);
	case SNDRV_PCM_IOCTL_DELAY32:
		return snd_pcm_ioctl_delay_compat(substream, argp);
	case SNDRV_PCM_IOCTL_REWIND32:
		return snd_pcm_ioctl_rewind_compat(substream, argp);
	case SNDRV_PCM_IOCTL_FORWARD32:
		return snd_pcm_ioctl_forward_compat(substream, argp);
	}

	return -ENOIOCTLCMD;
}