Commit 0f5c4c6e authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Rafael J. Wysocki
Browse files

PM / sleep: handle the compat case in snapshot_set_swap_area() 



Use in_compat_syscall to copy directly from the 32-bit ABI structure.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 88a77559

kernel/power/user.c

+22 −32
Original line number Diff line number Diff line
@@ -196,28 +196,44 @@ static ssize_t snapshot_write(struct file *filp, const char __user *buf, 
	return res;

}



struct compat_resume_swap_area {

	compat_loff_t offset;

	u32 dev;

} __packed;



static int snapshot_set_swap_area(struct snapshot_data *data,

		void __user *argp)

{

	struct resume_swap_area swap_area;

	sector_t offset;

	dev_t swdev;



	if (swsusp_swap_in_use())

		return -EPERM;



	if (in_compat_syscall()) {

		struct compat_resume_swap_area swap_area;



		if (copy_from_user(&swap_area, argp, sizeof(swap_area)))

			return -EFAULT;

		swdev = new_decode_dev(swap_area.dev);

		offset = swap_area.offset;

	} else {

		struct resume_swap_area swap_area;



		if (copy_from_user(&swap_area, argp, sizeof(swap_area)))

			return -EFAULT;

		swdev = new_decode_dev(swap_area.dev);

		offset = swap_area.offset;

	}



	/*

	 * User space encodes device types as two-byte values,

	 * so we need to recode them

	 */

	swdev = new_decode_dev(swap_area.dev);

	if (!swdev) {

		data->swap = -1;

		return -EINVAL;

	}

	offset = swap_area.offset;

	data->swap = swap_type_of(swdev, offset, NULL);

	if (data->swap < 0)

		return -ENODEV;
@@ -394,12 +410,6 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd, 
}



#ifdef CONFIG_COMPAT



struct compat_resume_swap_area {

	compat_loff_t offset;

	u32 dev;

} __packed;



static long

snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)

{
@@ -410,33 +420,13 @@ snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 
	case SNAPSHOT_AVAIL_SWAP_SIZE:

	case SNAPSHOT_ALLOC_SWAP_PAGE:

	case SNAPSHOT_CREATE_IMAGE:

	case SNAPSHOT_SET_SWAP_AREA:

		return snapshot_ioctl(file, cmd,

				      (unsigned long) compat_ptr(arg));



	case SNAPSHOT_SET_SWAP_AREA: {

		struct compat_resume_swap_area __user *u_swap_area =

			compat_ptr(arg);

		struct resume_swap_area swap_area;

		mm_segment_t old_fs;

		int err;



		err = get_user(swap_area.offset, &u_swap_area->offset);

		err |= get_user(swap_area.dev, &u_swap_area->dev);

		if (err)

			return -EFAULT;

		old_fs = get_fs();

		set_fs(KERNEL_DS);

		err = snapshot_ioctl(file, SNAPSHOT_SET_SWAP_AREA,

				     (unsigned long) &swap_area);

		set_fs(old_fs);

		return err;

	}



	default:

		return snapshot_ioctl(file, cmd, arg);

	}

}



#endif /* CONFIG_COMPAT */



static const struct file_operations snapshot_fops = {