Re: [patch 21/21] Add ioctl support for EMC Symmetrix SubsystemControl I/O
From: Christoph Hellwig
Date: Wed Oct 01 2008 - 07:03:18 EST
> +static int dasd_symm_io(struct dasd_device *device, void __user *argp)
> +{
> + struct dasd_symmio_parms usrparm;
> + char *psf_data, *rssd_result;
> + struct dasd_ccw_req *cqr;
> + struct ccw1 *ccw;
> + int rc;
> +
> + /* Copy parms from caller */
> + rc = copy_from_user(&usrparm, argp, sizeof(usrparm)) ? -EFAULT : 0;
> + if (rc)
> + goto out;
That style is quite odd, what about the more normal
rc = -EFAULT;
if (copy_from_user(&usrparm, argp, sizeof(usrparm)))
goto out;
instead?
> + /* alloc I/O data area */
> + psf_data = kzalloc(usrparm.psf_data_len, GFP_KERNEL | GFP_DMA);
> + rssd_result = kzalloc(usrparm.rssd_result_len, GFP_KERNEL | GFP_DMA);
> + if (!psf_data || !rssd_result) {
> + rc = -ENOMEM;
> + goto out_free;
> + }
just check each on individually and do individual unwinding. Makes the
code a little more easily readable.
> + /* get syscall header from user space */
> + rc = copy_from_user(psf_data,
> + (void __user *)(unsigned long) usrparm.psf_data,
> + usrparm.psf_data_len) ? -EFAULT : 0;
> + if (rc)
> + goto out_free;
Same as the first copy_from_user
> + rc = copy_to_user((void __user *)(unsigned long) usrparm.rssd_result,
> + rssd_result, usrparm.rssd_result_len) ? -EFAULT : 0;
And here again.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/