Subject: Re: [net-next PATCH v4 1/3] sysctl: refactor integer handling proc code

From: Cong Wang <[email-masked]>
Date: Tue, 16 Feb 2010 21:09:51 +0800

Octavian Purdila wrote:
> On Tuesday 16 February 2010 10:41:07 you wrote:
> 
>>> +static int proc_skip_wspace(char __user **buf, size_t *size)
>>> +{
>>> +     char c;
>>> +
>>> +     while (*size) {
>>> +             if (get_user(c, *buf))
>>> +                     return -EFAULT;
>>> +             if (!isspace(c))
>>> +                     break;
>>> +             (*size)--; (*buf)++;
>>> +     }
>>> +
>>> +     return 0;
>>> +}
>> In lib/string.c we have skip_spaces(), I think we can use it
>> here instead of inventing another one.
>>
> 
> I'm afraid we can't, skip_spaces does not accept userspace buffers.

Well, you need to use copy_from_user() before call it.