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

[Cong Wang]

Octavian Purdila wrote:
> On Tuesday 16 February 2010 15:09:51 you wrote:
> > 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.
>
> And how much would you copy? You need to either use a stack buffer and do a 
> loop copy or you would need to copy the whole userspace buffer which means we 
> need to allocate a kernel buffer. I think its much cleaner the way is currently 
> done.

Yeah, maybe just a personal preference. :-/

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