Re: + sysctl-add-proc_dointvec_unsigned-handler.patch added to -mm tree

[Alexey Dobriyan <adobriyan@gmail.com>]

On Tue, Mar 08, 2011 at 01:43:31PM +0800, Dave Young wrote:
> On Tue, Mar 8, 2011 at 1:15 PM, Dave Young <hidave.darkstar@gmail.com> wrote:
> > On Tue, Mar 8, 2011 at 7:26 AM, Alexey Dobriyan <adobriyan@gmail.com> wrote:
> >> On Mon, Mar 07, 2011 at 03:05:43PM -0800, akpm@linux-foundation.org wrote:
> >>> Add a proc_dointvec_unsigned() sysctl handler for positive value cases.
> >>
> >>> --- a/kernel/sysctl.c~sysctl-add-proc_dointvec_unsigned-handler
> >>> +++ a/kernel/sysctl.c
> >>
> >>> +int proc_dointvec_unsigned(struct ctl_table *table, int write,
> >>> +               void __user *buffer, size_t *lenp, loff_t *ppos)
> >>> +{
> >>> +     struct do_proc_dointvec_minmax_conv_param param = {
> >>> +             .min = &zero,
> >>> +     };
> >>> +     return do_proc_dointvec(table, write, buffer, lenp, ppos,
> >>> +                             do_proc_dointvec_minmax_conv, &param);
> >>> +}
> >>
> >> This silently ignored max value in .extra2 .
> >
> > Hi,
> >
> > Good cache, should set .max = NULL here
> 
> Oh, c99 set default value to 0, isn't it?
> 
> What do you mean silently ignore here?
> 
> Let's see the code:
> 
>  if ((param->min && *param->min > val) ||
>                     (param->max && *param->max < val))
>                     return -EINVAL;
> 
> There's no problem max == NULL

I mean literally "silently ignore".

Try
	{
		.name = "foo",
		.data = &foo,
		.maxlen = sizeof(foo),
		.proc_handler = proc_dointvec_unsigned,
		.extra2 = &_42,
	}