Re: [PATCH 1/2] lib/string_helpers: Introduce strsplit_u32()

From: Andy Shevchenko
Date: Fri Jul 08 2022 - 11:26:03 EST


On Fri, Jul 8, 2022 at 2:34 PM Péter Ujfalusi
<peter.ujfalusi@xxxxxxxxxxxxxxx> wrote:
> On 08/07/2022 15:30, Andy Shevchenko wrote:
> > On Fri, Jul 08, 2022 at 02:13:14PM +0200, Cezary Rojewski wrote:

...

> > It seems you are missing the (1). The code has checks for the case where you
> > can do get number upfront, it would just require two passes, but it's nothing
> > in comparison of heave realloc().
> >
> > unsigned int *tokens;
> > char *p;
> > int num;
> >
> > p = get_options(str, 0, &num);
> > if (num == 0)
> > // No numbers in the string!
> >
> > tokens = kcalloc(num + 1, sizeof(*tokens), GFP_KERNEL);
> > if (!tokens)
> > return -ENOMEM;
> >
> > p = get_oprions(str, num, &tokens);
> > if (*p)
> > // String was parsed only partially!
> > // assuming it's not a fatal error
> >
> > return tokens;

> This diff is tested and works:

Thanks, Peter!

But at least you can memove() to avoid second allocation.
ideally to refactor that the result of get_options is consumed as is
(it may be casted to struct tokens { int n; u32 v[]; })

...

> Could be made nicer with some brain work put to it, we need strict u32 within the IPC message for the array...

True, it needs to be thought through. But I guess you got the idea of
how to use existing library routines.

--
With Best Regards,
Andy Shevchenko