Re: [PATCH] comedi: Annotate struct comedi_lrange with __counted_by

[Kees Cook]

On Sun, Oct 01, 2023 at 02:22:17PM -0700, Kees Cook wrote:
> On Sun, Oct 01, 2023 at 02:05:46PM -0700, Kees Cook wrote:
> > On Sun, Oct 01, 2023 at 09:14:02PM +0200, Julia Lawall wrote:
> > > Kees,
> > > 
> > > You can try the following.
> > 
> > Cool! Yeah, this finds the example:
> > 
> > drivers/comedi/drivers/rti800.c:74: struct comedi_lrange: field at offset 0 is the counter for the flex array
> > drivers/comedi/drivers/rti800.c:83: struct comedi_lrange: field at offset 0 is the counter for the flex array
> > drivers/comedi/drivers/rti800.c:92: struct comedi_lrange: field at offset 0 is the counter for the flex array
> > 
> > I'll run it on the whole codebase...
> 
> It found only the struct comedi_lrange instances, but that's good to
> know. :)

On a related note, why doesn't this work?

@allocated@
identifier STRUCT, ARRAY;
expression COUNT;
struct STRUCT *PTR;
identifier ALLOC;
type ELEMENT_TYPE;
@@

        PTR = ALLOC(..., sizeof(\(*PTR\|struct STRUCT\)) +
                         COUNT * sizeof(\(*PTR->ARRAY\|PTR->ARRAY[0]\|ELEMENT_TYPE\)), ...);


minus: parse error: 
  File "alloc.cocci", line 15, column 34, charpos = 485
  around = 'struct',
  whole content =       PTR = ALLOC(..., sizeof(\(*PTR\|struct STRUCT\)) +

if I drop "struct", then it complains about ELEMENT_TYPE...

-Kees

-- 
Kees Cook