Re: [PATCH v3 08/19] pc-bios/s390-ccw: Remove panics from ECKD IPL path

[Thomas Huth]

On 10/10/2024 03.37, Jared Rossi wrote:
> On 10/9/24 6:53 AM, Thomas Huth wrote:
> > On 08/10/2024 03.15, jrossi@linux.ibm.com wrote:
> > > [snip...]
> >
> > load_eckd_segments() returns a value of type block_number_t which is an 
> > unsigned type, so returning a negative error value will likely not work as 
> > expected...
> >
> > ...
> > > @@ -317,21 +352,28 @@ static void run_eckd_boot_script(block_number_t 
> > > bmt_block_nr,
> > >             do {
> > >               block_nr = load_eckd_segments(block_nr, ldipl, &address);
> > > -        } while (block_nr != -1);
> > > +        } while (block_nr >= 0);
> > [snip...]
>
> There already exists a special block number defined in bootmap.h, 
> NULL_BLOCK_NR 0xffffffffffffffffULL. Therefore I would propose simply adding 
> another as ERROR_BLOCK_NR 0xfffffffffffffffeULL.
>
> ERROR_BLOCK_NR would replace the negative error codes and NULL_BLOCK_NR 
> would represent expected end of chunk.  Does this seem reasonable?

Sounds like a good idea.

Alternatively, you could do casting to signed long here and there, but 
that's ugly, too.

 Thomas