Re: [PATCHv5 03/12] efi/x86: Get full memory map in allocate_e820()

Kirill A. Shutemov
2022-04-27T23:47:23Z

On Wed, Apr 27, 2022 at 10:25:11PM +0200, Borislav Petkov wrote:
> On Mon, Apr 25, 2022 at 06:39:25AM +0300, Kirill A. Shutemov wrote:
> > static efi_status_t allocate_e820(struct boot_params *params,
> > + struct efi_boot_memmap *map,
> > struct setup_data **e820ext,
> > u32 *e820ext_size)
> > {
> > - unsigned long map_size, desc_size, map_key;
> > efi_status_t status;
> > - __u32 nr_desc, desc_version;
> > + __u32 nr_desc;
> >
> > - /* Only need the size of the mem map and size of each mem descriptor */
> > - map_size = 0;
> > - status = efi_bs_call(get_memory_map, &map_size, NULL, &map_key,
> > - &desc_size, &desc_version);
> > - if (status != EFI_BUFFER_TOO_SMALL)
> > - return (status != EFI_SUCCESS) ? status : EFI_UNSUPPORTED;
> > -
> > - nr_desc = map_size / desc_size + EFI_MMAP_NR_SLACK_SLOTS;
> > + status = efi_get_memory_map(map);
> > + if (status != EFI_SUCCESS)
> > + return status;
> >
> > - if (nr_desc > ARRAY_SIZE(params->e820_table)) {
> > - u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table);
> > + nr_desc = *map->map_size / *map->desc_size;
> > + if (nr_desc > ARRAY_SIZE(params->e820_table) - EFI_MMAP_NR_SLACK_SLOTS) {
> > + u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table) +
> > + EFI_MMAP_NR_SLACK_SLOTS;
> >
> > status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size);
> > if (status != EFI_SUCCESS)
> > - return status;
> > + goto out;
>
> Still silly, that label is useless then. Pasting the whole, simplified
> function below.
>
> It looks like it all boils down to propagating the retval up the chain...

Right. That's true. But having goto here makes patch 5/12 a bit cleaner.
I will move the goto there. Is that what you want to see?

--
Kirill A. Shutemov