Re: [Xen-devel] [GRUB2 PATCH v4 3/4 - FOR REVIEW ONLY] multiboot2: Do not pass memory maps to image if EFI boot services are enabled

["Vladimir 'phcoder' Serbinenko" <phcoder@xxxxxxxxx>]

Looks good. Let's give a day for others to comment. Is the second email the version for commit?

On Tuesday, March 15, 2016, Daniel Kiper <daniel.kiper@xxxxxxxxxx> wrote:
> Do not pass memory maps to image if it asked for EFI boot services.
> Main reason for not providing maps is because they will likely be
> invalid. We do a few allocations after filling them, e.g. for relocator
> needs. Usually we do not care as we would already finish boot services.
> If we keep boot services then it is easier to not provide maps. However,
> if image needs memory maps and they are not provided by bootloader then
> it should get them itself just before ExitBootServices() call.
>
> Signed-off-by: Daniel Kiper <daniel.kiper@xxxxxxxxxx>
> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
> ---
> v3 - suggestions/fixes:
>    - improve commit message
>      (suggested by Konrad Rzeszutek Wilk and Vladimir 'phcoder' Serbinenko).
> ---
>  grub-core/loader/multiboot_mbi2.c |   71 ++++++++++++++++++-------------------
>  1 file changed, 35 insertions(+), 36 deletions(-)
>
> diff --git a/grub-core/loader/multiboot_mbi2.c b/grub-core/loader/multiboot_mbi2.c
> index 6c04402..ad1553b 100644
> --- a/grub-core/loader/multiboot_mbi2.c
> +++ b/grub-core/loader/multiboot_mbi2.c
> @@ -390,7 +390,7 @@ static grub_size_t
>  grub_multiboot_get_mbi_size (void)
>  {
>  #ifdef GRUB_MACHINE_EFI
> -  if (!efi_mmap_size)
> +  if (!keep_bs && !efi_mmap_size)
>      find_efi_mmap_size ();
>  #endif
>    return 2 * sizeof (grub_uint32_t) + sizeof (struct multiboot_tag)
> @@ -755,12 +755,13 @@ grub_multiboot_make_mbi (grub_uint32_t *target)
>        }
>    }
>
> -  {
> -    struct multiboot_tag_mmap *tag = (struct multiboot_tag_mmap *) ptrorig;
> -    grub_fill_multiboot_mmap (tag);
> -    ptrorig += ALIGN_UP (tag->size, MULTIBOOT_TAG_ALIGN)
> -      / sizeof (grub_properly_aligned_t);
> -  }
> +  if (!keep_bs)
> +    {
> +      struct multiboot_tag_mmap *tag = (struct multiboot_tag_mmap *) ptrorig;
> +      grub_fill_multiboot_mmap (tag);
> +      ptrorig += ALIGN_UP (tag->size, MULTIBOOT_TAG_ALIGN)
> +       / sizeof (grub_properly_aligned_t);
> +    }
>
>    {
>      struct multiboot_tag_elf_sections *tag
> @@ -776,18 +777,19 @@ grub_multiboot_make_mbi (grub_uint32_t *target)
>        / sizeof (grub_properly_aligned_t);
>    }
>
> -  {
> -    struct multiboot_tag_basic_meminfo *tag
> -      = (struct multiboot_tag_basic_meminfo *) ptrorig;
> -    tag->type = MULTIBOOT_TAG_TYPE_BASIC_MEMINFO;
> -    tag->size = sizeof (struct multiboot_tag_basic_meminfo);
> +  if (!keep_bs)
> +    {
> +      struct multiboot_tag_basic_meminfo *tag
> +       = (struct multiboot_tag_basic_meminfo *) ptrorig;
> +      tag->type = MULTIBOOT_TAG_TYPE_BASIC_MEMINFO;
> +      tag->size = sizeof (struct multiboot_tag_basic_meminfo);
>
> -    /* Convert from bytes to kilobytes.  */
> -    tag->mem_lower = grub_mmap_get_lower () / 1024;
> -    tag->mem_upper = grub_mmap_get_upper () / 1024;
> -    ptrorig += ALIGN_UP (tag->size, MULTIBOOT_TAG_ALIGN)
> -       / sizeof (grub_properly_aligned_t);
> -  }
> +      /* Convert from bytes to kilobytes.  */
> +      tag->mem_lower = grub_mmap_get_lower () / 1024;
> +      tag->mem_upper = grub_mmap_get_upper () / 1024;
> +      ptrorig += ALIGN_UP (tag->size, MULTIBOOT_TAG_ALIGN)
> +       / sizeof (grub_properly_aligned_t);
> +    }
>
>    {
>      struct grub_net_network_level_interface *net;
> @@ -886,27 +888,24 @@ grub_multiboot_make_mbi (grub_uint32_t *target)
>      grub_efi_uintn_t efi_desc_size;
>      grub_efi_uint32_t efi_desc_version;
>
> -    tag->type = MULTIBOOT_TAG_TYPE_EFI_MMAP;
> -    tag->size = sizeof (*tag) + efi_mmap_size;
> -
>      if (!keep_bs)
> -      err = grub_efi_finish_boot_services (&efi_mmap_size, tag->efi_mmap, NULL,
> -                                          &efi_desc_size, &efi_desc_version);
> -    else
>        {
> -       if (grub_efi_get_memory_map (&efi_mmap_size, (void *) tag->efi_mmap,
> -                                    NULL,
> -                                    &efi_desc_size, &efi_desc_version) <= 0)
> -         err = grub_error (GRUB_ERR_IO, "couldn't retrieve memory map");
> +       tag->type = MULTIBOOT_TAG_TYPE_EFI_MMAP;
> +       tag->size = sizeof (*tag) + efi_mmap_size;
> +
> +       err = grub_efi_finish_boot_services (&efi_mmap_size, tag->efi_mmap, NULL,
> +                                            &efi_desc_size, &efi_desc_version);
> +
> +       if (err)
> +         return err;
> +
> +       tag->descr_size = efi_desc_size;
> +       tag->descr_vers = efi_desc_version;
> +       tag->size = sizeof (*tag) + efi_mmap_size;
> +
> +       ptrorig += ALIGN_UP (tag->size, MULTIBOOT_TAG_ALIGN)
> +         / sizeof (grub_properly_aligned_t);
>        }
> -    if (err)
> -      return err;
> -    tag->descr_size = efi_desc_size;
> -    tag->descr_vers = efi_desc_version;
> -    tag->size = sizeof (*tag) + efi_mmap_size;
> -
> -    ptrorig += ALIGN_UP (tag->size, MULTIBOOT_TAG_ALIGN)
> -      / sizeof (grub_properly_aligned_t);
>    }
>
>    if (keep_bs)
> --
> 1.7.10.4


-- 
Regards
Vladimir 'phcoder' Serbinenko

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