[PATCH] efi_loader: fix AllocatePages overlap status

[Ilias Apalodimas]

Hi Harsiman,

On Mon, 27 Apr 2026 at 18:05, Harsimran Singh Tungal
<harsimransingh.tungal at arm.com> wrote:
>
> Return EFI_NOT_FOUND for EFI_ALLOCATE_ADDRESS overlap
>
> When efi_allocate_pages() is called with EFI_ALLOCATE_ADDRESS, UEFI
> expects EFI_NOT_FOUND if the requested address range is already
> allocated or unavailable.
>  U-Boot currently returns
> EFI_OUT_OF_RESOURCES when efi_update_memory_map() detects an overlap
> after a successful lmb_alloc_mem(), which does not match
> EFI_ALLOCATE_ADDRESS semantics.
>
> Return EFI_NOT_FOUND for EFI_ALLOCATE_ADDRESS requests that fail due
> to an overlapping EFI memory descriptor, while keeping
> EFI_OUT_OF_RESOURCES for other allocation types.
>
> The UEFI specification [1] specifies that
> EFI_BOOT_SERVICES.AllocatePages must return EFI_NOT_FOUND when the
> requested address range is unavailable or already allocated;
> EFI_OUT_OF_RESOURCES applies to non‑address‑specific allocation
> failures.

Where does the EFI spec say that? EDKII indeed returns EFI_NOT_FOUND
for AllocateAddress but looking at the function description, I can't
find anything specific.

Thanks
/Ilias

>
> [1] https://uefi.org/specs/UEFI/2.10_A/07_Services_Boot_Services.html
>
> Signed-off-by: Harsimran Singh Tungal <harsimransingh.tungal at arm.com>
> ---
>  lib/efi_loader/efi_memory.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
> index b77c2f980cc..63cf1a7277f 100644
> --- a/lib/efi_loader/efi_memory.c
> +++ b/lib/efi_loader/efi_memory.c
> @@ -510,7 +510,9 @@ efi_status_t efi_allocate_pages(enum efi_allocate_type type,
>                 /* Map would overlap, bail out */
>                 lmb_free(addr, (u64)pages << EFI_PAGE_SHIFT, flags);
>                 unmap_sysmem((void *)(uintptr_t)efi_addr);
> -               return  EFI_OUT_OF_RESOURCES;
> +               if (type == EFI_ALLOCATE_ADDRESS)
> +                       return EFI_NOT_FOUND;
> +               return EFI_OUT_OF_RESOURCES;
>         }
>
>         *memory = efi_addr;
> --
> 2.34.1
>