[PATCH] efi_loader: Don't allocate from Special purpose memory

[Heinrich Schuchardt]

On 17.09.24 11:02, Ilias Apalodimas wrote:
> The EFI spec defines special-purpose memory in §7.2. That memory
> serves as a hint to the OS to avoid allocating this memory for core
> OS data or code that can not be relocated. So let's ignore it when
> allocating from conventional memory.
>
> Signed-off-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
> ---
>   lib/efi_loader/efi_memory.c | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
> index c6f1dd09456e..74732e37f8aa 100644
> --- a/lib/efi_loader/efi_memory.c
> +++ b/lib/efi_loader/efi_memory.c
> @@ -422,7 +422,8 @@ static efi_status_t efi_check_allocated(u64 addr, bool must_be_allocated)
>
>   		if (addr >= start && addr < end) {
>   			if (must_be_allocated ^
> -			    (item->desc.type == EFI_CONVENTIONAL_MEMORY))
> +			    (item->desc.type == EFI_CONVENTIONAL_MEMORY) &&
> +			    !(item->desc.attribute & EFI_MEMORY_SP))
>   				return EFI_SUCCESS;
>   			else
>   				return EFI_NOT_FOUND;
> @@ -460,6 +461,9 @@ static uint64_t efi_find_free_memory(uint64_t len, uint64_t max_addr)

Now that Sushosh's LMB patches are merged this function does not exist
anymore.

I think we should next move the EFI memory map to LMB to avoid double
book keeping.

Best regards

Heinrich

>   		if (desc->type != EFI_CONVENTIONAL_MEMORY)
>   			continue;
>
> +		if (desc->attribute & EFI_MEMORY_SP)
> +			continue;
> +
>   		/* Out of bounds for max_addr */
>   		if ((ret + len) > max_addr)
>   			continue;