[PATCH] efi_loader: access __efi_runtime_start/stop without &

[Heinrich Schuchardt]

On 4/4/24 08:35, Ilias Apalodimas wrote:
> A symbol defined in a linker script (e.g. __efi_runtime_start = .;) is
> only a symbol, not a variable and should not be dereferenced.
> The common practice is either define it as
> extern uint32_t __efi_runtime_start or
> extern char __efi_runtime_start[] and access it as
> &__efi_runtime_start or __efi_runtime_start respectively.
> 
> So let's access it properly since we define it as an array

Thanks for investigating this.

Beyond this patch I guess we should eliminate these duplicate defintions:

include/asm-generic/sections.h:38:extern char __efi_runtime_start[], 
__efi_runtime_stop[];
include/efi_loader.h:348:extern char __efi_runtime_start[], 
__efi_runtime_stop[];

> 
> Signed-off-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
> ---
>   lib/efi_loader/efi_memory.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
> index edfad2d95a1d..98f104390c8d 100644
> --- a/lib/efi_loader/efi_memory.c
> +++ b/lib/efi_loader/efi_memory.c
> @@ -933,8 +933,8 @@ static void add_u_boot_and_runtime(void)
>   	 * Add Runtime Services. We mark surrounding boottime code as runtime as
>   	 * well to fulfill the runtime alignment constraints but avoid padding.
>   	 */
> -	runtime_start = (ulong)&__efi_runtime_start & ~runtime_mask;
> -	runtime_end = (ulong)&__efi_runtime_stop;
> +	runtime_start = (ulong)__efi_runtime_start & ~runtime_mask;

Using (uintptr_t) would make it clearer that we are converting from a 
pointer to an integer type.

Best regards

Heinrich

> +	runtime_end = (ulong)__efi_runtime_stop;
>   	runtime_end = (runtime_end + runtime_mask) & ~runtime_mask;
>   	runtime_pages = (runtime_end - runtime_start) >> EFI_PAGE_SHIFT;
>   	efi_add_memory_map_pg(runtime_start, runtime_pages,