On 05/09/2025 11:05 am, Gerald Elder-Vass wrote:
> diff --git a/xen/common/efi/boot.c b/xen/common/efi/boot.c
> index e12fa1a7ec04..e7e3dffa7ddc 100644
> --- a/xen/common/efi/boot.c
> +++ b/xen/common/efi/boot.c
> @@ -901,6 +901,28 @@ static void __init pre_parse(const struct file *file)
> " last line will be ignored.\r\n");
> }
>
> +static void __init init_secure_boot_mode(void)
> +{
> + static EFI_GUID __initdata gv_uuid = EFI_GLOBAL_VARIABLE;
> + EFI_STATUS status;
> + uint8_t data = 0;
> + UINTN size = sizeof(data);
> + UINT32 attr = 0;
> +
> + status = efi_rs->GetVariable((CHAR16 *)L"SecureBoot", &gv_uuid, &attr,
> + &size, &data);
This turns out to be a MISRA R7.4 violation, complaining about casing a
string literal to a non-const pointer.
The real problem here is that the EFI spec. GetVariable() ought to take
a const CHAR16 *, but doesn't.
We could fix this with:
diff --git a/xen/include/efi/efiapi.h b/xen/include/efi/efiapi.h
index a616d1238aa4..56775d553109 100644
--- a/xen/include/efi/efiapi.h
+++ b/xen/include/efi/efiapi.h
@@ -224,7 +224,7 @@ VOID
typedef
EFI_STATUS
(EFIAPI *EFI_GET_VARIABLE) (
- IN CHAR16 *VariableName,
+ IN const CHAR16 *VariableName,
IN EFI_GUID *VendorGuid,
OUT UINT32 *Attributes OPTIONAL,
IN OUT UINTN *DataSize,
but I fear this might get some objections.
I don't think we want to be deviating every use of GetVariable() for a
problem ultimately outside of our control.
Another option would be to have a wrapper for GetVariable() which does
the cast once, which lets us deviate in one place only.
Thoughts?
~Andrew
