[PATCH] x86/xen/efi: Fix EFI variable 'name' type conversion

[PATCH] x86/xen/efi: Fix EFI variable 'name' type conversion

[Adam Zerella]

This resolves a type conversion from 'char *' to 'unsigned short'.
and static usage warning as hinted by Sparse.

Signed-off-by: Adam Zerella <adam.zerella@gmail.com>
---
 arch/x86/xen/efi.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/x86/xen/efi.c b/arch/x86/xen/efi.c
index 0d3365cb64de..1d4eff6c6f06 100644
--- a/arch/x86/xen/efi.c
+++ b/arch/x86/xen/efi.c
@@ -118,8 +118,8 @@ static enum efi_secureboot_mode xen_efi_get_secureboot(void)
 	unsigned long size;
 
 	size = sizeof(secboot);
-	status = efi.get_variable(L"SecureBoot", &efi_variable_guid,
-				  NULL, &size, &secboot);
+	status = efi.get_variable((efi_char16_t *)L"SecureBoot",
+				  &efi_variable_guid, NULL, &size, &secboot);
 
 	if (status == EFI_NOT_FOUND)
 		return efi_secureboot_mode_disabled;
@@ -128,8 +128,8 @@ static enum efi_secureboot_mode xen_efi_get_secureboot(void)
 		goto out_efi_err;
 
 	size = sizeof(setupmode);
-	status = efi.get_variable(L"SetupMode", &efi_variable_guid,
-				  NULL, &size, &setupmode);
+	status = efi.get_variable((efi_char16_t *)L"SetupMode",
+				  &efi_variable_guid, NULL, &size, &setupmode);
 
 	if (status != EFI_SUCCESS)
 		goto out_efi_err;
@@ -139,8 +139,8 @@ static enum efi_secureboot_mode xen_efi_get_secureboot(void)
 
 	/* See if a user has put the shim into insecure mode. */
 	size = sizeof(moksbstate);
-	status = efi.get_variable(L"MokSBStateRT", &shim_guid,
-				  NULL, &size, &moksbstate);
+	status = efi.get_variable((efi_char16_t *)L"MokSBStateRT",
+				  &shim_guid, NULL, &size, &moksbstate);
 
 	/* If it fails, we don't care why. Default to secure. */
 	if (status != EFI_SUCCESS)
@@ -158,7 +158,7 @@ static enum efi_secureboot_mode xen_efi_get_secureboot(void)
 	return efi_secureboot_mode_unknown;
 }
 
-void __init xen_efi_init(struct boot_params *boot_params)
+static void __init xen_efi_init(struct boot_params *boot_params)
 {
 	efi_system_table_t *efi_systab_xen;
 
-- 
2.21.0

Re: [Xen-devel] [PATCH] x86/xen/efi: Fix EFI variable 'name' type conversion

[Jan Beulich]

On 01.09.2019 08:58, Adam Zerella wrote:
> This resolves a type conversion from 'char *' to 'unsigned short'.

Could you explain this? There's no ...

> --- a/arch/x86/xen/efi.c
> +++ b/arch/x86/xen/efi.c
> @@ -118,8 +118,8 @@ static enum efi_secureboot_mode xen_efi_get_secureboot(void)
>  	unsigned long size;
>  
>  	size = sizeof(secboot);
> -	status = efi.get_variable(L"SecureBoot", &efi_variable_guid,
> -				  NULL, &size, &secboot);
> +	status = efi.get_variable((efi_char16_t *)L"SecureBoot",
> +				  &efi_variable_guid, NULL, &size, &secboot);

... "char *" resulting as type for L"" type strings, hence there
should be no need for a cast: In fact I consider such casts
dangerous, as they may hide actual problems. To me this looks
more like something that wants fixing in sparse; the compilers,
after all, have no issue with such wide character string literals.

> @@ -158,7 +158,7 @@ static enum efi_secureboot_mode xen_efi_get_secureboot(void)
>  	return efi_secureboot_mode_unknown;
>  }
>  
> -void __init xen_efi_init(struct boot_params *boot_params)
> +static void __init xen_efi_init(struct boot_params *boot_params)
>  {
>  	efi_system_table_t *efi_systab_xen;

If I was a maintainer of this code, I'd request this not be part
of a patch with a title being entirely unrelated to the change.

Jan