2019-09-01 07:02:14

by Adam Zerella

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

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

Signed-off-by: Adam Zerella <[email protected]>
---
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

2019-09-02 07:56:48

by Jan Beulich

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

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