Re: [PATCH] efi: Constify sysfs attributes

[Thomas Weißschuh]

On 2026-10-07 17:51:31+0200, Ard Biesheuvel wrote:
> From: Ard Biesheuvel <ardb@xxxxxxxxxx>
> 
> Implement Thomas's suggestions to constify sysfs kobject attributes.
> 
> Cc: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
> Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>

Thanks! But some remarks.

> ---
>  arch/x86/platform/efi/efi.c | 11 ++++---
>  drivers/firmware/efi/efi.c  | 34 +++++++++++---------
>  include/linux/efi.h         |  3 +-
>  3 files changed, 27 insertions(+), 21 deletions(-)
> 
> diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
> index 0c39adb96b91..d8fe93770c2a 100644
> --- a/arch/x86/platform/efi/efi.c
> +++ b/arch/x86/platform/efi/efi.c
> @@ -891,7 +891,7 @@ bool efi_is_table_address(unsigned long phys_addr)
>  
>  #define EFI_ATTR_SHOW(name) \
>  static ssize_t name##_show(struct kobject *kobj, \
> -				struct kobj_attribute *attr, char *buf) \
> +			   const struct kobj_attribute *attr, char *buf) \
>  { \
>  	return sprintf(buf, "0x%lx\n", EFI_FIELD(name)); \
>  }
> @@ -900,11 +900,12 @@ EFI_ATTR_SHOW(fw_vendor);
>  EFI_ATTR_SHOW(runtime);
>  EFI_ATTR_SHOW(config_table);
>  
> -struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor);
> -struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime);
> -struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table);
> +const struct kobj_attribute efi_attr_fw_vendor = __KOBJ_ATTR_RO(fw_vendor);
> +const struct kobj_attribute efi_attr_runtime = __KOBJ_ATTR_RO(runtime);
> +const struct kobj_attribute efi_attr_config_table = __KOBJ_ATTR_RO(config_table);
>  
> -umode_t efi_attr_is_visible(struct kobject *kobj, struct attribute *attr, int n)
> +umode_t efi_attr_is_visible(struct kobject *kobj, const struct attribute *attr,
> +			    int n)

The break looks unnecessary.

>  {
>  	if (attr == &efi_attr_fw_vendor.attr) {
>  		if (efi_enabled(EFI_PARAVIRT) ||
> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
> index e08ce813a3d4..93d6ffd9bc0d 100644
> --- a/drivers/firmware/efi/efi.c
> +++ b/drivers/firmware/efi/efi.c
> @@ -155,21 +155,21 @@ static ssize_t systab_show(struct kobject *kobj,
>  	return str - buf;
>  }
>  
> -static struct kobj_attribute efi_attr_systab = __ATTR_RO_MODE(systab, 0400);
> +static const struct kobj_attribute efi_attr_systab = __ATTR_RO_MODE(systab, 0400);

__KOBJ_ATTR_RO_MODE()

(and the callback prototype)

>  static ssize_t fw_platform_size_show(struct kobject *kobj,
> -				     struct kobj_attribute *attr, char *buf)
> +				     const struct kobj_attribute *attr, char *buf)
>  {
>  	return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32);

This should switch to sysfs_emit() at some point.

>  }

(...)