[PATCH] efi: Constify sysfs attributes

From: Ard Biesheuvel

Date: Wed Oct 07 2026 - 11:53:32 EST


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>
---
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)
{
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);

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);
}

-extern __weak struct kobj_attribute efi_attr_fw_vendor;
-extern __weak struct kobj_attribute efi_attr_runtime;
-extern __weak struct kobj_attribute efi_attr_config_table;
-static struct kobj_attribute efi_attr_fw_platform_size =
- __ATTR_RO(fw_platform_size);
+extern __weak const struct kobj_attribute efi_attr_fw_vendor;
+extern __weak const struct kobj_attribute efi_attr_runtime;
+extern __weak const struct kobj_attribute efi_attr_config_table;
+static const struct kobj_attribute efi_attr_fw_platform_size =
+ __KOBJ_ATTR_RO(fw_platform_size);

-static struct attribute *efi_subsys_attrs[] = {
+static const struct attribute *const efi_subsys_attrs[] = {
&efi_attr_systab.attr,
&efi_attr_fw_platform_size.attr,
&efi_attr_fw_vendor.attr,
@@ -178,15 +178,16 @@ static struct attribute *efi_subsys_attrs[] = {
NULL,
};

-umode_t __weak efi_attr_is_visible(struct kobject *kobj, struct attribute *attr,
+umode_t __weak efi_attr_is_visible(struct kobject *kobj,
+ const struct attribute *attr,
int n)
{
return attr->mode;
}

static const struct attribute_group efi_subsys_attr_group = {
- .attrs = efi_subsys_attrs,
- .is_visible = efi_attr_is_visible,
+ .attrs_const = efi_subsys_attrs,
+ .is_visible_const = efi_attr_is_visible,
};

struct blocking_notifier_head efivar_ops_nh;
@@ -401,12 +402,15 @@ static void __init efi_debugfs_init(void)
static inline void efi_debugfs_init(void) {}
#endif

-static ssize_t efi_runtime_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+static ssize_t efi_runtime_show(struct kobject *kobj,
+ const struct kobj_attribute *attr,
+ char *buf)
{
return sprintf(buf, "%d\n", efi_enabled(EFI_RUNTIME_SERVICES));
}

-static ssize_t efi_runtime_store(struct kobject *kobj, struct kobj_attribute *attr,
+static ssize_t efi_runtime_store(struct kobject *kobj,
+ const struct kobj_attribute *attr,
const char *buf, size_t count)
{
int ret;
@@ -424,8 +428,8 @@ static ssize_t efi_runtime_store(struct kobject *kobj, struct kobj_attribute *at
return count;
}

-static struct kobj_attribute efi_runtime_attr =
- __ATTR(runtime_enable, 0644, efi_runtime_show, efi_runtime_store);
+static const struct kobj_attribute efi_runtime_attr =
+ __KOBJ_ATTR(runtime_enable, 0644, efi_runtime_show, efi_runtime_store);

static int __init efipostcore_init(void)
{
diff --git a/include/linux/efi.h b/include/linux/efi.h
index ecb34be37a87..fda81d7c4850 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -1353,7 +1353,8 @@ bool efi_config_table_is_usable(const efi_guid_t *guid, unsigned long table)
return xen_efi_config_table_is_usable(guid, 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);

int ovmf_log_probe(unsigned long ovmf_debug_log_table);

--
2.56.0.360.g66cac248cb-goog