This can be used by userspace to determine the address size of the running kernel. It frees userspace from having to interpret this information from the UTS machine field. Userspace implementation: https://github.com/util-linux/util-linux/pull/1966 Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx> --- Cc: linux-kernel@xxxxxxxxxxxxxxx To: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> To: "Rafael J. Wysocki" <rafael@xxxxxxxxxx> Cc: "Karel Zak" <kzak@xxxxxxxxxx> Cc: linux-api@xxxxxxxxxxxxxxx --- Documentation/ABI/testing/sysfs-kernel-address_bits | 10 ++++++++++ kernel/ksysfs.c | 9 +++++++++ 2 files changed, 19 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-kernel-address_bits b/Documentation/ABI/testing/sysfs-kernel-address_bits new file mode 100644 index 000000000000..5d09ff84d4d6 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-kernel-address_bits @@ -0,0 +1,10 @@ +What: /sys/kernel/address_bit +Date: May 2023 +KernelVersion: 6.3 +Contact: Thomas Weißschuh <linux@xxxxxxxxxxxxxx> +Description: + The address size of the running kernel in bits. + + Access: Read + +Users: util-linux diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c index 2df00b789b90..0408aab80941 100644 --- a/kernel/ksysfs.c +++ b/kernel/ksysfs.c @@ -51,6 +51,14 @@ static ssize_t cpu_byteorder_show(struct kobject *kobj, } KERNEL_ATTR_RO(cpu_byteorder); +/* address bits */ +static ssize_t address_bits_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%zu\n", sizeof(void *) * 8 /* CHAR_BIT */); +} +KERNEL_ATTR_RO(address_bits); + #ifdef CONFIG_UEVENT_HELPER /* uevent helper program, used during early boot */ static ssize_t uevent_helper_show(struct kobject *kobj, @@ -233,6 +241,7 @@ static struct attribute * kernel_attrs[] = { &fscaps_attr.attr, &uevent_seqnum_attr.attr, &cpu_byteorder_attr.attr, + &address_bits_attr.attr, #ifdef CONFIG_UEVENT_HELPER &uevent_helper_attr.attr, #endif --- base-commit: b6bb9676f2165d518b35ba3bea5f1fcfc0d969bf change-id: 20221221-address-bits-622a8782e73d Best regards, -- Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
