diff options
| author | Thomas Weißschuh <linux@weissschuh.net> | 2022-12-21 16:17:52 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-01-20 14:30:45 +0100 |
| commit | 00142bfd5a916a0b3899cc709bf8f5042cf3d084 (patch) | |
| tree | 461d76a47c3a81156d5d6a8c9bfc94c5d1350243 | |
| parent | e5da06b27ff5a148e42265c8e306670a9d913969 (diff) | |
kernels/ksysfs.c: export kernel address bits
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@weissschuh.net>
Link: https://lore.kernel.org/r/20221221-address-bits-v1-1-8446b13244ac@weissschuh.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | Documentation/ABI/testing/sysfs-kernel-address_bits | 10 | ||||
| -rw-r--r-- | kernel/ksysfs.c | 9 |
2 files changed, 19 insertions, 0 deletions
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@weissschuh.net> +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 |