Linux Kernel Architecture

Chapter 2: Process Management and Scheduling

.uts_ns = &init_uts_ns, \

.mnt_ns = NULL, \

INIT_NET_NS(net_ns) \

INIT_IPC_NS(ipc_ns) \

.user_ns = &init_user_ns, \

}

The UTS Namespace

The UTS namespace can be handled with particularly little effort because it only has to manage simple

quantities and does not require a hierarchical organization. All relevant information is collected in an

instance of the following structure:

<utsname.h>

struct uts_namespace {

struct kref kref;

struct new_utsname name;

};

krefis an embedded reference counter that can be used to track from how many places in the kernel

an instance ofstruct uts_namespaceis used (recall that Chapter 1 provides more information about

the generic framework to handle reference counting). The information proper is contained instruct

new_utsname:

<utsname.h>

struct new_utsname {

char sysname[65];

char nodename[65];

char release[65];

char version[65];

char machine[65];

char domainname[65];

};

The individual strings store the name of the system (Linux...), the kernel release, the machine

name, and so on. The current values can be determined using theunametool, but are also visible in

/proc/sys/kernel/:

wolfgang@meitner>cat /proc/sys/kernel/ostype

Linux

wolfgang@meitner>cat /proc/sys/kernel/osrelease

2.6.24

The initial settings are stored ininit_uts_ns:

init/version.c

struct uts_namespace init_uts_ns = {

...

.name = {

.sysname = UTS_SYSNAME,

.nodename = UTS_NODENAME,

.release = UTS_RELEASE,

.version = UTS_VERSION,