laboursonline – MCQs, Mock Tests | Unix/Lunux Linux Mcqs Questions Set 12

The directories of /sys directory

1. are created at system startup when the subsystems register themselves with kobject core
2. are created when any device is connects with the system
3. are created at the time of kernel compilation
4. none of the mentioned

✅ Correct Answer: 1

The directory /sys/block contains

1. sub-directories for each block device
2. symbolic link for each block device only
3. device file for each block device only
4. none of the mentioned

✅ Correct Answer: 1

In sysfs, each represented bus type has two directories named as

1. attributes and kobjects
2. devices and drivers
3. devices and kobjects
4. none of the mentioned

✅ Correct Answer: 2

A device class describes the ____ type of device.

1. physical
2. stuctural
3. functional
4. none of the mentioned

✅ Correct Answer: 3

Which one of the following directory contains every physical device that has been discovered by the bus types registered with the kernel?

1. /sys/devices
2. /sys/bus/devices
3. /devices
4. none of the mentioned

✅ Correct Answer: 1

Which type of devices are peripheral devices?

1. platform devices
2. system devices
3. both system and platform devices
4. none of the mentioned

✅ Correct Answer: 2

Which one of the following is not a system device?

1. CPU
2. APIC
3. Timer
4. None of the mentioned

✅ Correct Answer: 4

Which one of the following is not a platform specific code?

1. x86 BIOS
2. EFI on ia64
3. both x86 BIOS and EFI on ia64
4. none of the mentioned

✅ Correct Answer: 4

In device driver model bus_type object contains the

1. name of the bus type
2. name of the bus type
3. set of kobjects of the devices
4. all of the mentioned

✅ Correct Answer: 4

The file fs/sysfs/sysfs.h contains the

1. internal header files for sysfs
2. function definitions will not shared locally among the sysfs source
3. all of the mentioned
4. none of the mentioned

✅ Correct Answer: 1

Sysfs is initialised in ______ file via sysfs_init function.

1. fs/sysfs/mount.c
2. sysfs/mount.c
3. fs/mount.c
4. none of the mentioned

✅ Correct Answer: 1

Kernel objects are exported as _____ via sysfs.

1. regular files
2. symbolic links
3. directories
4. none of the mentioned

✅ Correct Answer: 3

Sysfs internally stores the pointer to the ____ that implements the directory in the file system.

1. kobjects
2. kstructures
3. kinodes
4. none of the mentioned

✅ Correct Answer: 1

Attributes can be exported for objects in the form of _______ in the file system.

1. regular files
2. directories
3. symbolic links
4. none of the mentioned

✅ Correct Answer: 1

In sysfs every subsystem has

1. a shared attribute structure
2. its own attribute structure
3. a shared & own attribute structure
4. none of the mentioned

✅ Correct Answer: 2

sysfs is based on

1. rootfs
2. ramfs
3. initramfs
4. none of the mentioned

✅ Correct Answer: 2

Which one of the following is a notification to user space from the kernel that something has changed in the system’s configuration?

1. hotplug event
2. module event
3. attach event
4. none of the mentioned

✅ Correct Answer: 1

In the device driver model the device_driver object contains the

1. name of the device driver
2. embedded kobjects
3. method for probing a device
4. all of the mentioned

✅ Correct Answer: 4

A ____ is a higher level view of a device that abstracts out low level implementation details/

1. inode
2. class
3. major number
4. minor number

✅ Correct Answer: 2

When a device is removed from the system

1. files and directories of that device in the sysfs are removed automatically
2. all the files of sysfs are preserved until the system turn offs
3. it does not create any change in the sysfs
4. none of the mentioned

✅ Correct Answer: 1

Relationship between components of device driver models are expressed in the sysfs as

1. a directory
2. a regular file
3. symbolic links between files and directories
4. none of the mentioned

✅ Correct Answer: 3

What is the main role of the regular files in the sysfs?

1. regular files represent the attributes of devices and drivers
2. regular files represent the kernel objects
3. regular files represent the kernel sets
4. none of the mentioned

✅ Correct Answer: 1

The core data structure of device driver model is

1. kobject
2. kfile
3. kmodule
4. none of the mentioned

✅ Correct Answer: 1

The kset contains

1. pointer to subsystem descriptor
2. pointer to the kobject type descriptor of the kset
3. head of the kobjects included in the kset
4. all of the mentioned

✅ Correct Answer: 4

Which one of the following is a read-write semaphore in linux that protects all ksets and kobjects included in the filesystem?

1. rwsem
2. rwsemaphore
3. rws
4. none of the mentioned

✅ Correct Answer: 1

Each device in the device driver model is represented by a _____ object.

1. driver
2. device
3. node
4. none of the mentioned

✅ Correct Answer: 2

Each driver in the device driver model is described by a ______ object.

1. dev_d
2. device_d
3. dev_driver
4. device_driver

✅ Correct Answer: 4

The channel between the processor and devices is called?

1. bus
2. driver
3. class
4. none of the mentioned

✅ Correct Answer: 1

In which directory every kernel module of the system is represented?

1. /sys/kernel
2. /sys/module
3. /sys/kernel/module
4. none of the mentioned

✅ Correct Answer: 3

In sysfs the device drivers of same _____ are expected to provide same functionalities to the user mode application.

1. class
2. kobjects
3. ksets
4. none of the mentioned

✅ Correct Answer: 1

Which one of the following is not true?

1. kobjects are included in a hierarchic organisation
2. kobjects can have a parent
3. kobjects can be included in a kset
4. none of the mentioned

✅ Correct Answer: 4

In sysfs.h which one of the following structure represents the directory entries?

1. struct sysfs_dirent
2. struct sysfs_dir
3. struct sysfs
4. none of the mentioned

✅ Correct Answer: 1

The name pointer of the attribute data structure represents the _____ in sysfs.

1. directory
2. file
3. symbolic link
4. none of the mentioned

✅ Correct Answer: 2

To read/write attribute, which one of the following method is required?

1. show
2. store
3. both show and store
4. none of the mentioned

✅ Correct Answer: 3

Which one of the following is not contained in the kobject data structure?

1. pointer to the kobject type descriptor
2. pointer to the containing kset
3. pointer to the parent kobject
4. none of the mentioned

✅ Correct Answer: 4

The kobjects can be organized in a hierarchical tree by means of

1. ksets
2. kref
3. kref
4. none of the mentioned

✅ Correct Answer: 1

Which one of the following is a element of a kset data structure?

1. pointer to the subsystem descriptor
2. pointer to the kobject type descriptor of the kset
3. pointer to the subsystem descriptor & kobject type descriptor of the kset
4. none of the mentioned

✅ Correct Answer: 3

Which one of the following function is used to add the kobject to sysfs?

1. kobject_add()
2. kobject_register()
3. kobject_init()
4. all of the mentioned

✅ Correct Answer: 4

Which one of the following function is used to create a new attribute?

1. sysfs_create_file()
2. sysfs_attribute
3. both sysfs_create_file() and sysfs_attribute
4. none of the mentioned

✅ Correct Answer: 1

Sysfs attribute should export ____ value per file.

1. one
2. two
3. three
4. four

✅ Correct Answer: 1

The major number identifies the _____ associated with the device.

1. driver
2. protocol
3. port
4. none of the mentioned

✅ Correct Answer: 1

The minor number range should be

1. 0 to 15
2. 0 to 63
3. 0 to 255
4. none of the mentioned

✅ Correct Answer: 3

Which one of the following is not true?

1. dynamic allocation of major numbers is not possible
2. major number can not be shared among drivers
3. dynamic allocation of major numbers is not possible & also major number can not be shared among drivers
4. none of the mentioned

✅ Correct Answer: 3

In linux kernel 2.4, we can have

1. 256 character drivers only
2. 256 block drivers only
3. 256 character drivers and 256 block drivers at the same time
4. none of the mentioned

✅ Correct Answer: 3

In we use a driver for N number of files, then we have to create ____ device files.

1. N
2. 1
3. N-1
4. None of the mentioned

✅ Correct Answer: 1

If we use a driver for various device files, then

1. minor number will be different for every device file
2. minor number will be same for every device file
3. minor number can not be allocated for any device file
4. none of the mentioned

✅ Correct Answer: 1

The connection between the device file and device driver is based on the

1. name of device file
2. number of device file
3. name & number of device file
4. none of the mentioned

✅ Correct Answer: 2

In linux kernel 2.1, the minor numbers were used to

1. represnt the sub-functionalitites of the driver
2. identify the driver
3. represent the device files
4. none of the mentioned

✅ Correct Answer: 1

The kernel identifies the driver with its

1. module
2. major number
3. device file
4. none of the mentioned

✅ Correct Answer: 2

In linux, a device driver can work without the

1. major number
2. minor number
3. device file name
4. none of the mentioned

✅ Correct Answer: 4