Stack Overflow
Stack Overflow

Questions tagged [user-mode-linux]

User-mode Linux (UML) is a para-virtualized variant of the Linux kernel, which makes it possible to run a complete Linux kernel and application processes as single process on a host Linux system.

The processes in a UML environment are completely isolated from the main system. Often UML is also used to install a so-called "honeypot", with which the security of a computer or network can be tested. Another field of application is testing and bug fixes of software, for example, a version of the Linux kernel.

32 questions
6
votes
2 answers

Is user mode linux (UML) project stopped?

For some educational project I need to work with user-mode-linux (UML). Based on the homepage of UML, it seems that the project was stopped at 2004. However, the author of project was hired by Intel in 2004 to work on UML full-time. Is the project…
Tail of Godzilla
  • 531
  • 1
  • 6
  • 20
4
votes
0 answers

How do I compile a module in User Mode Linux

Having a tough time compiling a module for User Mode Linux. I just need a basic way to compile a very basic module in user mode linux and cannot seem to get it to work. I checked out the how-to on sourceforge for UML but had no luck. Anyone have a…
Zach
  • 343
  • 1
  • 3
  • 9
3
votes
1 answer

Cannot assign "...'": "..." must be a "User" instance

models.py for assistance class AssistanceQuest (models.Model): Customer = models.ForeignKey(settings.AUTH_USER_MODEL,on_delete=models.CASCADE,blank=True,null=False) Status = models.BooleanField(default=False,null=False,blank=False) …
Nicola Migliaccio
  • 45
  • 1
  • 5
3
votes
1 answer

Correct way to exit init in Linux User Mode

I compiled Linux kernel 5.6 in User Mode with my custom initrd, created with following method: mkdir initrd cd initrd mkdir bin dev etc home mnt proc sys usr mknod dev/console c 5 1 with initrd/init.c init file #include #include…
ventaquil
  • 2,780
  • 3
  • 23
  • 48
3
votes
1 answer

Why does call_usermodehelper fail most of the times?

From a kernel module, I am trying to use call_usermodehelper function to execute an executable sha1 which takes a file as argument and writes the SHA1 hash sum of the file to another file (named output). The executable works perfectly. int…
Subin Pulari
  • 193
  • 2
  • 11
2
votes
0 answers

TLB flush on a switch from kernel to user UNIX

I was looking for an answer for this question but didn't find any clear answer. When calling a sys call such as getpid(), while returning from kernel mode to user mode, does the TLB get flushed? My "logic" says yes, in order to prevent the user to…
Asurii
  • 69
  • 6
2
votes
3 answers

How to find out if a function is part of the kernel/user mode?

How can i check if a function is part of the kernel or user space? (or could be both too) Is there any overview over all kernel libs/functions? Working with C in Unix environment. e.g. rand() is pure user space, malloc() is user and kernel space…
Leviathan
  • 928
  • 1
  • 6
  • 15
2
votes
1 answer

MPTCP in user mode

Is there any implementation of MPTCP in user mode, not kernel mode? If no, is there any suggestions to reuse kernel mode source code in user mode? http://www.multipath-tcp.org https://github.com/multipath-tcp/mptcp
k06a
  • 17,755
  • 10
  • 70
  • 110
1
vote
1 answer

Please enter the correct Email and password for a staff account. Note that both fields may be case-sensitive

I complete makemigrations and migrate then create a superuser. After this http://127.0.0.1:8000/admin i try to log in then show this error Please enter the correct Email and password for a staff account. Note that both fields may be…
Motalib Hossain
  • 63
  • 1
  • 9
1
vote
0 answers

Can we bypass the user mode/kernel mode limitation by overriding segment register?

I'm learning interrupt in operating system now and got this question. I know that we cannot directly call system functions in user mode because the CPL in CS is 3 and the DPL of system_call is 0. I'm wondering that if we can just set CPL in CS to 0…
Changda Li
  • 123
  • 1
  • 8
1
vote
0 answers

Direct access to structure task_struct from Usermode as root

I know it is supposed to be used in Kernel Modules. But if I want to pass a pointer to struct task_struct and read the data (for example process name) from it in user mode with root privileges, will it be possible? I want to access raw virtual…
dev
  • 1,119
  • 1
  • 11
  • 34
1
vote
0 answers

Python in Usermode linux

so I managed to use Python in helloworld C program. #include int main(){ printf("This is C\n"); Py_Initialize(); PyRunSimpleString("print('this is python')"); Py_Finalize(); return 1;} I had to sudo apt-get install python-dev and…
alli
  • 11
  • 1
1
vote
1 answer

Calling schedule() inside Linux IRQ

I'm making an emulation driver that requires me to call schedule() in ATOMIC contexts in order to make the emulation part work. For now I have this hack that allows me to call schedule() inside ATOMIC (e.g. spinlock) context: int p_count =…
rnunes
  • 2,785
  • 7
  • 28
  • 56
1
vote
1 answer

How does the user-mode kernel in UML interface with the underlying kernel on the host

In user mode linux (UML) a trace thread annuls system calls made by the user-space process and redirects them to a kernel running in user-space. Now at some point this userspace kernel would require assistance of the host OS. How does the user-mode…
syed
  • 173
  • 3
  • 10
1
vote
2 answers

User Mode Linux - Installing a module error

I am trying to run 'make' on a module in User Mode Linux to install a simple makefile. Here is my make file: obj-m := hello.o KDIR := /lib/modules/$(shell uname -r)/build PWD := $(shell pwd) default: $(MAKE) -C $(KDIR) SUBDIRS=$(PWD)…
Zach
  • 343
  • 1
  • 3
  • 9
1
2 3