How to implement the refcount in the file handle struct?
I have an assignment which asks for implementing some files related syscalls as well as the structures needed to make them work (i.e. file table and file handle).This is my implementation of the...
View ArticleJava process not respoding but resuming after I do a thread dump with jstack -F
I have an weird issue with a Java process which is stuck (once/twice per day) and it only recovers after I execute:jstack -F ${PID}While the Java process is stuck, If I try to do a thread dump with...
View Articleactive/inactive list in linux kernel
Where can I get active/inactive page lists inside Linux kernel which is maintained for memory management?Basically I want to dump these lists' info periodically, so I could understand which pages are...
View ArticleReading memory to a file [closed]
I want to be able to write all memory from kernel and user space to a file. My machine is running Linux kernel version 4.18. Is there a straightforward way to read and write kernel memory?
View ArticleYocto project proble with qemu
after running source oe-init-build-env in poky(git of yocto) i run bitbake and i compile everything running smoothly after i do source oe-init-build-env i move into the right folder path and i do...
View ArticleWhat happens to preempted interrupt handler?
I could not find a proper answer for the following questions even in some well written kernel books:They are saying that an ISR can't sleep because its not possible to reschedule an ISR as it is not...
View ArticleHow to prevent Yocto project BadValue error?
After running source oe-init-build-env in poky (Git of yocto), I run bitbake and I compile, everything is running smoothly. After I do source oe-init-build-env, I move into the right folder path and I...
View ArticleReading memory with GDB vmlinux /proc/kcore
I am trying to use gdb to read memory from vmlinux. The exact syntax issudo gdb vmlinux-4.18.0-rc1+ /proc/kcoreI use this file because vmlinux is a symlink to this file.The result is the...
View ArticleInstall Python 3.8 kernel in Google Colaboratory
I try to install a new Python version (3.8) using conda.!wget -O mini.sh https://repo.anaconda.com/miniconda/Miniconda3-py38_4.8.2-Linux-x86_64.sh!chmod +x mini.sh!bash ./mini.sh -b -f -p...
View Articlelinux kernel socket source macro container_of
i was trying to understand how created is socket but i have ran into the problem which i really dont understand. This problem is the code below:static inline struct socket *SOCKET_I(struct inode...
View ArticleLinux driver loading - function name resolving at dynamic linking stage
Let's say I have a Linux driver A, which has a non-static and non-extern function void f(int) declared and defined in driver's .h and .c source code and also gets used in the driver module too; When I...
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How do I create an SVector/SMatrix with a function and arbitrary indices?
The prof demonstrated a 2D Gaussian kernel using an SMatrix (see pic below). I am trying to implement a 1D kernel of arbitrary size in a similar fashion. I have tried code as below and am unable to...
View ArticleWhat does double ampersand do in bpf filter?
I'm reading bpf(berkeley packet filter) core part in linux kernel, and I'm a little bit confused in the following.This is the part of the code:static unsigned int ___bpf_prog_run(u64 *regs, const...
View ArticleWindows kernel driver: How to safely enumerate all modules in a process?
After searching, I didn't find that Microsoft provides a reliable API to do this.I know it is possible to traverse the Peb->Ldr->InLoadOrderModuleList double linked list, but this seems insecure...
View ArticleThread in user-space schedulling dilemma
Recently I've started reading (again) Tanenbaum's 'Modern Operating Systems 4ed' and I am a little stuck in Chapter 2 that discusses processes and threads. Especially I am confused about user-space...
View ArticleAttributeError: module 'matplotlib' has no attribute 'get_data_path' on...
I get the following error when I want to import matplotlib.pyplot on the Visual Studio's jupyter-notebook.---------------------------------------------------------------------------AttributeError...
View ArticleShould the parent process have a pointer to the child or the child have a...
I'm designing a process structure for an operating systems assignment now.Also I'm implementing the sys_fork, sys_waitpid, sys__exit syscalls.I have two options for the design of the process struct:To...
View ArticleBasic- kernel written in basic
I have read somewhere that higher level languages are not good to create kernels, So my question is, Can we make Kernel in Basic, the simplest language?
View ArticleWhy does `nanosleep` need the argument of `req` while kernel has the chance...
As per the documentation(https://lwn.net/Articles/17744/), which says "nanosleep(), which is currently the only user of this mechanism, need only save the wakeup time in the restart block, along with...
View ArticleHow to get shell to a running custom linux container
I am developing a container launcher by referring to https://gist.github.com/zserge/4ce3c1ca837b96d58cc5bdcf8befb80e.When I launch /sbin/init process using the container launcher I get the tty console...
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