Do any operating systems utilize user threads only?
We're reading a basic/simple guide to Operating Systems in my CS class. The text gives multiple examples of OSs that use 1:1 threading, and some that formerly did hybrid/ M:N. But there are no examples...
View ArticleWhat is the order of memory allocation when demand exceeds single numa node
With a 4 numa node linux server(128G each), I was trying to allocate 300G memory by kmalloc_node(2) to specify the allocation start node. Could any great master tell me what is the order of allocation...
View ArticleWhat are the error values for find_get_pid() kernel function?
I am using find_get_pid() call to obtain the struct pid * for a given pid_t pid i.e process id. However I want to include some sanity checks as the pid value will be supplied by a user process, let's...
View ArticleHow to call ntoskrnl.exe srand function?
With dumpbin.exe, we can see that ntoskrnl.exe exports the srand function.With the Windows Driver Kit, how to call this function ? I have already tested with stdlib.h, but I would like to call...
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Register a driver & start it with NtLoadDriver (windows)
I'm trying to load a Kernel Driver on windows using NtLoadDriver in ntdll.I want to do things needed manually to understand the process better:Register the servicemyself and then call NtLoadDriver.I...
View ArticleCreate proc entry in existing dir not possible?
Why it is not possible to create a proc_create_data entry in an existing folder like "/proc/foo/"??this one is fine:parent = proc_mkdir("foo/subfolder", NULL);entry = proc_create_data("myentry", 0444,...
View ArticleWhat do the values in a dissasembler mean?
I created some C code, compiled it, and loaded it in a dissasembler...#include <stdio.h>int main() { // printf() displays the string inside quotation printf("Hello, World!"); return 0;}I compiled...
View Articlechar device catch multiple (int) ioctl-arguments
I have to write a linux char device, which handles ioctl (without BKL) functions per unlock_ioctl. At the moment I can receive one argument from the userspace ioctl command per __get_user(myint, (int...
View ArticleIncreasing serial console suspend time in linux kernel?
I want to increase suspend time for serial console which is approximately 5 mins right now.For disabling the suspend I'm using no_console_suspend in BOARD_KERNEL_CMDLINE. But ultimate goal is to...
View ArticleWhy does behavior of `./example` and `sh example` different? (`zsh: text file...
I tried this:$ exec 3> example$ lsof example COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAMEzsh 10711 lane 3w REG 253,0 0 9231034 exampleIt will show text file busy if I do this:$ ./example zsh:...
View ArticleNumpythonic way for applying convolution kernel
I would like to know if there is another way of applying the kernel using some non-standard numpy function.Complexity is not going to be reduced since the operation involves applying to an image with...
View ArticleHow to run two functions at the same time in C? [closed]
I am creating a kernel in C, and I wanted to make it so that I could run two sets of code or functions at the same time. Is it possible, or is it not?I've seen that there are ways to do it in C, but...
View ArticleFaster alternatives too WINAPI ReadProcessMemory
I am making an application that reads a target process's memory. The memory that I read needs to be as up-to-date as possible, and the total memory read time preferably <1ms (right now I'm hovering...
View ArticleUpdated linux kernel and mount.cifs removes the 'sec=ntlm' option; how do I...
What changed?sudo mount -t cifs //mikes-airport-time-capsule/Data -o username=mike,sec=ntlm,vers=1.0 /media/timecapsuleused to work and now it doesn't. Apparently, a linux kernel update version dated...
View ArticleAccess /proc//ns/pid -> inode number
I am trying to get access to inode number of pid namespace which can be seen using ls -Li /proc/<pid>/ns/mnt or /proc/<pid>/ns/pid.I am a newbie to kernel code, want to know in kernel, from...
View ArticleWhy did QEMU give me the (null) instead of a string?
I am learning OS recently, but I got a problem that QEMU outputs (null) instead of a string what I want when I was debugging the program.The QEMU emulator version is 4.2.1 (Debian 1:4.2-3ubuntu6.18),...
View ArticleWhy does Bochs say "No bootable devices found" when I concatenate a kernel to...
I am following along with this guide in order to try to write my own (very basic) operating system. I have gotten my boot sector to run with Bochs perfectly fine (I've just tested it with writing to...
View ArticleInstall RT Linux patch for Ubuntu
Trying to make my generic Ubuntu to real time Ubuntu by modifying the kernel by patching / installing RT Linux but couldn't find a straight setup. Can someone help with the steps?
View ArticleLinux Kernel Module Development "module: x86/modules: Skipping invalid...
I am currently trying to develop a simple linux kernel module. It should just log something, its 1:1 copied from the internet.I have the following files:lkm_example.c#include...
View ArticleCan I use `strlen()`, `strcpy()`, `strrev()`, `strcmp()` or `strcat()` when...
I am trying to make a kernel which has some functions that print out characters, draw, etc. And these functions will later be linked with assembly. I was wondering if I could still use these...
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