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Why kernel code change on load? Are pointer addresses change on load?
I took the kernel code from the memory and the zmlinuz (vmlinuz) file from the disk. I decompressed the vmlinuz to elf file and I compared the code sections of the memory and the disk files. I found...
View ArticleDoes Linux 3.1 support Intel Optane?
Does Linux Arch 3.1 support Intel Optane? I have booted kernel 3.1 on SATA. Is there Intel Optane on SATA? Or does Linux 3.1 support any other Optane interface?EDITIt is Arch based Audiophile Linux...
View ArticleHow does Linux kernel flush_write_buffers() work on x86?
The following code is from include/asm-i386/io.h, and it is invoked from dma_map_single(). My understanding is that flush_write_buffers() is supposed to flush CPU memory cache before mapping the memory...
View ArticleError: conflicting types when trying to make a simple syscall
I'm brand new to Linux programming and I'm trying to implement a simple system call loosely following this guide:...
View ArticleWhy I get this error ‘init_task’ undeclared (first use in this function)?
I want to add a moudle to linux; This is my part of my code:1 #include<linux/module.h> 2 #include<linux/kernel.h> 3 #include<linux/init.h> 4 #include<linux/sched.h> 5...
View ArticleHow can I assign the head of a linked list to a pointer in Linux kernel?
I am writing a program for the Linux kernel to implement a linked list and add the date of births of some people. After they are added I need to find the max age and delete that node. To find the node...
View Articleintercept usb packets in linux before they stary getting handled by the kernel
I want to do a project in which my program prevents all usb packets from getting parsed by the kernel (so that as far as the kernel is concerned they don't exist), take those packets and send them to a...
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Why VirtAddr of my LOAD segment in ELF binary shows 0x0000000000000000?
I compiled a hello world C program and this is the file information :hello: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/l, for GNU/Linux 3.2.0,...
View ArticleIdentify DMA memory in /proc/mtrr and /proc/iomem?
I wonder if there is a way to identify memory used for DMA mapping in some proc files, such as mtrr and iomem, or via lspic -vv.In my /proc/mtrr, there is only one uncachable region, and it seems to be...
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Xenserver Goes to dracut shell time to time
I am using Citrix Hypervisor Xenserver 7.5. I have 3 VM running Ubuntu 18.04, Everything is running file except it goes to dracut shell time to time and everything shuts down until I reboot. Anybody...
View ArticleDoes DMA use uncachable memory type?
If so, shouldn't dma_alloc_coherent() tweak PTEs of the allocated pages to ensure they are uncachable (for arch x86)?As a comparison, I can clearly see how ioremap() eventually calls into...
View ArticleCentOS8 overlayfs - operation not supported [closed]
The overlayfs kernel module is not working properly in CentOS8. It seems like a bug but maybe is due to improper usage. Is there any solution?CentOS8.1 uses 4.18.0-147.el8.x86_64 kernel.To reproduce an...
View ArticleHow can I run OV5647_mipi on iMX8QXP
Hi I have iMX8QXP kit and I want to get stream from ov5647 camera.DISTRO = fsl-imx-wayland.My ov5647 camera's pin connected to :MIPI_CSI0_ACM_MCLK_OUT MIPI_CSI0_MCLK_OUT ALT0MIPI_CSI0_CKN...
View ArticleLinux Hooking getdents syscall and hiding files
Forgive my English )I am wanting to learn more about kernel development and I have been curious about the getdents syscall. I thought a good practice would be to try hiding a file. Getdents is the...
View ArticleConflicting Types Error when Creating a System Call in Ubuntu? No Output when...
Just a college student trying to make a simple system call on my kernel in Ubuntu. I've been following this tutorial, but I ran into some problems. I think my error is originating from the...
View ArticleHow do I emulate I2C_RDWR ioctl with the help of I2C_SMBUS ioctl?
The underlying driver on my system does not support I2C_RDWR ioctl. It only supports I2C_SMBUS. My requirement is to support single message I2C_RDWR ioctl with I2C_SMBUS either in user or kernel space....
View ArticleDoes mutex lock put waiting thread to sleep in POSIX API?
We can use mutex lock in POSIX API as follows:/* acquire the mutex lock */ pthread_mutex_lock(&mutex); /* critical section */ /* release the mutex lock */ pthread_mutex_unlock(&mutex); Does...
View ArticlePatch and build only one kernel module (Ubuntu 19)
I'm trying go get work my Boss GT-1 Guitar effect processor in Linux. I have a patch that needs to be applied to a file sound/usb/endpoint.c in kernel source, and recompile kernel. I succeeded in doing...
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Kill Java Proccess And Restart Again [closed]
I recently switch on my system and without starting any application on port 8080.No applications are running, but the system automatically runs by default if I'm killing the PID of 8080 another PID...
View ArticleHow to get the process ID of the program that called a system function
I am writing a small kernel driver that has the job to act as a honeypot and monitor actions taken on a specific file on the system. To start things off, I used the code in this repository, which I...
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