Fedora 31 does not shut down
I am using fedora 31 for two days. When i try turn off my laptop, i encounter screen in below and laptop does not shut down. I search this issue but can't fix it. Thanks for help.error screen
View ArticleHow to finding all runnable processes
I'm learning about the scheduler and trying to print all runnable proceeses. So I have written a kernel module that uses the for_each_process macro to iterate over all processes, and prints the ones at...
View ArticleHow 'logcat -b kernel' command dumps the logs on console ? Please explain the...
Please anyone explain the flow of logcat -b kernel command which dumps the kernel logs on console.From which buffer the kernel logs are pulled by logcat?
View ArticleCan't set the IRQ 's trigger type in Linux kernel
I am working a problem in Linux kernel 3.18.20 with RTAI Patch 5.2. I found the frequency of interrupt which my driver had registered was high, about 20us/time.I tried to change its trigger type to see...
View ArticleUsing wait_event_interruptible and wake_up_all together
For a class project involving scheduling processes using blocking and locks, we're supposed to use two kernel functions:int wait_event_interruptible(wait_queue_head_t q, CONDITION); void...
View ArticleWhy define a macro to a function with the same name?
I found the code below in https://github.com/torvalds/linux/blob/master/arch/x86/include/asm/atomic.hstatic __always_inline bool arch_atomic_sub_and_test(int i, atomic_t *v) { return...
View ArticleCan't seem to apt-get update on kali linux [tried many ways
I keep getting such errors: None of these work for me guys, I've tried to change the sources in the sources.list files by enabling one, disabling the other and still no avail, I even tried to connect...
View ArticleClik here to view.
How to see CentOS7 running in VMWare WS serial console output in putty
I am having problems viewing serial console output coming from CentOS7 kernel in putty. Here are my settings:contents of /etc/defaults/grub:GRUB_TIMEOUT=5 GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g'...
View ArticleWhy my Linux has crashed after going to init 1? [closed]
I went to init 1 and then came back to normal but my Linux starts up too slow! also programs run after a long period for example 10 seconds I have to wait. another problem that init 1 made is that my...
View Articlevboxdrv kernel module is not loaded..[redhat 8]
I had followed all of them:https://www.if-not-true-then-false.com/2010/install-virtualbox-with-yum-on-fedora-centos-red-hat-rhel/https://www.binarytides.com/fix-vbox-kernel-driver-error/At the time I...
View ArticleWhere is source code for linux kernel syscall service routines?
My understanding of a syscall (high level) workflow is:User calls libc wrapperwrapper puts syscall number and arguments in the right place, registers or stackwrapper executes syscall or int 0x80...
View ArticleUnderstanding the device tree overlay format
I have a plan to write a module using a custom device tree base on this onecompatible = "allwinner,sun8i-h3"; fragment@0 { target-path = "/aliases"; __overlay__ { spi0 = "/soc/spi@01c68000"; spi1 =...
View ArticleWhy are some of the CPU's counters zeroes in /proc/interrupts [closed]
I am looking at 'cat /proc/interrupts' output and observed that some of the counters are zeroes. Can anyone provide me the reason behind this, is not IO-APIC responsible for sharing the interrupts in...
View ArticleIs it possible to run the rootfs containing kernel and DTB files for a...
Our hardware vendor provides us the yocto based rootfs for a gateway device (ARM softfloat) as a tar file. This file includes kernel image and the DTB files for that board. Is it possible to run this...
View ArticleSPI device passthrough to guest domain (domU) in Xen
I was going through the documentation of xen for device passthrough. From this, i understood that the dom0 doesn't have any control on passthrough of device. However, the modifications to be done to...
View Articleunlinkat_entry_handler, copy_from_user failed: 47
Manufacturer: HP Product Name: ProLiant DL380 Gen9 OS:centos6.3 kernel:4.1.0-15 This error is often reported in my machine system log. What do these misstatements mean？need helpDec 11 18:03:50...
View ArticlePinning user space buffer for DMA from Linux kernel
I'm writing driver for devices that produce around 1GB of data per second. Because of that I decided to map user buffer allocated by application directly for DMA instead of copying through intermediate...
View ArticleRegistering a module_load tracepoint using the exported kernel symbol
While debugging a 3rd party debugging tool, I came across this problematic piece of code:tracepoint_probe_register((struct tracepoint *)kallsyms_lookup_name("__tracepoint_module_load"),...
View ArticleEquivalent of fprintf function in Linux Kernel Module
I am developing a Linux Kernel Module and I need to use an equivalent of fprintf function to print some informations in a file.I wonder if there is an equivalent of this function in kernel mode.Thank you!
View ArticleThe call-back function (scull_read) for read system call of a custum...
This question already has an answer here:cat function calling read() infinite times 3 answersI have written a character device driver to toggle two GPIO pins. For reading the device, callback function...
View Article