Problem with character device in Linux kernel
I have a problem in my Kernel module, I am writing a module that allows threads from different processes to exchange messages,I am generating different CHRDriver to achieve it. I wrote the skeleton of...
View ArticleNetwork-packets buffering in kernel qdiscs module
I want to buffer output packets originating from a container's network interface.This netlink library file named sch_plug.c https://code.woboq.org/linux/linux/net/sched/sch_plug.c.html looks like it...
View Articlesh: 1: Syntax error: "(" unexpected Getting this error when tries to run a...
Here is my script I don't even know what caused the error so I am posting the whole script.from bs4 import BeautifulSoupimport requestsimport pandas as pdimport timeimport osdef main(): url =...
View Articlewhy does linux kernel (often) hold pointer in unsigned long object
I often see (in Linux kernel for example) that unsigned long is used to hold the pointers. I wonder what is the reason for this given that size of a pointer may be larger than integer type (including...
View ArticleHard time in understanding MODULE_DEVICE_TABLE(usb, id_table) usage
I have a hard time understanding the exact usage of MODULE_DEVICE_TABLE(usb, id_table)AFAIK this will generate the map files that will be used later by modprobe whenever a new device is inserted, it...
View ArticleIs there any possible to write file system like ext4 or btrfs via FUSE? [closed]
I am a little confused about it. Because I feel that the API provided by FUSE is less than the API provided by VFS( Virtual File System), a file system like ext4 cannot be implemented by FUSE.
View ArticleCompile a linux kernel for run a specific program at start
So I've come up with the idea of starting to create my own Linux build (only for fun) but I'm already stuck.I know how to compile the Linux kernel (Although I have never done it) but now I can tell the...
View Articlewhere in the kernel source init_net namespace is populated from skb
We get status of interfaces by /proc/net/dev in the console. I find that /proc/net/dev shows init_net status(tx, rx etc). But I cannot find out where in the kernel source code init_net is populated(tx,...
View Articlestring.h: No such file or directory upon trying to build using kbuild Makefile
I'm trying to send a string to the kernel module from the user space and the kernel returns back the string reversed. I followed a simple example code and added strrev() function in the kernel code...
View ArticleHow to getting symbol address vmalloc_node_range in Centos6
static struct kprobe kp={.symbol_name = "kallsyms_lookup_name",};int get_kallsyms_lookup_name(void){ int ret = register_kprobe(&kp); if(ret < 0){ printk("[err] %s. register_kprobe failed,...
View Articletakes very long time to boot up ubuntu 20.04 [closed]
I upgraded Ubuntu from 18.04 to 20.04. I am experiencing very slow boot up times. It takes about 2+ minutes to fully boot up.I have tried to find the solution but couldn't find it.Log from...
View ArticleIn Linux, how to measure/sampling GPIO pulse width
My board was running ARM Linux. It will be having a GPIO to connect to an input signal, which encodes information with different pulse width but the same period. Say the period is 10ms, and a 2ms...
View ArticleHow to raise max file limit on Linux CentOS 7
This question is asked before but it is still not clear how this works to me. SonarQube fails to start with this messageERROR: [1] bootstrap checks failed [1]: max file descriptors [4096] for...
View ArticleUnknown options when running makefiles for linux kernel building
I'm building a linux kernel on macbook OS X, and the same error happens whenever I run a make command. I've already tried everything I know, including:Check if any packages need to be installed.Create...
View Articlefeh ERROR: Can't open X display, but it is running [closed]
If I run the command feh PPP.jpg in my bash shell it gives this error:feh ERROR: Can't open X display.But it is running.Is there a better way to open images?
View ArticleCan hardware breakpoints (x86 debug registers) at interrupt handler cause...
I was wondering if setting an x86 Debug Register (hardware breakpoint) at interrupt context may cause a double/triple fault?
View ArticleWhich registers are protected from user space in linux?
How can I find out which registers are protected by the Linux kernel to keep user assembly from writing to them?
View ArticleDevice-Tree for eth network based on marvell mv88e6390x crashes Xilinx's...
This is my system's network topology. It relies on Xilinx's Zynq-7000 soc.zynq-7000 'switch0''switch1' (cpu) mv88e6390x mv88e6390x------- --------- ---------| | | | | || gem0|------|p0 p10|-----|p10 ||...
View ArticleWhy is the content of rx_bytes and tx_bytes changing when I'm reading it?
I'm trying to make a code to monitor current network speed by caching the rx_bytes and tx_bytes on /sys/class/net/<interface>/statistics/ and compare them with the current one. But I encounter...
View ArticleWhy mmap still increase disk read? [duplicate]
For Ubuntu 20.04, I use mmap map a disk file(about 4G).The file changed by day, so I have to mmap another file day by day.And I found sometimes(not always), the disk read increase fast although mmap...
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