Questions tagged [linux-kernel]

This tag is for questions about the internals of the Linux kernel itself - particularly about writing code that runs within the context of the kernel (like kernel modules or drivers). Questions about writing userspace code in Linux should generally be tagged [linux] instead. Since the internals of the Linux kernel are constantly changing, it is helpful to include the precise kernel version(s) that you are interested in.

This tag is for questions about the internals of the Linux kernel itself - particularly about writing code that runs within the context of the kernel (like kernel modules or drivers).

Questions about writing userspace code in Linux should generally be tagged instead. Since the internals of the Linux kernel are constantly changing, it is helpful to include the precise kernel version(s) that you are interested in.

The kernel is a UNIX-like kernel initially created by Linus Torvalds in 1991 and now is maintained by developers around the world.

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17371 questions
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How to customize or remove extra Linux kernel version details shown at boot?

For this kernel version string (displayed on boot): Linux version 3.12.18 (vagrant@vagrant-ubuntu-trusty-64) (gcc version 4.8.2 (Ubuntu 4.8.2-19ubuntu1) ) #1 SMP Thu May 1 18:56:23 UTC 2014 How can the part in bold be removed or customized as part…
Axel Fontaine
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compiling linux kernel with non-gcc

Linux kernel is written for compiling with gcc and uses a lot of small and ugly gcc-hacks. Which compilers can compile linux kernel except gcc? The one, which can, is the Intel Compiler. What minimal version of it is needed for kernel…
osgx
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Linux Kernel Changing Default CPU Scheduler

I am trying to hack the Linux kernel and I am wondering. How can I change the default Linux Process scheduler with another one? And can I just set every processes as a real time process?
Güngör Basa
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Driver CH341 USB Adapter Serial Port or QSerialPort not Works in Linux

The following code works for me correctly in Windows, but Linux does not work. I am using the same PC, both operating systems are installed native. I do not use virtual machine. I need to work on Linux. I have tried in different linux distributions…
Kijam
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Linux kernel makefile cscope target

When I generate Linux kernel cscope database by issuing make cscope I get database file along with a list of files with relative path. This is a problem for me because later on when I attach that external kernel's database in vim editor from…
mesmerizingr
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How to install a bare Linux kernel without any distribution to study it?

I want to study the kernel of Linux without any distribution. I found the LoadLin boatloader of Ms-dos, but i think it works only in older version of windows (windows 95,98, ME). So i need to install the kernel only in my PC if Possible. How I can…
Ahmed Djamel
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How to fix mismatch between kernel and kernel-devel versions in fedora?

I have this preferences: # yum info kernel|grep -E "Name|Version|Release" Name : kernel Version : 3.13.6 Release : 200.fc20 # yum info kernel-devel Installed Packages Name : kernel-devel Arch : i686 Version :…
ZuzEL
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How to set intel_idle.max_cstate=0 to disable c-states?

I would like to disable c-states on my computer. I disabled c-state on BIOS but I don't obtain any result. However, I found an explanation : "Most newer Linux distributions, on systems with Intel processors, use the “intel_idle” driver (probably…
Paquito
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Getting file descriptors and details within kernel space without open()

Could anyone provide the code to overcome this problem? Effectively how do we obtain the struct inode* from kernel level given the file /dev/driver1? Given in user space that: int fd; fd = open("/dev/driver1", O_RDWR | O_SYNC); In Kernel…
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Help writing a DVB driver for OS X

I'm looking at options to access DVB data on OS X. Initially I want to support the EyeTV DTT USB device, but in the long-run I'd like to support a number of popular devices. The problem I have is that there is no standard way of controlling such…
jkp
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Is Linux kernel splice() zero copy?

I know splice() is designed for zero copy and used Linux kernel pipe buffer to achieve that. For example if I wanted to copy data from one file descriptor(fp1) to another file descriptor(fp2), it didn't need to copy data from "kernel space->user…
VTxyer
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Who generate a core dump file? Kernel or glibc?

(Here I'm targeting only Linux) I'm assuming core is generated by the glibc's default signal handler. But if I google most of result says OS generate a core dump. If OS generates core, signal handler will be called first (or) core dumped first?
Arunprasad Rajkumar
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Searching for hidden modules reading virtual kernel memory?

I am currently working on a small LKM that searches for modules which hide themselves inside the kernel-space like some kernel-level-rootkits used to do. Cause kernel-space for a module is allocated via vmalloc() find_module_list() iterates over all…
clumsy
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how does tombstones works in android-kernel

mkdir /data/tombstones 0771 system system symlink /data/tombstones /tombstones mkdir /tombstones/mdm 0771 system system mkdir /tombstones/modem 0771 system system mkdir /tombstones/lpass 0771 system system # For firmwares …
Ravike14
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kmalloc() functionality in linux kernel

I did come across through the LDD book that using the kmalloc we can allocate from high memory. I have one basic question here. 1)But to my knowledge we can't access the high memory directly from the kernel (unless it is mapped to the kernel space…
user52106
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