The kernel of operating systems popularly known as Linux, or sometimes GNU/Linux.
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Avoiding a buggy kernel version with “Oops” in radeon module
I have exactly the same problem as described here. I can find the same "Oops" messages in /var/log/kern.log. I also have an older Radeon HD (so I have to use the free driver). I downloaded the current ...
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0answers
10 views
How do I write to a __user memory from within the top half of an interrupt handler? [migrated]
I am working on a proprietary device driver. The driver is implemented as a kernel module. This module is then coupled with an user-space process.
It is essential that each time the device generates ...
0
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0answers
15 views
cpupower can't be unable to call hardware when it tries to get the current cpu frequency
I tried cpupower on Archlinux, but it always was unable to call hardware when it tries to get the current cpu frequency.
# cpupower frequncy-info
analyzing CPU 0:
driver: intel_pstate
CPUs which ...
0
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0answers
8 views
Error occured with USB modem
I have MPC8309 Tower Board and connected USB Modem to it and then established Async PPP on Modem, now I started applying ping from different terminal from my laptop by applying nat commands and ...
1
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0answers
8 views
Invalid module format
I try to install a module using this command:
sudo insmod mymod.ko [arg1] [arg2]
but I get this error while loading the module:
insmod: error inserting 'mymod.ko': -1 Invalid module format
my ...
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votes
1answer
11 views
iptables REJECT icmp-admin-prohibited
The iptables man page says:
Using icmp-admin-prohibited with kernels that do not support it will result in a plain DROP instead of REJECT
I have been unsuccessful at finding out at which kernel ...
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0answers
25 views
Linux kernel root= parameter
I'm trying to make a portable distro of linux on a 16MB SD card. I have a 2.4 kernel and extlinux as a bootloader. How can I pass the root= parameter to the kernel that the distro would be still ...
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0answers
27 views
Intermediate programmer seeks comprehensible info on which blobs are included in the Linux kernel, 4.2
I am specifically asking about the kernel included in Ubuntu 15.10 and my technical skills are meek-I can code in C, make system calls, use XCB. I barely know make, don't comprehend GIT.
I cannot ...
1
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0answers
14 views
How to let kernel not run the printk with KERN_DEBUG
I noticed that kernel has different console levels for the printk.
I also noticed this post [1].
I understand that we can change the /proc/sys/kernel/printk to change the printk level for the ...
1
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0answers
22 views
How to trace the life cycle of kernel threads by following creation and switching?
How to trace the life cycle of kernel threads by following creation and switching ?
kernel_thread() and schedule() are the 2 functions I know that but have no idea how to implement it..
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0answers
6 views
How to handle memory obtained by module_param when writing a Linux kernel module? [migrated]
When writing a kernel module for Linux, module_param and its variants can take a string as a module parameter, and the memory space required for that string is allocated behind the scenes without ...
2
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0answers
14 views
Cannot create 16-bit LDT segments on kernel 3.8.11
Running Crossover, I get the warning, Your system does not allow creation of 16-bit LDT segments. I am aware that this was a problem around kernel 3.1.x, but I am on 3.8.11. Also, the fix suggested in ...
2
votes
2answers
24 views
How to get the absolute position (x, y coordinates) of a finger on a touchpad?
Main question: How to get the absolute finger position on the touchpad?
I would like to get the absolute position (x, y coordinates) of a finger on a touchpad? I believe it is possible to extract it ...
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votes
0answers
17 views
Linux Kernel v0.01 source code licensing [migrated]
The source for the Linux kernel v0.01 can easily be found online, however it does not seem to contain a license or any redistribution rules. Is it, therefore, safe to assume that this code is in the ...
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0answers
14 views
what exactly is the role of device driver in the bluetooth stack (bluez or bluedroid)
I have a bluetooth USB dongle and I wish to get a grasp of what the USB device driver that will be assigned to the bluetooth USB dongle will do and which part of the bluetooth stack it will cover.
I ...
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0answers
25 views
using cpu.cfs_quota_us and cpu.cfs_period_us to limit CPU usage
There are 32 cores in a system (2 cpus each 16 cores) and I want to
limit a user to use only 4 cores (100% usage for that 4 cores). There
are two kernel parameter for that according to the manuals:
...
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0answers
13 views
How to call a device's power management methods in another way than during suspend to ram?
Let us consider the e1000e driver for an Ethernet card. This driver provide two power management methods .suspend and .resume to respectively turn off and turn on the card. Those methods are naturally ...
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0answers
24 views
Virtual serial ports /dev/pts
I'm trying to create virtual ports using GSM cmux. It creates virtual ports in /dev/chn 1 2 & 3. Which is linked to /dev/pts 0 1 & 2. But when I list dev directory there is no pts folder and ...
1
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1answer
58 views
Why do the Linux kernel headers contain references to nonexistent headers?
I'm trying to build IBCS (source here) on Ubuntu 15.10 (Linux 4.2.35).
This module is obviously pretty old, because its CONFIG.i386 file gives gcc an option -m486, which doesn't exist anymore, but ...
4
votes
3answers
247 views
Do tmpfs and devtmpfs share the same memory region?
My system disk usage is like this:
# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/rhel-root 50G 39G 12G 77% /
devtmpfs 5.8G 0 5.8G 0% /dev
...
2
votes
1answer
24 views
How to map Linux hard drive identifiers like “sd 3:0:0:0:” to ones like “ata8:”? [duplicate]
In my kernel log, I can see entries like:
[ 0.765510] sd 3:0:0:0: [sdb] 3907029168 512-byte logical blocks: (2.00 TB/1.81 TiB)
and when something fails, it's usually something like:
[ ...
3
votes
1answer
48 views
Unable to compile Linux kernel
I am trying to upgrade my kernel to 4.5 in Linux Mint 17.3, but I get the following error:
Makefile:666: Cannot use CONFIG_CC_STACKPROTECTOR_STRONG: -fstack-protector-strong not supported by compiler
...
9
votes
1answer
99 views
What program(s) is(are) lowering my entropy pool level?
I've made a simple bash script that checks the entropy pool level in /dev/random. I realize that the way I do it, I lower it very slightly at each check (cat /proc/sys/kernel/random/entropy_avail) but ...
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0answers
23 views
Unable to establish PPP on USB dongle?
I have USB Dongle and i am willing to setup ppp through the dongle.
I have done following steps to setup ppp.
1.When i plugged the dongle into Ubuntu 14.04.
It has been detected as the Mass ...
2
votes
1answer
31 views
Difference between architecture and platform in linux kernel
I want to know the difference between architecture and platform in Linux kernel. When I had downloaded the latest kernel tarball, observed that a directory named with arch, it contains different names ...
9
votes
3answers
700 views
How to reduce the size of the initrd when compiling your kernel?
When I compile my own kernel, basically what I do is the following:
I download the sources from www.kernel.org and uncompress it.
I copy my previous .config to the sources and do a make menuconfig ...
1
vote
0answers
16 views
Selinux inode security struct allocation
i'm trying to understand allocation of inode_security_struct in Selinux. I looked for a source code of selinux and there is only one allocation of this struct on line 230 in hooks.c file. This ...
1
vote
1answer
29 views
mkdir under /cgroup creates files along with directories
All this while I have been thinking that mkdir can only create directories. But I am surprised to see that it was able to create files also under some conditions. I recently started working with ...
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votes
0answers
22 views
How to recover content of the file in unix? [duplicate]
I accidentally gave cat >filename instead of cat filename and my content is lost.Now I have only my file,but content is deleted.How to recover the content alone?
Please help me to get back the ...
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votes
1answer
32 views
How to create /usr/src/linux-headers-{version} files
I am trying to compile a custom kernel for Nvidia's Jetson TK1 board, and it seems that as well as the kernel itself (zImage) I will need /usr/src/linux-headers-{version} and /lib/modules/{version}.
...
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2answers
42 views
How can I crash the kernel?
I was writing a system call, done that and its working correctly.
but I'm now looking for a way to crash the kernel somehow, and when does the kernel actually crash? I managed to put some pieces of ...
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0answers
21 views
Linux: Voltage and current regulator framework
When configuring the new 4.5 kernel, several questions arose regarding the "Linux voltage and current regulator framework". Of course I read the config help text and have a clue about what it does, ...
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0answers
61 views
In 4.4.0-kali1-amd64 all application are installed without errors ,but when i double click on the installed one,No response from the Icon at all.
The application that I installed on my Kali rolling are
Google Chrome
Banshee
FlashPeak Slimjet
Wine
Everyone are installed,These are the steps that I followed while installing Google chrome
...
3
votes
0answers
32 views
What process state(s) is counted into cpu time?
Two observations of mine (correct me if wrong):
In the output of time for timing a process,
'User' and 'Sys' come from wait (2) or times (2), depending on the particular system.
In Linux ...
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0answers
41 views
Linux kernel 4.3 has issue with GPU/graphics hardware
I updated to linux kernel 4.3 on Debian Jessie via backports, i.e.
apt-get -t jessie-backports install linux-image-686-pae
on my 32Bit laptop with physical address extension and now, after booting, ...
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0answers
13 views
qemu - linux kernel doesn't recognize the supplied disk image
I'm trying to run Linux kernel on qemu from scratch.
I've started working on a minimal configured kernel (after running make allnoconfig) and trying to configure only the things needed.
So I have an ...
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0answers
12 views
How to trigger kernel driver _exit function [migrated]
I'm testing a driver that I've built into the kernel and would like to verify that my DRIVER_exit command functions as expected. The DRIVER_init command executes automatically during boot, I assume ...
1
vote
0answers
10 views
Delaying a kernel task [migrated]
I am trying to write a kernel module which will delay a certain kernel task by some n seconds if it meets a certain condition.
I have found which tasks meet my condition just fine, and have the pid ...
4
votes
0answers
54 views
Silent disk errors and reliability of Linux swap
My understanding is that hard drives and SSDs implement some basic error correction inside the drive, and most RAID configurations e.g. mdadm will depend on this to decide when a drive has failed to ...
0
votes
1answer
16 views
Where is the kernel source for a cross-complied kernel rpi
I have cross-compiled and installed the Linux kernel with the real-time patch, version 3.18.16-rt13-v7+, on a raspberrypi but then I can't find the current kernel source in /usr/src. Then I tried the ...
1
vote
1answer
34 views
Cannot compile a linux kernel for an ARM board [closed]
I am trying to compile a linux kernel (2.6.32.70) for an ARM board (versatilepb), it is my first steps in embedded linux.
At the end of the compilation, two compressed kernel images are generated ...
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votes
0answers
5 views
What need to be noticed if I call my own syscall functions in entry_64.S [migrated]
I wirte my code based on Linux Kernel 3.14.60. My main purpose is that recording some syscalls and making some rules that prohibit some syscalls.
My new system functions:
int (* ...
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0answers
44 views
No data or clock on BeagleBone Green SPIDEV0
I've recently upgraded to the 26-02-16 Beaglebone Black/Green Debian image (Kernel 4.1.18) on a BeagleBone Green, and am trying to get SPI0 working like it was when I was back on kernel 3.8. I've ...
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0answers
18 views
How do I get a reference to the idle task from within a module? [migrated]
I am using kernel version 3.0. I need to get a reference to the idle task running on the CPU from within a module. In the mainline kernel, you can do this using the function idle_task() declared in ...
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0answers
21 views
CJDNS `Network is unreachable`
I'm not shure if this question belongs here, but anyway. I was trying to run cjdns on my android phone (OnePlus One runnig CyanogenMod 13) (actually tried on several devices), but it ain't working. It ...
2
votes
3answers
95 views
How does Linux kernel find out which process to wake up during interrupt handling?
I was reading the book Linux Kernel Development on Chapter Process Scheduling. On Page 61, section Waking Up, the first paragraph reads:
Waking is handled via wake_up(), which wakes up all the ...
0
votes
1answer
27 views
What is a kernel-source-tree?
What is the Linux kernel source tree?
What does it contain and what is its purpose?
I'm trying to build an external module and the tutorial I'm using says to make sure that a kernel source tree is ...
1
vote
1answer
25 views
SATA ssd drives
I have a question regarding the support for SATA ssd drives in the Linux Kernel.
I read on the internet that one should enable PCI support for proper usage of the sata drives. Could someone please ...
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0answers
8 views
How “ata_for_each_link” and “ata_for_each_dev” macros works in linux kernel?
I am trying to understanding the SATA device enumeration sequence from the ata_piix.c Host controller driver which resides at /driver/ata/ata_piix.c in linux kernel.
During understanding the flow,a ...
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0answers
45 views
Netlink access inside a network namespace
I'm trying set up an IPsec gateway (strongSwan) on a Raspberry Pi 2.
The Pi was already providing a number of services on the LAN using a private IP address.
My initial attempt to turn it into an ...
