Questions tagged [linux-kernel]

This tag is for questions about the internals of the Linux kernel itself - particularly about use or configuration of kernel modules or drivers.

Filter by
Sorted by
Tagged with
1 vote
1 answer
360 views

Cannot create Security Association in CentOS 7.4 using Setkey

I've been asked to migrate from CentOS 6.8 to 7.4 on all of our Linux devices. I'm running into an issue with loading Security Associations into the Linux kernel. I'm using ipsec-tools' ...
dutsnekcirf's user avatar
2 votes
1 answer
10k views

How to Turn Off KPTI to Improve Performance in Fedora

Following the outbreak of KPTI news, I recently updated my kernel to 4.14.11-300. In addition to a quite sufficient RAM (8 GB) and fast IO (SSD disk), I have started to feel remarkable slowdown in my ...
Mehdi Haghgoo's user avatar
0 votes
1 answer
187 views

Dynamic or virtual file content, similar to /sys/*

Imagine you wanted a file - for example /etc/hosts - but every time the file was read, rather than reading it from the filesystem, its contents were the output of an application - for example a script ...
user208769's user avatar
1 vote
0 answers
662 views

Slow command execution time in linux

We experience some slow simple command execution time in Linux, possibly related to procfs slowness. Like simple uptime command can take few seconds to execute. Here are the inputs: Platform: AWS ...
Sergey Pronin's user avatar
0 votes
1 answer
660 views

Does kernel compiling depends on DTS files

I am trying to build a custom Linux kernel. However I don't understand whether compilation is affected by DTS files under "arch/<...>/boot/dts" or it's only up to the bootloader to pass parameters (...
SOFuser's user avatar
0 votes
0 answers
157 views

How to understand this crash dump

This a sample crash dump I have from the unit. Could anyone help me in understanding what these details mean? Example: [<c406dde4>] (sys_init_module+0x0/0x1878) from [<c400dd00>] (...
Ravi's user avatar
  • 113
35 votes
7 answers
124k views

VirtualBox Ubuntu Guest Additions not installing : modprobe vboxsf failed

I just installed this software off virtual box, i downloaded the ISO off the official ubuntu website, was the lastest LTS. I attempted to install Guest Additions using the 'Insert Guest Additions CD ...
Apthos's user avatar
  • 451
0 votes
1 answer
361 views

Configure built-in modules in cross-compiled linux

I'm in the beginning stages of using a cross compiler (ELDK) to build an embedded Linux system from the kernel source. The Kernel is built successfully with make ARCH=powerpc CROSS_COMPILE=powerpc-...
cstricklan's user avatar
1 vote
1 answer
3k views

GRUB doesn't show all kernels

I installed 16.04 over 14.04. $ lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 16.04.3 LTS Release: 16.04 Codename: xenial The problem is that old ...
bendyna's user avatar
  • 11
1 vote
0 answers
370 views

No TTY Terminal after CENTOS Kernel Upgrade and reboot

have a VPS and recently I installed a new kernel yum history info Loaded plugins: fastestmirror Transaction ID : 17 Begin time : Wed Sep 13 18:52:31 2017 Begin rpmdb : 326:...
4ndr0m3d4's user avatar
0 votes
0 answers
1k views

USB 3 hard drive and card not working in super-speed mode

So, I recently added a USB3 card to my computer, and I thought everything was good, Linux detected it, though weirdly (or not?) it comes up as 2 hubs [ 2.086988] xhci_hcd 0000:07:00.0: xHCI Host ...
spotter's user avatar
  • 101
4 votes
2 answers
2k views

Enable serial system console in runtime

There is Linux kernel boot option to enable system console, the console=, for example, console=ttyS0,115200 or console=ttyS0,115200n8 http://www.linuxtopia.org/online_books/linux_kernel/...
osgx's user avatar
  • 6,807
2 votes
2 answers
5k views

Forcing Ping to Egress When Destination Interface is Local (Debian)

I am running a Debian-based Linux container under Proxmox 4.4. This host has five network interfaces (though only two come into play in the problem I'm having). While I am shelled into this host, I ...
Dave's user avatar
  • 1,019
1 vote
4 answers
2k views

Is there any Linux command that I can use to show all the network interfaces except ifconfig

I have to set up a network connection on a Arch Linux install (in Virtualbox) and I need to know what network interfaces I’m using. How can I do this without using ifconfig?
user18297's user avatar
  • 451
0 votes
1 answer
118 views

Ubuntu 16.04 hanging VPS server

I have a weird issue with a VPS server I am using for a personal project. The server started hanging at 10:40 yesterday The last line from /var/log/syslog before hanging was: ^@^@^@^@^@^@^@^@^@^@^@^@...
Boggio's user avatar
  • 158
1 vote
1 answer
309 views

What is the hardware source of Kernel Clock?

According to docs of my South Bridge (ICH9M) it has 4 HPET. How should I found interrupt line, from which System Clock (aka Kernel Clock, Software Clock) is derived? Seems that it is LOC, but which ...
Dzmitry Sankouski's user avatar
0 votes
1 answer
122 views

Where to report issues about "genkernel all" not selecting reasonable defaults?

genkernel states that bugs ought not to be reported against genkernel after a failure like drivers/scsi/aha1542.c: In function ‘aha1542_interrupt’: drivers/scsi/aha1542.c:306:3: error: implicit ...
Kalle Richter's user avatar
0 votes
0 answers
3k views

ubuntu doesn't treat touchscreen input as touch (just left click)

I have a ThinkPad X230T with multitouch-screen, and Ubuntu treats multitouch inputs as just 'clicks'. Here's my xinputs outout: ⎡ Virtual core pointer id=2 [master pointer (...
user2899136's user avatar
0 votes
2 answers
222 views

Creating a Linux installation on external SSD with both 32 and 64 bit boot options

So, my old 60G SSD now lives in an external USB enclosure. I want to install Linux in it, but I want to have the option to run on older hardware if necessary, so I would like to have both 32 and 64-...
Esa's user avatar
  • 123
1 vote
1 answer
2k views

UNMET DEPENDENCIES in parrot 3.6?

i tried some solutions from the web to solve but of no vain. please help how i can solve the issue. sudo apt-get upgrade [sudo] password for harry: Reading package lists... Done Building dependency ...
hardeep's user avatar
  • 83
2 votes
2 answers
2k views

Is it possible to run a process in chroot with virtual /proc filesystem under Linux?

I need to run a process in a chroot with a virtual /proc filesystem, so the process is unable to get access to other processes running on the same host. The process must be run under root and have ...
user4674453's user avatar
21 votes
4 answers
92k views

How to view all boot messages in Linux after booting?

Relevant questions are: Where Linux places the messages of boot? Name of log file where boot process is logged However, these do not answer this question. This question is concerned with how all ...
AttributedTensorField's user avatar
2 votes
1 answer
5k views

Latest version of parrot security os?

I recently updated my parrot security os and it got upgraded to version 3.5 cyberGalleon. But in the parrot website downloads the latest version is 3.4.1. is the 3.5 cyberGalleon with kernel 4.9.0 ...
hardeep's user avatar
  • 83
0 votes
1 answer
1k views

Where is the source code for the classic init system?

I know that systemd and SysVinit have their own projects and are developed independent of the Linux kernel. But what about the classic init system? where its source code located? is it part of the ...
feeling_lonely's user avatar
1 vote
0 answers
3k views

Kworker thread has high CPU usage

I have a kworker thread with high cpu usage, which is causing my touchscreen to be very lag-y and unresponsive. Running a beaglebone with Debian. uname -r 4.1.15-ti-rt-r43 pid user pr ni ...
avelampudi's user avatar
0 votes
1 answer
422 views

How can I safely delete the old kernel version from the /boot partition on Ubuntu?

I am not so into Linux and I have the following problem related to the fact that my /boot partition seems to be full and it seems to cause a problem trying to install a program. I am using Ubuntu ...
AndreaNobili's user avatar
  • 7,161
0 votes
2 answers
427 views

Specific kernel version needed by elrepo on CentOS5

I can not install elrepo in an updated CentOS 5 system. This is the error we get when we tried to install it: [root@static ~]# rpm -Uvh http://www.elrepo.org/elrepo-release-5-5.el5.elrepo.noarch.rpm ...
user avatar
2 votes
2 answers
7k views

Fuse file system with “default permission” option

I am new to fuse. I have mounted fuse by the following command. /home/bin/fusexmp /mnt/fuse -o default_permissions -o allow_other -o nonempty -o hard_remove -d Now If I login as "test" user and ...
kayle's user avatar
  • 203
0 votes
1 answer
994 views

Linux recovery mode graphics state Versus the normal graphics state

What does booting to recovery mode then selecting resume normal boot do to the systems graphics? (on linux distributions like Debian) I'd like to know things like: What makes this state "safe". :...
Vencen's user avatar
  • 53
4 votes
1 answer
5k views

Linux kernel make keeps overwriting my .config /dropping changes

I’m trying to build a custom ARM kernel on a BeagleBone black wireless. I’m using this kernel as a start I copied the current .config file (make localmodconfig) and edited it manually to add support ...
rudib's user avatar
  • 178
12 votes
1 answer
5k views

How can I prevent the kernel from limiting TX power as advertised by AP

I am connecting to eduroam over a distance of about 150m using an external 23dBm Antenna and an Ubiquiti SR71-E with an Atheros AR9285 chip. My system is Debian Jessie server - so the connection is ...
Felix's user avatar
  • 121
0 votes
1 answer
691 views

Unable to enable zswap on digitalocean ubuntu 16.04

I'm trying to enable zswap on my digitalocean Ubuntu 16.04 droplet without any luck. I tried to apend zswap.enabled=1 to grub's GRUB_CMD_LINUX_DEFAULT and to GRUB_CMD_LINUX and after that run update-...
valignatev's user avatar
2 votes
0 answers
1k views

How to reduce unmovable and and unevictable pages in linux

We have BBB based custom board and it has 256MB RAM and 4GB of eMMC, We are seeing fragmentation issue on it. And as a part of analysis I wanted understand, what are unmovable( from /proc/pagetypeinfo)...
ART's user avatar
  • 385
1 vote
0 answers
199 views

Linux menuconfig failed

When I configure linux, I come across the following error: [linux-devkit]:/opt/ti-processor-sdk-linux-am335x-evm-03.00.00.04/board-support/linux-4.4.12+gitAUTOINC+3639bea54a-g3639bea54a> make ...
SmallBird's user avatar
0 votes
1 answer
1k views

Odd behaviour with Unevictable cache (Linux kernel)

I'm seeing a behaviour I cannot explain on my embedded Linux target (initramfs and no swapping). As there is no swapping, I would expect anything in /tmp (tmpfs) to be flagged unevictable. Instead, I'...
kashikai's user avatar
1 vote
0 answers
33 views

What is the suggested version of oprofile on Linux kernel 3.4?

I want to use the oprofile tool on Linux kernel version 3.4. If I understand correctly, the latest oprofile version is 1.1.0. Is this correct? In one of the articles I saw, 0.9x versions of oprofile ...
Agamanraju's user avatar
1 vote
0 answers
46 views

How do I update my kernel

So I have this kernel source and I need to update the selinux version, in order to make it support android 6.0 the last thing it supported was 4.4, how do I do that? https://github.com/Packmaan7144/...
Jean Reus's user avatar
1 vote
1 answer
104 views

What means this code? [closed]

I cant understand .type and .func in this code. static struct packet_type ip_packet_type __read_mostly = { .type = cpu_to_be16(ETH_P_IP), .func = ip_rcv,}; This is referenced in: net/ipv4/af_inet....
m-tech's user avatar
  • 176
0 votes
1 answer
156 views

What is the path of ip_input.c?

The ip_rcv funcion defined in the ip_input.c file, is responsible for delivering the datagrams to a higher layer protocol or forwarding it to another host. It consists of functions and netfilter hooks ...
m-tech's user avatar
  • 176
0 votes
0 answers
33 views

Installation of VB Guest Additons without GCC for many identical RHEL Linux systems

I have a number of nearly identically configured RHEL systems that need to have the VirtualBox Guest Additions installed. Unfortunately, the installation requires the addition of basically the ...
mdpc's user avatar
  • 4,467
2 votes
0 answers
1k views

Strongswan enable ESP packets hardware acceleration

My Linux kernel already support CESA hardware acceleration, and openssl can use this feature: # openssl speed -evp des3 -elapsed # cat /proc/interrupts | grep cesa 51: 464810 GIC cesa0 ...
code farmer's user avatar
0 votes
0 answers
3k views

Disconnect and close serial port from console so I can use it in my application

Ubuntu 16.04 I need /dev/ttyS0 (serial port) for use in my application. Command: ~$ dmesg | grep tty Response with: [ 0.000000] console [tty0] enabled [ 0.691609] 00:05: ttyS0 at I/O ...
teach me's user avatar
  • 107
0 votes
1 answer
88 views

Newest 4.4 kernal not running after updates?

I was farting around with dpkg on my recently re-installed system, looking for a way to see which packages took up the most space (which had been an issue previously) and discovered the following: $ ...
DrDR's user avatar
  • 330
0 votes
0 answers
529 views

Why would a linux system mount partitions from fstab with one kernel config, but not another?

I have a linux ROM image made by Buildroot with BusyBox init and eudev. The image has an /etc/fstab, which mounts /dev/mmcblk0p1 at /boot, and /dev/mmcblk0p2 at /mnt/var.rw (the upper filesystem for /...
jakogut's user avatar
  • 101
32 votes
1 answer
65k views

Enable user namespaces in Debian kernel

I'm trying to figure out how to enable user namespaces capability in my kernel (I think CAP_SYS_USER_NS). I'm using Debian Stretch, kernel 4.6.0-1-amd64. My assumption is there is a way to turn on ...
Senrabdet's user avatar
  • 321
1 vote
0 answers
673 views

What is the minimum amount of RAM required to run Linux Kernel in ARM cortex-a5?

I want to know what is the minimum amount of RAM required to run Linux Kernel (4.6) in ARM cortex-a5. Now I am using 32MB PSRAM but whenever I am loading vmlinux (elf format) through debugger to ...
Anindya's user avatar
  • 19
0 votes
1 answer
182 views

Is Kali Linux 2 broken?

This might be just on my part but I really doubt that. I'm running it in persistence from USB, the most notable problems come when trying to login as root, can't it just acknowledges test and even the ...
user601334's user avatar
1 vote
0 answers
693 views

Kernel panic not syncing attempting to kill init

We have a Citrix Xenserver 6.2 install. Today we had an incident where power to the server was suddenly cut off from the server. It had been running for quite some time without issue. It has quite a ...
Joe m's user avatar
  • 11
3 votes
2 answers
2k views

Which is the user‑space command for resuming from hibernation?

During a long time, I used echo disk > /sys/power/state In order to hibernate to/dev/sda10and I was using the initrd of my Debian distribution to resume. But recently, I switched to a raid ...
user2284570's user avatar
  • 1,823
1 vote
2 answers
2k views

Which address space is used in system calls? physical? or virtual?

Explanation There’s two kind of address space virtual and physical. On the physical model (typically used by the kernel) the memory is bounded and each address correspond to physical ones. The virtual ...
user2284570's user avatar
  • 1,823

1 2 3
4
5
10