Everything about UNIX kernels: development, configuration, compilation, design, etc.
1
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1answer
32 views
net.ipv4.conf.all.mc_forwarding: why is my access denied?
On Debian 12.04 LTS
I am trying to access the key net.ipv4.conf.all.mc_forwarding by doing :
sudo sysctl -w net.ipv4.conf.all.mc_forwarding=1
But every time I am doing this, I get the message
...
3
votes
1answer
79 views
init: is it a user thread or a kernel thread?
init is the first task executed after kernel is loaded, right?
Then who is its owner.
also I can see [swapper/0] [swapper/1] ..... [swapper/7] having pid 0
PID PPID CPU TASK ST %MEM ...
-3
votes
0answers
52 views
What is changed in Linux Kernel comparing to Unix [duplicate]
It is a well known fact that Linux is not Unix. Linus Trovalds wrote the Linux kernel,independently from unix.
Most of the commands used in linux is said to be working in Unix as well. What did ...
1
vote
1answer
16 views
Cannot mount eCryptfs
I tried to install eCryptfs on my server to open an eCryptfs I did on my home computer.
I got these errors.
$ sudo mount -t ecryptfs /home/(place)/enc/ /home/(place)/enc/
Unable to get the ...
5
votes
1answer
60 views
What does the “00:00:00” timestamp mean in kern.log?
I'm looking for causes of a particular problem in kern.log. There are many entries with a 00:00:00 timestamp:
Jun 11 00:00:00 mymachine kernel: [ 0.000000] Initializing cgroup subsys cpusetJun 11 ...
-2
votes
0answers
34 views
Is the tc driver in the Linux Kernel for Thin Clients or Telecine devices? [migrated]
Is the tc driver in the Linux Kernel source code (./drivers/tc) for Thin Clients or Telecine devices? I am wanting to learn the Linux kernel thoroughly.
2
votes
1answer
31 views
How can I prevent drivers from binding USB devices on a certain bus?
I have a setup with two Logitech Unifying receivers, each receiver has a keyboard bound to it. One of the receiver is to be used by the physical machine to which the devices are connected, the other ...
1
vote
1answer
54 views
What is TX status timeout and do I have to worry about it?
Recently, after performing a routine software upgrade, I notice a huge surge in the number of warnings from the kernel that goes like this:
warning kern [10839.717480] phy0 -> rt2800usb_txdone: ...
1
vote
1answer
43 views
Kernelpanic Fedora 18 with kernel 3.9.2-200
Since upgrading to kernel 3.9 I now get this error every time at start up:
BUG: unable to handle kernel NULL pointer dereferences at (null)
IP[<ffff8800ca93bfcd>] 0xffff8800ca93bfcc
PGD 0
...
2
votes
1answer
36 views
using devtmpfs for /dev
I have noticed the following option in the kernel: CONFIG_DEVTMPFS
Device Drivers -> Generic Driver Options -> Maintain devtmpfs to mount at /dev
And I see that it is enabled by default in ...
-1
votes
0answers
62 views
How to be a LINUX Kernel Developer? [closed]
I want to be a linux kernel developer. I am good at C Programming and have knowledge of LINUX Operating system. What should I do to become a good Kernel Developer ?
1
vote
2answers
69 views
Using newest kernel version on an older system
I always compile my own kernel, and therefore I am not reliant on the distribution kernel (in my case Debian). I have always wondered, whether there is an optimal combination of userspace and ...
2
votes
1answer
46 views
Where can I find documentation or source code for udev properties?
Specifically, I've been trying to find what the possible values are for the property UDISKS_PARTITION_FLAGS. It seems to be set to "boot" if the partition has the boot/active flag set, and unset if ...
2
votes
1answer
189 views
Kernel panic in Fedora 18 after updating to kernel-3.9
I'm really a beginner in Linux, I've installed Fedora 18 and did yum update to update my system.
I got a bunch of updates (around 350 MB download), among them is kernel-3.9.4-200.fc18.x86_64.
Now, ...
2
votes
4answers
94 views
How to make sure, that certain functionality (like Alt+Ctrl+F1 switching into tty) is available in havily swapping system?
At the moment, when I accidentally launch application that eats a lot of memory (that causes system to heavily swap), the system become so unresponsive (waiting hours just to see the mouse move/or ...
0
votes
0answers
18 views
Kernel dependency on Grub in LinuxMint
I have several linux OS's on my laptop the main one being Ubuntu which I used to boot the other OS's with. I recently had to reinstall Mint Cinnamon, during the installation grub was installed ...
0
votes
0answers
28 views
Are these memory leaks or is it normal?
I want to find out if there are memory leaks in my kernel.
First log: http://pastebin.com/wD2Bhduz Second log: http://pastebin.com/ZWhr7T7S
Memory increases for example in UDPv6, cfq_io_context, ...
8
votes
1answer
127 views
How do pdflush, kjournald, swapd, etc interoperate?
Recently saw a question that sparked this thought. Couldn't really find an answer here or via the Google machine. Basically, I'm interested in knowing how the kernel I/O architecture is layered. For ...
3
votes
0answers
40 views
What kernel module function gets called, when I say “cat myfile > /dev/sda” [migrated]
I've skimmed through the Linux Kernel Module Programming guide, but can't figure out:
When I say cat image.iso > /dev/sda, will it cause the write function of file_operations structure to be ...
0
votes
2answers
61 views
obtaining kernel build tree
Could anyone explain me what the kernel build tree is?
What files does it include?
How can I obtain it from a cross-compiled kernel source (e.g. 3.4.0)?
1
vote
2answers
54 views
What does longterm mean on kernel.org?
It's fairly easy to understand EOL, mainline and stable kernel, but I'm not sure about longterm here,
What does it mean, or how does it differ from stable kernel?
-1
votes
0answers
38 views
create a /proc symlink
I'm trying to build a module using the method shown in this answer.
Basically I need to create a symlink I got it to build, when I try to load it using insmod I get:
-1 invalid module format
and ...
1
vote
1answer
50 views
compressed and uncompressed kernel on an embedded device
I have been using several different embedded boards that store kernel, init files, filesystem, etc. on partitions of a (micro)SD card. I notice in the example usage or instructions that compressed ...
0
votes
1answer
51 views
building/compiling kernel headers
I am compiling kernel 3.4 and 3.8 for different target devices. I would like to install compat wireless driver which requires kernel header. Could anyone tell me how I can compile/build the kernel ...
1
vote
1answer
108 views
Problem compiling a driver : “No rule to make target”
First of all I am running a CentOS 6.4 installation.
My computer is a laptop and I am trying to install the drivers for my ethernet card, because this week end I lost my ability to connect to the ...
1
vote
1answer
44 views
Virtual mouse driver, possible X11 problems
I created virtual mouse driver according to Essential Linux Device Drivers book. After I wrote coordinates echo x y > /sys/ ... /coordinates into sysfs node, my program generates event packets ...
0
votes
0answers
17 views
Is ZONE_NORMAL mapped on the kernel space only?
In several textbooks I've stumbled upon a strange phrase, that "if the amount of physical RAM available is small, the ZONE_HIGH might not exist at all and all the memory would belong to ZONE_NORMAL".
...
1
vote
1answer
76 views
Excluding kernel modules through /etc/modprobe.d/blacklist.conf does not work
I don't want to load the kernel module nouveau on my debian box at startup, so I put the following in /etc/modprobe.d/blacklist.conf:
blacklist ttm
blacklist drm
blacklist nouveau
I even did a ...
2
votes
1answer
64 views
What is user address space and what is it's purpose?
I am reading about processes. I came across a topic "How a process is created" wherein I encountered the following :-
The process image as viewed by the kernel runs in its own user address space ...
0
votes
1answer
56 views
Assembly files in obj-m list when building kernel modules
I'm trying to build kexec as a module, but I'm running into a weird problem. My obj-m is:
obj-m += kexec.o machine_kexec.o relocate_kernel.o
When I run the makefile, it complains that there's "no ...
1
vote
1answer
68 views
Can kexec be built to a standalone binary, to be used where kexec was not built into the kernel?
I have remote embedded Linux devices I am trying to update to a new kernel without having to physically access. However, the command line options they boot with make one of the MTDs read only - I ...
6
votes
1answer
170 views
How to blacklist a correct bad RAM sector according to MemTest86+ error imdocation?
MemTest86+ (the version included with Ubuntu 13.04) says
Failing address: 002f796c48 - 759.5 MB
What should I specify in the memmap kernel parameter to bypass this area?
I've tried running ...
1
vote
3answers
60 views
What considerations need to be made when choosing the version of kernel for an embedded device?
I have used buildroot to successfully create a kernel, root file system and cross-compilers to enable me to write application code to run on an embedded device. Currently I have no need to write ...
0
votes
1answer
90 views
how to gpio interrupt registering/handling and accessing them from user space in linux [closed]
I am newbie for the linux device drivers please guide me how to do this..
suppose I have connected a switch to one of the controller pin and whenever the switched is press the LED connected to other ...
0
votes
1answer
40 views
debian cannot install kernel source
I want to use debian linux for my laptop again. So I took my old debian 6.0 cds and installed it.
From the last time I know, that I have to build the driver for my Atheros AR8151 Gigabit Ethernet ...
0
votes
0answers
17 views
Nested Linked List in Kernel [closed]
I have a Linux kernel (3.2) module that requires a nested linked list. The main linked list keep track of target programs. For each target program, we need to keep track of another linked list which ...
0
votes
0answers
77 views
*ERROR* timed out waiting for panel to power on
I'm using Ubuntu 13.04 on Asus VX6 (1.8GHz Atom - 2 cores, optimus nVidia ION) with Kernel 3.9.0.
When I start my system I get this error:
[ 15.728106] [drm:intel_enable_lvds] *ERROR* timed out ...
0
votes
0answers
43 views
Decreasing mouse sensitivity at kernel level
I have developed a custom-GUI Server, which runs on virtual console of Linux.For mouse-handling purpose, it reads the mouse device file
/dev/input/mice
and retrieves the event data and updates ...
3
votes
1answer
63 views
Does the vmlinux header contain the length of the kernel image?
I am trying to disassemble a compound file that consists of several parts, one of which is an uncompressed kernel sandwiched between several other files. I am trying to find the exact length of the ...
1
vote
1answer
93 views
Booting encrypted root partion fails after system update
I have a problem booting my Debian Linux server. After a system update, GRUB loads the initrd and the system should ask for the password, but it doesn't. Instead, I get dropped to BusyBox. After ...
2
votes
1answer
47 views
Sign a module after kernel compilation
I've built a kernel in tmpfs, then I rebooted.
Now I see a message when I compile the 3rd party module,
NO SIGN [M] XXXX.ko
How can I get it signed? The key pair generated during rpmbuild is lost ...
-4
votes
2answers
128 views
Why is the UNIX kernel so crucial? [closed]
More specifically, how is the UNIX kernel treated differently from other parts of the Operating System?
0
votes
1answer
36 views
Understanding a XINU system call - getstk.c [closed]
I am having trouble conceptually understanding what is going on towards the end of this system call, and why. I understand the getstk.c method returns the highest memory address of available space, ...
4
votes
1answer
60 views
Making a recovery partition in embedded Linux
I have an Atmel SAM9X system running Angstrom. I am trying to make a recovery partition so when a user holds a button during boot up the recovery partition boots up.
I have modified the bootstrap so ...
7
votes
1answer
252 views
How can I mount filesystems with > 4KB block sizes?
I have a 3TB hard disk pulled out of a WD Mybook Live NAS. The partition table is as follows:
Model: ATA WDC WD30EZRS-11J (scsi)
Disk /dev/sdb: 3001GB
Sector size (logical/physical): 512B/4096B
...
1
vote
2answers
56 views
Does linux modules/drivers belong to kernal space or user space
Some articles say that modules/drivers belong to kernel space as it take part in forming the kernel; (reference: http://www.freesoftwaremagazine.com/articles/drivers_linux)
While others say that ...
0
votes
1answer
52 views
ixgbe: increase rx performance
I have an Intel 82598EB 10GBE NIC.
I need to receive traffic without packet loss.
Data rate is 4-5 Gbps, packet size is 1500-9600 bytes.
I had already configured smb and irq affinity.
I also tried ...
0
votes
0answers
50 views
microphones on apple macbookair1,1
I'm running Linux Ubuntu 12,04 on a mba. I can't make the microphones (neither external nor internal) work.
Speaking with some wise guys, it seems there is a problem with Linux kernel trying to ...
0
votes
0answers
17 views
PID Grabbing Via LSM Hooks
I am grabbing the LSM hooks in my own created module and showing into the securityfs psuedo filesystem which is showing correctly.
The path where these hooks are showing is
...
3
votes
1answer
69 views
How to measure the clock pulse of my computer manually?
My PC has two processors, and I know that each one runs at 1.86 GHz. I have just read about clock cycles and I only have a (very) rough understanding, so I apologize beforehand if my question is so ...
