Everything about UNIX kernels: development, configuration, compilation, design, etc.

learn more… | top users | synonyms

1
vote
0answers
48 views

How to find system call implementations in Linux/Android 2.6.29? [duplicate]

Possible Duplicate: Understanding the Linux kernel source I want to modify some system calls for tracing purposes. To be specific, whenever a system call open is made, I want to print some ...
2
votes
2answers
1k views

Automatic kernel configuration tool

Is there any developed automatic linux kernel configuration tool? I have found a method of make localmodconfig, but it is certainly very limited. I have searched the web but unfortunately have not ...
4
votes
3answers
124 views

What is contained in these addresses?

I am working on MUlti-processor record-replay feature of a virtual machine. I have a log of non-deterministic memory access done in the virtual machine by virtual CPUs. A very high proportion of these ...
2
votes
1answer
729 views

Build kernel in one machine, install in another

I want to build my Linux kernel on my host and use it in my VWware virtual machine. They both use the same Ubuntu kernel now. On my Host, I do make and make configure. Then, what files should I copy ...
4
votes
1answer
367 views

Buildroot ignoring configuration files - building wrong kernel

I'm using Buildroot to create a Linux system for the NXP LPC3250 microcontroller. There are patches to the vanilla kernel to make it compatible with the LPC3250 controller: http://git.lpclinux.com/ ...
12
votes
2answers
3k views

Why are the grsecurity patches not included in the Vanilla Kernel?

What are the reasons that grsecurity patches (or the security features it brings) are not included in the kernel by default. When looking at the benefits for security it seems the vanilla kernel is ...
2
votes
1answer
108 views

What does the CONFIG_NLS_UTF8 kernel option do?

The kernel configuration contains an NLS_UTF8 option. It can be found under File systems → Native language support. What does it do? Its description maintains that it is needed for using a FAT or ...
1
vote
0answers
375 views

Unusual vmware.modconfig-console output

Upon running a batch file I created to iterate recursive directories from / trying to find the Kernel headers for vmware-modconfig-console running on openSUSE, when it comes across /usr/include/ it ...
3
votes
1answer
272 views

How can Linux detect automatically if kernel must boot on dev hdc or hda

I have an industrial PC mounting Linux. These PC is delivered in two version, each with slightly different internal board and depending on the board type the disk inside the PC is see as hda or hdc. ...
1
vote
1answer
912 views

Building kernel module

I have a 3rd party device driver which I am trying to cross-compile. When I build the driver everything goes smooth but I don't see any driver.ko file, however driver.o file is generated fine and I ...
2
votes
1answer
598 views

Where is max process size specified?

I've got a RHEL4 machine with 1TB of memory and have discovered that malloc and mmap refuse to allocate any memory above 512GB. Meanwhile, I don't seem to have a problem with RHEL5 machines. I'm ...
1
vote
1answer
49 views

How can I tell if a kernel has some “new” config?

I'm making a simple kernel auto build script, right now I need to detect if there's a new config that need to ask the user (I don't want to use the default value), if so, it launches make menuconfig ...
4
votes
1answer
1k views

How does udev create /dev/sr*? (Or: Which rule does create /dev/sr*?)

udev is responsible for populating /dev. It adds and removes device nodes to /dev dynamically based on rules/configs/scripts under /lib/udev and /etc/udev/. If I have a CDROM device node /dev/sr0 I ...
2
votes
1answer
136 views

No /proc/sys/fs/binfmt_misc/CLR on my system?

I run docky which is programmed with mono so I think the binfmt is running correctly, but proc-sys-fs-binfmt_misc.automount complains about it, since I don't have /proc/sys/fs/binfmt_misc/CLR I ...
1
vote
2answers
859 views

Kernel not detecting multicore cpu

Kernel Version 3.3.4-5.fc17.x86_64 CPU info: sashan@dhcp-au-122 ~ $ cat /proc/cpuinfo processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 42 model name : Intel(R) Core(TM) ...
1
vote
2answers
284 views

Running the linux kernel and Ubuntu on custom processor

This is hardly a theoretical question as many have done this, albeit there's very little information on the underlying processes. I'm developing a custom MIPS-based processor on which I would like to ...
2
votes
1answer
68 views

How is the inherited file descritor vulnerability dealt with in Unices?

Ulrich Drepper describes a vulnerability in programs that have open file descriptors then they fork() and execve() without lots of very careful locking in place. He also talks about new kernel ...
2
votes
2answers
1k views

Why is rcS required after file system is mounted by the kernel?

I am a beginner in embedded Linux, I have compiled the kernel without initramfs and kernel is booting fine. But It shows me rcS file is not found I have put it in /etc/init.d/rcS and my rcS file look ...
2
votes
1answer
686 views

How to skip/exclude one SCSI bus from scanning during boot?

A "Linux debian 3.2.0-0.bpo.3-amd64 #1 SMP Thu Aug 23 07:41:30 UTC 2012 x86_64 GNU/Linux" system has at least 5 SCSI hosts: root@debian:~# ls /sys/class/scsi_host host0 host1 host2 host3 host4 ...
3
votes
1answer
1k views

Linux disk I/O performance issue — what config options to look at?

We discovered an I/O related performance problem when using the default SLES11 SP2 kernel. Our same application on the same hardware had no issue with (the admittedly ancient SLES9 SP3). We had a ...
3
votes
2answers
3k views

Prevent usbhid from claiming USB device

Directly related: Prevent claiming of novelty usb device by usbhid so I can control it with libusb? I want to access an RFID reader (works as HID device) from a program that uses libusb-0.1. In the ...
3
votes
1answer
655 views

Checking linux Kernel for RT-Preempt Patch

How to know whether a particular patch is applied to the kernel? Especially RT-Preempt Patch.
4
votes
2answers
91 views

Is there any sort of online kernel repository or sharing sites (possibly for laptops)

It just seems there should reasonably be something like this considering so many folks run *nix on laptops and laptops have such consistent hardware sets. At a guess I'd imagine there's likely in the ...
2
votes
1answer
837 views

“[sdc] Assuming drive cache: write through” Need to hide this message!

When you plug an external drive into my Ubuntu server this message pops up "[sdc] Assuming drive cache: write through"... I would really like it so it stops sending it to the screen. Any ideas on how ...
1
vote
1answer
855 views

Which “Processor family” to choose under “Processor type and features”?

I have recently compiled a minimal kernel for my Intel(R) Pentium(R) Dual CPU T3400 @ 2.16GHz, and chose CONFIG_MCORE2 (Core 2/newer Xeon) under "Processor type and features > Processor family" I ...
1
vote
3answers
913 views

Why kernel 3.6.2 is so much less energy efficient than 3.6.1 on Mint 13?

I noticed, that the power consumption in my ASUS P53E notebook is doubled (from 10W to 20W) when I change from kernel 3.6.1 to 3.6.2 (or later). I use Ubuntu Quantal mainline kernel from ...
1
vote
1answer
859 views

Apt-Get Install Unmet Dependencies

My debian computer will not install the new kernel. It says I have unmet dependencies, and those dependencies say they have unmet dependencies. Many of these dependencies are already installed ...
1
vote
0answers
401 views

Make and apt-get Have Stopped Working

So I downloaded the non-free broadcom driver(b44) for my debian install, however when I try to make it I get the following error: make make -C /lib/modules/2.6.32-5-amd64/build ...
1
vote
1answer
6k views

Partition table not recognized by Linux kernel

I experience relatively often that the partition table of a USB stick or SD card is suddenly no longer recognized by the kernel while (g)parted and fdisk still see it, as do other systems. I can even ...
2
votes
1answer
268 views

How do I determine the size of kernel block?

I need to find out what the kernel block size is from vmstat output. I am specifically looking for kernel block size as defined in Block devices and block sizes. There it says all Linux blocks are ...
2
votes
1answer
986 views

Unable to mount root fs after new kernel compile in VMware

So, I'm attempting to compile and use the 3.6.2 kernel on my Debian 6 VM (running under Windows 7 in VMware Workstation 9). I've already had several hick ups, but I am slowly getting through them but ...
3
votes
1answer
864 views

VGA and DVI, set default kernel console to one

this seems like a very basic question, but after searching the web for 2 hours I couldn't find any real help on the subject and it's driving me nuts. It's brutally simple: I have a radeon 4670 video ...
2
votes
1answer
1k views

What does “DMA: Out of SW-IOMMU space” error mean?

First the link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1060268 Since this affects the kernel and other Distros, what does this type of error mean and why it happens?
2
votes
1answer
628 views

Learning the Unix/Linux Kernel [closed]

I've been reading The Design of the UNIX OS by Maurice J Bach. It's good overall. However, I learn better with audio/visual aids so does anyone know some good video lecture series or tutorials for ...
1
vote
2answers
77 views

What modules in the Linux source code take care of hot-pluggability?

Could someone shed more light on the code/modules that are responsible for the hot-pluggabilty of the hardware used in Linux machines?
5
votes
1answer
293 views

Has anyone actually tested laptop battery life under different CPU governors?

In theory, switching from the ondemand governor to conservative should save battery life on laptops. However, I don't think I've ever seen any tests done to verify this or show how significant a ...
3
votes
0answers
149 views

Can I get WCHAN from ps on Mac OS X 10.7.4?

From the manual it seems that ps -AO wchan should tell me what everything is sleeping on, but everything comes up as -. (And nwchan as 0). Did they do away with the old sleep()/tsleep() interface in ...
1
vote
1answer
739 views

signal handling in the unix kernel

I was reading The Design Of UNIX OS and had a doubt. A signal handling function can be specified in the signal() call. The handler is supposed to execute when the process receives that particular ...
1
vote
2answers
869 views

Configure timestamp format of kernel log?

Is there a way to change the format of timestamp in kernel logs? It was something like 2012-08-27T8:54:35.939421+03:00 now, I also checked sysctl -a | grep log, nothing found really.
2
votes
1answer
401 views

What does “kernel-resident” mean?

Quoting from the ifconfig man page: ifconfig is used to configure the kernel-resident network interfaces. It is used at boot time to set up interfaces as necessary. After that, it is ...
1
vote
0answers
91 views

Change terminal resolution on Whiite (Wii Linux)

Is there a way to change the terminal resolution in Whiite (Linux for Wii)? All the answers I can find suggest editing grub configuration, but Whiite uses a custom bootloader instead of grub.
3
votes
3answers
2k views

Given vmlinuz and initrd.gz, how do I find out, where the kernel is going to load / (root) file system from?

I'm trying various ways of Linux installation (from iso, flash, iso on flash, kernel on flash, root FS in iso-file on flash...) and want to understand what's going on. My question is: is it possible, ...
3
votes
2answers
455 views

Linux: Is there a IPv6 equivalent to the IPv4 kernel option accept_local?

Since linux kernel >= 2.6.33 the kernel option "accept_local" can be modified: /proc/sys/net/ipv4/conf/${interfaceID}/ accept_local - BOOLEAN Accept packets with local source addresses. ...
0
votes
1answer
4k views

Kernel upgrade 2.6 to 3.5.3 on CentOS 5.8 -> switchroot: mount failed: No such file or directory

I upgraded kernel on my CentOS 5.8 from 2.6.18 to 3.5.3 and now it is unable to mount the root filesystem: I could not find any explanation through Google. Can you point me in the right direction? ...
1
vote
0answers
165 views

BackTrack5 R2 video driver works, but presents disturbing error message

I've installed backtrack 5 R2 on my computer and everything works fine but the video driver. The solution described here does work, but whenever I start the graphics mode, a message saying that the ...
1
vote
0answers
544 views

Install CentOS in a VirtualBox to a Compact Flash and use it on a mini PC

I got into a very specific situation and want to get to know your opinions. I have got a mini PC with Intel Atom processor which should run CentOS with an upgraded kernel to 3.x and some ...
3
votes
2answers
2k views

Adding a new System call to Linux 3.2.x with a loadable kernel module [closed]

I want to add a particular new system call in the linux kernel 3.2.x but as a loadable kernel module (as I don't want to recompile the kernel again and again) I read through many posts on internet ...
1
vote
2answers
113 views

Migrating Data from Debian to ubuntu server

I am current in the process of migrating my website(big and complex with mysql backend) from debian server to ubuntu server. The kernel of debian and ubuntu are different. I have some concerned ...
5
votes
2answers
2k views

What is resolv.conf and why VPN client's hack it?

As stated in a previous question I want to connect to 2 VPN servers at the same time and for each connection specify the IPs of computers I want to reach with it. One of this VPN connection is done ...
7
votes
2answers
6k views

How does the Linux kernel handle shared IRQs?

According to what I've read so far, "when the kernel receives an interrupt, all the registered handlers are invoked." I understand that the registered handlers for each IRQ can be viewed via ...