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

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510 views

USB3 Hard Drive Not Recognised by Linux

My external USB 3 hard drive is behaving very strangely: If I plug it into a USB 2 port, it works fine If I plug it into a USB 3 port, it doesn't work at all. It's not even mentioned in ...
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3answers
1k views

How to know <root of the kernel source tree>

In https://github.com/facebook/flashcache/ there is a saying make KERNEL_TREE=<root of the kernel source tree> This builds both the flashcache.ko and 3 utilities. ...
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0answers
315 views

Failed to execute shell script from “network” udev rule to change the MAC-address

I am trying to execute a shell script from udev rule, when a network interface is added, as follows: SUBSYSTEM=="net", ACTION=="add", KERNEL=="eth*", PROGRAM="/usr/local/bin/changemac.sh", ...
12
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1answer
2k views

Why does Red Hat Linux use such an old kernel?

Why does RHEL (and its derivatives) use such an old kernel? It uses 2.6.32-xxx, which seems old to me. How do they support newer hardware with that kernel? As far as I know these kind of distributions ...
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1answer
512 views

Compile Linux Kernel w/ Dynamically (Un)loadable usbserial Module

I've attempted to install drivers for an FPGA device, but require that I remove the usbserial module. This happens to be impossible because usbserial is a built-in module. It was suggested that I ...
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2answers
116 views

Upgrading the kernel in Redhat Linux 6.0

How do you upgrade the kernel in Redhat Linux 6.0? And how can I confirm whether it is updated or not?
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1answer
1k views

Removing builtin modules in Linux

I'm currently attempting to remove the usbserial module in order to install a new driver module. When I attempt to remove the module I get the following issue: [root@localhost xr21v141x-lnx-3.0-pak]# ...
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0answers
673 views

Kernel does not detect Hardware / Software or Hardware fault

I've got more of a basic question for you: My linux kernel (I tried several here from stock 2.6, 3.2 and 3.5 as well as a custom 3.7.3 one) does not detect my synaptics touchpad - or I'am too dumb ...
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1answer
2k views

Kernel and QEMU : Unable to mount root fs error

I am trying to run a distro in the virtual disk image with a custom kernel,so that I can experiment and debug the kernel. I followed this to make a disk image and then install Debian to it. Now I ...
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1answer
378 views

Linux + Kernel panic

when I reboot my Linux machine Linux version 5.5 red hat I get the following warning on the console screen , Linux cant startup and I can't login please advice , how to login as single user mode and ...
3
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1answer
906 views

Debugging Linux Kernel with QEMU

I was trying to study the debugging of kernel using QEMU. I tried initially and failed due to the fact that there was no virtual file system. The answers to this post suggests that there should be a ...
2
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1answer
414 views

Installing the kernel EFI stub loader in kernel 3.2?

Kernel EFI stub loader support was added in kernel 3.3, but I'm stuck on 3.2 running an Ubuntu 12.04 64bit distribution. Is there a way for me to somehow bring that stub loader support into my kernel? ...
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2answers
309 views

Misleading explanation of Virtual Memory in TLDP

I'm completely confused about explanation of virtual memory in TLDP: http://www.tldp.org/LDP/tlk/kernel/processes.html#tthFtNtAAB They say: Each individual process runs in its own virtual ...
1
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1answer
438 views

Why system call hooking produces different result everytime in Linux/Android 2.6.29?

I have implemented system call hooking for Android 2.6.29 kernel through a LKM module. I am tracing down one Android app for system calls. But interestingly, it returns different results every time I ...
2
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1answer
541 views

How to decode cmd = 3222823425 in ioctl in Linux 2.6.29

I am just confused like how can I break cmd=3222823425 value into different parts to figure out what this command means actually in the Linux kernel. I know, some functions are making ioctl command ...
10
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4answers
24k views

Determining cause of Linux kernel panic

I'm running an Ubuntu 12.04 derivative (amd64) and I've been having really strange issues recently. Out of the blue, seemingly, X will freeze completely for a while (1-3 minutes?) and then the system ...
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2answers
2k views

Is it normal that Fedora's yum list kernel-* shows two versions of kernel being used?

Is it true that the following shows that two versions of the kernel are being used? (Is the bold face -- the one enclosed in ** showing what is currently loaded / used). Basically, I just created a ...
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0answers
356 views

Booting over the LAN using uboot

I am trying to boot my beaglebone over the LAN. I am able to download the Kernel uImage from the TFTP server. Here is what I did - U-Boot SPL 2011.09-00053-gb423c52 (Aug 10 2012 - 11:26:55) Texas ...
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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 ...
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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
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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
757 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
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1answer
379 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
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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
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1answer
112 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 ...
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0answers
379 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 ...
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1answer
275 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. ...
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1answer
953 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 ...
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1answer
620 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 ...
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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 ...
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1answer
137 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 ...
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2answers
889 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) ...
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2answers
288 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
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1answer
69 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 ...
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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 ...
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1answer
701 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
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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
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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
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1answer
674 views

Checking linux Kernel for RT-Preempt Patch

How to know whether a particular patch is applied to the kernel? Especially RT-Preempt Patch.
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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
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1answer
847 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
869 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 ...
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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 ...
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1answer
879 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 ...
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0answers
404 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 ...
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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
278 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
996 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
883 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 ...