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2
votes
1answer
63 views

How to find official documentation about Linux kernel namespaces?

I've been using Docker for a while and I'm interested in learning its internals. I've read about kernel namespaces it uses. But I don't understand how they are used. So my problem is: I haven't found ...
0
votes
0answers
34 views

How Linux links driver with device file?

I have a question about device file and drivers, based on ULK hence 2.6.11 kernel. My understanding is the following: When user does syscall open() on some device file, at some point kernel will ask ...
0
votes
0answers
21 views

What would happen if we didn't map the kernel's memory in the virtual memory of every process, and force a context switch instead? [duplicate]

So can someone explain to me that what will happen if they did this and how much overhead will this cause, to have a seperate process for the kernel part of the virtual memory, and make a context ...
0
votes
1answer
38 views

How do proprietary modules work for majority of kernel versions?

A question has been bugging my mind recently. Since virtually all proprietary modules are out of tree (and therefore not compiled against any kernel versions), I'm wondering how exactly they are ...
1
vote
0answers
19 views

How to find the changes done to a particular kernel module through all releases

I need to access source code of all past versions of read_write.c under /fs/ from 3.10 to 5.3. So far I had to go through https://elixir.bootlin.com/ repeatedly and look at every single version that ...
0
votes
0answers
15 views

How to compile kernel in XU4 (armv7l)? Error compiling kernel 4.14.127: “sha512_block_data_order” undefined

I'm trying to compile the 4.14.127 kernel for my XU4 obtained here (https://wiki.odroid.com/odroid-xu4/os_images/linux/ubuntu_4.14/ubuntu_4.14) as I need the USP/IP related modules and, unfortunately,...
1
vote
2answers
44 views

How to cause kernel panic by deleting a device driver (module)?

Is it possible to cause kernel panic by removing a device driver and then making a system call that uses that driver so that kernel goes in panic?
0
votes
0answers
42 views

Failing to load kernel module

So, I have just started going through Designing BSD Rootkits and I seem to have ran into a problem right away. hello.c: #include <sys/param.h> #include <sys/module.h> #include <sys/...
0
votes
0answers
41 views

Unload running kernel module

With lsmod I can watch all kernel modules that running in my linux. How can I suspend and resume spesific kernel module? I tried use modprobe -r <module_name> but got error can't change ...
1
vote
0answers
311 views

ASUS USB-AC68 not connecting in Linux Mint

I recently bought a ASUS USB-AC68 which uses the Realtek RTL8814AU chipset, to replace the outdated WiFi card of my (new) PC, but there are no downloadable Linux drivers from the OEM. At the directive ...
0
votes
1answer
33 views

How do I Get Support for Acer E5-573-54zv Touchpad on a Custom Kernel

I'm compiling a kernel just for learning purpose, and I almost get all things working, bluetooth, hdmi, usb, card reader, webcam, wifi... etc. But I can't make touchpad works, all that I know about it ...
0
votes
1answer
53 views

/proc in Kernel Modules

Currently I am learning Kernel Module Programming reading "https://www.tldp.org/LDP/lkmpg/2.6/lkmpg.pdf" ,and in that book there is a chapter titled as "/proc File System", I have learnt how modules ...
0
votes
1answer
243 views

Understanding a dmesg kernel warning message

I am trying to debug my kernel module. When I run it I get the following kernel warnings, but it seems that there is no informative message like other warnings I've seen. Is it possible to get any ...
0
votes
2answers
1k views

TUN Module Loaded but OpenVPN /dev/net/tun no such file or directory

lsmod -> tun 16587 0 - Live 0xbf0e1000 Openvpn error: Cannot open TUN/TAP dev /dev/net/tun no such file or directory I tried creating a dummy directory but the error changes to Cannot open TUN/TAP ...
0
votes
0answers
29 views

MAC address is removed with tainted VirtualBox modules on Fedora 29

I am getting crash reports. net/mac80211/driver-ops results in drv_remove_interface. My network interface is removed and I can't connect to the WiFi. I can recover this by shutting down or going in ...
1
vote
0answers
149 views

How to additional public keys to .secondary_trusted_keys?

I am trying to add additional keys to .secondary_trusted_keys. Documentation says, to do so the additional keys has to be signed by a key which is already a resident in either .builtin_trusted_keys or ...
0
votes
0answers
97 views

Communicating between userland and kernel space (KEXT) on MacOS

In order to make it easier to develop a kernel module, I am considering Loadable kernel modules (LKMs) on MacOS. This way you have a base kernel module and your main kernel module which is an LKM ...
7
votes
1answer
2k views

How to verify a kernel module signature?

When you compile a kernel source, you can choose to sign kernel modules using the CONFIG_MODULE_SIG* options. The modinfo tool should handle the task of verifying the module signature, but there has ...
2
votes
1answer
157 views

Access grab state of evdev device

I need to retrieved the grab state of an evdev device in a program. More specifically, I need to retrieve the state of the grab pointer in the evdev struct seen here: https://elixir.bootlin.com/linux/...
2
votes
1answer
129 views

What happens to memory that wasn't freed in a kernel module after unloading?

Suppose I called kmalloc and didn't free that memory before rmmod was called on the module, what happens to that memory? Is it a memory leak and it is completely unusable until restart, or does the ...
0
votes
1answer
166 views

mismatch between kernel version and kernel header

I use an embedded with a bit old kernel 2.6.37. Now we need to update rootfs with more update gcc than the one used on building the image (Instead of 4.3 need to use 5.1, because it will support c++11,...
2
votes
0answers
155 views

Does the Linux Kernel use event-loops to keep itself alive? [duplicate]

I am just wondering what mechanism does the Linux Kernel program use to keep itself alive. Any normal C program will terminate by executing its statements sequentially. If we wanted to keep that ...
1
vote
0answers
131 views

Crypto CBC module doesn't show up in /proc/crypto

I want to decrypt an old volume that's using aes-cbc-plain So I am on arch linux kernel 4.9.130 I enabled the cbc as modular in the kernel and installed the modules and the kernel. CBC shows up in /...
1
vote
0answers
323 views

Cannot load compressed Kernel module?

I tried to load "hid-a4tech," but I got error the messages below: [net_client@netarchwork ~]$ modprobe hid-a4tech modprobe: FATAL: Module hid-a4tech not found in directory /lib/modules/4.18.7-...
1
vote
1answer
693 views

Changing a built-in kernel module parameter at booting time?

I am trying to change a parameter, called "sgl_threshold", in the nvme driver when booting into Ubuntu 16.04 running linux kernel v4.18-generic. It appears the nvme driver is actually built-in as it ...
0
votes
1answer
51 views

My Kernel modules don't match those of the VirtualBox installation guide. Should I be concerned?

Fabian Lee : Software Architect's steps to installing VitualBox: Make sure the kernel modules (vboxnetadp,vboxnetflt,vboxpic) were loaded properly: $ lsmod | grep vboxdrv vboxdrv 446464 3 ...
1
vote
2answers
1k views

CentOS 7: Kernel version has no module directory

I'm trying to compile and install a kernel. After download the code and configure the installation I have executed succesfully these comands: # make bzImage # make modules # make But when I try to ...
1
vote
0answers
297 views

how to use ftrace to function_trace a kernel modules interrupt?

I have a Banana Pi Arm device with 2 cores (1.2 GHz) running a Debian kernel which I enabled ftrace kernel debug options. I want to determine the amount of time spent in a kernel module function. The ...
0
votes
1answer
51 views

gNewSense livecd gives me an Error (callbacks suppressed)

I've a kernel-panic problem (I think) trying to use the liveCD of gNewSense 4.0 for i386. The error is the following: [8.598401] xhci_queue_intr_tx: 78 callbacks suppressed. . . . It's showing the ...
0
votes
0answers
96 views

Cross compiling Linux kernel module

On Ubuntu Trusty x86_84, I have successfully been able to compile Linux kernel v3.7.1 for x86, 32 bit. However, as I am trying to build a simple kernel module by feeding the same kernel sources, it ...
1
vote
1answer
2k views

How to add a public key into system keyring for kernel without recompile?

I want to add a public key from the keypair that I used to sign my kernel module, into system_keyring. However, there's a problem: With the command of cat /proc/keys | grep system_keyring, I've got ...
2
votes
0answers
480 views

Failure removing module, still in use/not found

I'm trying to remove a module I have created, but it doesn't work for me. Assuming my module name is xyz : When I try to run rmmod xyz I get the following error: rmmod: ERROR: Module xyz is in use ...
2
votes
1answer
739 views

How do I know if my kernel supports module unloading?

I'm using Debian Stretch 64-bit with Gnome 3.22.2. When trying to update the NVIDIA driver, I got the following message: ERROR: An NVIDIA kernel module 'nvidia-drm' appears to already be loaded ...
23
votes
9answers
33k views

How to unload kernel module 'nvidia-drm'?

I'm trying to install the most up-to-date NVIDIA driver in Debian Stretch. I've downloaded NVIDIA-Linux-x86_64-390.48.run from here, but when I try to do sudo sh ./NVIDIA-Linux-x86_64-390.48.run as ...
0
votes
0answers
61 views

how to redirect from stdin to dev driver

I am writing a device driver and have implemented file_operations write method. I would also like to be able to just redirect to the device driver, e.g.: echo "this text is sent to driver" > /dev/...
0
votes
3answers
3k views

Where exactly is the file linux/kernel.h?

I am reading through Salzman's Linux Kernel Module Programming Guide, and I was wondering about where the file linux/kernel.h is located. I couldn't find it with find. Or rather the files I found did ...
1
vote
0answers
94 views

What address can i pass as a parameter to kernel module?

I'm doing kind of test, and I already have spent two weeks researching that topic + yocto. What I'm trying to do: I'm writing loadable kernel module which "watches" if address (for example, ...
1
vote
1answer
472 views

Why is sys_call_table predictable?

In (or after?) 2.4 the sys_call_table symbol was no longer exported to make it harder to hook system calls. Ignoring that you can still obtain this information from the IDT or by reading /boot/System....
0
votes
1answer
684 views

How to replace one kernel module in the Linux kernel tree

I would like to update/exchange a single kernel module in a Linux kernel tree that I got from an embedded device vendor (Hardkernel) with the latest version from the Torvalds Linux kernel. Could ...
1
vote
1answer
567 views

How to compile Linux kernel with multimedia as module on Odroid C2

I am trying to compile Linux kernel on Odroid C2 and install DVB-T drivers using media_build. I followed steps described on the official wiki and forum. According to the forum, it is necessary to make ...
1
vote
2answers
1k views

Manually create grub entry for iso debian file : cannot copy cdrom

I'm trying to manually create my own custom usb drive, with a bunch of iso files on it, and a partition for data. I used the instruction I put here to create my key, but to sum-up, I have done a ...
2
votes
0answers
713 views

Is it possible to blacklist a built-in kernel module? [duplicate]

I'm asking this in relation to another question that was posted: Select which driver binds to a device I posted an answer suggesting that built-in device drivers can't be blacklisted, as they are ...
2
votes
1answer
505 views

Select which driver binds to a device

I have two different drivers for the same i2c device. Both drivers have the same string in their i2c module device table. One of the drivers is built into the kernel and the other was built as an ...
3
votes
1answer
71 views

Is there a way to know at runtime if a driver is a kernel module or if it was statically linked?

I need to create a test that would check if the driver for a specific device was a kernel module(as opposed to statically linked). Is there a way to know this information at run time? Thanks!
1
vote
0answers
497 views

Use TL-WN727N in AP mode

I have bought TL-WN727N to use it like AP because this page said it supports this mode: https://wikidevi.com/wiki/Mt7601u. I forgot to read the fine print. The driver installed with Linux kernel only ...
5
votes
1answer
3k views

Getting kernel source code (ubuntu)

I want to try my hand at writing a linux driver. I am trying to set up my environment. My current kernel: $ uname -r 4.10.0-37-generic I then download the source code: $ apt-get source linux-image-$...
-2
votes
1answer
264 views

Compile a kernel using a custom file system type such as “myext4”

Is it possible to take the source code of ext4, make no changes to it apart from changing its name to "myext4" and then compiling my kernel so that it accepts this custom file system type? Is it as ...
2
votes
1answer
790 views

Where are Kernel global variables stored?

I am currently writing a Linux kernel module. I am aware that in case of userspace programs, uninitialized global variables (exported to other modules using EXPORT_SYMBOL) are stored in BSS segment ...
2
votes
1answer
732 views

modinfo does not return self inserted module's information

The Scenario I'm trying Kernel Programming for Linux, where I've created module, Inserted, Removed and checked it's output in dmesg as well The Problem When I have inserted module, I can verify ...
1
vote
1answer
2k views

aes-x86_64.ko No such file or directory for Module Installation failure after 4.12.9 Kernel compilation

THE SCENARIO I'm writing a demo module to be inserted in Kernel and then write on system, for which I've already made entries in Header file and Table file. PROCEDURE FOLLOWED SO FAR I compiled the ...