date int64 1,220B 1,719B | question_description stringlengths 28 29.9k | accepted_answer stringlengths 12 26.4k | question_title stringlengths 14 159 |
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1,466,097,343,000 |
I am having a Red Hat 6.7 running on VM which I updated with the latest version kernel-2.6.32-573.26.1.el6.x86_64. but after this update I received the below error:
kernel panic-not syncing: VFS: unable to mount root fs on
unknown block(0,0)
Previous version was kernel-2.6.32-573.22.1.el6.x86_64 .
|
I have booted my system with my previous kernel which is working fine. while troubleshooting the system we found that there is no initrmfs image on the system and there is no initramfs line in the grub.conf file.
I have created the image with the below command and edited the grub.conf file
# mkinitrd /boot/initramfs-... | Unable to boot after updating the kernel rhel 6.7 |
1,466,097,343,000 |
I would like to boot Fedora 23 Workstation x86_64 with a kernel from QubesOS 3.1. I have copied vmlinuz-4.1.13-9.pvops.qubes.x86_64 and initramfs-4.1.13-9.pvops.qubes.x86_64.img into the /boot directory and run grub2-mkconfig -o /boot/efi/EFI/fedora/grub.cfg to generate the menuitem.
menuentry 'Fedora (4.1.13-9.pvops.... |
I had to copy the modules from Qubes and regenerate the initramfs using the sudo dracut -f command.
| Dracut failure when trying to boot Fedora with Qubes kernel |
1,466,097,343,000 |
I am working with (one of) my workstation(s) working under Scientific Linux 6, so, basically a quite old version of Red Hat Enterprise Linux. I would need to use 2 screens, but only have 2 DisplayPort and one VGA as outputs from my Intel IGP. I am unable to make the DisplayPort ports working, I guess because the driv... |
It is the lack of support for the GPU in kernel (and likely also in X.Org video driver) which you need to somehow solve. Proper support for Sky Lake based GPUs in i915 kernel driver should be available from kernel 4.4 on. Then again, myself I still couldn't get a Intel GPU with device code 1912 working in Debian Jessi... | How to use the proper video driver on Scientific Linux 6 for Display Port screens? |
1,466,097,343,000 |
I have already made a couple of tries in the last few days trying to install and run sysdig in Armbian 5.0/Debian Jessie 8.0, in my Lamobo R1.
After installing it with:
apt-get install -t jessie-backports sysdig sysdig-dkms dkms
When running it gives the following error:
# sysdig
Unable to load the driver
error open... |
I had to change in /lib/modules/4.4.1-sunxi/build the following occurrences of 4.4.1 to 4.4.1-sunxi
include/generated/utsrelease.h:#define UTS_RELEASE "4.4.1"
include/config/auto.conf.cmd:ifneq "$(KERNELVERSION)" "4.4.1"
include/config/kernel.release:4.4.1
After this I was able to install sysdig/compile s... | installing sysdig in ARM / Armbian Jessie - module compiled in wrong kernel version |
1,466,097,343,000 |
I am trying to cross-compile and boot a Linux 2.6 kernel for ARM using QEMU. I have basically followed the same instructions that are included in seemingly every single tutorial on the topic.
Specifically:
Download and compile kernel
$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- versatile_defconfig
$ #Disabled loa... |
Success!
The solution, as suggested, was to embed the initrd image into the kernel by pointing CONFIG_INITRAMFS_SOURCE to my BusyBox's "_install" directory. Many thanks to jc__ for that tip.
Also, for anyone else trying this, it is worthy of note that I needed to create in the Busybox _install directory:
dev/console
... | What step am I missing to get my 2.6 ARM kernel running in QEMU? |
1,466,097,343,000 |
I am looking to generate raw Ethernet frames with payload that is preloaded into memory.
The Ethernet frames (10-60 full frames) should be generated at 1 ms intervals with no exception.
What would be my option to do this? My concern is in regards to the real-time requirements of such an application. Interrupts shoul... |
1ms is plenty to generate a few Ethernet frames, but on a typical Linux system, you can't count on not having the occasional pause. Even if you make your process high-priority, I don't think you can expect to always make a 1ms deadline.
RTLinux combines a real-time operating system with Linux. Linux runs as a non-real... | Generate raw Ethernet frames with memory preloaded payloads at < 1 ms intervals |
1,466,097,343,000 |
the only information i found about this topic is outdated since 2011/02: it says there is no support for devices with usb 3.0 "so far"!
according to the german wikipedia since version 2.6.30 the linux kernel supports usb 3.0; so i assume that since OpenWrt Backfire usb 3.0 should be supported...
for example the poste... |
I use LEDE now instead of OpenWRT, but both do support USB 3.0 (assuming your router also supports it).
What I'm curious about is whether it supports USB hubs. My router has 2 USB ports, but only one is 3.0.
| Is there a general USB 3.0 support in OpenWrt? |
1,466,097,343,000 |
I want to upgrade Linux kernel from 3.16 to 4.3. Unfortunately when I run aptitude install linux-image-4.3.0-1-amd64 installation fails due to no space on rootfs partition. 117MB left, 174MB needed.
I have no old kernels to remove to free up more disk space (except the one that I'm using right now):
root@host:/# aptit... |
450MB is not much for a root+boot partition on a modern amd64 system. If you want to install multiple kernels, you're going to have to reorganize your partitions. Even if you don't, it's pretty tight.
Given the partitions you have now, I suggest moving the root partition to what is now /var. Since you're going to move... | No space left to free up on rootfs partition to upgrade kernel |
1,466,097,343,000 |
The i915 Kernel module has several "module options" like the infamous enable_rc6.
However, for the xorg config file, there are further options such as TearFree.
I was wondering - why are there two ways to (seemingly?) set options the same module? Why can't I pass the TearFree option to the kernel module? Is this a gen... |
Because they're two different drivers: the kernel driver and the xorg driver and each driver has its own, specific options.
The i915 kernel driver talks to the hardware device (it does basic, low level stuff like set up resolution, map a framebuffer etc).
The xorg intel driver includes OpenGL, DRI, DDX etc for 2D/3D a... | Why are there module options AND driver options - e.g. for the i915 module? |
1,466,097,343,000 |
I'm using the 4.1.2 mainline kernel. The package with image and all modules has 207 MB of installed size.
I built a patched 4.1.6 kernel, taking the config from the current kernel and now the drivers themselves take 2G!
marcin@asus ~/4.1.6/lib/modules/4.1.6/kernel $ du -sh *
19M arch
16M crypto
2,0G drivers
213M ... |
The kernel I used was stripped afterwards. My modules were not stripped. Hence they were so big.
| Linux modules take a lot of space [closed] |
1,466,097,343,000 |
My machine (ThinkPad x230) hangs on wake up from s2disk or s2ram after a recent aptitude safe-upgrade.† The hang looks like a blank screen with a blinking cursor in the upper right after loading data pages completes.
Confirmed the same behavior after sudo hibernate, sudo pm-hibernate, and echo disk | sudo tee /sys/pow... |
Found a solution that works:
sudo blkid and copy your swap UUID to clipboard
sudo vim /boot/grub/menu.lst, search for resume= and add resume=UUID=xxxxx-xxxxx-xxx-xxxx-xxxx
update grub with sudo update-grub
That worked once and never again. Still looking.
Update: My problems went away once I switched from Linux ker... | debian testing hangs on wakeup from s2disk / hibernate |
1,466,097,343,000 |
I have Windows 7 and Kali Linux on my computer, normally I don't use windows anymore. But today I started windows and it updated itself. I am writing my thesis and all my stuff is in Linux so I really need to get it started my deadline is near.
In the grub bootloader I choosed Lali Linux, and in the next windows it sa... |
Assuming that your Kali Linux install uses ext4 (or an older version, which will work even better), you may also be interested in installing ext4 drivers for your windows 7 installation, so you can access your files from within windows. I've used them with reasonable success (I run Windows 7 and Arch Linux). To be sa... | Linux fails with starting on a dualboot system after Windows update |
1,466,097,343,000 |
I'm reading some doc about UNIX but I don't understand two things:
Why is important for the kernel to know the current working directory of the running process?
Why not keeping the inode information in the directory?
|
The system needs to keep track of the current directory of all processes because otherwise processes couldn't use relative paths for anything (including for example file open or stat, and changing directories — what does chdir("..") mean if you don't track were the process currently sits?).
There's also the matter tha... | Kernel current working directory and inode information placement |
1,466,097,343,000 |
aptitude search linux-headers
provides this:
p linux-headers-3.16.0-4-all - All header files for Linux 3.16 (meta-pack
p linux-headers-3.16.0-4-all-amd6 - All header files for Linux 3.16 (meta-pack
i linux-headers-3.16.0-4-amd64 - Header files for Linux 3.16.0-4-amd64
i A linux-headers-3.16.0-4-co... |
It required to modify /etc/apt/sources.list
adding i386 to downloadable architectures like that:
deb [arch=amd64,i386] http://httpredir.debian.org/debian/ jessie main contrib
After that you need to make
apt-get update
dpkg --add-architecture i386
apt-get update
and to install package for i386 architecture:
apt-get... | how to get 32 bit kernel headers in 64 bit debian installation [duplicate] |
1,466,097,343,000 |
on my laptop, when I do ifup wlan0, sometimes I get following call trace in dmesg. Other times, the log looks perfectly normal, and there are no kernel Oops messages.
In both cases (with errors and without), my network seems to work fine.
But I would like to understand what is happening. Could somebody please help me ... |
Turns out to be a false warning.
To quote from the (now closed) kernel bug report:
Alfred Krohmer: If I unterstand your patch correctly it just removes the warning, but it won't actually fix the driver crash this bug report was submitted for. So why mark it as resolved?
Emmanuel Grumbach: There is no real bug. The co... | ifup wlan0 causes kernel Oops |
1,466,097,343,000 |
My embedded device is not working after updating firmware.
Thus I tried to update firmware using u-boot. I could successfully get u-boot console via serial connection, but updating firmware failed due to the lack of knowledge on firmware update using u-boot.
At last, I not only corrupted linux kernel but also u-boot... |
If available (ie. if there's a JTAG header on your board) , you can connect using a JTAG cable.
Remember: Before using it you might need to enable JTAG using Test Mode Select Input (sometimes a jumper somewhere).
You can then use that connection to upload a new firmware into your device.
| How to recover firmware on a embedded device with corrupted u-boot and kernel image? [closed] |
1,466,097,343,000 |
The Debian guide for compiling a kernel says:
Do not forget to select “Kernel module loader” in “Loadable module support” (it is not selected by default). If not included, your Debian installation will experience problems.
However, I have downloaded the 3.12.22 kernel, run make xconfig and searched for the “Kernel mod... |
Parts of this guide are seriously out of date.
“Loadable module support” is the name of the option that enables kmod, the kernel component that calls modprobe to load modules with a symbolic name based on hardware identification. You can see these symbolic names in /lib/modules/VERSION/modules.alias; they're automatic... | Debian + Linux kernel 3.12.22: “Kernel module loader” option is not available |
1,466,097,343,000 |
I just upgraded Linux Mint Debian Edition with the up7 package.
The update manager failed initially (can't remember where...) so I ran sudo apt update, sudo apt dist-upgrade, sudo apt upgrade and sudo dpkg --configure -a.
Situation now: when I reboot and select the new kernel (3.10-2-amd64) from the grub menu, the fol... |
Does sudo apt-get -f install help? Also have a look at the LMDE updates forum they seem to have screwed up with UP7, a lot of people are reporting problems. I am currently updating myself we'll see how it goes.
A common source of problems is the nvidia proprietary driver. This is compiled against your current kernel a... | Linux Mint Debian quits on boot |
1,466,097,343,000 |
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 through event interface /dev/input/event5 (I checked this). This event interface is attached to the GPM gpm -m /dev/input/even... |
I spent a huge amount of time, resolving this issue, and i would like to help other people, who run in this problem. I think some outer X11 features interfered my module work. After disabling GDM it now works fine (runlevel 3). Working code you can find here http://fred-zone.blogspot.ru/2010/01/mouse-linux-kernel-driv... | Virtual mouse driver, possible X11 problems |
1,466,097,343,000 |
I'm trying to debug a linux driver and a particular piece of code is behaving very strangely. In order to see what's going on I've filled the code with printk statements so I can see exactly what the variables I'm interested in do as the code executes. Unfortunately, when printing the ring buffer with dmesg lots of li... |
As far as I can tell, klogd uses a blocking read() to read from /proc/kmsg. It might help if you boost its priority via renice. You could also try writing the kernel logs to a ramfs/tmpfs to save some disk overhead, either via syslog, or with klogd's -f option to write directly to a file.
Otherwise, plan B is ftrace... | How to avoid overflowing the kernel printk ring buffer? |
1,354,782,873,000 |
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 don't see any error during the build process. I have also tried with the option V=1 and I see following error
echo;
echo... |
Ok, I have figured out the problem. I am having square bracket character "[" in the module source directory
LD [M] /home/farshad/Work/CSP/boards/imx6q/ar6k3/ar6003_3.1_RC_Linux_release_[posted_2011_8_19_olca3.1RC_553/imx6build/host/os/linux/ar6000.o
Removing this from the path worked well and I got my kernel modu... | Building kernel module |
1,354,782,873,000 |
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 first, otherwise skip that part.
Normally it just ask me to pick between N, Y, M.
Is it possible?
|
Check the output of make listnewconfig.
| How can I tell if a kernel has some "new" config? |
1,354,782,873,000 |
I'm using Arch Linux, kernel 3.5.3 on a MacBook. I'm trying to get the keyboard backlight working. I found the driver in the AUR: http://aur.archlinux.org/packages.php?ID=25467, but I'm having trouble compiling it.
When I run makepkg i get:
==> Making package: nvidia-bl 0.16.7-1 (Sat Sep 1 03:23:25 UTC 2012)
==> Ch... |
Looks like your PKGBUILD is outdated (0.16.7-1, but the current is 0.17.3-5). Try downloading the nvidia-bl tarball again and building it.
| Can't install driver in Arch |
1,354,782,873,000 |
Does ext4 / cifs system need kernel NLS support ? I'm not sure if it's being handled by user-space program (decoding / encoding) ?
|
NLS allows normalization of character sets used for filenames over the whole system, so you can have different charset used on two different systems and still have correct mappings.
So yes, it's necessary, especially for CIFS, which afaik uses Unicode by default on newer servers, but your local system might have diffe... | Is Native Language Support (NLS) kernel support still necessary? |
1,354,782,873,000 |
I'm suffering from a kernel bug in a production environment. The problem isn't causing a complete outage, but it's degrading service.
These are soft lockups.
I'd like to try a newer kernel, however Squeeze only has 2.6.32.5, but kernel.org has 2.6.32.59. I've compiled from source in the past, but should this reall... |
Squeeze currently has 2.6.32-59. For details have a look at the chanelog entry for 2.6.32-42.
What exactly is your problem and why do you think upgrading the kernel may help? As you can always downgrade packages there should be no problem using the newest Linux kernel in backports.
| install 2.6.32.59 on squeeze |
1,354,782,873,000 |
I've been asked to investigate adding extra memory (> 16gb) to a RHEL 4 server and moving to a huge mem kernel. The server is used for Oracle RAC.
Is it just a case of installing the hugh mem kernel and booting into ? or is it more complex than that ?
Any tips / gotcha's ?
|
I use a BIGMEM kernel on Debian squeeze. I've used a non-BIGMEM kernel before as well. I'm not aware of any issues or gotchas, and no changes to the system are necessary when switching between a BIGMEM and non-BIGMEM kernel. Of course, you only need to use a BIGMEM kernel if you are running a 32 bit kernel. If you hav... | What are the Implications of moving to Huge mem kernel on RHEL4 |
1,354,782,873,000 |
I have an issue with Fedora 15's available memory. The laptop it is installed on has 4GB of SDRAM, but Fedora only sees 2GB.
[njozwiak@calvin xpmc6720]$ free -m
total used free shared buffers cached
Mem: 2193 1994 198 0 59 1405
-/+ buffer... |
What kernel are you using? The kernel needs to have BIGMEM support.
Fedora 15 offers BIGMEM support in PAE kernels. So install (for example)
the Fedora 15 2.6.38 PAE kernel.
| Fedora 15 - Limited RAM Access |
1,354,782,873,000 |
I have a new Sandy Bridge i5-2500 and Intel H67 motherboard. As the onboard video didn't work, I put in an older 8600 gts graphics card. However, the S3 suspend won't work (and I can't test without the dedicated card). I've had this experience with all other desktops (all of which have nvidia cards).
Any help diagnosi... |
It seems to have been fixed now, I'm using OpenSuSE 11.4. My uname string is
Linux linux-sdia 2.6.37.6-0.7-desktop #1 SMP PREEMPT 2011-07-21 02:17:24 +0200 x86_64 x86_64 x86_64 GNU/Linux
and the nVidia driver is 275.21.
| S3 sleep problems -- nVidia or Intel H67 (Sandy Bridge motherboard) issue? |
1,354,782,873,000 |
I am trying to compile the mainline Linux kernel with a custom config. This one!
Running on a 64 bit system.
At the last step, when linking the Kernel, it fails because it goes OOM (error 137).
[...]
DESCEND objtool
INSTALL libsubcmd_headers
CALL scripts/checksyscalls.sh
LD vmlinux.o
Killed
make[2]: **... |
It's getting unaffordable to develop Linux
I am afraid it has always been.
32GB RAM is common on kernel devs desktops.
And yet some of them started encountering ooms when building their allyesconfig-ed kernel.
Lucky you… who are apparently not allyesconfig-ing… you should not need more than 32G… ;-)
On a side note, ... | Linux build with custom config using all RAM (8GB)? |
1,354,782,873,000 |
Can someone please explain how to apply a patch file to ubuntu server kernel? I'm trying to apply this patch file which enables the tcp_collapse_max_bytes option in the TCP communication options on an ubuntu server. I followed this answer and tried to apply the .patch but got the same error.
Here are my steps:
first, ... |
I found that I have to download the source code and patch the downloaded source code. For some reason that I don't know exactly, the codes in /usr/src/ were not the exact code of the official Linux. (Probably my VPS provider modified them).
I followed these steps and applied the patch after downloading the codes, then... | Applying patch file to ubuntu server |
1,354,782,873,000 |
This is a follow-up question to dentry/inode caching on multi-cpu machines / memory allocator configuration, but here I try to put the question differently.
My problem is that I have a dual socket machine, and memory for the kernel caches (dentry/inode/buffer) are allocated from bank0 (cpu0's memory bank), and that ev... |
"What is going on with kernel caching on NUMA architecture" under your linux-3.10 is governed by the zone_reclaim_mode sysctl which allows to select the appropriate action to be taken when a zone runs out of memory.
In other words, determine if the page allocator will reclaim easily reusable pages before allocating of... | NUMA aware caching on linux |
1,672,002,091,000 |
Is it possible to check the different status of video drivers when it is on, is off, in error, in no-signal?
Example: monitor off - some state 0-, monitor no-signal - some state not connected and so on?
|
Try this: grep . /sys/class/drm/card0-*/{status,enabled,dpms}.
If this doesn't satisfy your needs, just leave a comment below.
| How to detect display driver info |
1,672,002,091,000 |
My goal is to read CPU cycle with ARMv8 registers, and both kmod and my test program works fine on my ARM laptop. However, on my db410c board after loading the kmod, when executing the binary to access the pmccntr_el0 I get Illegal instruction.
Anyone could help me understand why? Since I have already enable the user ... |
found out reason, it needs properly to be enabled user mode access bit.
| userspace program gets "Illegal instruction" when reading pmccntr_el0 (with user mode access enabled) |
1,672,002,091,000 |
I am sending a synchronous control message to a USB device with the call usb_control_msg. It is taking .25 second to complete. Is it normal/expected? The USB port is USB 3.0. The device is a Cypress FX3 module. The similar test done a Windows system (same port, device, FX3 firmware) returns every message in much less ... |
I am going to guess that because async messages sent out sequentially, go out quickly but the completion callback and the responses from the USB device still take 0.25 second to occur, that the delay was because of the Cypress FX3 module. I am also including the code for the async messages.
static struct usb_ctrlreque... | Why does usb_control_msg take 0.25 second to complete |
1,672,002,091,000 |
So I'm building a custom Linux-based OS, and I chose to run it as a RAM disk (initramfs). Unfortunately, I keep getting a Kernel Panic during boot.
RAMDISK: gzip image found at block 0
using deprecated initrd support, will be removed in 2021.
exFAT-fs (ram0): invalid boot record signature
exFAT-fs (ram0): failed to re... |
The issue in this instance was directly related to the CPIO archive I created. Although I was using the correct cpio and gzip commands, I was piping incorrectly due to a typo in the TinyCore book. Using the following command, I was able to create a cpio file that was readable:
cd fs_folder
sudo find | sudo cpio -o -H... | Custom Build - Unable to mount filesystem |
1,672,002,091,000 |
I'm using Arch on a very old computer with Chrome and it crashes pretty often, plus the CPU consumption is very high.
I read that using cfs-zen-tweaks could improve the responsiveness.
Which is better, using cfs-zen-tweaks or a linux-zen kernel? What is the difference?
|
I have an older laptop with low processing power as well, I use it on the go as it's very light and the battery lasts quite long. It wasn't unstable, though, but got unresponsive whenever I did an update in the background. I run Arch on it.
I moved from the vanilla kernel over to the cfs-zen tweaks, which made a diffe... | linux-zen VS cfs-zen-tweaks |
1,672,002,091,000 |
I'm trying to boot CentOs already installed on an appliance.
This appliance has only two input connectors:
1 USB port, where I plugged in a USB hub, to which I connected a keyboard
1 Male 9 Pin Serial port / RS232
It also has 2 Gigabit Ethernet ports, one of which is used for remote administration with Intel BMC and... |
Adding console=ttyS0,115200 console=ttyS1,115200 to the linux command and dropping rhgb solved the problem.
| Missing console output after grub |
1,630,600,137,000 |
I am trying to declare a new variable in vvar.h and define it near my new VDSO function. So that I could use this variable in my vdso function.
I have a trouble about VVar. According to the description in arch/x86/include/asm/vvar.h, when I declare here a new variable as DECLARE_VVAR(0, int, count), I should use DEFIN... |
DECLARE_VVAR and DEFINE_VVAR are arch-specific vDSO implementation details, and you shouldn’t use them to add new vDSO data.
To add a vDSO variable, you should modify struct vdso_data include/vdso/datapage.h (you’ll see the relevance of the array construction there; it’s tied to clock sources, hence the reference to C... | how to declare a new variable in vvar.h |create a vdso in linux |
1,630,600,137,000 |
When listed down the running processes,
I can see several processes like 'chrome', 'notepad', 'intellij', 'sublime editor' etc.. are having "tty = ?"
Then how are they able to read the input from a keyboard?
Is TTY always related to terminals/cli?
|
XWindows applications receive keyboard and mouse input from the X Server, and display things through the X Server. It is unusual for these applications to have a controlling terminal (the tty column) unless they are started from a command line that has a controlling terminal.
There are really only a few XWindows appl... | TTY = ?, How input is read |
1,630,600,137,000 |
I'm trying to create a file with the following specifications.
The file "myfile" in a debugfs sub-directory is to be read only by any user, and when read,
should return the current value of the jiffies kernel timer.
I have written the following line of code in the function my_init that is directly called through mod... |
The return value was removed from debugfs_create_u32 at 2b07021a940ce1cdec736ec0cacad6af77717afc which went into v5.7:
debugfs: remove return value of debugfs_create_u32()
No one checks the return value of debugfs_create_u32(), as it's not
needed, so make the return value void, so that no one tries to do so in
the fu... | creating a debugfs file that is used to read/write u32 value |
1,592,330,370,000 |
I am trying to create my own PID 1 init script, to be called from the boot cmdline with init=/myscript. How can I make it work on a real filesystem, with any kernel?
When it runs in an initrd, it works fine and can mount things, etc. - but when I use it on my filesystem without an initrd, it fails to mount things, be... |
There's no special treatment for init on initrd, so there must be some other issue.
If run as root, the euid will match the owner of the binary if the setuid bit is set.
Check the ownership on /bin/mount.
| Why does a shebang script run as init= have an euid of 0 when run from an initrd, but not otherwise? |
1,592,330,370,000 |
I am relatively new to Linux and I was reading a book for LPIC-1. Reading the module part I was checking my modules and noticed that some modules don't have a description.
ac97_bus, autofs4, cdrom, crc32_pclmul, crypto_simd, glue_helper, hid, jbd2, sunrpc, usb_common, usbcore
I tried Google but I didn't find any answe... |
It's not mandatory for a Linux kernel module to have a description filled in. If one does have it, you can find it in the module source code as a MODULE_DESCRIPTION declaration like this:
MODULE_DESCRIPTION("Intel HDA driver");
which you can inspect via modinfo on the .ko object:
$ modinfo snd_hda_intel
filename: ... | Linux Module descriptions missing |
1,592,330,370,000 |
I am loading a kernel module at boot time, I added it to a config file in /etc/modules-load.d/, the module is loading correctly.
In my module I am using the wait_for_random_bytes() function from linux/random.h, so my module can have some delay in loading.
The modules are loaded sequentially? This module of mine can de... |
What the OS does ?
In my Debian (but i would bet that your CentOS just do the same), the module loading part of initialization is done by /etc/init.d/kmod.
Below is an extract of this script:
files=$(modules_files)
if [ "$files" ] ; then
grep -h '^[^#]' $files |
while read module args; do
[ "$module" ] || cont... | Loading a kernel module at boot time is blocking? |
1,592,330,370,000 |
I have a Linux system with two interfaces lo and eth0, I have some iptables rules which will block some tcp ports.
It's possible to teste my own firewall rules by implementing a probing service to port scan my own ports? the idea is to port scan my external interface eth0 but doing that inside.
I have made some basic ... |
You can use a network namespace, and link it to your system with a pair of veth interfaces. That way you'll really have two network stacks: the host's and the additional network namespace's. This will very cheaply (way more than a VM, only the network is separated) create an host to scan from. The easiest command to m... | Test iptables from localhost |
1,592,330,370,000 |
I am using the Linux's traffic control (tc) utility, which to my understanding is used to configure the Linux kernel packet scheduler.
I am also using the netem command in tc to add delay, drop, or corrupt traffic.
My main question is, does the netem modify transport layer datagrams, IP packets, or Link layer frames ... |
tc affects the queuing discipline, i.e. the order in which outgoing "packets" are sent to the hardware. The implementation operates on sk_buff structs, and
the documentation for sk_buff seems to imply that the packet format is whatever the particular network interfaces uses (e.g. Ethernet packets for an Ethernet inter... | Does the Linux traffic control utility modify datagrams, IP packets, or frames? |
1,563,892,725,000 |
I am trying to connect a custom device to this Linksys router. This device has a firmware file which I copy and paste into the /lib/firmware folder. The issue I am facing is, on bootup if the device is connected I get an error saying the firmware file was not present in the /lib/firmware folder. But the device works f... |
Custom files can be "installed" by use of cp on a running system (which will add them to the overlay), or by use of the ./files/ directory in the build system (which will add them to the ROM)
You'll see that it is common to copy files needed by the wireless drivers during boot and that it works quite well. See, for ex... | Custom Firmware Boot Issue For Linksys EA6350 |
1,563,892,725,000 |
My kernel driver needs to access battery's properties (get_property, set_property).
Problem: How to find the battery's struct power_supply?
I only find power_supply_get_by_name but there can be different names for the battery. I need to check the power_supply's type but this is where I am stuck.
A direct get_by_type ... |
Exactly a year late for the party. :) Here's the basic idea that loops over the all objects of power-supply class.
#include <linux/power_supply.h>
static int power_supply_printer(struct device *dev, const void *data)
{
struct power_supply *psy = dev_get_drvdata(dev);
(void)data;
printk(KERN_INF "power-su... | Find a power_supply of type |
1,563,892,725,000 |
I have been having problems compiling a router's kernel for QEMU. I have the router working in QEMU using an OpenWRT kernel, but networking does not work. This is why I want to compile the original kernel.
The below command is the problematic command that the (main) Makefile indirectly executes. I say indirectly becau... |
Using @filbranden's comment, I was able to compile the kernel for my router (there are more error's that need to be solved, but that isn't the scope of this question).
I left a log and my config of what I was doing to compile the kernel on Github gist (new logs and config). The config is broken and won't be apparent u... | Why does my Makefile not compile and how can I fix it? |
1,563,892,725,000 |
When trying to mount ext2 I get this error:
Creating 4 MTD partitions on "MPC8313RDB Flash Map Info":
0x000000000000-0x000000100000 : "U-Boot"
0x000000100000-0x000000300000 : "Kernel"
0x000000300000-0x000000700000 : "JFFS2"
0x000000700000-0x000000800000 : "dtb"
List of all partitions:
1f00 1024 mtdblock0 (... |
For some reason my U-boot is not letting my kernel know where the initrd is being loaded into ram so I manually set initrd_start and initrd_end in setup-common.c. I mapped the memory location in ram that the ramdisk was loaded to a virtual address space of the kernel. I had to remap because the PAGE_OFFSET was larger ... | Kernel can't find initrd? |
1,563,892,725,000 |
In 4.19 the dentry_update_name_case function was removed.
What's the replacement for this?
|
There is no replacement; the function was removed because its user, ncpfs, had been removed (as you know only too well). If you’re working on restoring ncpfs, I would consider adding the function locally in ncpfs.
| kernel 4.19: replacement for dentry_update_name_case()? |
1,563,892,725,000 |
I can control backlight using /sys/class/backlight/.. but is there a way to identify which driver (module) is used internally to actually control the backlight intensity?
|
$ ls -ld /sys/class/backlight/intel_backlight
lrwxrwxrwx. 1 root root 0 Jun 3 10:08 /sys/class/backlight/intel_backlight
-> ../../devices/pci0000:00/0000:00:02.0/drm/card0/card0-eDP-1/intel_backlight
$ ls -l /sys/devices/pci0000:00/0000:00:02.0/driver
lrwxrwxrwx. 1 root root 0 Jun 3 09:08 /sys/devices/pci0000:00/0... | Find driver used for backlight control |
1,563,892,725,000 |
How can I uninstall a kernel which is now being used by my laptop.
I have two kernel installed in my manjaro linux laptop
4.16*
4.14*
When I boot into my system 4.16 always runs by default. To run with 4.14 i goto advanced options and then select 4.14. I want to get rid of 4.16 I like 4.14. Can I remove 4.16 while i... |
From the advanced option of Grub menu you should boot the 4.14 kernel then remove the 4.16 version.
To prevent the kernel from being upgraded , edit your /etc/pacman.conf , add the following line:
IgnorePkg = linux
Then update grub.
| can i uninstall a kernel which is now running in a manjaro linux |
1,520,323,320,000 |
I would like to have the default for certain input pins be a weak pulldown. I am using a sama5d36 running Debian 4.12.8. I modified the dts file as follows:
ahb {
abp {
pinctrl@fffff200 {
board {
pinctrl_inputs: input_pins {
atmel,pins =
... |
Setting up a node in the device tree (dts) requires a compatible node like gpio-keys or gpio-leds. You can't just make up a node like I was trying to do. since the line I need is part of SPI BLE I added it to my spi1 node as follows:
spi1: spi@f8008000 {
cs-gpios = <0>, <0>, <0>, <0>;
... | Want pulldown on gpio pin |
1,520,323,320,000 |
I am trying to compile kernel for Allwinner A10 processor (sun4i, ARMV7) for Android 4.1.2. Config file is copied from the device. This is the output :
$ make ARCH=arm CROSS_COMPILE=/home/user/android_kernel/arm-eabi-4.4.3/bin/arm-eabi-
CHK include/linux/version.h
CHK include/generated/utsrelease.h
make[1... |
It seems like you're using a toolchain configured for softfloat targets. You'll need a hardware floating point-supported one.
| Kernel make error: “sorry, unimplemented: -mfloat-abi=hard and VFP” |
1,520,323,320,000 |
I'm using an NXP embedded linux board and I compiled u-boot, the kernel and am using a linaro rootfs.
On it I installed freeswitch and loaded mod_gsmopen with a Huawei module and it didn't work. After a little bit of reading the conf file I found that it was trying to read ttyUSB3, so I tried finding the correct ttyUS... |
Ok. So I had many problems, so let's start from the beginning.
At that time I was trying to compile the drivers builtin into the kernel and not as a module. For some reason that didn't work so I decided to compile them as modules separately and installing them later.
The main problema I wasn't finding any package wh... | Can't find /lib/modules/ |
1,520,323,320,000 |
I recently purchased a Samsung NP900X3N which came with Windows 10 installed. I used it for a while on Windows 10 and I noticed the battery lasted for a long time (I forgot to time it, but I felt like it lasted for as a long as it should have lasted for a new laptop with SSD and a 7th gen i5).
However, after I install... |
Turns out that powertop is a good alternative, but the fact that I have to re-do everything manually every time I turn on the computer kind of kills it for me. This made me have to install tlp, for which I found no alternative.
| Battery doesn't last long on Linux for Samsung series 9 |
1,484,913,249,000 |
After updating Arch Linux xfce4 has been crashed and When I reboot the machine I got this message
Failed to start loading kernel modules
This is the output of uname -a
Linux NasserLaptop 4.8.4-1ARCH #1SMP PREEMPT Sat Oct 22 18:26:57 CEST 2016 x86_64 GNU/Linux
Output of `pacman -Q Linux
linux 4.8.6-1
I have tri... |
I have solved ,Thank to u guys
I have booted from USB then remounting the partitions as in installation then generate fstab file and edit it to add /boot then arch-chroot and
pacman -S linux
The problem was that boot partition didn't mount correctly and I have to edit fstab file to add it
My post and more details her... | Failed to start loading kernel modules |
1,484,913,249,000 |
I'm now running XUbuntu 16.04 with kernel 4.4.0-31 and now I need to somehow downgrade kernel to version 4.1.24. Is there any way to do that?
|
Install required packages:
sudo apt-get install git fakeroot build-essential
sudo apt-get install libssl-dev bc ncurses-dev xz-utils
sudo apt-get install kernel-package
Download the Linux kernel
wget https://www.kernel.org/pub/linux/kernel/v4.x/linux-4.1.24.tar.xz
wget https://www.kernel.org/pub/linux/kernel/v4.x/l... | Downgrade XUbuntu kernel |
1,484,913,249,000 |
I just need to check some redhat machine version - 6
and I notice that grub.conf inst exists
how this Linux machine know with which kernel to start? ( in case grub.conf not exists )
is it safe to do a reboot to the linux in that case ?
08:16:41 root@test:~ # more /etc/grub.conf
/etc/grub.conf: No such file or director... |
Does cat /boot/grub/grub.conf work?
In those days the LILO bootloader was also a common choice to boot a UNIX machine.
| linux + grub.conf not exist |
1,484,913,249,000 |
On Linux 5 and 6 I can print the /etc/grub.conf
How to verify the latest kernel version on Linux 7? , like we do on Linux 5 and 6 from grub.conf
#boot=/dev/sda
default=0
timeout=15
#splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
serial --unit=0 --speed=115200 --word=8 --parity=no --stop=1
terminal --timeout=10 seri... |
For example ls /boot/config-* will print you all the installed kernel versions. But there will be a lot more possibilities how to achieve the same.
yum info 'kernel*' should do the job too on all the RHEL's
| How to print the latest kernel version from grub.conf on Linux 7 |
1,484,913,249,000 |
I wanted to create a simple Hello world driver as in here: Page2 and compile it with Makefile:
obj-m := hello.o
all:
make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
clean:
make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean
But I got:
make1: *** /lib/modules/4.3.5-300.fc23.x86_64/buil... |
Okay, so for me worked upgrading/installing kernel and all kernel-X modules.
After that a kernel (propriate version) directory appeared in /usr/src/kernels/
| Invalid Build path for driver creation |
1,484,913,249,000 |
I am trying to compile a linux kernel (2.6.32.70) for an ARM board (versatilepb), it is my first steps in embedded linux.
At the end of the compilation, two compressed kernel images are generated inside /arch/x86/boot and /arch/i386/boot directories, and not inside /arch/arm/boot. So it looks like that it doesn't co... |
Finally it works, it seems that my kernel directory was not so clean, even after a make clean && make mrproper.
After restarting from kernel sources extracted from the archive, i can do a make V=1 without root privilege and there isn't any questions asked. And the directory /arch/arm/boot contains an image of the com... | Cannot compile a linux kernel for an ARM board [closed] |
1,484,913,249,000 |
I want to setup a Linux environment, but I want the system to be bootable in two or more computer systems with different sets of hardware.
Can Linux provide that level of hardware abstraction given that computers are based on the same architecture (x86 64-bit) ?
I suspect that if I have one compatible kernel for eac... |
The short answer is yes.
As long as the processor architecture is the same (x86_32, x86_64, etc.), an installation will for the most part run anywhere. There are only three difficulties in practice:
You need to have the right drivers available at boot time. The best way to ensure this is to stick with your distributi... | Linux setup compatibility |
1,450,281,081,000 |
I am currently getting this error message:-
iptables v1.4.12: can't initialize iptables table `filter': Table does not exist (do you need to insmod?)
Perhaps iptables or your kernel needs to be upgraded.
I have tried insmod, updating the kernel from apt-get but I am really at a loss they are just not working and I... |
I solved this issue in the end, I recompiled the kernel, recopied over the modules and created a symlink between 3.15.0 to 3.15.0+ ... this + was not added to a file for some reason which messed up alot of things adding this I was able to make and install modules
| module issues with kernel |
1,450,281,081,000 |
Recently performed software update on a RHEL 6.6 (Santiago). Noticed that kernel version is not updated to latest one that was installed.
kernel version before doing software update:
[root@server01 ~]# uname -r
2.6.32-431.11.2.el6.x86_64
Below is the summary of kernel packages from yum list command:
[root@server01 ~]... |
While I'm unable to explain why the newest kernel wasn't booting automatically, the kernel booted by GRUB is set in /boot/grub/grub.conf using the default=<menu entry number>, where counting starts at 0. In this specific case, default=1 will boot your desired kernel.
| Kernel version not changing even though the new version is installed |
1,450,281,081,000 |
Reading the Debian Kernel Handbook I came across the config option CONFIG_DEBUG_INFO.
That option isn't in the official debian 3.2 kernel config, so what I'd like to know:
If a certain option is not in the .config file, does that count as "undefined" and is "undefined" the same as "disabled"?
|
In case of that config option, "undefined" means "disabled", see the Makefile:
ifdef CONFIG_DEBUG_INFO
KBUILD_CFLAGS += -g
KBUILD_AFLAGS += -gdwarf-2
endif
So, the answer is: it depends. There are config options in the Makefile with else, and other statements. Such a contant can also have a value that defines a ... | Kernel config: Is undefined the same as disabled? |
1,450,281,081,000 |
I am trying to install Kali on my Lenovo Yoga13, but after formatting the disk the setup failed to install grub because of no internet access (no Ethernet, need driver to get Wifi to work).
So, I decided to compile the Wifi driver to complete the setup just to realize I am missing kernel headers. I cannot apt-get inst... |
If it is not on the install media, then you need to get the deb into /var/cache/apt/archives/. If it is there then the download part of apt-get will be skipped.
| Missing kernel headers, but need them to install the Wifi driver |
1,450,281,081,000 |
On my debian laptop I installed kernel 3.14 so I have the alx driver so my ethernet works, I originally had the 3.2 kernel (Debian 7.7). AFter installing the new kernel, gnome3 went back to the "failed to start properly"-mode and startx didnt find the fglrx module .(
Is that a kernel compatibility issue? Can I install... |
FGLRX has very poor performance (among other issues, which may include kernel compatibility issues with newer kernels). Heed my advice: You need to use the Open-Source Radeon drivers.
https://wiki.debian.org/AtiHowTo
I'm running Kernel 3.14+ on an ATI Radeon 5770HD with the Open-Source drivers.
The solution is not to ... | Kernel 3.14 not working with ATIProprietary fglrx? |
1,407,668,336,000 |
Why, on every Linux I've used, when a program is really I/O bound, it bogs the machine down? It just happened when I (accidentally) tried to make gcc compile a (valid!) 50Mb C file. GCC was so I/O intensive it brought the machine to its knees.
Another moment is when apt-get or similar are downloading packages, somet... |
Sorry this question is just too broad to address. We can only really deal with specific issues here. There are any number of reasons as to why this is happening. Often poor performance is just misunderstood by the user.
Is the system out of RAM?
does it have a slow HDD?
Is the system not setup optimally?
I'm not ... | I/O brings a machine to its knees [closed] |
1,407,668,336,000 |
I installed latest DD-WRT firmware to my wifi router WZR-HP-AG300H. I got the firmware from here (05-27-2013-r21676).
I'm currently trying to install XFS file system support because my USB hard disk is formatted with it, but unfortunately DD-WRT firmware doesn't seem to support it.
I found that XFS module can be insta... |
It seems almost impossible to determine which versions of the Linux kernel are included with all the DD-WRT firmware versions, so I think I'd take a different tactic here and attempt to compile the xfs module myself. There are numerous tutorials that explain in pretty good details how to accomplish this.
Here are just... | DD-WRT on WZR-HP-AG300H: Want XFS support; what firmware has kernel 3.8.13-1? |
1,407,668,336,000 |
What are the standard and conventional ways of profiling the Linux kernel? I know there is perf tool but is there anything else?
|
I can suggest you using SystemTap using which you can add probe points to a running linux kernel. It is similar to DTrace which is similar tool developed for Solaris. You can write simple stap script to perform interesting tasks.
| Where to start profiling Linux kernel? |
1,407,668,336,000 |
We want to disable swap on all our RHEL servers (Hadoop servers). We have 2 options:
Set swappiness to 0, and swapoff -a & swapon -a
swapoff -a , and disable swap from fstab
From my understanding, both options disable swap completely
Option 2 for sure, since we swapoff -a and disable the swap from fstab.
But does o... |
What happened when you tested it?
Did you read the documentation?
A value of 0 instructs the kernel not to initiate swap until the amount of free and file-backed pages is less than the high water mark in a zone.
i.e., a value of zero does not disable swap, it just defers it.
| what is the different between settings swappiness to 0 to swapoff |
1,407,668,336,000 |
I have a theoretical question,
What would happen if I clean up all the swap space while running,
Would the operating system crash because of page faults that would happen in the kernel?
|
If you just mean running "swapoff -a" when you say "clean up", then no.
If you corrupt/overwrite the swap device/file, an application that gets swapped back in (with corrupted data) is very likely to crash, yes. The kernel does not get swapped out, so the "system" would not crash.
| Cleaning swap space while running |
1,407,668,336,000 |
/proc is a directory we find in root in linux. it contains processes' information. but actually, process table and all that stuff is stored in kernel which is in RAM. please answer my query. I may sound silly as i am new here.
|
From the manual page:
The proc filesystem is a pseudo-filesystem which provides an interface to kernel data structures.
/proc is not secondary storage. /proc, just like /sys, is a filesystem that provides a window into the kernel. /proc/1234/cmdline, as an example, is not a disk file. It doesn't occupy any space wit... | Why process information is stored in /proc as process information is in kernel which is in RAM and /proc in secondary storage? |
1,407,668,336,000 |
Assuming that all filesystems are specific, how tools like ls, touch, cat, etc interacting with them? I suppose that 'ls' doesn't know specifics about btrfs for example, but it reads directory entries anyway. When some process writes a file, it doesn't to know about block allocator's specifics for particular filesyste... |
On any POSIX system, the interface between applications and the kernel is a few function calls: open, read, write, close, etc. An application such as cat calls those functions; it doesn't care how the functions are implemented under the hood.
On Unix systems, those functions are actually system calls: the application ... | Filesystem kernel API |
1,407,668,336,000 |
I'm trying to install Virtualbox 4.1 from the .run file since Pacman had the 4.0 version only. But when I try installing the file using sh filelocation/filename.run, it gives me the following error-
Please install the build and header files for your current Linux
kernel. The current kernel version is 2.6.38-ARCH
I... |
You need the "kernel26-headers" package installed so VirtualBox can compile it's accompanying modules
| Why do I get this error installing virtualbox-4.1 on Arch? |
1,407,668,336,000 |
as all know after kernel upgrade (on RHEL 7), reboot is necessary in order to update the kernel version
So after reboot we can verify the kernel version by uname -r
since we are using scripts for kernel upgrade,
we want to verify what is the right approach that machines are required reboot as results of kernel upgrade... |
as all know after kernel upgrade (on RHEL 7), reboot is necessary in order to update the kernel version
no, it's already upgraded; but to run a new kernel, you'll need to load the new kernel if you want to use it. Since Linux is not that cool, the only way to do that is effectively a reboot¹.
yum comes with a tool t... | how to identify if rhel 7 machine requires reboot after kernel update |
1,593,753,506,000 |
I have a Debian 10 system. It has secure boot enabled. I am trying to sign and load a new kernel module for virtualbox.
I generated a certificate and private key using openssl req -new -x509 -newkey rsa:2048 -keyout MOK.priv -outform DER -out MOK.der -days 36500 -subj "/CN=My Name/" -nodes. Then I imported this key wi... |
sbsign is for signing .efi binaries and other PE32(+) formatted executables.
sign-file comes along with the kernel source code (in the scripts directory of the source code tarball) and in the linux-kbuild-4.19 .deb package for Debian 10. It signs ELF-formatted binary files, which is what Linux kernel modules are.
You ... | Cryptic Error When Attempted to Sign Kernel Modules |
1,593,753,506,000 |
I understand that Busybox is a single executable file that contains a set of unix commands/utilities.
My question is do we need an underlying OS on which it will run or it can be run directly on the machine without a kernel. If it can be run without an explicit OS, who will handle the stuff like CPU scheduling, user &... |
If it can be run without an explicit OS, who will handle the stuff like CPU scheduling, user & role management, etc.
That should answer your first question already: Those are things a kernel does, and without kernel, programs that rely on those features just cannot run, which includes busybox.
As for a platform agno... | Can I run Busybox without having an OS installed on the machine? |
1,593,753,506,000 |
Does anybody know the meaning of the string "People's Front" in the linux kernel source Makefile name?
> uname -a
Linux debian 4.19.0-6-amd64 #1 SMP Debian 4.19.67-2+deb10u2 (2019-11-11) x86_64 GNU/Linux
Just installed the kernel source from the debian official repository
> sudo apt-get install linux-source
the re... |
Most Linux kernel versions since 1.2 have included a NAME= field in their Makefile.
Wikipedia has a list of them: https://en.wikipedia.org/wiki/List_of_Linux_kernel_names
Note that the string "People's Front" is in double quotes, both the previous and the next names in the series, Merciless Moray and Shy Crocodile res... | linux kernel Makefile name="People's Front" |
1,593,753,506,000 |
I'm running Fedora 26, rpm -qa kernel outputs kernel-4.13.5-200.fc26.x86_64. And that's the one I want.
I had 3 kernels showing in grub, that one, and 2 newer ones, Wifi wasn't working when booting from the other two so I excluded kernel updates from dnf, and I removed the newer kernels sudo dnf remove kernel-4.x.
Al... |
You can set your default entry without removing the newest kernel through grub2-set-default command. In your case without updating grub2 use:
grub2-set-default 2
After grub update you should have tow kernel on your grub 2 configuration file the command should be (the first kernel is 0 the second one is 1):
grub2-mkco... | Grub boots from kernels that I removed |
1,593,753,506,000 |
the kernel version for debian 8 use 3.10. But under /sys/fs/cgroup/cpu, miss a lot of cpu items.
vagrant@debian-jessie:/sys/fs/cgroup/cpu$ ls -1 .
cgroup.clone_children
cgroup.procs
cgroup.sane_behavior
cpuacct.stat
cpuacct.usage
cpuacct.usage_percpu
cpu.shares
notify_on_release
release_agent
tasks
How do I enable cp... |
You recompile your kernel with CONFIG_CFS_BANDWIDTH=y.
There is a feature request about this already.
| Why cgroup cpu items are miss in Debian 8 |
1,593,753,506,000 |
When a page fault occurs for a virtual address for any process how does the linux/unix operating system determine whether that page (of that virtual address) was swapped previously present in memory and swapped out to disk (i.e. that page is currently present in swap space) or that page was never loaded to memory befo... |
The low level page fault handler in the OS (that is listed in the trap table from the CPU) get's the fault address from the CPU and uses this fault address to check the entries in process's address space description table.
This table contains a list of segment descriptors that each contain a base address and a size. I... | On page fault, how does Unix determine if the faulting address is in swap space? |
1,593,753,506,000 |
Today I learned that there had been a faulty Debian kernel version which caused ext4 data corruption (bug 1057843) in December 2023.
Searching through the /var/log/aptitude and /var/log/apt logs, I noticed that the faulty kernel version was installed for one full day by /usr/bin/unattended-upgrade .
The chronology:
0... |
As far as I understand, you are safe from this bug.
The only way to have the ext4 module changes to apply to the currently running non-buggy kernel would have been to first unmount all ext4 filesystems, then unload the old ext4 module and force-load the module from the buggy kernel version (overriding the kernel's pre... | Debian file corruption bug possible without reboot after unattended kernel update? |
1,593,753,506,000 |
Does anyone know if uname() makes an ioctl() call directly or indirectly? I reviewed the source, however didn't see that it does. I also used strace and did not see the kernel call made.
Thanks
strace uname
execve("/usr/bin/uname", ["una... |
The system call involved is … uname! You can see it in your trace:
uname({sysname="Linux", nodename="debian", ...}) = 0
It provides the operating system name, release, version etc.
| uname: what ioctl does it use? |
1,593,753,506,000 |
What is the technical minimum size for a functional (holds some pages) swap partition or file on Linux.
If it's architecture dependent, or depends on the size of physical memory or something, how would I calculate an estimate?
I'm not asking for recommendations, or viable sizes for a modern full-scale system. Just ho... |
So a swap file has some overhead because of header information and stuff.
If you try a too small file... in this case 1 byte
# dd if=/dev/zero of=tst1 bs=1c count=1
1+0 records in
1+0 records out
1 byte (1 B) copied, 0.000141358 s, 7.1 kB/s
# ls -l tst1
-rw-r--r-- 1 root root 1 Mar 10 22:19 tst1
# mkswap tst1
mkswap: ... | On Linux what is the technical minimum size for a functional swap partition |
1,593,753,506,000 |
on our RHEL servers , RHEL version - 7.2 , we saw many dmesg lines as:
example about sdb disk ( hard drive )
[Thu Dec 30 13:07:48 2021] EXT4-fs (sdb): error count since last fsck: 1329
[Thu Dec 30 13:07:48 2021] EXT4-fs (sdb): initial error at time 1614482941: ext4_find_entry:1312: inode 67240512
[Thu Dec 30 13:07:48 ... |
“Dying of old age” implies that the drive is old, which we can’t determine from the information in the logs.
However I’m assuming this is in a professional setting; if so, in my opinion, any disk medium error should trigger a disk replacement. The “critical medium error” message indicates that this is a disk error, no... | HDD IO errors from kernel messages + is this definitely a HDD failure |
1,593,753,506,000 |
I found this in my logs:
kernel: gpio gpiochip0: (gpio_aaeon): tried to insert a GPIO chip with zero lines
kernel: gpiochip_add_data_with_key: GPIOs 0..-1 (gpio_aaeon) failed to register, -22
kernel: gpio-aaeon: probe of gpio-aaeon.0 failed with error -22
What does it mean and how should I solve it?
lsb_release -a
No... |
Those messages are produced by the kernel General Purpose I/O code, apparently on trying to load the module that is introduced by this patch or its more developed equivalent.
Short version:
The module finds the WMI programming interface it's looking for, but overlooks the fact that the interface reports no controllabl... | What gpio gpiochip0 kernel error means and how to solve? |
1,593,753,506,000 |
How can I make registered extensions for binfmt_misc persist across reboots?
Consider the following command, which performs a binfmt_misc registration:
echo ':golang:E::go::/tmp/test:OC' | sudo tee /proc/sys/fs/binfmt_misc/register
It needs to be executed as root, since only root is allowed to write to /proc/sys/fs/b... |
Since you’re using Debian, you could install binfmt-support and register your extension using update-binfmts:
sudo update-binfmts --install golang /tmp/test --extension go --credentials yes
If that works, you can store the binfmt_misc specification in a file under /usr/share/binfmts, which will ensure it’s loaded eve... | How can I make registered extensions for `binfmt_misc` persist across reboots? |
1,593,753,506,000 |
I have a CentOS SFTP server which is critical for my company's operations. Currently, the server is running on a version of the Linux Kernel in which a vulnerability has been found:
Linux 3.10.0-1160.6.1.el7.x86_64 x86_64
I am trying to update CentOS with YUM, but it does not mention any missing update on the system. ... |
The Community Enterprise Linux Repository (ELRepo) focuses on kmod driver packages to enhance hardware support in EL6, EL7, and EL8 (including display, filesystem, hwmon, network, and storage drivers). Newer kernels are also available. Follow the ELRepo Home Page to install the elrepo-release package and import the G... | Vanilla CentOS: Do we need the ElRepo repository? |
1,593,753,506,000 |
I've been using CentOS 7 and its kernel version is 3.10. To check Kernel Version, I typed 'uname -r' and command showed 3.10.0-957.1.3.el7.x86_64
As far as I know, MemAvailable metric was introduced to Linux kernel version 3.14.
But, I ran /proc/meminfo and this command showed MemAvailable metric.
MemTotal: 388... |
Your kernel identifies itself as 3.10 because that’s the baseline ABI which is maintained for RHEL 7 (and CentOS 7). The ABI is preserved so that, among other things, kernel modules built with an earlier release of RHEL 7 will continue working, as-is, in later releases.
However, when this is possible without breaking ... | Why /proc/meminfo shows MemAvailable under Kernel Version 3.10? |
1,593,753,506,000 |
I have been asked to measure the contention of locks a write process is causing. I was looking at the data of the lockstat for that write process.
My questions are below:
Is contention related to the number of times threads wait for the particular lock, as it is taken by another thread or the time for which threads ... |
Looking at the Linux kernel docs it looks like it it's waiting for the lock to get freed.
- HOW
Lockdep already has hooks in the lock functions and maps lock instances to
lock classes. We build on that (see Documentation/locking/lockdep-design.txt).
The graph below shows the relation between the lock functions and th... | What is contention? [closed] |
1,593,753,506,000 |
I ask the following question as a followup to this question.
How come a Desktop Environment be one layer under a shell (kernel-DE-shell instead kernel-shell-DE)?
Why I ask this question
In Ubuntu, for example, both the Gnome Shell and Unity GUI for Gnome shell, are 2 layers above the Gnome Desktop Environment (DE), r... |
There is no primary shell.
If you’re running the default GNOME 3 desktop, then the stack is
Kernel → X.org or Wayland → GNOME session manager (which starts a number of GNOME helper applications) → GNOME Shell (which uses a number of GNOME libraries)
If you’re running Unity, then the stack is
Kernel → X.org or Mir o... | How come a Desktop Environment be one layer under a shell (kernel-DE-shell instead kernel-shell-DE)? [closed] |
1,593,753,506,000 |
I was browsing through kernel.org pages and reading changelogs from several different Linux kernel versions. I noticed the version number pattern is extremely awkward:
From Linux 2.6.x came Linux 3.0;
After it reached 3.19 it became 4.0;
The 4.x version is getting new versions at a surprisingly fast pace: Ubuntu 15.10... |
The reason to move from 3.19 to 4.0 is just to keep things simple. There was a public poll and discussion about that. I believe this is the poll: https://plus.google.com/+LinusTorvalds/posts/jmtzzLiiejc
So yes, linux kernel is rapidly developed and those switching is just in order to keep things simple.
| Why are Linux versions so confusing? |
1,593,753,506,000 |
I understand that Oracle doesn't provide sources for Solaris any more, as was done via OpenSolaris in the past. However, they do offer live CD images.
How much does a system installed with such images provide? I'm interested in Solaris from an academic perspective, such as studying Solaris device driver model. Will I ... |
You shouldn't be using the live media for this at all. That creates a new in-memory instance of the OS on every boot, with nothing saved from the previous boot. This means that if you write any code and save it, it is being saved to a RAM disk that will go away when you reboot. You could save your changes to some othe... | Writing drivers for Oracle Solaris |
1,593,753,506,000 |
After using Alsa and PulseAudio for a while, I feel they are not yet strong enough for Audio capture and audio playback.
When I test with loud-speaker and microphone, there is self feedback-loop.
When I test with some internal PCI-Express card, Linux audio creates static white noise.
It seems that a lot of problems ex... |
I'm not exactly sure what you meant with "ALSA or PulseAudio", I assume you meant PulseAudio over ALSA. I'm also in the dark, in regards to your distribution, so I'm prevented from being very specific. If you provide your distro + version, I can let you know if this problem has known workarounds. GNU/Linux audio h... | How to have CoreAudio from Mac to Linux/Unix? |
1,593,753,506,000 |
Can process execute new program without the kernel knowing? Usually, when the program is executing kernel gives to it its own process after receiving the syscall (such as exec() or fork()). In this case, everything goes through the kernel, which finally starts the program with, for example, ELF handler. In practice, o... |
Yes, this is possible. The already-running process needs to load (or map) the new program at the appropriate locations in the process’ virtual address space, load the dynamic loader if necessary, set up the required data structures on the stack, and jump to the new program’s entry point in memory. (Many of these opera... | Can process execute new program without the kernel knowing? |
1,593,753,506,000 |
When I login to a TTY/text terminal, I get a prompt that looks something like:
Debian GNU/Linux bookworm/sid ...
login:
I'm running testing, and purely for aesthetic purposes, I don't want it to say sid here. (Who would? I don't want to be reminded of this Pixar character every time I use my computer.) Is there a wa... |
That message is stored in /etc/issue and /etc/issue.net; you can edit them to display whatever you want instead.
These files are intended to be edited by administrators, and your changes will be preserved on upgrade (but you may be asked what to do with them).
| Change Debian TTY/text terminal login OS version name |
1,593,753,506,000 |
The latest official release of Linux kernel released by Centos is kernel-3.10.0-1160.45.1.el7.x86_64.rpm which is updated on 15th October 2021.
Furthermore, the kernel version recommended by CVE-2021-4326 is provided by a third party repository named ElRepo which means that the recommended kernel update is not yet su... |
The CentOS 7 and RHEL 7 kernels aren’t affected by CVE-2021-43267, so there’s no need to do anything.
| How to fix CVE-2021-43267 in centos 7 |
1,593,753,506,000 |
Despite having a data bus size of 64 bit, the address bus size of modern AMD64-compatible CPUs is/was 48 bit for some time which allows using 48-bit long virtual memory addresses with a maximum of addressable virtual memory of 2^48 => 256 TB.
Intel says [1] that since the Ice Lake CPU architecture, their CPUs support... |
No, they implement (at most) a 52-bit address bus. 4- and 5-level paging is described in section 4.5 of the Intel® 64 and IA-32 Architectures Software Developer Manuals, Volume 3A:
5-level paging translates 57-bit linear addresses to 52-bit physical addresses.
As far as I’m aware, current Intel CPUs support at most ... | Do CPUs that support 5-Level Papging implement a 57-bit long address bus? [closed] |
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