I'm aware that user-space programs have only their "portion" of the physical memory (and a little bit of the kernel memory that is necessary for context switches) mapped into their virtual address spaces, and (correct me if I'm wrong) on x86(_64), the entire physical memory is "mapped" into the kernel's address space. Does this also hold for other architectures, for example for ARM64? Is the entire physical memory always accessible to the kernel no matter the context that the kernel-space code is running in?

Hi all! Here’s my situation.

I have a react native application I’m working on with an iOS build on a physical phone. I use metro on my Mac to live sync file changes to the app. I also need to run new builds. But I prefer to use Linux for development for numerous reasons.

What I hope I can do is develop from my Linux machine and every time I save a file, I want those changes to trigger metro to refresh the app from my Mac.

I have a NAS share and my plan is to use the share as the repo source directory on both machines. When the file gets updated on the share from Linux, my Mac machine should detect the update and refresh metro.

Is this something that will work? Any gotchas? I don’t want to invest significant time trying to get this to work if it’s impossible or not worth the difficulty.

Thanks all!

I have the idea of building AI-powered OS. I just get into the field of Linux/VM and stuff. I'm just wondering what should I look into first? Whether to build on top of Virtual Box or must start from the OS itself. I really hope receiving as much ideas/contributions from you guys as I can!

Thanks for reading!

Hello, if possible could someone give a noobies guide on how to turn my usb stick into a way for me to unlock my disk password for me, i'm correctly dual booting windows 11 and Qubes OS and i want to have a way for me to get into Qubes OS while still having a safety on my Qubes OS but at the moment it takes 1-3 mins to get something up and going on qubes while it would just be easier to just launch windows and get in, within like 20-30 seconds, i tried asking an AI to help me make the usbkey but i don't think i did it right

Edit: Because i'm bad at writing, and people can't always read what i'm typing, i asked an AI to remake the message above

AI: The user is seeking guidance on how to use a USB stick as a key to unlock their Qubes OS disk password, aiming to streamline the boot process while maintaining security. They are currently dual-booting Windows 11 and Qubes OS but find the latter's startup time significantly longer, and their previous attempt to set up a USB key using AI assistance was unsuccessful.

I write software to monitor the health of computer systems, and I now get to port this software to Linux!

On MacOS, I am using the proc_pid_rusage function to get information about running processes. On Linux, I know I can get the same information by reading the /proc/${PROCESS_ID}/stat file, BUT my daemon will need to parse the text in those files to convert strings to integers (and the kernel has to convert integers to strings first!). Is there a more direct API I can call on linux to access process stats from within (for example) C code? What does top do on Linux?

Hi, I'm looking for an option to receive a message or notification on Android from Debian as a server.

• An application that is in the official Debian stable apt repositories, nothing from pip or others.
• On Android, it should be available on F-Droid.
• No intermediary server.
• No need to add accounts or use postfix, nor telegram-cli.

Example:
I need a script that indicates if a file exists in a directory, and if it does, I get the notification on Android.

TOX seems like the best option, being P2P it goes directly, but I can't find an app in apt that supports working with commands or scripts. I tried with toxic, but it doesn't work for automating a message.

It's basically about receiving a "yes" or "no" message on Android from Debian using tools available in the official Debian Stable and F-Droid repositories.

Thanks

I've been programming in Linux for years and always tacitly assumed the .tv_sec field from clock_gettime(CLOCK_REALTIME) was exactly equivalent to the value returned by time(). When some code of mine started acting oddly I determined it was because the code had made that assumption; but they are consistently different by one second. Yet both are described as seconds since Epoch.

My approach for ages has been to call time() and feed that to localtime() and now you know what time it is. But now I have two clocks so I don't know what time it is. There are situations where I really want clock_gettime() for the nanosecond field, but still need to produce a correct localtime() result.

Can someone explain best practice?

EDIT: for the curious:
Linux lachesis 4.15.0-99-generic #100-Ubuntu SMP Wed Apr 22 20:32:56 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

https://www.phoronix.com/news/Linus-2.6p-Faster-Scale-Patch

Ok so I have this status-script written in python for i3bar that, among other things, checks the network usage.

It uses the following function to look that up:

def network_usage(interface_name: str) -> str:
    with open("/sys/class/net/%s/statistics/rx_bytes" %interface_name) as fp_rx, \
         open("/sys/class/net/%s/statistics/tx_bytes" %interface_name) as fp_tx:
        pol1_ts = time_ns()
        rx_bytes_old: int = int(fp_rx.read())
        tx_bytes_old: int = int(fp_tx.read())
    sleep(0.25)
    with open("/sys/class/net/%s/statistics/rx_bytes" %interface_name) as fp_rx, \
         open("/sys/class/net/%s/statistics/tx_bytes" %interface_name) as fp_tx:
        pol2_ts = time_ns()
        rx_bytes_new: int = int(fp_rx.read())
        tx_bytes_new: int = int(fp_tx.read())
    rx_bytes_ps: float = (rx_bytes_new - rx_bytes_old) / ((pol2_ts - pol1_ts) / (10**9))
    tx_bytes_ps: float = (tx_bytes_new - tx_bytes_old) / ((pol2_ts - pol1_ts) / (10**9))
    byte_parser = lambda x:                              \
        f"{round(x)} BPS"            if x < 1000    else \
        f"{round(x / 1000)} KBPS"    if x < 1000**2 else \
        f"{round(x / 1000**2)} MBPS" if x < 1000**3 else \
        f"{round(x / 1000**3)} GBPS"
    return f"in {byte_parser(rx_bytes_ps)} - out {byte_parser(tx_bytes_ps)}"

Now, what I noticed is that the output of this function, is always a factor of 10 removed from the network usage Steam shows (e.g. if my script outputs 3 MBPS steam shows something like 27.8 MBps).
So is my math just wrong? (if so how exactly cause I'm stuck) or do the [r|t]x_bytes work differently than what this function assumes?

Sorry for the noobish question, thanks in advance!
(if it matters I'm using Debian 12.something)

Hi, I want to call a function which is there in a proprietary module from a GPL module.

If i do EXPORT_SYMBOL(function) in the proprietary module and call that function from GPL module. I am getting below error:

<GPL_file>: module using GPL-only symbols uses symbols from proprietary module <proprietary_module_name>

Looking for any legal ways I can use to access the function from GPL module.

Thanks in advance.

What am I doing wrong?

struct can_filter   g_socket_can_filter[CAN_MAX_FILTER_INDICES];

void
socket_can_filter_set
(uint8_t index, struct can_filter *filter)
{
    if (CAN_MAX_FILTER_INDICES > index)
    {
        g_socket_can_filter[index] = *filter;

        (void)setsockopt(g_socket_can_file_descriptor, SOL_CAN_RAW, CAN_RAW_FILTER,
            &g_socket_can_filter, sizeof(g_socket_can_filter));
    }
    return;
}

I can confirm that socket_can_filter_set() is getting called with appropriate parameters to effect a filtering of extended IDs of 0x10 with a mask of 0x3F. But then, when I send traffic for extended ID 0x0A on the bus, that traffic is making it past this filter. This filter is the only think in g_socket_can_filter[], which despite having CAN_MAX_FILTER_INDICES elements, only element 0 is being used. Is there a default-drop behaviour I should be setting somewhere?

I am writing an application overlay, a program that is mostly transparent and mostly unclickable. I have tested it a bunch on x11/gnome but users report errors to me with other desktop environments / display servers / compositors / window managers. It seems to be because each one of those is configured differently, especially the wayland compositors. Does anyone have experience writing automated tests for situations like this?

Hi all, I’m a comp sci student with most of my experience in c++ but a decent amount of experience with command line and I’m looking to get into shell scripting to learn software development better, especially at a root level

Any advice or resources I can use to learn more would be appreciated!

TLDR: looking to learn shell scripting, unsure where to start

Attempting to increase the volume level of samples produces clipping before it produces audio as loud as VLC or Audacity. I have to turn system volume to 100% (from 30%) to hear anything.

I know there's a multiplication, but also some technique to avoid clipping. My samples come from a 16-bit PCM WAV file. It's only a problem with my app. VLC behaves properly.

Rootfs was working fine to previously used uImage.

U-Boot 2018.09-00002-g0b54a51eee (Sep 10 2018 - 19:41:39 -0500), Build: jenkins-github_Bootloader-Builder-65

CPU : AM335X-GP rev 2.1

I2C: ready

DRAM: 512 MiB

No match for driver 'omap_hsmmc'

No match for driver 'omap_hsmmc'

Some drivers were not found

Reset Source: Power-on reset has occurred.

RTC 32KCLK Source: External.

MMC: OMAP SD/MMC: 0, OMAP SD/MMC: 1

Loading Environment from EXT4...

** Unable to use mmc 0:1 for loading the env **

Board: BeagleBone Black

<ethaddr> not set. Validating first E-fuse MAC

BeagleBone Black:

BeagleBone: cape eeprom: i2c_probe: 0x54:

BeagleBone: cape eeprom: i2c_probe: 0x55:

BeagleBone: cape eeprom: i2c_probe: 0x56:

BeagleBone: cape eeprom: i2c_probe: 0x57:

Net: eth0: MII MODE

cpsw, usb_ether

Press SPACE to abort autoboot in 2 seconds

board_name=[A335BNLT] ...

board_rev=[00C0] ...

switch to partitions #0, OK

mmc0 is current device

SD/MMC found on device 0

switch to partitions #0, OK

mmc0 is current device

Scanning mmc 0:1...

Found /extlinux/extlinux.conf

Retrieving file: /extlinux/extlinux.conf

119 bytes read in 2 ms (57.6 KiB/s)

1: Yocto

Retrieving file: /uImage

5334112 bytes read in 336 ms (15.1 MiB/s)

append: root=PARTUUID=a607f020-02 rootwait console=ttyS0,115200

Retrieving file: /am335x-boneblack.dtb

67160 bytes read in 6 ms (10.7 MiB/s)

Booting kernel from Legacy Image at 82000000 ...

Image Name: Linux-6.11.0-04557-g2f27fce67173

Created: 2024-09-18 10:21:14 UTC

Image Type: ARM Linux Kernel Image (uncompressed)

Data Size: 5334048 Bytes = 5.1 MiB

Load Address: 80000000

Entry Point: 80000000

Verifying Checksum ... OK

Flattened Device Tree blob at 88000000

Booting using the fdt blob at 0x88000000

Loading Kernel Image ... OK

Loading Device Tree to 8ffec000, end 8ffff657 ... OK

Starting kernel ...

Reboot again and again.

https://arstechnica.com/gadgets/2024/09/rust-in-linux-lead-retires-rather-than-deal-with-more-nontechnical-nonsense/

I want to make custom linux distribution based on Debain , I am trying to build it with live-build and calamares installer but there are many errors while building it, please guide me step by step

I want to make a cross platform drawing app that can take input from a drawing tablet, including pen pressure. Most libraries I would use for similar projects don't expose pen pressure in their APIs (SDL2, GLFW, SFML, etc.). As a result I'm considering doing window creation, OpenGL context creation, and input handling using the native platform APIs.

At this point I need to choose between using X11 or Wayland for my Linux version (I'll probably add the other eventually), and the available documentation is pushing me towards Wayland. X11 and the XInput2 extension are very poorly documented. Meanwhile, Wayland's protocols for drawing tablets are very nicely documented and well defined. The only thing keeping me from just jumping into Wayland is the number of people I could keep from using my app since (as far as I can tell) X11 is still used by the vast majority of Linux users.

Is there a better way forward? Should I start with Wayland? X11? Neither?

Vim Racer is a speed test for VIM! My goal with it is to help people learn new commands and navigate faster. It's similar to VIM golf, but the focus is speed and you can play it online.

The idea is to build something like this:

Virtualization for GPU that allows you to run local GPU apps and the code is actually run in the cloud, keeping your data local.

Functionality:

• vGPU is a virtualization layer for a GPU
• your local app "runs" on local vGPU
• local app decrypts the actual local data and sends the (CUDA) instructions to the remote GPU-Coortinator
• GPU-Coortinator distribute the instructions to multiple real GPUs
• then it sends the results back to vGPU which sends them to the local app

The advantage is your private data never leaves your network in plain. Only actual GPU instructions (CUDA instructions) are sent over the wire but encrypted with TLS.

I know it will be slow, but in cases where the data flow is small compared to processing time it could be a reasonable compromise for the security it gives you.

Also because instructions are distributed to multiple GPUs, when possible, it could offer better performance, in some cases, than locally

schema https://github.com/radumarias/rvirt-gpu/blob/main/website/resources/schema2.png

implementation ideas https://github.com/radumarias/rvirt-gpu/wiki/Implementation

I need to create a dice roll for different sized dice that needs to be crypto secure and eradicated sampling bias for the different sized dice. I'm using generand that uses dev/urandom and dev/random both according to reading are crypto secure on desktop PCs. And threshold to get rid of sampling bias. Is this the correct way to do it

unsigned long Dice::roll(unsigned long max_value) { if (max_value == 0) { return 0; // No valid range if max_value is 0 }

unsigned long random_value; unsigned long range = max_value + 1; unsigned long threshold = ULONG_MAX - (ULONG_MAX % range);

do { ssize_t result = getrandom(&random_value, sizeof(random_value), 0); if (result != sizeof(random_value)) { // Handle error, for example, by throwing an exception throw std::runtime_error("Failed to get random value"); } } while (random_value >= threshold);

return random_value % range; // add one when used for 1 to n size rolls }

Not because of GCC itself but because my build includes paths to GCC headers. Every time a new version of GCC appears, I have to manually update the header path in every project. The same also happens where clang is searching for headers for completion, symbol lookup and so on.

For example, today GCC changed from 14.1.1 to 14.2.1, and the path to its headers changed with it. Now all my builds fail unless I change header paths in several places. Is there some way to not require this? Can I get things to figure out where the current GCC headers are in an automated way?

After one year refactor, new CrossDB is born and open sourced. More features will be added.

Source Code

https://github.com/crossdb-org/CrossDB

Document

https://crossdb.org/

A proof-of-concept log monitoring solution built with a microservices architecture and containerization, designed to capture logs from a live application acting as the log simulator. This solution delivers actionable insights through dashboards, counters, and detailed metrics based on the generated logs. Think of it as a very lightweight internal tool for monitoring logs in real-time. All the core infrastructure (e.g., ECS, ECR, S3, Lambda, CloudWatch, Subnets, VPCs, etc...) deployed on AWS via Terraform.

There's some Linux internals/deployment specifics within the ECS module of the terraform config on the project's respective GH repo below... if any of you want to take a look and provide any feedback, that'd be great!

Feel free to take a look and give some feedback on the project :) https://github.com/akkik04/Trace

Hey everyone,

I’m at a crossroads and could really use some advice from this community.

I’ve been working on system tools and applications in Python for a while, but I’m realizing that I’ll eventually need to switch to a compiler-based language. My long-term goals involve some pretty low-level work, such as:

• Writing system tools and applications
• Kernel and driver development
• (Possibly) diving into compiler design and other foundational areas
• Focusing heavily on networking and related tech

I’m not really into high-level stuff—it doesn’t appeal to me as much as getting deep into the system does.

Here’s where I’m stuck: I’m trying to choose the right programming language for these tasks, but I’m torn between a few options:

• C: I love it for its power and simplicity, but memory safety is a concern.
• C++: Not interested in this one, to be honest.
• Java: I like it, but I’m unsure if it’s the best fit for low-level work due to the JVM.
• Rust: Looks promising, but the learning curve is steep.
• Go: I’ve heard great things, but I haven’t tried it yet.
• Zig: Same as Go—sounds interesting, but I haven’t had a chance to explore it.

I’d appreciate any suggestions or insights from those of you who have experience in these areas. What would you recommend based on my goals? Any resources, would be super helpful.