Version 2.33.0/node v22.21.0 - Error: write EFAULT

sdetweil

@Mr.Sponti we are trying to get the system information for this output

[2025-11-21 10:30:49.475] [LOG] Launching application.
[2025-11-21 10:30:50.438] [INFO]

System Information

SYSTEM: manufacturer: System manufacturer; model: System Product Name; virtual: false; MM: 2.33>
OS: platform: linux; distro: Ubuntu; release: 22.04.5 LTS; arch: x64; kernel: 5.15.0-160-ge>
VERSIONS: electron: 38.3.0; used node: 22.20.0; installed node: 22.18.0; npm: 10.9.3; pm2: 6.0.13
ENV: XDG_SESSION_TYPE: x11; MM_CONFIG_FILE: undefined
WAYLAND_DISPLAY: undefined; DISPLAY: :0.0; ELECTRON_ENABLE_GPU: undefined
RAM: total: 48077.12 MB; free: 6870.40 MB; used: 41206.72 MB
OTHERS: uptime: 44548 minutes; timeZone: America/Chicago

but appears there is a fault.

Mr.Sponti

Here my System Information (started with: node --run start:wayland):

[2025-11-22 10:47:48.003] [LOG]   Sockets connected & modules started ...
[2025-11-22 10:47:49.223] [ERROR] Error: write EFAULT
    at afterWriteDispatched (node:internal/stream_base_commons:159:15)
    at writeGeneric (node:internal/stream_base_commons:150:3)
    at Socket._writeGeneric (node:net:966:11)
    at Socket._write (node:net:978:8)
    at writeOrBuffer (node:internal/streams/writable:572:12)
    at _write (node:internal/streams/writable:501:10)
    at Writable.write (node:internal/streams/writable:510:10)
    at execSync (node:child_process:999:20)
    at node:electron/js2c/node_init:2:17346
    at /home/pi/MagicMirror/node_modules/systeminformation/lib/system.js:175:28
    at ChildProcess.exithandler (node:child_process:410:7)
    at ChildProcess.emit (node:events:519:28)
    at maybeClose (node:internal/child_process:1101:16)
    at Socket.<anonymous> (node:internal/child_process:456:11)
    at Socket.emit (node:events:519:28)
    at Pipe.<anonymous> (node:net:346:12)
[2025-11-22 10:47:49.224] [LOG]   Node NOT Exiting...
[2025-11-22 10:47:49.395] [LOG]   Launching application.
[2025-11-22 10:47:56.485] [INFO]
####  System Information  ####
- SYSTEM:   manufacturer: Raspberry Pi Foundation; model: Raspberry Pi 4 Model B Rev 1.1; virtual: false; MM: 2.33.0
- OS:       platform: linux; distro: Debian GNU/Linux; release: 13; arch: arm64; kernel: 6.12.47+rpt-rpi-v8
- VERSIONS: electron: 38.1.2; used node: 22.19.0; installed node: 22.21.0; npm: 10.9.4; pm2: 6.0.13
- ENV:      XDG_SESSION_TYPE: tty; MM_CONFIG_FILE: undefined
            WAYLAND_DISPLAY:  wayland-0; DISPLAY: :0; ELECTRON_ENABLE_GPU: undefined
- RAM:      total: 906.64 MB; free: 449.86 MB; used: 456.78 MB
- OTHERS:   uptime: 21 minutes; timeZone: Europe/Berlin

Mr.Sponti

So, after further investigations I found the issue in the module: ./MagicMirror/node_modules/systeminformation/lib/system.js:175:28

I’m not a nodejs expert, but it seems that execSync returns a invalid or corrupted raw buffer. The encoding option solved the issue, as in my case execSync returns now an empty string.

const stdout = execSync('dmesg 2>/dev/null | grep -iE "virtual|hypervisor" | grep -iE "vmware|qemu|kvm|xen" | grep -viE "Nested Virtualization|/virtual/"', {encoding: 'utf-8'});

sdetweil

@Mr.Sponti if you take the contents of the execSync() and run it at the command line does it work?

Mr.Sponti

Yes, without any error, but also without any output!

sdetweil

@Mr.Sponti how about the 1st command

dmesg

In the line in the execSync it throws away any errors

Mr.Sponti

Sam, the kernel buffer does not include a line with ‘virtual’ or ‘hypervisor’. So, the retuen value of the execSync is a emty string.

pi@devpi:~ $ dmesg | grep virtual
pi@devpi:~ $ dmesg | grep hypervisor
pi@devpi:~ $ dmesg | grep zram0
[    4.928549] zram_generator::config[229]: zram0: system has too much memory (905MB), limit is 0MB, ignoring.
[    5.775275] systemd[1]: Expecting device dev-zram0.device - /dev/zram0...
[    5.977908] zram: Added device: zram0
[    6.771158] zram0: detected capacity change from 0 to 1853440
[    6.998349] Adding 926716k swap on /dev/zram0.  Priority:100 extents:1 across:926716k SS

sdetweil

@Mr.Sponti yep errors, too much ram. Etc

What is this running in?