This is a text-only version of the following page on https://raymii.org:
---
Title : The Adventure of the Missing Syscall: Error 38
Author : Dr. John Watson
Date : 24-10-2024 21:33
URL : https://raymii.org/s/fiction/The_Adventure_of_the_Missing_Syscall_Error_38.html
Format : Markdown/HTML
---
Sherlock Holmes tackles a modern computing dilemma involving a missing system call. In this case, a frustrated developer attempts to port an embedded device running Yocto to a newer version, only to be met with `Error 38` due to a missing syscall. Holmes and Watson delve into the intricacies of kernel versions, glibc, and system calls to uncover the truth behind the missing `syscall_397` and provide a logical solution.
Recently I removed all Google Ads from this site due to their invasive tracking, as well as Google Analytics. Please, if you found this content useful, consider a small donation using any of the options below:
I'm developing an open source monitoring app called Leaf Node Monitoring, for windows, linux & android. Go check it out!
Consider sponsoring me on Github. It means the world to me if you show your appreciation and you'll help pay the server costs.
You can also sponsor me by getting a Digital Ocean VPS. With this referral link you'll get $200 credit for 60 days. Spend $25 after your credit expires and I'll get $25!
Disclaimer: This story was written by AI, inspired by a real-world technical issue encountered
in the process of upgrading an embedded system.
I recently listened to the Sherlock Holmes novels on a populair audiobook platform,
I thought this would be entertaining. I did actually encounter this issue while upgrading
an older Yocto system. Resolved it by upgrading more parts of yocto and the application.
Please send me a message on how you feel about this content. It's an experiment, if you
dislike it, or like it, just [send me an email](/s/static/About.html#toc_1). Most articles
I write result in at least 20 messages so don't let me down on this one.
### The Adventure of the Missing Syscall: Error 38
It was a foggy evening in London when I, Dr. John Watson, found myself once
again in the company of my esteemed friend, Mr. Sherlock Holmes. The fire
crackled in the hearth of our Baker Street lodgings, casting flickering
shadows on the walls. Holmes was deep in thought, his sharp eyes fixed on a
peculiar set of logs displayed on his laptop screen.
"Watson," he began, without looking up, "we have a most intriguing case on our
hands. It appears that a system call, `syscall_397`, has gone missing,
leading to a rather perplexing error: Error 38."
I leaned over to examine the output of `strace` that Holmes had been
scrutinizing. The sequence of events was clear:
openat(AT_FDCWD, "/lib/libm.so.6", O_RDONLY|O_LARGEFILE|O_CLOEXEC) = 3
read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\0\3\0(\0\1\0\0\0\0\0\0\0004\0\0\0"..., 512) = 512
syscall_397(0x3, 0xb6f1ca0c, 0x1800, 0x7ff, 0xbece2e08, 0xbece3008) = -1 (errno 38)
close(3) = 0
writev(2, [{"./busybox.nosuid", 16}, {": ", 2}, {"error while loading shared libra"..., 36}, {": ", 2}, {"libm.so.6", 9}, {": ", 2}, {"cannot stat shared object", 25}, {": ", 2}, {"Error 38", 8}, {"\n", 1}], 10) = 103
Holmes tapped the screen. "Notice, Watson, the `syscall_397` returns `-1` with
`errno 38`. This indicates that the function is not implemented."
He continued, "But Watson, there's more to this tale. The case arose because a
software developer was attempting to port an embedded device running Yocto to
a newer version. He endeavored to run the device's current kernel, version
3.17, with a new root filesystem, built using `glibc 2.39` on Yocto 5. The
`error 38` emerged when the system was booted with the old kernel and new
rootfs, and when executing a binary compiled by Yocto on the current
machine's rootfs."
Despite Holmes' logical deductions, the developer's frustration had boiled
over. The once marvelously engineered device had become a stubborn relic. On
a stormy night, with rain battering the windows, the developer's patience
snapped. Seizing the device, he stormed out into the tempest in a fit of
rage.
Holmes and I followed, our coats flapping violently in the wind. We watched
from a distance as the developer, standing at the edge of a cliff, hurled the
device into the churning sea below. The dramatic scene, the device
disappearing into the dark waters, echoed the developer's despair.
Back at Baker Street, drenched but undeterred, Holmes resumed his analysis. He
leaned back in his chair, eyes twinkling with satisfaction as he lit his
pipe, the familiar scent of tobacco filling the room. "Watson, despite the
theatrics, the solution is clear. The kernel and glibc must be updated. The
storm may rage, but logic and reason will prevail."
I poured us both a cup of tea, the steam rising gently as I handed Holmes his
cup. "Holmes, this is all quite fascinating, but I must confess, I am still
somewhat bewildered. What exactly does all this mean?"
Holmes took a thoughtful puff from his pipe, the smoke curling lazily towards
the ceiling. "Ah, Watson, the intricacies of modern computing can indeed be
perplexing. Allow me to elucidate."
As I pondered the situation, Holmes delved deeper into the system's
architecture. He pulled up the syscall tables and kernel headers,
meticulously searching for any discrepancies.
"Look here, Watson," he said, pointing to the syscall table. "The
`syscall_397` is indeed listed as `statx`. However, in our current kernel
version, this entry is absent."
He navigated to the kernel headers, examining the definitions and
structures. "The headers confirm our suspicion. The necessary definitions for
`statx` are missing in this version."
Holmes continued, "The syscall table, found in `arch/arm/tools/syscall.tbl`,
maps system call numbers to their corresponding functions. This table ensures
that when a program makes a system call, the kernel knows which function to
execute. In our case, the absence of `syscall_397` means the kernel does not
recognize the `statx` call."
Finally, Holmes turned to the `errno.h` file. "The error code `38, ENOSYS`, is
defined as 'Function not implemented.' This aligns perfectly with our
findings."
With a final flourish, Holmes closed his laptop. "Watson, our investigation
into the syscall tables, kernel headers, and `errno.h` has confirmed the root
cause. The missing `syscall_397` is due to outdated kernel and glibc
versions. Updating them will restore the missing functionality."
As the fog lifted outside, I couldn't help but marvel at Holmes' unparalleled
deductive skills. Once again, he had turned a seemingly insurmountable
problem into a simple matter of logic and observation.
---
License:
All the text on this website is free as in freedom unless stated otherwise.
This means you can use it in any way you want, you can copy it, change it
the way you like and republish it, as long as you release the (modified)
content under the same license to give others the same freedoms you've got
and place my name and a link to this site with the article as source.
This site uses Google Analytics for statistics and Google Adwords for
advertisements. You are tracked and Google knows everything about you.
Use an adblocker like ublock-origin if you don't want it.
All the code on this website is licensed under the GNU GPL v3 license
unless already licensed under a license which does not allows this form
of licensing or if another license is stated on that page / in that software:
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see .
Just to be clear, the information on this website is for meant for educational
purposes and you use it at your own risk. I do not take responsibility if you
screw something up. Use common sense, do not 'rm -rf /' as root for example.
If you have any questions then do not hesitate to contact me.
See https://raymii.org/s/static/About.html for details.