nexoniarz/SchOS
nexoniarz/SchOS
Watch
1
0
Fork
You've already forked SchOS
 0
Code Issues Pull requests Projects Releases 1 Packages Wiki Activity Actions
SchOS/NOTICE
Nexoniarz 14f0e4d0e2 kernel: processes have an environment now, and zsh is the shell 
Porting zsh found four defects in the kernel and one in the filesystem. None
of them were about zsh; all of them had been there the whole time.

**exec threw the environment away.** kernel/fs/exec.c wrote a single zero for
envp with the comment "(no environment)" -- not yet, but ever, for every
process. musl has been passing a perfectly good envp to execve (Linux 59, which
SchOS answers) and it was never read. So $TERM was unset, $PATH was whatever
each program invented, and a variable exported in a shell did not survive the
exec meant to carry it. exec() takes an envp, sys_exec reads argument three,
and schinit manifests grew an Environment key. The userland two-argument
exec(path, argv) stays as a wrapper that passes null explicitly -- the raw stub
is execve now, so a short caller cannot leave %rdx holding a stray pointer.

**Which overflowed the kernel stack.** Three pointer arrays, ~1.8 KB, on a
4096-byte stack, under exec -> loaduvm -> readi -> SchFS -> btree. Pid 1 went
down on the first exec. The canary caught it and named the process, which is
what it is for. They live in one kalloc'd page now.

**waitpid returned a bare -1** for both "no children" and "interrupted". musl
reads [-4095,-1] as -errno, so userspace saw EPERM; zsh printed "wait failed:
operation not permitted" and abandoned the rest of /etc/zsh/zshrc. -ECHILD and
-EINTR now. Third time a bare -1 has cost real time -- on a system with no
permission model, EPERM should be read as "a syscall returned -1".

**NVMA was 64.** musl's allocator takes a mapping per size class and does not
release them eagerly, so compinit ran out of slots and got -1, which is EPERM,
which malloc turns into NULL, which zsh reports as "fatal error: out of memory"
-- on a machine with 1000 MB free. 256 slots, and -ENOMEM.

**And a small write to SchFS costs 58 ms.** 200 writes to one open file take
11.75 s; the same to /dev/null take 0.14 s. That is the design stated at the
top of kmount.c -- one transaction group per operation, and a commit is two
flushes and an uberblock -- not a bug. But compdump writes its digest with
thousands of separate prints, so it takes minutes and looks like a hang.
compinit -D, which skips the dump, finishes in 3.6 s. This one is a decision
rather than a fix, so it is written up and left: /etc/zsh/zshrc keeps compinit
switched off and explains exactly why, with the measurements.

zsh runs as /bin/zsh and is the console shell. ZLE works -- arrow keys recall
history through terminfo, $COLUMNS reads the real 160 because TIOCGWINSZ was
fixed, colour and prompt expansion work, startup is 0.14 s. mksh keeps /bin/sh,
so schinit's no-jobs fallback is a different program from the one that could
have failed.

Also fixed while here: AT_CLKTCK was the literal 100 and is USER_HZ; the
extract rule in four ports could move a source tree inside itself when make
re-ran it, which is how zsh's configure came to write modfile=zsh-5.9/... into
config.modules and fail three steps later.

schfs-check passes. Full writeup in docs/history/kernel.md section 14.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VQ7Qx8E1q1M1bbCq8QLHS2
2026-09-12 23:26:50 +02:00

214 lines
11 KiB
Text
Raw Blame History

SchOS
Copyright 2026 Nexoniarz
This product includes software developed as part of the SchOS project,
licensed under the Apache License, Version 2.0. See LICENSE.
================================================================================
Third-party software
================================================================================
SchOS incorporates and redistributes software written by others. Their
licences apply to their code and are NOT superseded by the SchOS licence.
A built SchOS image contains binaries derived from all of the following.
--------------------------------------------------------------------------------
xv6-x86_64 / xv6 MIT License
--------------------------------------------------------------------------------
Copyright (c) 2006-2019 Frans Kaashoek, Robert Morris, Russ Cox,
Massachusetts Institute of Technology CSAIL
The SchIFT kernel is a derivative work of xv6. Substantial portions of
kernel/ -- notably the process, trap, virtual memory, buffer cache and v1
filesystem code -- descend from it, however heavily rewritten. The MIT licence
requires that this notice be preserved in all copies; see LICENSE.MIT.
--------------------------------------------------------------------------------
musl libc 1.2.5 MIT License
--------------------------------------------------------------------------------
Copyright (c) 2005-2020 Rich Felker and contributors
Built from ports/musl. Provides the C library every userland program links
against. See the extracted source's COPYRIGHT file for the full contributor
list, which the MIT terms require be carried along with binaries.
--------------------------------------------------------------------------------
toybox 0.8.12 Zero-Clause BSD (0BSD)
--------------------------------------------------------------------------------
Copyright (c) 2006-2024 Rob Landley and contributors
Built from ports/toybox. Supplies the standard command set in /bin. 0BSD
imposes no attribution requirement at all; this entry is courtesy, not
obligation.
--------------------------------------------------------------------------------
mksh R59c MirOS Licence
--------------------------------------------------------------------------------
Copyright (c) 2002-2023 Thorsten Glaser and contributors
Portions derived from the Public Domain Korn Shell (pdksh)
Built from ports/mksh. Supplies /bin/sh. The MirOS Licence is permissive and
requires the copyright notice be retained.
--------------------------------------------------------------------------------
zsh 5.9 MIT-like
--------------------------------------------------------------------------------
Copyright (c) 1992-2017 Paul Falstad, Richard Coleman, Zoltan Hidvegi,
Andrew Main, Peter Stephenson, Sven Wischnowsky, and others
Built from ports/zsh. Installed as /bin/zsh and used as the interactive shell;
/bin/sh remains mksh.
zsh's LICENCE notes that a few shell functions are licensed under the GNU
General Public Licence and states that, since no core function is affected,
those files may simply be omitted. They are. ports/zsh/Makefile removes four
files after extraction -- completions for darcs, qdbus, osc and zypper -- and
refuses to install if any of them is still present. No GPL-licensed file is
shipped in a SchOS image.
--------------------------------------------------------------------------------
ncurses 6.4 MIT License
--------------------------------------------------------------------------------
Copyright 2018-2022 Thomas E. Dickey
Copyright 1998-2018 Free Software Foundation, Inc.
Built from ports/ncurses. Linked into zsh so that its line editor can drive a
terminal, and into sysroot/bin/tinfotest. Built with --disable-database and
compiled-in fallbacks, so no terminfo files are installed.
--------------------------------------------------------------------------------
lwIP 2.2.0 BSD 3-Clause
--------------------------------------------------------------------------------
Copyright (c) 2001, 2002 Swedish Institute of Computer Science
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
3. The name of the author may not be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Fetched by ports/lwip and compiled into the kernel -- it is the TCP/IP stack,
not a userland library, so it is present in every built kernel image rather
than in a binary under /bin. The port layer written for SchOS
(kernel/net/lwip/) is Apache-2.0 and is not part of lwIP; lwIP's own sources
are unmodified. Clause 3 is a no-endorsement term, not the four-clause
advertising requirement, so it combines with Apache-2.0 without difficulty.
--------------------------------------------------------------------------------
Intel 8254x device identifiers BSD 3-Clause
--------------------------------------------------------------------------------
Copyright (c) 2001-2020, Intel Corporation
All rights reserved.
The PCI device IDs in include/e1000.h are transcribed from FreeBSD's
sys/dev/e1000/e1000_hw.h, which carries the Intel 3-clause BSD licence above
(verified: no advertising clause). Only the identifier constants are used --
data, not implementation. kernel/drivers/net/e1000/e1000.c is written from
Intel's public manual 317453 and contains no FreeBSD or Intel driver code.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the conditions of the 3-clause BSD
licence are met, including retention of this notice and the disclaimer, and
that neither the name of Intel Corporation nor the names of its contributors
are used to endorse or promote products derived from this software without
specific prior written permission.
--------------------------------------------------------------------------------
usb.ids -- USB vendor and product database BSD 3-Clause (dual-licensed)
--------------------------------------------------------------------------------
Maintained by Stephen J. Gowdy <linux.usb.ids@gmail.com>
http://www.linux-usb.org/usb.ids
Distributed by its maintainer under the terms of *either* the GNU General
Public License version 2 or later, *or* the 3-clause BSD Licence. SchOS takes
the BSD option; the GPL option is not exercised and could not be, since
Apache-2.0 and GPL-2.0-only cannot be combined (see docs/licensing.md section
2).
Shipped verbatim as /usr/share/usb.ids. Cached in dist/ and refreshed with
`make usb-ids`, never automatically -- the version and date are in the file's
own header, so what shipped is always knowable.
--------------------------------------------------------------------------------
Roboto Apache-2.0
--------------------------------------------------------------------------------
Copyright the Roboto Project Authors (https://github.com/googlefonts/roboto)
Shipped as /usr/share/fonts/Roboto-Regular.ttf, from ports/Roboto. Licensed
under Apache-2.0 -- the same licence as SchOS itself, so it carries no
obligation beyond this notice. Intended for the desktop, window manager and
compositor.
--------------------------------------------------------------------------------
JetBrains Mono SIL OFL 1.1
--------------------------------------------------------------------------------
Copyright 2020 The JetBrains Mono Project Authors
(https://github.com/JetBrains/JetBrainsMono)
Shipped as /usr/share/fonts/JetBrainsMono-Regular.ttf, from ports/JetBrains_Mono
(full licence text at ports/JetBrains_Mono/OFL.txt). Intended for the terminal
and TTY.
Under the SIL Open Font License 1.1 the font remains under OFL even inside this
Apache-2.0 system -- that does not reach any other part of SchOS -- and it may
not be sold on its own. Bundling it with an operating system is expressly
permitted. JetBrains Mono declares no Reserved Font Name, so a modified version
(a pre-rasterised bitmap, for instance) may keep the name.
--------------------------------------------------------------------------------
"New File System For XV6" MIT License
--------------------------------------------------------------------------------
Copyright (c) Qi Ma, Leyi Pan, Ao Sun, Peiran Xu
kernel/fs/fs.c and parts of tools/mkfs.c derive from this project, which extends
xv6's file system with features SchOS still uses today:
- the HTree hashed directory index (BKDRHash, HASHRANGE, the primary/overflow
bucket layout), after Daniel Phillips, "A Directory Index for EXT2",
5th Annual Linux Showcase & Conference, 2001
- Ext4-style extents (T_EXTENT)
- the inode bitmap
- symbolic links, file permissions, lseek and append
Licensed under the MIT License, which permits this use and requires that the
copyright notice and permission notice be retained. This entry is that
retention; it was missing until 2026-08-09 and is recorded here regardless of
what happens to the code, because the obligation attaches to every copy already
made.
Distinct from xv6 itself (LICENSE.MIT), which this project in turn derives from.
================================================================================
The build downloads upstream tarballs into dist/ and applies the patches in
ports/<name>/patches/. Nothing in ports/ is SchOS code; do not add first-party
work there. See docs/layout.md.
Licence questions -- what may be copied in, what may never be, and how to check
a NetBSD file's clause before using it -- are worked through in
docs/licensing.md.
fastfetch MIT
https://github.com/fastfetch-cli/fastfetch
Copyright (c) 2022 Linus Dierheimer and contributors
Built from source by ports/fastfetch and installed as /bin/fastfetch.
Unpatched: see the note at the top of that Makefile about why what it
cannot detect becomes work in the kernel rather than a patch here.
Reference in a new issue View git blame Copy permalink