Red Bear OS
733da06876
fcntl(F_DUPFD_CLOEXEC) reached redox_rt/kernel with the POSIX/C value 1030 instead of the Redox syscall value (syscall::F_DUPFD_CLOEXEC=5). redox_rt did not recognize it as a dup, forwarded the raw command to the kernel, and the kernel's fcntl fell through to its EINVAL catch-all. That made OwnedFd::try_clone() return EINVAL, which broke tokio Runtime::build() (its I/O reactor try_clones the epoll fd) for every tokio user on Redox: all the zbus system daemons (sessiond/polkit/udisks/upower) and the login shell. F_DUPFD and plain dup worked because they share the same value in both namespaces; F_DUPFD_CLOEXEC was the sole untranslated command. Also drop the ineffective epoll_ctl EINVAL/EBADF retry loop: it was based on a disproven 'transient scheme churn' theory; epoll registrations always succeed immediately. The real dup failure is fixed above.
Redox C Library (relibc)
relibc is a portable C standard library written in Rust and is under heavy development, this library contains the following items:
- C, Linux, BSD functions and extensions
- POSIX compatibility layer
- Interfaces for system components
The motivation for this project is twofold: Reduce issues that the Redox developers were having with newlib, and create a more stable and safe alternative to C standard libraries written in C. It is mainly designed to be used under Redox, as an alternative to newlib, but it also supports Linux via the sc crate.
Currently Redox and Linux are supported.
redox-rt
redox-rt is a runtime library that provides much of the code that enables POSIX on Redox, like fork, exec, signal handling, etc.
Relibc uses it as backend in src/platform/redox, and it's intended to eventually be usable independently, without relibc.
Repository Layout
include- Header files (mostly macros and variadic functionscbindgencan't generate)src- Source filessrc/c- C codesrc/crt0- Runtime codesrc/crti- Runtime codesrc/crtn- Runtime codesrc/header- Header files implementationsrc/header/*- Each folder has acbindgen.tomlfile, it generates a C-to-Rust interface and header filessrc/ld_so- Dynamic loader codesrc/platform- Platform-specific and common codesrc/platform/redox- Redox-specific codesrc/platform/linux- Linux-specific codesrc/pthread- pthread implementationsrc/sync- Synchronization primitivestests- C tests (each MR needs to give success in all of them)
Download the sources
To download the relibc sources run the following command:
git clone --recursive https://gitlab.redox-os.org/redox-os/relibc
Build Instructions
To build relibc out of the Redox build system, do the following steps:
Dependencies
- Install
cbindgen
cargo install cbindgen
Install the expect tool
- Debian, Ubuntu and PopOS:
sudo apt install expect
- Fedora:
sudo dnf install expect
- Arch Linux:
sudo pacman -S expect
Build Relibc
To build the relibc library objects, run the following command:
make all
- Clean old library objects and tests
make clean
Build relibc inside the Redox build system
Inside of your Redox build system, run:
make prefix
If you need to rebuild relibc for testing a Cookbook recipe, run:
touch relibc
make prefix r.recipe-name
Touching (changing the "last modified time" of) the relibc folder is needed to trigger recompilation for make prefix. Replace recipe-name with your desired recipe name.
Note: Do not edit relibc inside prefix folder! Do your work on relibc folder directly inside your Redox build system instead.
Tests
Relibc has a test suite that also runs every time a new commit get pushed. You can see .gitlab-ci.yml to see how it's being executed. That being said, ./check.sh is the recommended way to run tests. Here's few examples:
./check.sh- Run build, without running the test./check.sh --test- Run all tests in x86_64 Redox using Redoxer./check.sh --test --host- Run all tests in host (Linux)./check.sh --test --arch=aarch64- Run all tests in specified arch- Arch can be
x86_64,aarch64,i586, orriscv64gc
- Arch can be
./check.sh --test=stdio/printf- Run a single test- Can be combined with
--hostor--arch - Will run statically linked test in Linux, dynamically linked in Redox
- Can be combined with
Couple of notes:
- Relibc and its tests will rebuild if files are changed, however switching between arch or host requires you to run
make clean - Redoxer is needed to run tests for Redox without
--host. You can install it usingcargo install redoxer - Tests can hang, the test runner can anticipate this, assuming the kernel doesn't hang too.
Issues
I'm building for my own platform which I run, and am getting x86_64-linux-gnu-ar: command not found (or similar)
The Makefile expects GNU compiler tools prefixed with the platform specifier, as would be present when you installed a cross compiler. Since you are building for your own platform, some Linux distributions (like Manjaro) don't install/symlink the prefixed executables.
An easy fix would be to replace the corresponding lines in config.mk, e.g.
ifeq ($(TARGET),x86_64-unknown-linux-gnu)
- export CC=x86_64-linux-gnu-gcc
- export LD=x86_64-linux-gnu-ld
- export AR=x86_64-linux-gnu-ar
- export NM=x86_64-linux-gnu-nm
+ export CC=gcc
+ export LD=ld
+ export AR=ar
+ export NM=nm
export OBJCOPY=objcopy
export CPPFLAGS=
LD_SO_PATH=lib/ld64.so.1
endif
Contributing
Before starting to contribute, read this document.
Supported OSes
- Redox OS
- Linux
Supported architectures
- i586 (Intel/AMD)
- x86_64 (Intel/AMD)
- aarch64 (ARM64)
- riscv64gc (RISC-V)
Funding - Unix-style Signals and Process Management
This project is funded through NGI Zero Core, a fund established by NLnet with financial support from the European Commission's Next Generation Internet program. Learn more at the NLnet project page.
