Redesign the interface to the unikernel HermitCore
We are developing the unikernel HermitCore, where the kernel is written in Rust and is already part of the Rust Standard Library. The interface between the standard library and the kernel based on a small C library. With this pull request, we remove completely the dependency to C and use lld as linker. Currently, the kernel will be linked to the application as static library, which is published at https://github.com/hermitcore/libhermit-rs.
We don’t longer support the C interface to the kernel. Consequently, we remove this part from the Rust Standard Library.
Fix check of `statx` and handle EPERM
Should fix#65662https://github.com/rust-lang/rust/issues/65662#issuecomment-544593939
> I think a reasonable solution might be to do something like try to stat AT_CWD initially and if that fails with EPERM or ENOSYS we disable the syscall entirely, otherwise it's cached as always good to use.
r? @alexcrichton
- Compatible with Emscripten 1.38.46-upstream or later upstream.
- Refactors the Emscripten target spec to share code with other wasm
targets.
- Replaces the old incorrect wasm32 C call ABI with the correct one,
preserving the old one as wasm32_bindgen_compat for wasm-bindgen
compatibility.
- Updates the varargs ABI used by Emscripten and deletes the old one.
- Removes the obsolete wasm32-experimental-emscripten target.
- Uses EMCC_CFLAGS on CI to avoid the timeout problems with #63649.
- the old interface between HermitCore and the Rust Standard Library
based on a small C library (newlib)
- remove this interface and call directly the unikernel
- remove the dependency to the HermitCore linker
- use rust-lld as linker
- Refactors the Emscripten target spec to share code with other wasm
targets.
- Replaces the incorrect wasm32 C call ABI with the old asmjs
version, which is correct for both wasm32 and JS.
- Updates the varargs ABI used by Emscripten and deletes the old one.
- Removes the obsolete wasm32-experimental-emscripten target.
- Temporarily makes Emscripten targets use panic=abort by default
because supporting unwinding will require an LLVM patch.
Fuchsia exit codes don't follow the convention of libc::WEXITSTATUS et
al, and they are 64 bits instead of 32 bits. This gives Fuchsia its own
representation of ExitStatus.
Additionally, the zircon syscall structs were out of date, causing us to
see bogus return codes.
libstd fuchsia fixes
This fixes two bugs in libstd on Fuchsia:
- `zx_time_t` was changed to an `i64`, but this never made it into libstd
- When spawning processes where any of the stdio were null, libstd attempts to open `/dev/null`, which doesn't exist on Fuchsia
r? @cramertj
This commit rejiggers the generics used in the implementation of
`Command::env` with the purpose of reducing the amount of codegen that
needs to happen in consumer crates, instead preferring to generate code
into libstd.
This was found when profiling the compile times of the `cc` crate where
the binary rlib produced had a lot of `BTreeMap` code compiled into it
but the crate doesn't actually use `BTreeMap`. It turns out that
`Command::env` is generic enough to codegen the entire implementation in
calling crates, but in this case there's no performance concern so it's
fine to compile the code into the standard library.
This change is done by removing the generic on the `CommandEnv` map
which is intended to handle case-insensitive variables on Windows.
Instead now a generic isn't used but rather a `use` statement defined
per-platform is used.
With this commit a debug build of `Command::new("foo").env("a", "b")`
drops from 21k lines of LLVM IR to 10k.
In sys/unix/process, we work around the sigemptyset linking issues
on android in two different ways. This change consolidates these
workarounds, and avoids duplicating bindings from `libc`.
provide thread name to OS for Solarish systems
Fixes#62302
Passes a Linux bootstrap build. python x.py test src/tools/tidy happy.
I tested this with a small test binary that spawns a few threads, and verified
that:
- on an illumos system lacking the libc function, the binary runs but no OS-level
thread names are set
- on an illumos system with the feature, the binary runs, and the thread names are
visible and correct under tools like MDB, pstack, core dump, etc.
filedesc: don't use ioctl(FIOCLEX) on Linux
All `ioctl(2)`s will fail on `O_PATH` file descriptors on Linux (because
they use `&empty_fops` as a security measure against `O_PATH` descriptors
affecting the backing file).
As a result, `File::try_clone()` and various other methods would always
fail with `-EBADF` on `O_PATH` file descriptors. The solution is to simply
use `F_SETFD` (as is used on other unices) which works on `O_PATH`
descriptors because it operates through the `fnctl(2)` layer and not
through `ioctl(2)`s.
Since this code is usually only used in strange error paths (a broken or
ancient kernel), the extra overhead of one syscall shouldn't cause any
dramas. Most other systems programming languages also use the fnctl(2)
so this brings us in line with them.
Fixes: rust-lang/rust#62314
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
All ioctl(2)s will fail on O_PATH file descriptors on Linux (because
they use &empty_fops as a security measure against O_PATH descriptors
affecting the backing file).
As a result, File::try_clone() and various other methods would always
fail with -EBADF on O_PATH file descriptors. The solution is to simply
use F_SETFD (as is used on other unices) which works on O_PATH
descriptors because it operates through the fnctl(2) layer and not
through ioctl(2)s.
Since this code is usually only used in strange error paths (a broken or
ancient kernel), the extra overhead of one syscall shouldn't cause any
dramas. Most other systems programming languages also use the fnctl(2)
so this brings us in line with them.
Fixes: rust-lang/rust#62314
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
