Commit Graph

4 Commits

Author SHA1 Message Date
Miguel Ojeda
feadd06287 rust: alloc: add Vec::try_with_capacity{,_in}() constructors
Add `Vec::try_with_capacity()` and `Vec::try_with_capacity_in()` as
the fallible versions of `Vec::with_capacity()` and
`Vec::with_capacity_in()`, respectively.

The implementations follow the originals and use the previously
added `RawVec::try_with_capacity_in()`.

In turn, `Vec::try_with_capacity()` will be used to implement
the `CString` type (which wraps a `Vec<u8>`) in a later patch.

Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:15 +01:00
Miguel Ojeda
51d3a25ab3 rust: alloc: add RawVec::try_with_capacity_in() constructor
Add the `RawVec::try_with_capacity_in()` constructor as the fallible
version of `RawVec::with_capacity_in()`.

The implementation follows the original.

The infallible constructor is implemented in terms of the private
`RawVec::allocate_in()` constructor, thus also add the private
`RawVec::try_allocate_in()` constructor following the other.

It will be used to implement `Vec::try_with_capacity{,_in}()` in
the next patch.

Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:15 +01:00
Miguel Ojeda
057b8d2571 rust: adapt alloc crate to the kernel
This customizes the subset of the Rust standard library `alloc` that
was just imported as-is, mainly by:

  - Adding SPDX license identifiers.

  - Skipping modules (e.g. `rc` and `sync`) via new `cfg`s.

  - Adding fallible (`try_*`) versions of existing infallible methods
    (i.e. returning a `Result` instead of panicking).

    Since the standard library requires stable/unstable attributes,
    these additions are annotated with:

        #[stable(feature = "kernel", since = "1.0.0")]

    Using "kernel" as the feature allows to have the additions
    clearly marked. The "1.0.0" version is just a placeholder.

    (At the moment, only one is needed, but in the future more
    fallible methods will be added).

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Co-developed-by: Matthew Bakhtiari <dev@mtbk.me>
Signed-off-by: Matthew Bakhtiari <dev@mtbk.me>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-09-28 08:57:01 +02:00
Miguel Ojeda
753dece88d rust: import upstream alloc crate
This is a subset of the Rust standard library `alloc` crate,
version 1.62.0, licensed under "Apache-2.0 OR MIT", from:

    https://github.com/rust-lang/rust/tree/1.62.0/library/alloc/src

The files are copied as-is, with no modifications whatsoever
(not even adding the SPDX identifiers).

For copyright details, please see:

    https://github.com/rust-lang/rust/blob/1.62.0/COPYRIGHT

The next patch modifies these files as needed for use within
the kernel. This patch split allows reviewers to double-check
the import and to clearly see the differences introduced.

Vendoring `alloc`, at least for the moment, allows us to have fallible
allocations support (i.e. the `try_*` versions of methods which return
a `Result` instead of panicking) early on. It also gives a bit more
freedom to experiment with new interfaces and to iterate quickly.

Eventually, the goal is to have everything the kernel needs in
upstream `alloc` and drop it from the kernel tree.

For a summary of work on `alloc` happening upstream, please see:

    https://github.com/Rust-for-Linux/linux/issues/408

The following script may be used to verify the contents:

    for path in $(cd rust/alloc/ && find . -type f -name '*.rs'); do
        curl --silent --show-error --location \
            https://github.com/rust-lang/rust/raw/1.62.0/library/alloc/src/$path \
            | diff --unified rust/alloc/$path - && echo $path: OK
    done

Reviewed-by: Kees Cook <keescook@chromium.org>
Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-09-28 08:57:01 +02:00