From: Danilo Krummrich <dakr@xxxxxxxxxx> commit eb6f92cd3f755c179204ea1f933b07cf992892fd upstream. The current implementation of tests in str.rs use `format!` to format strings for comparison, which, internally, creates a new `String`. In order to prepare for getting rid of Rust's alloc crate, we have to cut this dependency. Instead, implement `format!` for `CString`. Note that for userspace tests, `Kmalloc`, which is backing `CString`'s memory, is just a type alias to `Cmalloc`. Reviewed-by: Alice Ryhl <aliceryhl@xxxxxxxxxx> Reviewed-by: Benno Lossin <benno.lossin@xxxxxxxxx> Reviewed-by: Gary Guo <gary@xxxxxxxxxxx> Signed-off-by: Danilo Krummrich <dakr@xxxxxxxxxx> Link: https://lore.kernel.org/r/20241004154149.93856-27-dakr@xxxxxxxxxx Signed-off-by: Miguel Ojeda <ojeda@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- rust/kernel/str.rs | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) --- a/rust/kernel/str.rs +++ b/rust/kernel/str.rs @@ -524,7 +524,28 @@ macro_rules! c_str { #[cfg(test)] mod tests { use super::*; - use alloc::format; + + struct String(CString); + + impl String { + fn from_fmt(args: fmt::Arguments<'_>) -> Self { + String(CString::try_from_fmt(args).unwrap()) + } + } + + impl Deref for String { + type Target = str; + + fn deref(&self) -> &str { + self.0.to_str().unwrap() + } + } + + macro_rules! format { + ($($f:tt)*) => ({ + &*String::from_fmt(kernel::fmt!($($f)*)) + }) + } const ALL_ASCII_CHARS: &'static str = "\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\x09\\x0a\\x0b\\x0c\\x0d\\x0e\\x0f\ Patches currently in stable-queue which might be from ojeda@xxxxxxxxxx are queue-6.12/drm-panic-avoid-reimplementing-iterator-find.patch queue-6.12/documentation-rust-add-coding-guidelines-on-lints.patch queue-6.12/rust-provide-proper-code-documentation-titles.patch queue-6.12/rust-alloc-make-allocator-module-public.patch queue-6.12/rust-alloc-remove-vecext-extension.patch queue-6.12/rust-alloc-implement-reallocfunc.patch queue-6.12/rust-alloc-separate-aligned_size-from-krealloc_aligned.patch queue-6.12/rust-enable-clippy-unnecessary_safety_comment-lint.patch queue-6.12/rust-alloc-update-module-comment-of-alloc.rs.patch queue-6.12/rust-kbuild-expand-rusttest-target-for-macros.patch queue-6.12/rust-error-use-core-alloc-layouterror.patch queue-6.12/rust-str-test-replace-alloc-format.patch queue-6.12/loongarch-use-asm_reachable.patch queue-6.12/rust-alloc-implement-allocator-for-kmalloc.patch queue-6.12/rust-alloc-implement-collect-for-intoiter.patch queue-6.12/rust-alloc-introduce-arraylayout.patch queue-6.12/rust-alloc-implement-vmalloc-allocator.patch queue-6.12/documentation-rust-discuss-in-the-guidelines.patch queue-6.12/rust-error-check-for-config-test-in-error-name.patch queue-6.12/rust-enable-clippy-ignored_unit_patterns-lint.patch queue-6.12/rust-enable-clippy-unnecessary_safety_doc-lint.patch queue-6.12/rust-alloc-add-box-to-prelude.patch queue-6.12/kbuild-rust-remove-the-alloc-crate-and-globalalloc.patch queue-6.12/rust-alloc-add-allocator-trait.patch queue-6.12/rust-treewide-switch-to-our-kernel-box-type.patch queue-6.12/rust-introduce-.clippy.toml.patch queue-6.12/rust-alloc-rename-kernelallocator-to-kmalloc.patch queue-6.12/rust-alloc-implement-cmalloc-in-module-allocator_test.patch queue-6.12/drm-panic-allow-verbose-version-check.patch queue-6.12/rust-map-__kernel_size_t-and-friends-also-to-usize-isize.patch queue-6.12/rust-alloc-add-module-allocator_test.patch queue-6.12/rust-replace-clippy-dbg_macro-with-disallowed_macros.patch queue-6.12/rust-alloc-add-__gfp_nowarn-to-flags.patch queue-6.12/rust-enable-clippy-s-check-private-items.patch queue-6.12/rust-error-make-conversion-functions-public.patch queue-6.12/rust-sort-global-rust-flags.patch queue-6.12/rust-alloc-implement-contains-for-flags.patch queue-6.12/rust-init-remove-unneeded.patch queue-6.12/rust-use-custom-ffi-integer-types.patch queue-6.12/rust-sync-remove-unneeded.patch queue-6.12/rust-treewide-switch-to-the-kernel-vec-type.patch queue-6.12/rust-alloc-implement-kvmalloc-allocator.patch queue-6.12/drm-panic-correctly-indent-continuation-of-line-in-list-item.patch queue-6.12/rust-alloc-implement-kernel-vec-type.patch queue-6.12/rust-workqueue-remove-unneeded.patch queue-6.12/rust-error-optimize-error-type-to-use-nonzero.patch queue-6.12/drm-panic-remove-unnecessary-borrow-in-alignment_pattern.patch queue-6.12/rust-alloc-remove-extension-of-std-s-box.patch queue-6.12/rust-block-fix-formatting-in-gendisk-doc.patch queue-6.12/rust-enable-rustdoc-unescaped_backticks-lint.patch queue-6.12/rust-fix-size_t-in-bindgen-prototypes-of-c-builtins.patch queue-6.12/rust-enable-clippy-undocumented_unsafe_blocks-lint.patch queue-6.12/rust-alloc-add-vec-to-prelude.patch queue-6.12/rust-alloc-implement-intoiterator-for-vec.patch queue-6.12/rust-alloc-implement-kernel-box.patch queue-6.12/drm-panic-remove-redundant-field-when-assigning-value.patch queue-6.12/rust-types-avoid-repetition-in-as-from-bytes-impls.patch queue-6.12/rust-start-using-the-attribute.patch queue-6.12/drm-panic-allow-verbose-boolean-for-clarity.patch queue-6.12/maintainers-add-entry-for-the-rust-alloc-module.patch queue-6.12/rust-alloc-fix-arraylayout-allocations.patch queue-6.12/drm-panic-prefer-eliding-lifetimes.patch