From f41941aab3acd33f13d65a2ae496329bc8ae4de0 Mon Sep 17 00:00:00 2001 From: Gary Guo Date: Mon, 2 Mar 2026 16:42:35 +0000 Subject: rust: ptr: add projection infrastructure Add a generic infrastructure for performing field and index projections on raw pointers. This will form the basis of performing I/O projections. Pointers manipulations are intentionally using the safe wrapping variants instead of the unsafe variants, as the latter requires pointers to be inside an allocation which is not necessarily true for I/O pointers. This projection macro protects against rogue `Deref` implementation, which can causes the projected pointer to be outside the bounds of starting pointer. This is extremely unlikely and Rust has a lint to catch this, but is unsoundness regardless. The protection works by inducing type inference ambiguity when `Deref` is implemented. This projection macro also stops projecting into unaligned fields (i.e. fields of `#[repr(packed)]` structs), as misaligned pointers require special handling. This is implemented by attempting to create reference to projected field inside a `if false` block. Despite being unreachable, Rust still checks that they're not unaligned fields. The projection macro supports both fallible and infallible index projections. These are described in detail inside the documentation. Signed-off-by: Gary Guo Reviewed-by: Benno Lossin Acked-by: Miguel Ojeda Link: https://patch.msgid.link/20260302164239.284084-3-gary@kernel.org [ * Add intro-doc links where possible, * Fix typos and slightly improve wording, e.g. "as documentation describes" -> "as the documentation of [`Self::proj`] describes", * Add an empty line between regular and safety comments, before examples, and between logically independent comments, * Capitalize various safety comments. - Danilo ] Signed-off-by: Danilo Krummrich --- scripts/Makefile.build | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'scripts') diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 32e209bc7985..3652b85be545 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -310,16 +310,18 @@ $(obj)/%.lst: $(obj)/%.c FORCE # The features in this list are the ones allowed for non-`rust/` code. # +# - Stable since Rust 1.79.0: `feature(slice_ptr_len)`. # - Stable since Rust 1.81.0: `feature(lint_reasons)`. # - Stable since Rust 1.82.0: `feature(asm_const)`, # `feature(offset_of_nested)`, `feature(raw_ref_op)`. +# - Stable since Rust 1.84.0: `feature(strict_provenance)`. # - Stable since Rust 1.87.0: `feature(asm_goto)`. # - Expected to become stable: `feature(arbitrary_self_types)`. # - To be determined: `feature(used_with_arg)`. # # Please see https://github.com/Rust-for-Linux/linux/issues/2 for details on # the unstable features in use. -rust_allowed_features := asm_const,asm_goto,arbitrary_self_types,lint_reasons,offset_of_nested,raw_ref_op,used_with_arg +rust_allowed_features := asm_const,asm_goto,arbitrary_self_types,lint_reasons,offset_of_nested,raw_ref_op,slice_ptr_len,strict_provenance,used_with_arg # `--out-dir` is required to avoid temporaries being created by `rustc` in the # current working directory, which may be not accessible in the out-of-tree -- cgit v1.2.3 From 3cc319d5f433a4d560cc944ecfb1fe50b866cd66 Mon Sep 17 00:00:00 2001 From: Alexandre Courbot Date: Sat, 14 Mar 2026 10:06:11 +0900 Subject: rust: enable the `generic_arg_infer` feature This feature is stable since 1.89, and used in subsequent patches. Reviewed-by: Gary Guo Tested-by: Dirk Behme Acked-by: Miguel Ojeda Signed-off-by: Alexandre Courbot Link: https://patch.msgid.link/20260314-register-v9-1-86805b2f7e9d@nvidia.com [ Resolve merge conflict. - Danilo ] Signed-off-by: Danilo Krummrich --- rust/kernel/lib.rs | 3 +++ scripts/Makefile.build | 3 ++- 2 files changed, 5 insertions(+), 1 deletion(-) (limited to 'scripts') diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index d93292d47420..34b924819288 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -41,6 +41,9 @@ // Stable since Rust 1.84.0. #![feature(strict_provenance)] // +// Stable since Rust 1.89.0. +#![feature(generic_arg_infer)] +// // Expected to become stable. #![feature(arbitrary_self_types)] // diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 3652b85be545..010d08472fb2 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -316,12 +316,13 @@ $(obj)/%.lst: $(obj)/%.c FORCE # `feature(offset_of_nested)`, `feature(raw_ref_op)`. # - Stable since Rust 1.84.0: `feature(strict_provenance)`. # - Stable since Rust 1.87.0: `feature(asm_goto)`. +# - Stable since Rust 1.89.0: `feature(generic_arg_infer)`. # - Expected to become stable: `feature(arbitrary_self_types)`. # - To be determined: `feature(used_with_arg)`. # # Please see https://github.com/Rust-for-Linux/linux/issues/2 for details on # the unstable features in use. -rust_allowed_features := asm_const,asm_goto,arbitrary_self_types,lint_reasons,offset_of_nested,raw_ref_op,slice_ptr_len,strict_provenance,used_with_arg +rust_allowed_features := asm_const,asm_goto,arbitrary_self_types,generic_arg_infer,lint_reasons,offset_of_nested,raw_ref_op,slice_ptr_len,strict_provenance,used_with_arg # `--out-dir` is required to avoid temporaries being created by `rustc` in the # current working directory, which may be not accessible in the out-of-tree -- cgit v1.2.3