From db7193a5c9db4babbfc99798f2e636b12419c12b Mon Sep 17 00:00:00 2001 From: Ben Gooding Date: Sun, 7 May 2023 17:27:39 +0100 Subject: rust: lock: Add intra-doc links to the Backend trait Add missing intra-doc links to the Backend trait to make navigating the documentation easier. Suggested-by: Benno Lossin Link: https://lore.kernel.org/rust-for-linux/94625fe6-b87a-a8f0-5b2a-a8152d5f7436@proton.me/ Link: https://github.com/Rust-for-Linux/linux/issues/1001 Signed-off-by: Ben Gooding Link: https://lore.kernel.org/r/20230509202314.8248-1-ben.gooding.dev@gmail.com Signed-off-by: Miguel Ojeda --- rust/kernel/sync/lock.rs | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'rust') diff --git a/rust/kernel/sync/lock.rs b/rust/kernel/sync/lock.rs index a2216325632d..70a785f04754 100644 --- a/rust/kernel/sync/lock.rs +++ b/rust/kernel/sync/lock.rs @@ -72,8 +72,8 @@ pub unsafe trait Backend { /// A mutual exclusion primitive. /// -/// Exposes one of the kernel locking primitives. Which one is exposed depends on the lock backend -/// specified as the generic parameter `B`. +/// Exposes one of the kernel locking primitives. Which one is exposed depends on the lock +/// [`Backend`] specified as the generic parameter `B`. #[pin_data] pub struct Lock { /// The kernel lock object. @@ -126,7 +126,7 @@ impl Lock { /// A lock guard. /// -/// Allows mutual exclusion primitives that implement the `Backend` trait to automatically unlock +/// Allows mutual exclusion primitives that implement the [`Backend`] trait to automatically unlock /// when a guard goes out of scope. It also provides a safe and convenient way to access the data /// protected by the lock. #[must_use = "the lock unlocks immediately when the guard is unused"] -- cgit v1.2.3 From 917b2e00b90f7a0f21ab3f28e7cf165825a7aba7 Mon Sep 17 00:00:00 2001 From: Ariel Miculas Date: Wed, 26 Apr 2023 23:49:23 +0300 Subject: rust: helpers: sort includes alphabetically in rust/helpers.c Sort the #include directives of rust/helpers.c alphabetically and add a comment specifying this. The reason for this is to improve readability and to be consistent with the other files with a similar approach within 'rust/'. Suggested-by: Miguel Ojeda Link: https://github.com/Rust-for-Linux/linux/issues/1003 Signed-off-by: Ariel Miculas Reviewed-by: Martin Rodriguez Reboredo Reviewed-by: Gary Guo Link: https://lore.kernel.org/r/20230426204923.16195-1-amiculas@cisco.com Signed-off-by: Miguel Ojeda --- rust/helpers.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'rust') diff --git a/rust/helpers.c b/rust/helpers.c index bb594da56137..f946f2ea640a 100644 --- a/rust/helpers.c +++ b/rust/helpers.c @@ -16,16 +16,18 @@ * * All symbols are exported as GPL-only to guarantee no GPL-only feature is * accidentally exposed. + * + * Sorted alphabetically. */ #include #include #include #include -#include #include -#include +#include #include +#include #include __noreturn void rust_helper_BUG(void) -- cgit v1.2.3 From f39a97d0d8a765268b8de17f2e34393e7cb2cd2d Mon Sep 17 00:00:00 2001 From: Boqun Feng Date: Sat, 29 Jul 2023 18:29:03 -0700 Subject: rust: allocator: Use krealloc_aligned() in KernelAllocator::alloc This fixes the potential issue that when KernelAllocator is used, the allocation may be mis-aligned due to SLAB's alignment guarantee. Signed-off-by: Boqun Feng Reviewed-by: Andreas Hindborg Link: https://lore.kernel.org/r/20230730012905.643822-3-boqun.feng@gmail.com Signed-off-by: Miguel Ojeda --- rust/kernel/allocator.rs | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'rust') diff --git a/rust/kernel/allocator.rs b/rust/kernel/allocator.rs index 9363b527be66..d4a3670ef405 100644 --- a/rust/kernel/allocator.rs +++ b/rust/kernel/allocator.rs @@ -41,9 +41,9 @@ unsafe fn krealloc_aligned(ptr: *mut u8, new_layout: Layout, flags: bindings::gf unsafe impl GlobalAlloc for KernelAllocator { unsafe fn alloc(&self, layout: Layout) -> *mut u8 { - // `krealloc()` is used instead of `kmalloc()` because the latter is - // an inline function and cannot be bound to as a result. - unsafe { bindings::krealloc(ptr::null(), layout.size(), bindings::GFP_KERNEL) as *mut u8 } + // SAFETY: `ptr::null_mut()` is null and `layout` has a non-zero size by the function safety + // requirement. + unsafe { krealloc_aligned(ptr::null_mut(), layout, bindings::GFP_KERNEL) } } unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) { -- cgit v1.2.3 From 0beaf546b4f198dd767b5a01a73f24db269ff6e2 Mon Sep 17 00:00:00 2001 From: Björn Roy Baron Date: Sat, 29 Jul 2023 18:29:04 -0700 Subject: rust: alloc: Add realloc and alloc_zeroed to the GlobalAlloc impl MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit While there are default impls for these methods, using the respective C api's is faster. Currently neither the existing nor these new GlobalAlloc method implementations are actually called. Instead the __rust_* function defined below the GlobalAlloc impl are used. With rustc 1.71 these functions will be gone and all allocation calls will go through the GlobalAlloc implementation. Link: https://github.com/Rust-for-Linux/linux/issues/68 Signed-off-by: Björn Roy Baron [boqun: add size adjustment for alignment requirement] Signed-off-by: Boqun Feng Reviewed-by: Andreas Hindborg Link: https://lore.kernel.org/r/20230730012905.643822-4-boqun.feng@gmail.com Signed-off-by: Miguel Ojeda --- rust/kernel/allocator.rs | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'rust') diff --git a/rust/kernel/allocator.rs b/rust/kernel/allocator.rs index d4a3670ef405..72d66c23883c 100644 --- a/rust/kernel/allocator.rs +++ b/rust/kernel/allocator.rs @@ -51,6 +51,33 @@ unsafe impl GlobalAlloc for KernelAllocator { bindings::kfree(ptr as *const core::ffi::c_void); } } + + unsafe fn realloc(&self, ptr: *mut u8, layout: Layout, new_size: usize) -> *mut u8 { + // SAFETY: + // - `new_size`, when rounded up to the nearest multiple of `layout.align()`, will not + // overflow `isize` by the function safety requirement. + // - `layout.align()` is a proper alignment (i.e. not zero and must be a power of two). + let layout = unsafe { Layout::from_size_align_unchecked(new_size, layout.align()) }; + + // SAFETY: + // - `ptr` is either null or a pointer allocated by this allocator by the function safety + // requirement. + // - the size of `layout` is not zero because `new_size` is not zero by the function safety + // requirement. + unsafe { krealloc_aligned(ptr, layout, bindings::GFP_KERNEL) } + } + + unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 { + // SAFETY: `ptr::null_mut()` is null and `layout` has a non-zero size by the function safety + // requirement. + unsafe { + krealloc_aligned( + ptr::null_mut(), + layout, + bindings::GFP_KERNEL | bindings::__GFP_ZERO, + ) + } + } } #[global_allocator] -- cgit v1.2.3 From 49a9ef76740206d52e7393f6fe25fc764de8df32 Mon Sep 17 00:00:00 2001 From: Vinay Varma Date: Tue, 11 Apr 2023 17:17:15 +0800 Subject: scripts: `make rust-analyzer` for out-of-tree modules Adds support for out-of-tree rust modules to use the `rust-analyzer` make target to generate the rust-project.json file. The change involves adding an optional parameter `external_src` to the `generate_rust_analyzer.py` which expects the path to the out-of-tree module's source directory. When this parameter is passed, I have chosen not to add the non-core modules (samples and drivers) into the result since these are not expected to be used in third party modules. Related changes are also made to the Makefile and rust/Makefile allowing the `rust-analyzer` target to be used for out-of-tree modules as well. Link: https://github.com/Rust-for-Linux/linux/pull/914 Link: https://github.com/Rust-for-Linux/rust-out-of-tree-module/pull/2 Signed-off-by: Vinay Varma Link: https://lore.kernel.org/r/20230411091714.130525-1-varmavinaym@gmail.com Signed-off-by: Miguel Ojeda --- Makefile | 11 ++++++----- rust/Makefile | 6 ++++-- scripts/generate_rust_analyzer.py | 27 ++++++++++++++++++--------- 3 files changed, 28 insertions(+), 16 deletions(-) (limited to 'rust') diff --git a/Makefile b/Makefile index 6bbf9db6b414..64ec209b26f0 100644 --- a/Makefile +++ b/Makefile @@ -1859,11 +1859,6 @@ rustfmt: rustfmtcheck: rustfmt_flags = --check rustfmtcheck: rustfmt -# IDE support targets -PHONY += rust-analyzer -rust-analyzer: - $(Q)$(MAKE) $(build)=rust $@ - # Misc # --------------------------------------------------------------------------- @@ -1924,6 +1919,7 @@ help: @echo ' modules - default target, build the module(s)' @echo ' modules_install - install the module' @echo ' clean - remove generated files in module directory only' + @echo ' rust-analyzer - generate rust-project.json rust-analyzer support file' @echo '' __external_modules_error: @@ -2065,6 +2061,11 @@ quiet_cmd_tags = GEN $@ tags TAGS cscope gtags: FORCE $(call cmd,tags) +# IDE support targets +PHONY += rust-analyzer +rust-analyzer: + $(Q)$(MAKE) $(build)=rust $@ + # Script to generate missing namespace dependencies # --------------------------------------------------------------------------- diff --git a/rust/Makefile b/rust/Makefile index 4124bfa01798..1ffdff6c2a34 100644 --- a/rust/Makefile +++ b/rust/Makefile @@ -373,8 +373,10 @@ quiet_cmd_rustc_library = $(if $(skip_clippy),RUSTC,$(RUSTC_OR_CLIPPY_QUIET)) L $(if $(rustc_objcopy),;$(OBJCOPY) $(rustc_objcopy) $@) rust-analyzer: - $(Q)$(srctree)/scripts/generate_rust_analyzer.py $(srctree) $(objtree) \ - $(RUST_LIB_SRC) > $(objtree)/rust-project.json + $(Q)$(srctree)/scripts/generate_rust_analyzer.py \ + $(abs_srctree) $(abs_objtree) \ + $(RUST_LIB_SRC) $(KBUILD_EXTMOD) > \ + $(if $(KBUILD_EXTMOD),$(extmod_prefix),$(objtree))/rust-project.json redirect-intrinsics = \ __eqsf2 __gesf2 __lesf2 __nesf2 __unordsf2 \ diff --git a/scripts/generate_rust_analyzer.py b/scripts/generate_rust_analyzer.py index 946e250c1b2a..848fa1ad92ba 100755 --- a/scripts/generate_rust_analyzer.py +++ b/scripts/generate_rust_analyzer.py @@ -6,10 +6,11 @@ import argparse import json import logging +import os import pathlib import sys -def generate_crates(srctree, objtree, sysroot_src): +def generate_crates(srctree, objtree, sysroot_src, external_src): # Generate the configuration list. cfg = [] with open(objtree / "include" / "generated" / "rustc_cfg") as fd: @@ -65,7 +66,7 @@ def generate_crates(srctree, objtree, sysroot_src): [], is_proc_macro=True, ) - crates[-1]["proc_macro_dylib_path"] = "rust/libmacros.so" + crates[-1]["proc_macro_dylib_path"] = f"{objtree}/rust/libmacros.so" append_crate( "build_error", @@ -95,19 +96,26 @@ def generate_crates(srctree, objtree, sysroot_src): "exclude_dirs": [], } + def is_root_crate(build_file, target): + try: + return f"{target}.o" in open(build_file).read() + except FileNotFoundError: + return False + # Then, the rest outside of `rust/`. # # We explicitly mention the top-level folders we want to cover. - for folder in ("samples", "drivers"): - for path in (srctree / folder).rglob("*.rs"): + extra_dirs = map(lambda dir: srctree / dir, ("samples", "drivers")) + if external_src is not None: + extra_dirs = [external_src] + for folder in extra_dirs: + for path in folder.rglob("*.rs"): logging.info("Checking %s", path) name = path.name.replace(".rs", "") # Skip those that are not crate roots. - try: - if f"{name}.o" not in open(path.parent / "Makefile").read(): - continue - except FileNotFoundError: + if not is_root_crate(path.parent / "Makefile", name) and \ + not is_root_crate(path.parent / "Kbuild", name): continue logging.info("Adding %s", name) @@ -126,6 +134,7 @@ def main(): parser.add_argument("srctree", type=pathlib.Path) parser.add_argument("objtree", type=pathlib.Path) parser.add_argument("sysroot_src", type=pathlib.Path) + parser.add_argument("exttree", type=pathlib.Path, nargs="?") args = parser.parse_args() logging.basicConfig( @@ -134,7 +143,7 @@ def main(): ) rust_project = { - "crates": generate_crates(args.srctree, args.objtree, args.sysroot_src), + "crates": generate_crates(args.srctree, args.objtree, args.sysroot_src, args.exttree), "sysroot_src": str(args.sysroot_src), } -- cgit v1.2.3 From 35cad617df2eeef8440a38e82bb2d81ae32ca50d Mon Sep 17 00:00:00 2001 From: Alice Ryhl Date: Wed, 14 Jun 2023 11:53:28 +0000 Subject: rust: make `UnsafeCell` the outer type in `Opaque` When combining `UnsafeCell` with `MaybeUninit`, it is idiomatic to use `UnsafeCell` as the outer type. Intuitively, this is because a `MaybeUninit` might not contain a `T`, but we always want the effect of the `UnsafeCell`, even if the inner value is uninitialized. Now, strictly speaking, this doesn't really make a difference. The compiler will always apply the `UnsafeCell` effect even if the inner value is uninitialized. But I think we should follow the convention here. Signed-off-by: Alice Ryhl Reviewed-by: Benno Lossin Reviewed-by: Gary Guo Reviewed-by: Martin Rodriguez Reboredo Link: https://lore.kernel.org/r/20230614115328.2825961-1-aliceryhl@google.com Signed-off-by: Miguel Ojeda --- rust/kernel/types.rs | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'rust') diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs index d479f8da8f38..c0b8bb1a7539 100644 --- a/rust/kernel/types.rs +++ b/rust/kernel/types.rs @@ -206,17 +206,17 @@ impl Drop for ScopeGuard { /// /// This is meant to be used with FFI objects that are never interpreted by Rust code. #[repr(transparent)] -pub struct Opaque(MaybeUninit>); +pub struct Opaque(UnsafeCell>); impl Opaque { /// Creates a new opaque value. pub const fn new(value: T) -> Self { - Self(MaybeUninit::new(UnsafeCell::new(value))) + Self(UnsafeCell::new(MaybeUninit::new(value))) } /// Creates an uninitialised value. pub const fn uninit() -> Self { - Self(MaybeUninit::uninit()) + Self(UnsafeCell::new(MaybeUninit::uninit())) } /// Creates a pin-initializer from the given initializer closure. @@ -240,7 +240,7 @@ impl Opaque { /// Returns a raw pointer to the opaque data. pub fn get(&self) -> *mut T { - UnsafeCell::raw_get(self.0.as_ptr()) + UnsafeCell::get(&self.0).cast::() } /// Gets the value behind `this`. @@ -248,7 +248,7 @@ impl Opaque { /// This function is useful to get access to the value without creating intermediate /// references. pub const fn raw_get(this: *const Self) -> *mut T { - UnsafeCell::raw_get(this.cast::>()) + UnsafeCell::raw_get(this.cast::>>()).cast::() } } -- cgit v1.2.3 From 0b4e3b6f6b79b1add04008a6ceaaf661107e8902 Mon Sep 17 00:00:00 2001 From: Benno Lossin Date: Fri, 30 Jun 2023 15:03:23 +0000 Subject: rust: types: make `Opaque` be `!Unpin` Adds a `PhantomPinned` field to `Opaque`. This removes the last Rust guarantee: the assumption that the type `T` can be freely moved. This is not the case for many types from the C side (e.g. if they contain a `struct list_head`). This change removes the need to add a `PhantomPinned` field manually to Rust structs that contain C structs which must not be moved. Signed-off-by: Benno Lossin Reviewed-by: Gary Guo Reviewed-by: Alice Ryhl Reviewed-by: Andreas Hindborg Link: https://lore.kernel.org/r/20230630150216.109789-1-benno.lossin@proton.me Signed-off-by: Miguel Ojeda --- rust/kernel/types.rs | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) (limited to 'rust') diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs index c0b8bb1a7539..50cbd767ea9d 100644 --- a/rust/kernel/types.rs +++ b/rust/kernel/types.rs @@ -6,7 +6,7 @@ use crate::init::{self, PinInit}; use alloc::boxed::Box; use core::{ cell::UnsafeCell, - marker::PhantomData, + marker::{PhantomData, PhantomPinned}, mem::MaybeUninit, ops::{Deref, DerefMut}, ptr::NonNull, @@ -206,17 +206,26 @@ impl Drop for ScopeGuard { /// /// This is meant to be used with FFI objects that are never interpreted by Rust code. #[repr(transparent)] -pub struct Opaque(UnsafeCell>); +pub struct Opaque { + value: UnsafeCell>, + _pin: PhantomPinned, +} impl Opaque { /// Creates a new opaque value. pub const fn new(value: T) -> Self { - Self(UnsafeCell::new(MaybeUninit::new(value))) + Self { + value: UnsafeCell::new(MaybeUninit::new(value)), + _pin: PhantomPinned, + } } /// Creates an uninitialised value. pub const fn uninit() -> Self { - Self(UnsafeCell::new(MaybeUninit::uninit())) + Self { + value: UnsafeCell::new(MaybeUninit::uninit()), + _pin: PhantomPinned, + } } /// Creates a pin-initializer from the given initializer closure. @@ -240,7 +249,7 @@ impl Opaque { /// Returns a raw pointer to the opaque data. pub fn get(&self) -> *mut T { - UnsafeCell::get(&self.0).cast::() + UnsafeCell::get(&self.value).cast::() } /// Gets the value behind `this`. -- cgit v1.2.3 From 823d4737d4c226699f4378b71675822f5ebe78ba Mon Sep 17 00:00:00 2001 From: Gary Guo Date: Wed, 28 Jun 2023 18:11:01 +0100 Subject: rust: macros: add `paste!` proc macro MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This macro provides a flexible way to concatenated identifiers together and it allows the resulting identifier to be used to declare new items, which `concat_idents!` does not allow. It also allows identifiers to be transformed before concatenated. The `concat_idents!` example let x_1 = 42; let x_2 = concat_idents!(x, _1); assert!(x_1 == x_2); can be written with `paste!` macro like this: let x_1 = 42; let x_2 = paste!([]); assert!(x_1 == x_2); However `paste!` macro is more flexible because it can be used to create a new variable: let x_1 = 42; paste!(let [] = [];); assert!(x_1 == x_2); While this is not possible with `concat_idents!`. This macro is similar to the `paste!` crate [1], but this is a fresh implementation to avoid vendoring large amount of code directly. Also, I have augmented it to provide a way to specify span of the resulting token, allowing precise control. For example, this code is broken because the variable is declared inside the macro, so Rust macro hygiene rules prevents access from the outside: macro_rules! m { ($id: ident) => { // The resulting token has hygiene of the macro. paste!(let [<$id>] = 1;) } } m!(a); let _ = a; In this version of `paste!` macro I added a `span` modifier to allow this: macro_rules! m { ($id: ident) => { // The resulting token has hygiene of `$id`. paste!(let [<$id:span>] = 1;) } } m!(a); let _ = a; Link: http://docs.rs/paste/ [1] Signed-off-by: Gary Guo Reviewed-by: Björn Roy Baron Reviewed-by: Benno Lossin Reviewed-by: Alice Ryhl Reviewed-by: Martin Rodriguez Reboredo Link: https://lore.kernel.org/r/20230628171108.1150742-1-gary@garyguo.net [ Added SPDX license identifier as discussed in the list and fixed typo. ] Signed-off-by: Miguel Ojeda --- rust/macros/lib.rs | 97 ++++++++++++++++++++++++++++++++++++++++++++++++++++ rust/macros/paste.rs | 96 +++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 193 insertions(+) create mode 100644 rust/macros/paste.rs (limited to 'rust') diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs index 3fc74cb4ea19..b4bc44c27bd4 100644 --- a/rust/macros/lib.rs +++ b/rust/macros/lib.rs @@ -7,6 +7,7 @@ mod quote; mod concat_idents; mod helpers; mod module; +mod paste; mod pin_data; mod pinned_drop; mod vtable; @@ -246,3 +247,99 @@ pub fn pin_data(inner: TokenStream, item: TokenStream) -> TokenStream { pub fn pinned_drop(args: TokenStream, input: TokenStream) -> TokenStream { pinned_drop::pinned_drop(args, input) } + +/// Paste identifiers together. +/// +/// Within the `paste!` macro, identifiers inside `[<` and `>]` are concatenated together to form a +/// single identifier. +/// +/// This is similar to the [`paste`] crate, but with pasting feature limited to identifiers +/// (literals, lifetimes and documentation strings are not supported). There is a difference in +/// supported modifiers as well. +/// +/// # Example +/// +/// ```ignore +/// use kernel::macro::paste; +/// +/// macro_rules! pub_no_prefix { +/// ($prefix:ident, $($newname:ident),+) => { +/// paste! { +/// $(pub(crate) const $newname: u32 = [<$prefix $newname>];)+ +/// } +/// }; +/// } +/// +/// pub_no_prefix!( +/// binder_driver_return_protocol_, +/// BR_OK, +/// BR_ERROR, +/// BR_TRANSACTION, +/// BR_REPLY, +/// BR_DEAD_REPLY, +/// BR_TRANSACTION_COMPLETE, +/// BR_INCREFS, +/// BR_ACQUIRE, +/// BR_RELEASE, +/// BR_DECREFS, +/// BR_NOOP, +/// BR_SPAWN_LOOPER, +/// BR_DEAD_BINDER, +/// BR_CLEAR_DEATH_NOTIFICATION_DONE, +/// BR_FAILED_REPLY +/// ); +/// +/// assert_eq!(BR_OK, binder_driver_return_protocol_BR_OK); +/// ``` +/// +/// # Modifiers +/// +/// For each identifier, it is possible to attach one or multiple modifiers to +/// it. +/// +/// Currently supported modifiers are: +/// * `span`: change the span of concatenated identifier to the span of the specified token. By +/// default the span of the `[< >]` group is used. +/// * `lower`: change the identifier to lower case. +/// * `upper`: change the identifier to upper case. +/// +/// ```ignore +/// use kernel::macro::paste; +/// +/// macro_rules! pub_no_prefix { +/// ($prefix:ident, $($newname:ident),+) => { +/// kernel::macros::paste! { +/// $(pub(crate) const fn [<$newname:lower:span>]: u32 = [<$prefix $newname:span>];)+ +/// } +/// }; +/// } +/// +/// pub_no_prefix!( +/// binder_driver_return_protocol_, +/// BR_OK, +/// BR_ERROR, +/// BR_TRANSACTION, +/// BR_REPLY, +/// BR_DEAD_REPLY, +/// BR_TRANSACTION_COMPLETE, +/// BR_INCREFS, +/// BR_ACQUIRE, +/// BR_RELEASE, +/// BR_DECREFS, +/// BR_NOOP, +/// BR_SPAWN_LOOPER, +/// BR_DEAD_BINDER, +/// BR_CLEAR_DEATH_NOTIFICATION_DONE, +/// BR_FAILED_REPLY +/// ); +/// +/// assert_eq!(br_ok(), binder_driver_return_protocol_BR_OK); +/// ``` +/// +/// [`paste`]: https://docs.rs/paste/ +#[proc_macro] +pub fn paste(input: TokenStream) -> TokenStream { + let mut tokens = input.into_iter().collect(); + paste::expand(&mut tokens); + tokens.into_iter().collect() +} diff --git a/rust/macros/paste.rs b/rust/macros/paste.rs new file mode 100644 index 000000000000..385a78434224 --- /dev/null +++ b/rust/macros/paste.rs @@ -0,0 +1,96 @@ +// SPDX-License-Identifier: GPL-2.0 + +use proc_macro::{Delimiter, Group, Ident, Spacing, Span, TokenTree}; + +fn concat(tokens: &[TokenTree], group_span: Span) -> TokenTree { + let mut tokens = tokens.iter(); + let mut segments = Vec::new(); + let mut span = None; + loop { + match tokens.next() { + None => break, + Some(TokenTree::Literal(lit)) => segments.push((lit.to_string(), lit.span())), + Some(TokenTree::Ident(ident)) => { + let mut value = ident.to_string(); + if value.starts_with("r#") { + value.replace_range(0..2, ""); + } + segments.push((value, ident.span())); + } + Some(TokenTree::Punct(p)) if p.as_char() == ':' => { + let Some(TokenTree::Ident(ident)) = tokens.next() else { + panic!("expected identifier as modifier"); + }; + + let (mut value, sp) = segments.pop().expect("expected identifier before modifier"); + match ident.to_string().as_str() { + // Set the overall span of concatenated token as current span + "span" => { + assert!( + span.is_none(), + "span modifier should only appear at most once" + ); + span = Some(sp); + } + "lower" => value = value.to_lowercase(), + "upper" => value = value.to_uppercase(), + v => panic!("unknown modifier `{v}`"), + }; + segments.push((value, sp)); + } + _ => panic!("unexpected token in paste segments"), + }; + } + + let pasted: String = segments.into_iter().map(|x| x.0).collect(); + TokenTree::Ident(Ident::new(&pasted, span.unwrap_or(group_span))) +} + +pub(crate) fn expand(tokens: &mut Vec) { + for token in tokens.iter_mut() { + if let TokenTree::Group(group) = token { + let delimiter = group.delimiter(); + let span = group.span(); + let mut stream: Vec<_> = group.stream().into_iter().collect(); + // Find groups that looks like `[< A B C D >]` + if delimiter == Delimiter::Bracket + && stream.len() >= 3 + && matches!(&stream[0], TokenTree::Punct(p) if p.as_char() == '<') + && matches!(&stream[stream.len() - 1], TokenTree::Punct(p) if p.as_char() == '>') + { + // Replace the group with concatenated token + *token = concat(&stream[1..stream.len() - 1], span); + } else { + // Recursively expand tokens inside the group + expand(&mut stream); + let mut group = Group::new(delimiter, stream.into_iter().collect()); + group.set_span(span); + *token = TokenTree::Group(group); + } + } + } + + // Path segments cannot contain invisible delimiter group, so remove them if any. + for i in (0..tokens.len().saturating_sub(3)).rev() { + // Looking for a double colon + if matches!( + (&tokens[i + 1], &tokens[i + 2]), + (TokenTree::Punct(a), TokenTree::Punct(b)) + if a.as_char() == ':' && a.spacing() == Spacing::Joint && b.as_char() == ':' + ) { + match &tokens[i + 3] { + TokenTree::Group(group) if group.delimiter() == Delimiter::None => { + tokens.splice(i + 3..i + 4, group.stream()); + } + _ => (), + } + + match &tokens[i] { + TokenTree::Group(group) if group.delimiter() == Delimiter::None => { + tokens.splice(i..i + 1, group.stream()); + } + _ => (), + } + } + } +} -- cgit v1.2.3 From 41bdc6decda074afc4d8f8ba44c69b08d0e9aff6 Mon Sep 17 00:00:00 2001 From: Andrea Righi Date: Tue, 4 Jul 2023 07:21:36 +0200 Subject: btf, scripts: rust: drop is_rust_module.sh With commit c1177979af9c ("btf, scripts: Exclude Rust CUs with pahole") we are now able to use pahole directly to identify Rust compilation units (CUs) and exclude them from generating BTF debugging information (when DEBUG_INFO_BTF is enabled). And if pahole doesn't support the --lang-exclude flag, we can't enable both RUST and DEBUG_INFO_BTF at the same time. So, in any case, the script is_rust_module.sh is just redundant and we can drop it. NOTE: we may also be able to drop the "Rust loadable module" mark inside Rust modules, but it seems safer to keep it for now to make sure we are not breaking any external tool that may potentially rely on it. Signed-off-by: Andrea Righi Reviewed-by: Nathan Chancellor Tested-by: Eric Curtin Reviewed-by: Eric Curtin Reviewed-by: Neal Gompa Reviewed-by: Masahiro Yamada Reviewed-by: Martin Rodriguez Reboredo Acked-by: Daniel Xu Link: https://lore.kernel.org/r/20230704052136.155445-1-andrea.righi@canonical.com [ Picked the `Reviewed-by`s from the old patch too. ] Signed-off-by: Miguel Ojeda --- rust/macros/module.rs | 2 +- scripts/Makefile.modfinal | 2 -- scripts/is_rust_module.sh | 16 ---------------- 3 files changed, 1 insertion(+), 19 deletions(-) delete mode 100755 scripts/is_rust_module.sh (limited to 'rust') diff --git a/rust/macros/module.rs b/rust/macros/module.rs index fb1244f8c2e6..d62d8710d77a 100644 --- a/rust/macros/module.rs +++ b/rust/macros/module.rs @@ -199,7 +199,7 @@ pub(crate) fn module(ts: TokenStream) -> TokenStream { /// Used by the printing macros, e.g. [`info!`]. const __LOG_PREFIX: &[u8] = b\"{name}\\0\"; - /// The \"Rust loadable module\" mark, for `scripts/is_rust_module.sh`. + /// The \"Rust loadable module\" mark. // // This may be best done another way later on, e.g. as a new modinfo // key or a new section. For the moment, keep it simple. diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal index fc19f67039bd..b3a6aa8fbe8c 100644 --- a/scripts/Makefile.modfinal +++ b/scripts/Makefile.modfinal @@ -41,8 +41,6 @@ quiet_cmd_btf_ko = BTF [M] $@ cmd_btf_ko = \ if [ ! -f vmlinux ]; then \ printf "Skipping BTF generation for %s due to unavailability of vmlinux\n" $@ 1>&2; \ - elif [ -n "$(CONFIG_RUST)" ] && $(srctree)/scripts/is_rust_module.sh $@; then \ - printf "Skipping BTF generation for %s because it's a Rust module\n" $@ 1>&2; \ else \ LLVM_OBJCOPY="$(OBJCOPY)" $(PAHOLE) -J $(PAHOLE_FLAGS) --btf_base vmlinux $@; \ $(RESOLVE_BTFIDS) -b vmlinux $@; \ diff --git a/scripts/is_rust_module.sh b/scripts/is_rust_module.sh deleted file mode 100755 index 464761a7cf7f..000000000000 --- a/scripts/is_rust_module.sh +++ /dev/null @@ -1,16 +0,0 @@ -#!/bin/sh -# SPDX-License-Identifier: GPL-2.0 -# -# is_rust_module.sh module.ko -# -# Returns `0` if `module.ko` is a Rust module, `1` otherwise. - -set -e - -# Using the `16_` prefix ensures other symbols with the same substring -# are not picked up (even if it would be unlikely). The last part is -# used just in case LLVM decides to use the `.` suffix. -# -# In the future, checking for the `.comment` section may be another -# option, see https://github.com/rust-lang/rust/pull/97550. -${NM} "$*" | grep -qE '^[0-9a-fA-F]+ [Rr] _R[^[:space:]]+16___IS_RUST_MODULE[^[:space:]]*$' -- cgit v1.2.3 From 89eed1ab1161e7d60595917e3b982e03dfcc0f8d Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sun, 30 Jul 2023 00:03:16 +0200 Subject: rust: upgrade to Rust 1.71.1 This is the second upgrade to the Rust toolchain, from 1.68.2 to 1.71.1 (i.e. the latest). See the upgrade policy [1] and the comments on the first upgrade in commit 3ed03f4da06e ("rust: upgrade to Rust 1.68.2"). # Unstable features No unstable features (that we use) were stabilized. Therefore, the only unstable feature allowed to be used outside the `kernel` crate is still `new_uninit`, though other code to be upstreamed may increase the list. Please see [2] for details. # Required changes For the upgrade, this patch requires the following changes: - Removal of the `__rust_*` allocator functions, together with the addition of the `__rust_no_alloc_shim_is_unstable` static. See [3] for details. - Some more compiler builtins added due to `::midpoint()` that got added in Rust 1.71 [4]. # `alloc` upgrade and reviewing The vast majority of changes are due to our `alloc` fork being upgraded at once. There are two kinds of changes to be aware of: the ones coming from upstream, which we should follow as closely as possible, and the updates needed in our added fallible APIs to keep them matching the newer infallible APIs coming from upstream. Instead of taking a look at the diff of this patch, an alternative approach is reviewing a diff of the changes between upstream `alloc` and the kernel's. This allows to easily inspect the kernel additions only, especially to check if the fallible methods we already have still match the infallible ones in the new version coming from upstream. Another approach is reviewing the changes introduced in the additions in the kernel fork between the two versions. This is useful to spot potentially unintended changes to our additions. To apply these approaches, one may follow steps similar to the following to generate a pair of patches that show the differences between upstream Rust and the kernel (for the subset of `alloc` we use) before and after applying this patch: # Get the difference with respect to the old version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > old.patch git -C linux restore rust/alloc # Apply this patch. git -C linux am rust-upgrade.patch # Get the difference with respect to the new version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > new.patch git -C linux restore rust/alloc Now one may check the `new.patch` to take a look at the additions (first approach) or at the difference between those two patches (second approach). For the latter, a side-by-side tool is recommended. Link: https://rust-for-linux.com/rust-version-policy [1] Link: https://github.com/Rust-for-Linux/linux/issues/2 [2] Link: https://github.com/rust-lang/rust/pull/86844 [3] Link: https://github.com/rust-lang/rust/pull/92048 [4] Closes: https://github.com/Rust-for-Linux/linux/issues/68 Reviewed-by: Martin Rodriguez Reboredo Reviewed-by: Trevor Gross Link: https://lore.kernel.org/r/20230729220317.416771-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- Documentation/process/changes.rst | 2 +- rust/Makefile | 4 +- rust/alloc/alloc.rs | 20 +++--- rust/alloc/boxed.rs | 131 +++++++++++++++++++------------------- rust/alloc/lib.rs | 48 +++++++------- rust/alloc/raw_vec.rs | 18 ++++-- rust/alloc/slice.rs | 43 ++++++++++--- rust/alloc/vec/drain.rs | 8 +-- rust/alloc/vec/drain_filter.rs | 8 +-- rust/alloc/vec/into_iter.rs | 35 ++++++---- rust/alloc/vec/mod.rs | 84 ++++++------------------ rust/compiler_builtins.rs | 7 ++ rust/kernel/allocator.rs | 51 +-------------- scripts/min-tool-version.sh | 2 +- 14 files changed, 208 insertions(+), 253 deletions(-) (limited to 'rust') diff --git a/Documentation/process/changes.rst b/Documentation/process/changes.rst index 5561dae94f85..1382bccc8818 100644 --- a/Documentation/process/changes.rst +++ b/Documentation/process/changes.rst @@ -31,7 +31,7 @@ you probably needn't concern yourself with pcmciautils. ====================== =============== ======================================== GNU C 5.1 gcc --version Clang/LLVM (optional) 11.0.0 clang --version -Rust (optional) 1.68.2 rustc --version +Rust (optional) 1.71.1 rustc --version bindgen (optional) 0.56.0 bindgen --version GNU make 3.82 make --version bash 4.2 bash --version diff --git a/rust/Makefile b/rust/Makefile index 1ffdff6c2a34..b278908c19e5 100644 --- a/rust/Makefile +++ b/rust/Makefile @@ -379,8 +379,8 @@ rust-analyzer: $(if $(KBUILD_EXTMOD),$(extmod_prefix),$(objtree))/rust-project.json redirect-intrinsics = \ - __eqsf2 __gesf2 __lesf2 __nesf2 __unordsf2 \ - __unorddf2 \ + __addsf3 __eqsf2 __gesf2 __lesf2 __ltsf2 __mulsf3 __nesf2 __unordsf2 \ + __adddf3 __ledf2 __ltdf2 __muldf3 __unorddf2 \ __muloti4 __multi3 \ __udivmodti4 __udivti3 __umodti3 diff --git a/rust/alloc/alloc.rs b/rust/alloc/alloc.rs index acf22d45e6f2..0b6bf5b6da43 100644 --- a/rust/alloc/alloc.rs +++ b/rust/alloc/alloc.rs @@ -16,8 +16,6 @@ use core::ptr::{self, NonNull}; #[doc(inline)] pub use core::alloc::*; -use core::marker::Destruct; - #[cfg(test)] mod tests; @@ -41,6 +39,9 @@ extern "Rust" { #[rustc_allocator_zeroed] #[rustc_nounwind] fn __rust_alloc_zeroed(size: usize, align: usize) -> *mut u8; + + #[cfg(not(bootstrap))] + static __rust_no_alloc_shim_is_unstable: u8; } /// The global memory allocator. @@ -94,7 +95,14 @@ pub use std::alloc::Global; #[must_use = "losing the pointer will leak memory"] #[inline] pub unsafe fn alloc(layout: Layout) -> *mut u8 { - unsafe { __rust_alloc(layout.size(), layout.align()) } + unsafe { + // Make sure we don't accidentally allow omitting the allocator shim in + // stable code until it is actually stabilized. + #[cfg(not(bootstrap))] + core::ptr::read_volatile(&__rust_no_alloc_shim_is_unstable); + + __rust_alloc(layout.size(), layout.align()) + } } /// Deallocate memory with the global allocator. @@ -333,16 +341,12 @@ unsafe fn exchange_malloc(size: usize, align: usize) -> *mut u8 { #[cfg_attr(not(test), lang = "box_free")] #[inline] -#[rustc_const_unstable(feature = "const_box", issue = "92521")] // This signature has to be the same as `Box`, otherwise an ICE will happen. // When an additional parameter to `Box` is added (like `A: Allocator`), this has to be added here as // well. // For example if `Box` is changed to `struct Box(Unique, A)`, // this function has to be changed to `fn box_free(Unique, A)` as well. -pub(crate) const unsafe fn box_free( - ptr: Unique, - alloc: A, -) { +pub(crate) unsafe fn box_free(ptr: Unique, alloc: A) { unsafe { let size = size_of_val(ptr.as_ref()); let align = min_align_of_val(ptr.as_ref()); diff --git a/rust/alloc/boxed.rs b/rust/alloc/boxed.rs index 14af9860c36c..c8173cea8317 100644 --- a/rust/alloc/boxed.rs +++ b/rust/alloc/boxed.rs @@ -152,16 +152,13 @@ use core::any::Any; use core::async_iter::AsyncIterator; use core::borrow; use core::cmp::Ordering; -use core::convert::{From, TryFrom}; use core::error::Error; use core::fmt; use core::future::Future; use core::hash::{Hash, Hasher}; -#[cfg(not(no_global_oom_handling))] -use core::iter::FromIterator; -use core::iter::{FusedIterator, Iterator}; +use core::iter::FusedIterator; use core::marker::Tuple; -use core::marker::{Destruct, Unpin, Unsize}; +use core::marker::Unsize; use core::mem; use core::ops::{ CoerceUnsized, Deref, DerefMut, DispatchFromDyn, Generator, GeneratorState, Receiver, @@ -218,6 +215,7 @@ impl Box { #[inline(always)] #[stable(feature = "rust1", since = "1.0.0")] #[must_use] + #[rustc_diagnostic_item = "box_new"] pub fn new(x: T) -> Self { #[rustc_box] Box::new(x) @@ -287,9 +285,7 @@ impl Box { #[must_use] #[inline(always)] pub fn pin(x: T) -> Pin> { - (#[rustc_box] - Box::new(x)) - .into() + Box::new(x).into() } /// Allocates memory on the heap then places `x` into it, @@ -381,12 +377,11 @@ impl Box { /// ``` #[cfg(not(no_global_oom_handling))] #[unstable(feature = "allocator_api", issue = "32838")] - #[rustc_const_unstable(feature = "const_box", issue = "92521")] #[must_use] #[inline] - pub const fn new_in(x: T, alloc: A) -> Self + pub fn new_in(x: T, alloc: A) -> Self where - A: ~const Allocator + ~const Destruct, + A: Allocator, { let mut boxed = Self::new_uninit_in(alloc); unsafe { @@ -411,12 +406,10 @@ impl Box { /// # Ok::<(), std::alloc::AllocError>(()) /// ``` #[unstable(feature = "allocator_api", issue = "32838")] - #[rustc_const_unstable(feature = "const_box", issue = "92521")] #[inline] - pub const fn try_new_in(x: T, alloc: A) -> Result + pub fn try_new_in(x: T, alloc: A) -> Result where - T: ~const Destruct, - A: ~const Allocator + ~const Destruct, + A: Allocator, { let mut boxed = Self::try_new_uninit_in(alloc)?; unsafe { @@ -446,13 +439,12 @@ impl Box { /// assert_eq!(*five, 5) /// ``` #[unstable(feature = "allocator_api", issue = "32838")] - #[rustc_const_unstable(feature = "const_box", issue = "92521")] #[cfg(not(no_global_oom_handling))] #[must_use] // #[unstable(feature = "new_uninit", issue = "63291")] - pub const fn new_uninit_in(alloc: A) -> Box, A> + pub fn new_uninit_in(alloc: A) -> Box, A> where - A: ~const Allocator + ~const Destruct, + A: Allocator, { let layout = Layout::new::>(); // NOTE: Prefer match over unwrap_or_else since closure sometimes not inlineable. @@ -487,10 +479,9 @@ impl Box { /// ``` #[unstable(feature = "allocator_api", issue = "32838")] // #[unstable(feature = "new_uninit", issue = "63291")] - #[rustc_const_unstable(feature = "const_box", issue = "92521")] - pub const fn try_new_uninit_in(alloc: A) -> Result, A>, AllocError> + pub fn try_new_uninit_in(alloc: A) -> Result, A>, AllocError> where - A: ~const Allocator + ~const Destruct, + A: Allocator, { let layout = Layout::new::>(); let ptr = alloc.allocate(layout)?.cast(); @@ -518,13 +509,12 @@ impl Box { /// /// [zeroed]: mem::MaybeUninit::zeroed #[unstable(feature = "allocator_api", issue = "32838")] - #[rustc_const_unstable(feature = "const_box", issue = "92521")] #[cfg(not(no_global_oom_handling))] // #[unstable(feature = "new_uninit", issue = "63291")] #[must_use] - pub const fn new_zeroed_in(alloc: A) -> Box, A> + pub fn new_zeroed_in(alloc: A) -> Box, A> where - A: ~const Allocator + ~const Destruct, + A: Allocator, { let layout = Layout::new::>(); // NOTE: Prefer match over unwrap_or_else since closure sometimes not inlineable. @@ -559,10 +549,9 @@ impl Box { /// [zeroed]: mem::MaybeUninit::zeroed #[unstable(feature = "allocator_api", issue = "32838")] // #[unstable(feature = "new_uninit", issue = "63291")] - #[rustc_const_unstable(feature = "const_box", issue = "92521")] - pub const fn try_new_zeroed_in(alloc: A) -> Result, A>, AllocError> + pub fn try_new_zeroed_in(alloc: A) -> Result, A>, AllocError> where - A: ~const Allocator + ~const Destruct, + A: Allocator, { let layout = Layout::new::>(); let ptr = alloc.allocate_zeroed(layout)?.cast(); @@ -578,12 +567,11 @@ impl Box { /// construct a (pinned) `Box` in a different way than with [`Box::new_in`]. #[cfg(not(no_global_oom_handling))] #[unstable(feature = "allocator_api", issue = "32838")] - #[rustc_const_unstable(feature = "const_box", issue = "92521")] #[must_use] #[inline(always)] - pub const fn pin_in(x: T, alloc: A) -> Pin + pub fn pin_in(x: T, alloc: A) -> Pin where - A: 'static + ~const Allocator + ~const Destruct, + A: 'static + Allocator, { Self::into_pin(Self::new_in(x, alloc)) } @@ -592,8 +580,7 @@ impl Box { /// /// This conversion does not allocate on the heap and happens in place. #[unstable(feature = "box_into_boxed_slice", issue = "71582")] - #[rustc_const_unstable(feature = "const_box", issue = "92521")] - pub const fn into_boxed_slice(boxed: Self) -> Box<[T], A> { + pub fn into_boxed_slice(boxed: Self) -> Box<[T], A> { let (raw, alloc) = Box::into_raw_with_allocator(boxed); unsafe { Box::from_raw_in(raw as *mut [T; 1], alloc) } } @@ -610,12 +597,8 @@ impl Box { /// assert_eq!(Box::into_inner(c), 5); /// ``` #[unstable(feature = "box_into_inner", issue = "80437")] - #[rustc_const_unstable(feature = "const_box", issue = "92521")] #[inline] - pub const fn into_inner(boxed: Self) -> T - where - Self: ~const Destruct, - { + pub fn into_inner(boxed: Self) -> T { *boxed } } @@ -829,9 +812,8 @@ impl Box, A> { /// assert_eq!(*five, 5) /// ``` #[unstable(feature = "new_uninit", issue = "63291")] - #[rustc_const_unstable(feature = "const_box", issue = "92521")] #[inline] - pub const unsafe fn assume_init(self) -> Box { + pub unsafe fn assume_init(self) -> Box { let (raw, alloc) = Box::into_raw_with_allocator(self); unsafe { Box::from_raw_in(raw as *mut T, alloc) } } @@ -864,9 +846,8 @@ impl Box, A> { /// } /// ``` #[unstable(feature = "new_uninit", issue = "63291")] - #[rustc_const_unstable(feature = "const_box", issue = "92521")] #[inline] - pub const fn write(mut boxed: Self, value: T) -> Box { + pub fn write(mut boxed: Self, value: T) -> Box { unsafe { (*boxed).write(value); boxed.assume_init() @@ -1110,9 +1091,8 @@ impl Box { /// /// [memory layout]: self#memory-layout #[unstable(feature = "allocator_api", issue = "32838")] - #[rustc_const_unstable(feature = "const_box", issue = "92521")] #[inline] - pub const fn into_raw_with_allocator(b: Self) -> (*mut T, A) { + pub fn into_raw_with_allocator(b: Self) -> (*mut T, A) { let (leaked, alloc) = Box::into_unique(b); (leaked.as_ptr(), alloc) } @@ -1122,10 +1102,9 @@ impl Box { issue = "none", reason = "use `Box::leak(b).into()` or `Unique::from(Box::leak(b))` instead" )] - #[rustc_const_unstable(feature = "const_box", issue = "92521")] #[inline] #[doc(hidden)] - pub const fn into_unique(b: Self) -> (Unique, A) { + pub fn into_unique(b: Self) -> (Unique, A) { // Box is recognized as a "unique pointer" by Stacked Borrows, but internally it is a // raw pointer for the type system. Turning it directly into a raw pointer would not be // recognized as "releasing" the unique pointer to permit aliased raw accesses, @@ -1183,9 +1162,8 @@ impl Box { /// assert_eq!(*static_ref, [4, 2, 3]); /// ``` #[stable(feature = "box_leak", since = "1.26.0")] - #[rustc_const_unstable(feature = "const_box", issue = "92521")] #[inline] - pub const fn leak<'a>(b: Self) -> &'a mut T + pub fn leak<'a>(b: Self) -> &'a mut T where A: 'a, { @@ -1246,16 +1224,16 @@ unsafe impl<#[may_dangle] T: ?Sized, A: Allocator> Drop for Box { #[stable(feature = "rust1", since = "1.0.0")] impl Default for Box { /// Creates a `Box`, with the `Default` value for T. + #[inline] fn default() -> Self { - #[rustc_box] Box::new(T::default()) } } #[cfg(not(no_global_oom_handling))] #[stable(feature = "rust1", since = "1.0.0")] -#[rustc_const_unstable(feature = "const_default_impls", issue = "87864")] -impl const Default for Box<[T]> { +impl Default for Box<[T]> { + #[inline] fn default() -> Self { let ptr: Unique<[T]> = Unique::<[T; 0]>::dangling(); Box(ptr, Global) @@ -1264,8 +1242,8 @@ impl const Default for Box<[T]> { #[cfg(not(no_global_oom_handling))] #[stable(feature = "default_box_extra", since = "1.17.0")] -#[rustc_const_unstable(feature = "const_default_impls", issue = "87864")] -impl const Default for Box { +impl Default for Box { + #[inline] fn default() -> Self { // SAFETY: This is the same as `Unique::cast` but with an unsized `U = str`. let ptr: Unique = unsafe { @@ -1461,8 +1439,7 @@ impl From for Box { } #[stable(feature = "pin", since = "1.33.0")] -#[rustc_const_unstable(feature = "const_box", issue = "92521")] -impl const From> for Pin> +impl From> for Pin> where A: 'static, { @@ -1482,9 +1459,36 @@ where } } +/// Specialization trait used for `From<&[T]>`. +#[cfg(not(no_global_oom_handling))] +trait BoxFromSlice { + fn from_slice(slice: &[T]) -> Self; +} + +#[cfg(not(no_global_oom_handling))] +impl BoxFromSlice for Box<[T]> { + #[inline] + default fn from_slice(slice: &[T]) -> Self { + slice.to_vec().into_boxed_slice() + } +} + +#[cfg(not(no_global_oom_handling))] +impl BoxFromSlice for Box<[T]> { + #[inline] + fn from_slice(slice: &[T]) -> Self { + let len = slice.len(); + let buf = RawVec::with_capacity(len); + unsafe { + ptr::copy_nonoverlapping(slice.as_ptr(), buf.ptr(), len); + buf.into_box(slice.len()).assume_init() + } + } +} + #[cfg(not(no_global_oom_handling))] #[stable(feature = "box_from_slice", since = "1.17.0")] -impl From<&[T]> for Box<[T]> { +impl From<&[T]> for Box<[T]> { /// Converts a `&[T]` into a `Box<[T]>` /// /// This conversion allocates on the heap @@ -1498,19 +1502,15 @@ impl From<&[T]> for Box<[T]> { /// /// println!("{boxed_slice:?}"); /// ``` + #[inline] fn from(slice: &[T]) -> Box<[T]> { - let len = slice.len(); - let buf = RawVec::with_capacity(len); - unsafe { - ptr::copy_nonoverlapping(slice.as_ptr(), buf.ptr(), len); - buf.into_box(slice.len()).assume_init() - } + >::from_slice(slice) } } #[cfg(not(no_global_oom_handling))] #[stable(feature = "box_from_cow", since = "1.45.0")] -impl From> for Box<[T]> { +impl From> for Box<[T]> { /// Converts a `Cow<'_, [T]>` into a `Box<[T]>` /// /// When `cow` is the `Cow::Borrowed` variant, this @@ -1620,7 +1620,6 @@ impl From<[T; N]> for Box<[T]> { /// println!("{boxed:?}"); /// ``` fn from(array: [T; N]) -> Box<[T]> { - #[rustc_box] Box::new(array) } } @@ -1899,8 +1898,7 @@ impl fmt::Pointer for Box { } #[stable(feature = "rust1", since = "1.0.0")] -#[rustc_const_unstable(feature = "const_box", issue = "92521")] -impl const Deref for Box { +impl Deref for Box { type Target = T; fn deref(&self) -> &T { @@ -1909,8 +1907,7 @@ impl const Deref for Box { } #[stable(feature = "rust1", since = "1.0.0")] -#[rustc_const_unstable(feature = "const_box", issue = "92521")] -impl const DerefMut for Box { +impl DerefMut for Box { fn deref_mut(&mut self) -> &mut T { &mut **self } diff --git a/rust/alloc/lib.rs b/rust/alloc/lib.rs index 5f374378b0d4..85e91356ecb3 100644 --- a/rust/alloc/lib.rs +++ b/rust/alloc/lib.rs @@ -89,35 +89,37 @@ #![warn(missing_debug_implementations)] #![warn(missing_docs)] #![allow(explicit_outlives_requirements)] +#![warn(multiple_supertrait_upcastable)] // // Library features: +// tidy-alphabetical-start +#![cfg_attr(not(no_global_oom_handling), feature(const_alloc_error))] +#![cfg_attr(not(no_global_oom_handling), feature(const_btree_len))] +#![cfg_attr(test, feature(is_sorted))] +#![cfg_attr(test, feature(new_uninit))] #![feature(alloc_layout_extra)] #![feature(allocator_api)] #![feature(array_chunks)] #![feature(array_into_iter_constructors)] #![feature(array_methods)] #![feature(array_windows)] +#![feature(ascii_char)] #![feature(assert_matches)] #![feature(async_iterator)] #![feature(coerce_unsized)] -#![cfg_attr(not(no_global_oom_handling), feature(const_alloc_error))] +#![feature(const_align_of_val)] #![feature(const_box)] -#![cfg_attr(not(no_global_oom_handling), feature(const_btree_len))] #![cfg_attr(not(no_borrow), feature(const_cow_is_borrowed))] -#![feature(const_convert)] -#![feature(const_size_of_val)] -#![feature(const_align_of_val)] -#![feature(const_ptr_read)] -#![feature(const_maybe_uninit_zeroed)] -#![feature(const_maybe_uninit_write)] +#![feature(const_eval_select)] #![feature(const_maybe_uninit_as_mut_ptr)] +#![feature(const_maybe_uninit_write)] +#![feature(const_maybe_uninit_zeroed)] +#![feature(const_pin)] #![feature(const_refs_to_cell)] +#![feature(const_size_of_val)] +#![feature(const_waker)] #![feature(core_intrinsics)] #![feature(core_panic)] -#![feature(const_eval_select)] -#![feature(const_pin)] -#![feature(const_waker)] -#![feature(cstr_from_bytes_until_nul)] #![feature(dispatch_from_dyn)] #![feature(error_generic_member_access)] #![feature(error_in_core)] @@ -128,7 +130,6 @@ #![feature(hasher_prefixfree_extras)] #![feature(inline_const)] #![feature(inplace_iteration)] -#![cfg_attr(test, feature(is_sorted))] #![feature(iter_advance_by)] #![feature(iter_next_chunk)] #![feature(iter_repeat_n)] @@ -136,8 +137,6 @@ #![feature(maybe_uninit_slice)] #![feature(maybe_uninit_uninit_array)] #![feature(maybe_uninit_uninit_array_transpose)] -#![cfg_attr(test, feature(new_uninit))] -#![feature(nonnull_slice_from_raw_parts)] #![feature(pattern)] #![feature(pointer_byte_offsets)] #![feature(provide_any)] @@ -153,6 +152,7 @@ #![feature(slice_ptr_get)] #![feature(slice_ptr_len)] #![feature(slice_range)] +#![feature(std_internals)] #![feature(str_internals)] #![feature(strict_provenance)] #![feature(trusted_len)] @@ -163,40 +163,42 @@ #![feature(unicode_internals)] #![feature(unsize)] #![feature(utf8_chunks)] -#![feature(std_internals)] +// tidy-alphabetical-end // // Language features: +// tidy-alphabetical-start +#![cfg_attr(not(test), feature(generator_trait))] +#![cfg_attr(test, feature(panic_update_hook))] +#![cfg_attr(test, feature(test))] #![feature(allocator_internals)] #![feature(allow_internal_unstable)] #![feature(associated_type_bounds)] +#![feature(c_unwind)] #![feature(cfg_sanitize)] -#![feature(const_deref)] #![feature(const_mut_refs)] -#![feature(const_ptr_write)] #![feature(const_precise_live_drops)] +#![feature(const_ptr_write)] #![feature(const_trait_impl)] #![feature(const_try)] #![feature(dropck_eyepatch)] #![feature(exclusive_range_pattern)] #![feature(fundamental)] -#![cfg_attr(not(test), feature(generator_trait))] #![feature(hashmap_internals)] #![feature(lang_items)] #![feature(min_specialization)] +#![feature(multiple_supertrait_upcastable)] #![feature(negative_impls)] #![feature(never_type)] +#![feature(pointer_is_aligned)] #![feature(rustc_allow_const_fn_unstable)] #![feature(rustc_attrs)] -#![feature(pointer_is_aligned)] #![feature(slice_internals)] #![feature(staged_api)] #![feature(stmt_expr_attributes)] -#![cfg_attr(test, feature(test))] #![feature(unboxed_closures)] #![feature(unsized_fn_params)] -#![feature(c_unwind)] #![feature(with_negative_coherence)] -#![cfg_attr(test, feature(panic_update_hook))] +// tidy-alphabetical-end // // Rustdoc features: #![feature(doc_cfg)] diff --git a/rust/alloc/raw_vec.rs b/rust/alloc/raw_vec.rs index 5db87eac53b7..65d5ce15828e 100644 --- a/rust/alloc/raw_vec.rs +++ b/rust/alloc/raw_vec.rs @@ -6,7 +6,6 @@ use core::alloc::LayoutError; use core::cmp; use core::intrinsics; use core::mem::{self, ManuallyDrop, MaybeUninit, SizedTypeProperties}; -use core::ops::Drop; use core::ptr::{self, NonNull, Unique}; use core::slice; @@ -274,10 +273,15 @@ impl RawVec { if T::IS_ZST || self.cap == 0 { None } else { - // We have an allocated chunk of memory, so we can bypass runtime - // checks to get our current layout. + // We could use Layout::array here which ensures the absence of isize and usize overflows + // and could hypothetically handle differences between stride and size, but this memory + // has already been allocated so we know it can't overflow and currently rust does not + // support such types. So we can do better by skipping some checks and avoid an unwrap. + let _: () = const { assert!(mem::size_of::() % mem::align_of::() == 0) }; unsafe { - let layout = Layout::array::(self.cap).unwrap_unchecked(); + let align = mem::align_of::(); + let size = mem::size_of::().unchecked_mul(self.cap); + let layout = Layout::from_size_align_unchecked(size, align); Some((self.ptr.cast().into(), layout)) } } @@ -465,11 +469,13 @@ impl RawVec { assert!(cap <= self.capacity(), "Tried to shrink to a larger capacity"); let (ptr, layout) = if let Some(mem) = self.current_memory() { mem } else { return Ok(()) }; - + // See current_memory() why this assert is here + let _: () = const { assert!(mem::size_of::() % mem::align_of::() == 0) }; let ptr = unsafe { // `Layout::array` cannot overflow here because it would have // overflowed earlier when capacity was larger. - let new_layout = Layout::array::(cap).unwrap_unchecked(); + let new_size = mem::size_of::().unchecked_mul(cap); + let new_layout = Layout::from_size_align_unchecked(new_size, layout.align()); self.alloc .shrink(ptr, layout, new_layout) .map_err(|_| AllocError { layout: new_layout, non_exhaustive: () })? diff --git a/rust/alloc/slice.rs b/rust/alloc/slice.rs index 245e01590df7..6ac463bd3edc 100644 --- a/rust/alloc/slice.rs +++ b/rust/alloc/slice.rs @@ -784,6 +784,38 @@ impl BorrowMut<[T]> for Vec { } } +// Specializable trait for implementing ToOwned::clone_into. This is +// public in the crate and has the Allocator parameter so that +// vec::clone_from use it too. +#[cfg(not(no_global_oom_handling))] +pub(crate) trait SpecCloneIntoVec { + fn clone_into(&self, target: &mut Vec); +} + +#[cfg(not(no_global_oom_handling))] +impl SpecCloneIntoVec for [T] { + default fn clone_into(&self, target: &mut Vec) { + // drop anything in target that will not be overwritten + target.truncate(self.len()); + + // target.len <= self.len due to the truncate above, so the + // slices here are always in-bounds. + let (init, tail) = self.split_at(target.len()); + + // reuse the contained values' allocations/resources. + target.clone_from_slice(init); + target.extend_from_slice(tail); + } +} + +#[cfg(not(no_global_oom_handling))] +impl SpecCloneIntoVec for [T] { + fn clone_into(&self, target: &mut Vec) { + target.clear(); + target.extend_from_slice(self); + } +} + #[cfg(not(no_global_oom_handling))] #[stable(feature = "rust1", since = "1.0.0")] impl ToOwned for [T] { @@ -799,16 +831,7 @@ impl ToOwned for [T] { } fn clone_into(&self, target: &mut Vec) { - // drop anything in target that will not be overwritten - target.truncate(self.len()); - - // target.len <= self.len due to the truncate above, so the - // slices here are always in-bounds. - let (init, tail) = self.split_at(target.len()); - - // reuse the contained values' allocations/resources. - target.clone_from_slice(init); - target.extend_from_slice(tail); + SpecCloneIntoVec::clone_into(self, target); } } diff --git a/rust/alloc/vec/drain.rs b/rust/alloc/vec/drain.rs index d503d2f478ce..78177a9e2ad0 100644 --- a/rust/alloc/vec/drain.rs +++ b/rust/alloc/vec/drain.rs @@ -18,7 +18,7 @@ use super::Vec; /// /// ``` /// let mut v = vec![0, 1, 2]; -/// let iter: std::vec::Drain<_> = v.drain(..); +/// let iter: std::vec::Drain<'_, _> = v.drain(..); /// ``` #[stable(feature = "drain", since = "1.6.0")] pub struct Drain< @@ -114,9 +114,7 @@ impl<'a, T, A: Allocator> Drain<'a, T, A> { let unyielded_ptr = this.iter.as_slice().as_ptr(); // ZSTs have no identity, so we don't need to move them around. - let needs_move = mem::size_of::() != 0; - - if needs_move { + if !T::IS_ZST { let start_ptr = source_vec.as_mut_ptr().add(start); // memmove back unyielded elements @@ -199,7 +197,7 @@ impl Drop for Drain<'_, T, A> { } } - let iter = mem::replace(&mut self.iter, (&mut []).iter()); + let iter = mem::take(&mut self.iter); let drop_len = iter.len(); let mut vec = self.vec; diff --git a/rust/alloc/vec/drain_filter.rs b/rust/alloc/vec/drain_filter.rs index 4b019220657d..09efff090e42 100644 --- a/rust/alloc/vec/drain_filter.rs +++ b/rust/alloc/vec/drain_filter.rs @@ -1,7 +1,7 @@ // SPDX-License-Identifier: Apache-2.0 OR MIT use crate::alloc::{Allocator, Global}; -use core::mem::{self, ManuallyDrop}; +use core::mem::{ManuallyDrop, SizedTypeProperties}; use core::ptr; use core::slice; @@ -18,7 +18,7 @@ use super::Vec; /// #![feature(drain_filter)] /// /// let mut v = vec![0, 1, 2]; -/// let iter: std::vec::DrainFilter<_, _> = v.drain_filter(|x| *x % 2 == 0); +/// let iter: std::vec::DrainFilter<'_, _, _> = v.drain_filter(|x| *x % 2 == 0); /// ``` #[unstable(feature = "drain_filter", reason = "recently added", issue = "43244")] #[derive(Debug)] @@ -98,9 +98,7 @@ where unsafe { // ZSTs have no identity, so we don't need to move them around. - let needs_move = mem::size_of::() != 0; - - if needs_move && this.idx < this.old_len && this.del > 0 { + if !T::IS_ZST && this.idx < this.old_len && this.del > 0 { let ptr = this.vec.as_mut_ptr(); let src = ptr.add(this.idx); let dst = src.sub(this.del); diff --git a/rust/alloc/vec/into_iter.rs b/rust/alloc/vec/into_iter.rs index 34a2a70d6ded..aac0ec16aef1 100644 --- a/rust/alloc/vec/into_iter.rs +++ b/rust/alloc/vec/into_iter.rs @@ -13,6 +13,7 @@ use core::iter::{ }; use core::marker::PhantomData; use core::mem::{self, ManuallyDrop, MaybeUninit, SizedTypeProperties}; +use core::num::NonZeroUsize; #[cfg(not(no_global_oom_handling))] use core::ops::Deref; use core::ptr::{self, NonNull}; @@ -109,7 +110,7 @@ impl IntoIter { /// ``` /// # let mut into_iter = Vec::::with_capacity(10).into_iter(); /// let mut into_iter = std::mem::replace(&mut into_iter, Vec::new().into_iter()); - /// (&mut into_iter).for_each(core::mem::drop); + /// (&mut into_iter).for_each(drop); /// std::mem::forget(into_iter); /// ``` /// @@ -215,7 +216,7 @@ impl Iterator for IntoIter { } #[inline] - fn advance_by(&mut self, n: usize) -> Result<(), usize> { + fn advance_by(&mut self, n: usize) -> Result<(), NonZeroUsize> { let step_size = self.len().min(n); let to_drop = ptr::slice_from_raw_parts_mut(self.ptr as *mut T, step_size); if T::IS_ZST { @@ -229,10 +230,7 @@ impl Iterator for IntoIter { unsafe { ptr::drop_in_place(to_drop); } - if step_size < n { - return Err(step_size); - } - Ok(()) + NonZeroUsize::new(n - step_size).map_or(Ok(()), Err) } #[inline] @@ -315,7 +313,7 @@ impl DoubleEndedIterator for IntoIter { } #[inline] - fn advance_back_by(&mut self, n: usize) -> Result<(), usize> { + fn advance_back_by(&mut self, n: usize) -> Result<(), NonZeroUsize> { let step_size = self.len().min(n); if T::IS_ZST { // SAFETY: same as for advance_by() @@ -329,10 +327,7 @@ impl DoubleEndedIterator for IntoIter { unsafe { ptr::drop_in_place(to_drop); } - if step_size < n { - return Err(step_size); - } - Ok(()) + NonZeroUsize::new(n - step_size).map_or(Ok(()), Err) } } @@ -349,6 +344,24 @@ impl FusedIterator for IntoIter {} #[unstable(feature = "trusted_len", issue = "37572")] unsafe impl TrustedLen for IntoIter {} +#[stable(feature = "default_iters", since = "1.70.0")] +impl Default for IntoIter +where + A: Allocator + Default, +{ + /// Creates an empty `vec::IntoIter`. + /// + /// ``` + /// # use std::vec; + /// let iter: vec::IntoIter = Default::default(); + /// assert_eq!(iter.len(), 0); + /// assert_eq!(iter.as_slice(), &[]); + /// ``` + fn default() -> Self { + super::Vec::new_in(Default::default()).into_iter() + } +} + #[doc(hidden)] #[unstable(issue = "none", feature = "std_internals")] #[rustc_unsafe_specialization_marker] diff --git a/rust/alloc/vec/mod.rs b/rust/alloc/vec/mod.rs index 94995913566b..05c70de0227e 100644 --- a/rust/alloc/vec/mod.rs +++ b/rust/alloc/vec/mod.rs @@ -58,13 +58,9 @@ #[cfg(not(no_global_oom_handling))] use core::cmp; use core::cmp::Ordering; -use core::convert::TryFrom; use core::fmt; use core::hash::{Hash, Hasher}; -use core::intrinsics::assume; use core::iter; -#[cfg(not(no_global_oom_handling))] -use core::iter::FromIterator; use core::marker::PhantomData; use core::mem::{self, ManuallyDrop, MaybeUninit, SizedTypeProperties}; use core::ops::{self, Index, IndexMut, Range, RangeBounds}; @@ -381,8 +377,8 @@ mod spec_extend; /// Currently, `Vec` does not guarantee the order in which elements are dropped. /// The order has changed in the past and may change again. /// -/// [`get`]: ../../std/vec/struct.Vec.html#method.get -/// [`get_mut`]: ../../std/vec/struct.Vec.html#method.get_mut +/// [`get`]: slice::get +/// [`get_mut`]: slice::get_mut /// [`String`]: crate::string::String /// [`&str`]: type@str /// [`shrink_to_fit`]: Vec::shrink_to_fit @@ -708,14 +704,14 @@ impl Vec { /// /// // The vector contains no items, even though it has capacity for more /// assert_eq!(vec.len(), 0); - /// assert_eq!(vec.capacity(), 10); + /// assert!(vec.capacity() >= 10); /// /// // These are all done without reallocating... /// for i in 0..10 { /// vec.push(i); /// } /// assert_eq!(vec.len(), 10); - /// assert_eq!(vec.capacity(), 10); + /// assert!(vec.capacity() >= 10); /// /// // ...but this may make the vector reallocate /// vec.push(11); @@ -766,14 +762,14 @@ impl Vec { /// /// // The vector contains no items, even though it has capacity for more /// assert_eq!(vec.len(), 0); - /// assert_eq!(vec.capacity(), 10); + /// assert!(vec.capacity() >= 10); /// /// // These are all done without reallocating... /// for i in 0..10 { /// vec.push(i); /// } /// assert_eq!(vec.len(), 10); - /// assert_eq!(vec.capacity(), 10); + /// assert!(vec.capacity() >= 10); /// /// // ...but this may make the vector reallocate /// vec.push(11); @@ -999,7 +995,7 @@ impl Vec { /// ``` /// let mut vec: Vec = Vec::with_capacity(10); /// vec.push(42); - /// assert_eq!(vec.capacity(), 10); + /// assert!(vec.capacity() >= 10); /// ``` #[inline] #[stable(feature = "rust1", since = "1.0.0")] @@ -1150,7 +1146,7 @@ impl Vec { /// ``` /// let mut vec = Vec::with_capacity(10); /// vec.extend([1, 2, 3]); - /// assert_eq!(vec.capacity(), 10); + /// assert!(vec.capacity() >= 10); /// vec.shrink_to_fit(); /// assert!(vec.capacity() >= 3); /// ``` @@ -1177,7 +1173,7 @@ impl Vec { /// ``` /// let mut vec = Vec::with_capacity(10); /// vec.extend([1, 2, 3]); - /// assert_eq!(vec.capacity(), 10); + /// assert!(vec.capacity() >= 10); /// vec.shrink_to(4); /// assert!(vec.capacity() >= 4); /// vec.shrink_to(0); @@ -1212,7 +1208,7 @@ impl Vec { /// let mut vec = Vec::with_capacity(10); /// vec.extend([1, 2, 3]); /// - /// assert_eq!(vec.capacity(), 10); + /// assert!(vec.capacity() >= 10); /// let slice = vec.into_boxed_slice(); /// assert_eq!(slice.into_vec().capacity(), 3); /// ``` @@ -1358,11 +1354,7 @@ impl Vec { pub fn as_ptr(&self) -> *const T { // We shadow the slice method of the same name to avoid going through // `deref`, which creates an intermediate reference. - let ptr = self.buf.ptr(); - unsafe { - assume(!ptr.is_null()); - } - ptr + self.buf.ptr() } /// Returns an unsafe mutable pointer to the vector's buffer, or a dangling @@ -1395,11 +1387,7 @@ impl Vec { pub fn as_mut_ptr(&mut self) -> *mut T { // We shadow the slice method of the same name to avoid going through // `deref_mut`, which creates an intermediate reference. - let ptr = self.buf.ptr(); - unsafe { - assume(!ptr.is_null()); - } - ptr + self.buf.ptr() } /// Returns a reference to the underlying allocator. @@ -2891,35 +2879,6 @@ impl ops::DerefMut for Vec { } } -#[cfg(not(no_global_oom_handling))] -trait SpecCloneFrom { - fn clone_from(this: &mut Self, other: &Self); -} - -#[cfg(not(no_global_oom_handling))] -impl SpecCloneFrom for Vec { - default fn clone_from(this: &mut Self, other: &Self) { - // drop anything that will not be overwritten - this.truncate(other.len()); - - // self.len <= other.len due to the truncate above, so the - // slices here are always in-bounds. - let (init, tail) = other.split_at(this.len()); - - // reuse the contained values' allocations/resources. - this.clone_from_slice(init); - this.extend_from_slice(tail); - } -} - -#[cfg(not(no_global_oom_handling))] -impl SpecCloneFrom for Vec { - fn clone_from(this: &mut Self, other: &Self) { - this.clear(); - this.extend_from_slice(other); - } -} - #[cfg(not(no_global_oom_handling))] #[stable(feature = "rust1", since = "1.0.0")] impl Clone for Vec { @@ -2940,7 +2899,7 @@ impl Clone for Vec { } fn clone_from(&mut self, other: &Self) { - SpecCloneFrom::clone_from(self, other) + crate::slice::SpecCloneIntoVec::clone_into(other.as_slice(), self); } } @@ -2948,7 +2907,6 @@ impl Clone for Vec { /// as required by the `core::borrow::Borrow` implementation. /// /// ``` -/// #![feature(build_hasher_simple_hash_one)] /// use std::hash::BuildHasher; /// /// let b = std::collections::hash_map::RandomState::new(); @@ -3330,7 +3288,7 @@ impl<'a, T: Copy + 'a, A: Allocator + 'a> Extend<&'a T> for Vec { } } -/// Implements comparison of vectors, [lexicographically](core::cmp::Ord#lexicographical-comparison). +/// Implements comparison of vectors, [lexicographically](Ord#lexicographical-comparison). #[stable(feature = "rust1", since = "1.0.0")] impl PartialOrd for Vec { #[inline] @@ -3342,7 +3300,7 @@ impl PartialOrd for Vec { #[stable(feature = "rust1", since = "1.0.0")] impl Eq for Vec {} -/// Implements ordering of vectors, [lexicographically](core::cmp::Ord#lexicographical-comparison). +/// Implements ordering of vectors, [lexicographically](Ord#lexicographical-comparison). #[stable(feature = "rust1", since = "1.0.0")] impl Ord for Vec { #[inline] @@ -3365,8 +3323,7 @@ unsafe impl<#[may_dangle] T, A: Allocator> Drop for Vec { } #[stable(feature = "rust1", since = "1.0.0")] -#[rustc_const_unstable(feature = "const_default_impls", issue = "87864")] -impl const Default for Vec { +impl Default for Vec { /// Creates an empty `Vec`. /// /// The vector will not allocate until elements are pushed onto it. @@ -3462,10 +3419,7 @@ impl From<[T; N]> for Vec { /// ``` #[cfg(not(test))] fn from(s: [T; N]) -> Vec { - <[T]>::into_vec( - #[rustc_box] - Box::new(s), - ) + <[T]>::into_vec(Box::new(s)) } #[cfg(test)] @@ -3490,8 +3444,8 @@ where /// /// ``` /// # use std::borrow::Cow; - /// let o: Cow<[i32]> = Cow::Owned(vec![1, 2, 3]); - /// let b: Cow<[i32]> = Cow::Borrowed(&[1, 2, 3]); + /// let o: Cow<'_, [i32]> = Cow::Owned(vec![1, 2, 3]); + /// let b: Cow<'_, [i32]> = Cow::Borrowed(&[1, 2, 3]); /// assert_eq!(Vec::from(o), Vec::from(b)); /// ``` fn from(s: Cow<'a, [T]>) -> Vec { diff --git a/rust/compiler_builtins.rs b/rust/compiler_builtins.rs index 43378357ece9..fb8ac3f211de 100644 --- a/rust/compiler_builtins.rs +++ b/rust/compiler_builtins.rs @@ -37,14 +37,21 @@ macro_rules! define_panicking_intrinsics( ); define_panicking_intrinsics!("`f32` should not be used", { + __addsf3, __eqsf2, __gesf2, __lesf2, + __ltsf2, + __mulsf3, __nesf2, __unordsf2, }); define_panicking_intrinsics!("`f64` should not be used", { + __adddf3, + __ledf2, + __ltdf2, + __muldf3, __unorddf2, }); diff --git a/rust/kernel/allocator.rs b/rust/kernel/allocator.rs index 72d66c23883c..a8f3d5be1af1 100644 --- a/rust/kernel/allocator.rs +++ b/rust/kernel/allocator.rs @@ -83,53 +83,6 @@ unsafe impl GlobalAlloc for KernelAllocator { #[global_allocator] static ALLOCATOR: KernelAllocator = KernelAllocator; -// `rustc` only generates these for some crate types. Even then, we would need -// to extract the object file that has them from the archive. For the moment, -// let's generate them ourselves instead. -// -// Note: Although these are *safe* functions, they are called by the compiler -// with parameters that obey the same `GlobalAlloc` function safety -// requirements: size and align should form a valid layout, and size is -// greater than 0. -// -// Note that `#[no_mangle]` implies exported too, nowadays. +// See . #[no_mangle] -fn __rust_alloc(size: usize, align: usize) -> *mut u8 { - // SAFETY: See assumption above. - let layout = unsafe { Layout::from_size_align_unchecked(size, align) }; - - // SAFETY: `ptr::null_mut()` is null, per assumption above the size of `layout` is greater - // than 0. - unsafe { krealloc_aligned(ptr::null_mut(), layout, bindings::GFP_KERNEL) } -} - -#[no_mangle] -fn __rust_dealloc(ptr: *mut u8, _size: usize, _align: usize) { - unsafe { bindings::kfree(ptr as *const core::ffi::c_void) }; -} - -#[no_mangle] -fn __rust_realloc(ptr: *mut u8, _old_size: usize, align: usize, new_size: usize) -> *mut u8 { - // SAFETY: See assumption above. - let new_layout = unsafe { Layout::from_size_align_unchecked(new_size, align) }; - - // SAFETY: Per assumption above, `ptr` is allocated by `__rust_*` before, and the size of - // `new_layout` is greater than 0. - unsafe { krealloc_aligned(ptr, new_layout, bindings::GFP_KERNEL) } -} - -#[no_mangle] -fn __rust_alloc_zeroed(size: usize, align: usize) -> *mut u8 { - // SAFETY: See assumption above. - let layout = unsafe { Layout::from_size_align_unchecked(size, align) }; - - // SAFETY: `ptr::null_mut()` is null, per assumption above the size of `layout` is greater - // than 0. - unsafe { - krealloc_aligned( - ptr::null_mut(), - layout, - bindings::GFP_KERNEL | bindings::__GFP_ZERO, - ) - } -} +static __rust_no_alloc_shim_is_unstable: u8 = 0; diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh index 2ade63149466..8da3b53fe36a 100755 --- a/scripts/min-tool-version.sh +++ b/scripts/min-tool-version.sh @@ -31,7 +31,7 @@ llvm) fi ;; rustc) - echo 1.68.2 + echo 1.71.1 ;; bindgen) echo 0.56.0 -- cgit v1.2.3 From 08ab786556ff177086ce93b26daf2a58edd10968 Mon Sep 17 00:00:00 2001 From: Aakash Sen Sharma Date: Tue, 13 Jun 2023 01:13:11 +0530 Subject: rust: bindgen: upgrade to 0.65.1 In LLVM 16, anonymous items may return names like `(unnamed union at ..)` rather than empty names [1], which breaks Rust-enabled builds because bindgen assumed an empty name instead of detecting them via `clang_Cursor_isAnonymous` [2]: $ make rustdoc LLVM=1 CLIPPY=1 -j$(nproc) RUSTC L rust/core.o BINDGEN rust/bindings/bindings_generated.rs BINDGEN rust/bindings/bindings_helpers_generated.rs BINDGEN rust/uapi/uapi_generated.rs thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... This was fixed in bindgen 0.62.0. Therefore, upgrade bindgen to a more recent version, 0.65.1, to support LLVM 16. Since bindgen 0.58.0 changed the `--{white,black}list-*` flags to `--{allow,block}list-*` [3], update them on our side too. In addition, bindgen 0.61.0 moved its CLI utility into a binary crate called `bindgen-cli` [4]. Thus update the installation command in the Quick Start guide. Moreover, bindgen 0.61.0 changed the default functionality to bind `size_t` to `usize` [5] and added the `--no-size_t-is-usize` flag to not bind `size_t` as `usize`. Then bindgen 0.65.0 removed the `--size_t-is-usize` flag [6]. Thus stop passing the flag to bindgen. Finally, bindgen 0.61.0 added support for the `noreturn` attribute (in its different forms) [7]. Thus remove the infinite loop in our Rust panic handler after calling `BUG()`, since bindgen now correctly generates a `BUG()` binding that returns `!` instead of `()`. Link: https://github.com/llvm/llvm-project/commit/19e984ef8f49bc3ccced15621989fa9703b2cd5b [1] Link: https://github.com/rust-lang/rust-bindgen/pull/2319 [2] Link: https://github.com/rust-lang/rust-bindgen/pull/1990 [3] Link: https://github.com/rust-lang/rust-bindgen/pull/2284 [4] Link: https://github.com/rust-lang/rust-bindgen/commit/cc78b6fdb6e829e5fb8fa1639f2182cb49333569 [5] Link: https://github.com/rust-lang/rust-bindgen/pull/2408 [6] Link: https://github.com/rust-lang/rust-bindgen/issues/2094 [7] Signed-off-by: Aakash Sen Sharma Closes: https://github.com/Rust-for-Linux/linux/issues/1013 Tested-by: Ariel Miculas Reviewed-by: Gary Guo Link: https://lore.kernel.org/r/20230612194311.24826-1-aakashsensharma@gmail.com [ Reworded commit message. Mentioned the `bindgen-cli` binary crate change, linked to it and updated the Quick Start guide. Re-added a deleted "as" word in a code comment and reflowed comment to respect the maximum length. ] Signed-off-by: Miguel Ojeda --- Documentation/process/changes.rst | 2 +- Documentation/rust/quick-start.rst | 2 +- rust/Makefile | 6 +++--- rust/helpers.c | 15 +++++++-------- rust/kernel/lib.rs | 3 --- scripts/min-tool-version.sh | 2 +- 6 files changed, 13 insertions(+), 17 deletions(-) (limited to 'rust') diff --git a/Documentation/process/changes.rst b/Documentation/process/changes.rst index 1382bccc8818..0bbd040f6a55 100644 --- a/Documentation/process/changes.rst +++ b/Documentation/process/changes.rst @@ -32,7 +32,7 @@ you probably needn't concern yourself with pcmciautils. GNU C 5.1 gcc --version Clang/LLVM (optional) 11.0.0 clang --version Rust (optional) 1.71.1 rustc --version -bindgen (optional) 0.56.0 bindgen --version +bindgen (optional) 0.65.1 bindgen --version GNU make 3.82 make --version bash 4.2 bash --version binutils 2.25 ld -v diff --git a/Documentation/rust/quick-start.rst b/Documentation/rust/quick-start.rst index 58a183bb90b1..2cdf75eeae1d 100644 --- a/Documentation/rust/quick-start.rst +++ b/Documentation/rust/quick-start.rst @@ -98,7 +98,7 @@ the ``bindgen`` tool. A particular version is required. Install it via (note that this will download and build the tool from source):: - cargo install --locked --version $(scripts/min-tool-version.sh bindgen) bindgen + cargo install --locked --version $(scripts/min-tool-version.sh bindgen) bindgen-cli ``bindgen`` needs to find a suitable ``libclang`` in order to work. If it is not found (or a different ``libclang`` than the one found should be used), diff --git a/rust/Makefile b/rust/Makefile index b278908c19e5..c3dfb3f6071b 100644 --- a/rust/Makefile +++ b/rust/Makefile @@ -300,7 +300,7 @@ quiet_cmd_bindgen = BINDGEN $@ $(BINDGEN) $< $(bindgen_target_flags) \ --use-core --with-derive-default --ctypes-prefix core::ffi --no-layout-tests \ --no-debug '.*' \ - --size_t-is-usize -o $@ -- $(bindgen_c_flags_final) -DMODULE \ + -o $@ -- $(bindgen_c_flags_final) -DMODULE \ $(bindgen_target_cflags) $(bindgen_target_extra) $(obj)/bindings/bindings_generated.rs: private bindgen_target_flags = \ @@ -320,8 +320,8 @@ $(obj)/uapi/uapi_generated.rs: $(src)/uapi/uapi_helper.h \ # given it is `libclang`; but for consistency, future Clang changes and/or # a potential future GCC backend for `bindgen`, we disable it too. $(obj)/bindings/bindings_helpers_generated.rs: private bindgen_target_flags = \ - --blacklist-type '.*' --whitelist-var '' \ - --whitelist-function 'rust_helper_.*' + --blocklist-type '.*' --allowlist-var '' \ + --allowlist-function 'rust_helper_.*' $(obj)/bindings/bindings_helpers_generated.rs: private bindgen_target_cflags = \ -I$(objtree)/$(obj) -Wno-missing-prototypes -Wno-missing-declarations $(obj)/bindings/bindings_helpers_generated.rs: private bindgen_target_extra = ; \ diff --git a/rust/helpers.c b/rust/helpers.c index f946f2ea640a..ebd69490127b 100644 --- a/rust/helpers.c +++ b/rust/helpers.c @@ -138,19 +138,18 @@ void rust_helper_put_task_struct(struct task_struct *t) EXPORT_SYMBOL_GPL(rust_helper_put_task_struct); /* - * We use `bindgen`'s `--size_t-is-usize` option to bind the C `size_t` type - * as the Rust `usize` type, so we can use it in contexts where Rust - * expects a `usize` like slice (array) indices. `usize` is defined to be - * the same as C's `uintptr_t` type (can hold any pointer) but not - * necessarily the same as `size_t` (can hold the size of any single - * object). Most modern platforms use the same concrete integer type for + * `bindgen` binds the C `size_t` type as the Rust `usize` type, so we can + * use it in contexts where Rust expects a `usize` like slice (array) indices. + * `usize` is defined to be the same as C's `uintptr_t` type (can hold any + * pointer) but not necessarily the same as `size_t` (can hold the size of any + * single object). Most modern platforms use the same concrete integer type for * both of them, but in case we find ourselves on a platform where * that's not true, fail early instead of risking ABI or * integer-overflow issues. * * If your platform fails this assertion, it means that you are in - * danger of integer-overflow bugs (even if you attempt to remove - * `--size_t-is-usize`). It may be easiest to change the kernel ABI on + * danger of integer-overflow bugs (even if you attempt to add + * `--no-size_t-is-usize`). It may be easiest to change the kernel ABI on * your platform such that `size_t` matches `uintptr_t` (i.e., to increase * `size_t`, because `uintptr_t` has to be at least as big as `size_t`). */ diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index 85b261209977..d59041ff5ff2 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -93,7 +93,4 @@ fn panic(info: &core::panic::PanicInfo<'_>) -> ! { pr_emerg!("{}\n", info); // SAFETY: FFI call. unsafe { bindings::BUG() }; - // Bindgen currently does not recognize `__noreturn` so `BUG` returns `()` - // instead of `!`. See . - loop {} } diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh index 8da3b53fe36a..d65ab8bfeaf4 100755 --- a/scripts/min-tool-version.sh +++ b/scripts/min-tool-version.sh @@ -34,7 +34,7 @@ rustc) echo 1.71.1 ;; bindgen) - echo 0.56.0 + echo 0.65.1 ;; *) echo "$1: unknown tool" >&2 -- cgit v1.2.3 From 4f353e0d1282dfe6b8082290fe8e606c5739a954 Mon Sep 17 00:00:00 2001 From: Martin Rodriguez Reboredo Date: Fri, 4 Aug 2023 14:14:39 -0300 Subject: scripts: generate_rust_analyzer: provide `cfg`s for `core` and `alloc` Both `core` and `alloc` have their `cfgs` (such as `no_rc`) missing in `rust-project.json`. To remedy this, pass the flags to `generate_rust_analyzer.py` for them to be added to a dictionary where each key corresponds to a crate and each value to a list of `cfg`s. The dictionary is then used to pass the `cfg`s to each crate in the generated file (for `core` and `alloc` only). Signed-off-by: Martin Rodriguez Reboredo Link: https://lore.kernel.org/r/20230804171448.54976-1-yakoyoku@gmail.com [ Removed `Suggested-by` as discussed in mailing list. ] Signed-off-by: Miguel Ojeda --- rust/Makefile | 1 + scripts/generate_rust_analyzer.py | 16 ++++++++++++++-- 2 files changed, 15 insertions(+), 2 deletions(-) (limited to 'rust') diff --git a/rust/Makefile b/rust/Makefile index c3dfb3f6071b..31a5fb01d56b 100644 --- a/rust/Makefile +++ b/rust/Makefile @@ -374,6 +374,7 @@ quiet_cmd_rustc_library = $(if $(skip_clippy),RUSTC,$(RUSTC_OR_CLIPPY_QUIET)) L rust-analyzer: $(Q)$(srctree)/scripts/generate_rust_analyzer.py \ + --cfgs='core=$(core-cfgs)' --cfgs='alloc=$(alloc-cfgs)' \ $(abs_srctree) $(abs_objtree) \ $(RUST_LIB_SRC) $(KBUILD_EXTMOD) > \ $(if $(KBUILD_EXTMOD),$(extmod_prefix),$(objtree))/rust-project.json diff --git a/scripts/generate_rust_analyzer.py b/scripts/generate_rust_analyzer.py index 848fa1ad92ba..fc52bc41d3e7 100755 --- a/scripts/generate_rust_analyzer.py +++ b/scripts/generate_rust_analyzer.py @@ -10,7 +10,15 @@ import os import pathlib import sys -def generate_crates(srctree, objtree, sysroot_src, external_src): +def args_crates_cfgs(cfgs): + crates_cfgs = {} + for cfg in cfgs: + crate, vals = cfg.split("=", 1) + crates_cfgs[crate] = vals.replace("--cfg", "").split() + + return crates_cfgs + +def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs): # Generate the configuration list. cfg = [] with open(objtree / "include" / "generated" / "rustc_cfg") as fd: @@ -24,6 +32,7 @@ def generate_crates(srctree, objtree, sysroot_src, external_src): # Avoid O(n^2) iterations by keeping a map of indexes. crates = [] crates_indexes = {} + crates_cfgs = args_crates_cfgs(cfgs) def append_crate(display_name, root_module, deps, cfg=[], is_workspace_member=True, is_proc_macro=False): crates_indexes[display_name] = len(crates) @@ -45,6 +54,7 @@ def generate_crates(srctree, objtree, sysroot_src, external_src): "core", sysroot_src / "core" / "src" / "lib.rs", [], + cfg=crates_cfgs.get("core", []), is_workspace_member=False, ) @@ -58,6 +68,7 @@ def generate_crates(srctree, objtree, sysroot_src, external_src): "alloc", srctree / "rust" / "alloc" / "lib.rs", ["core", "compiler_builtins"], + cfg=crates_cfgs.get("alloc", []), ) append_crate( @@ -131,6 +142,7 @@ def generate_crates(srctree, objtree, sysroot_src, external_src): def main(): parser = argparse.ArgumentParser() parser.add_argument('--verbose', '-v', action='store_true') + parser.add_argument('--cfgs', action='append', default=[]) parser.add_argument("srctree", type=pathlib.Path) parser.add_argument("objtree", type=pathlib.Path) parser.add_argument("sysroot_src", type=pathlib.Path) @@ -143,7 +155,7 @@ def main(): ) rust_project = { - "crates": generate_crates(args.srctree, args.objtree, args.sysroot_src, args.exttree), + "crates": generate_crates(args.srctree, args.objtree, args.sysroot_src, args.exttree, args.cfgs), "sysroot_src": str(args.sysroot_src), } -- cgit v1.2.3 From b3068ac37b1c10ee4b9fb6c07a2e46021376c374 Mon Sep 17 00:00:00 2001 From: Benno Lossin Date: Mon, 14 Aug 2023 08:46:26 +0000 Subject: rust: init: consolidate init macros MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Merges the implementations of `try_init!` and `try_pin_init!`. These two macros are very similar, but use different traits. The new macro `__init_internal!` that is now the implementation for both takes these traits as parameters. This change does not affect any users, as no public API has been changed, but it should simplify maintaining the init macros. Reviewed-by: Björn Roy Baron Reviewed-by: Martin Rodriguez Reboredo Reviewed-by: Alice Ryhl Signed-off-by: Benno Lossin Link: https://lore.kernel.org/r/20230814084602.25699-2-benno.lossin@proton.me [ Cleaned a couple trivial nits. ] Signed-off-by: Miguel Ojeda --- rust/kernel/init.rs | 388 +++------------------------------------------ rust/kernel/init/macros.rs | 237 ++++++++++++++++++++++++++- 2 files changed, 259 insertions(+), 366 deletions(-) (limited to 'rust') diff --git a/rust/kernel/init.rs b/rust/kernel/init.rs index b4332a4ec1f4..d9a91950cba2 100644 --- a/rust/kernel/init.rs +++ b/rust/kernel/init.rs @@ -540,11 +540,14 @@ macro_rules! pin_init { ($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? { $($fields:tt)* }) => { - $crate::try_pin_init!( + $crate::__init_internal!( @this($($this)?), @typ($t $(::<$($generics),*>)?), @fields($($fields)*), @error(::core::convert::Infallible), + @data(PinData, use_data), + @has_data(HasPinData, __pin_data), + @construct_closure(pin_init_from_closure), ) }; } @@ -593,205 +596,29 @@ macro_rules! try_pin_init { ($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? { $($fields:tt)* }) => { - $crate::try_pin_init!( + $crate::__init_internal!( @this($($this)?), @typ($t $(::<$($generics),*>)? ), @fields($($fields)*), @error($crate::error::Error), + @data(PinData, use_data), + @has_data(HasPinData, __pin_data), + @construct_closure(pin_init_from_closure), ) }; ($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? { $($fields:tt)* }? $err:ty) => { - $crate::try_pin_init!( + $crate::__init_internal!( @this($($this)?), @typ($t $(::<$($generics),*>)? ), @fields($($fields)*), @error($err), + @data(PinData, use_data), + @has_data(HasPinData, __pin_data), + @construct_closure(pin_init_from_closure), ) }; - ( - @this($($this:ident)?), - @typ($t:ident $(::<$($generics:ty),*>)?), - @fields($($fields:tt)*), - @error($err:ty), - ) => {{ - // We do not want to allow arbitrary returns, so we declare this type as the `Ok` return - // type and shadow it later when we insert the arbitrary user code. That way there will be - // no possibility of returning without `unsafe`. - struct __InitOk; - // Get the pin data from the supplied type. - let data = unsafe { - use $crate::init::__internal::HasPinData; - $t$(::<$($generics),*>)?::__pin_data() - }; - // Ensure that `data` really is of type `PinData` and help with type inference: - let init = $crate::init::__internal::PinData::make_closure::<_, __InitOk, $err>( - data, - move |slot| { - { - // Shadow the structure so it cannot be used to return early. - struct __InitOk; - // Create the `this` so it can be referenced by the user inside of the - // expressions creating the individual fields. - $(let $this = unsafe { ::core::ptr::NonNull::new_unchecked(slot) };)? - // Initialize every field. - $crate::try_pin_init!(init_slot: - @data(data), - @slot(slot), - @munch_fields($($fields)*,), - ); - // We use unreachable code to ensure that all fields have been mentioned exactly - // once, this struct initializer will still be type-checked and complain with a - // very natural error message if a field is forgotten/mentioned more than once. - #[allow(unreachable_code, clippy::diverging_sub_expression)] - if false { - $crate::try_pin_init!(make_initializer: - @slot(slot), - @type_name($t), - @munch_fields($($fields)*,), - @acc(), - ); - } - // Forget all guards, since initialization was a success. - $crate::try_pin_init!(forget_guards: - @munch_fields($($fields)*,), - ); - } - Ok(__InitOk) - } - ); - let init = move |slot| -> ::core::result::Result<(), $err> { - init(slot).map(|__InitOk| ()) - }; - let init = unsafe { $crate::init::pin_init_from_closure::<_, $err>(init) }; - init - }}; - (init_slot: - @data($data:ident), - @slot($slot:ident), - @munch_fields($(,)?), - ) => { - // Endpoint of munching, no fields are left. - }; - (init_slot: - @data($data:ident), - @slot($slot:ident), - // In-place initialization syntax. - @munch_fields($field:ident <- $val:expr, $($rest:tt)*), - ) => { - let $field = $val; - // Call the initializer. - // - // SAFETY: `slot` is valid, because we are inside of an initializer closure, we - // return when an error/panic occurs. - // We also use the `data` to require the correct trait (`Init` or `PinInit`) for `$field`. - unsafe { $data.$field(::core::ptr::addr_of_mut!((*$slot).$field), $field)? }; - // Create the drop guard. - // - // We only give access to `&DropGuard`, so it cannot be forgotten via safe code. - // - // SAFETY: We forget the guard later when initialization has succeeded. - let $field = &unsafe { - $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field)) - }; - - $crate::try_pin_init!(init_slot: - @data($data), - @slot($slot), - @munch_fields($($rest)*), - ); - }; - (init_slot: - @data($data:ident), - @slot($slot:ident), - // Direct value init, this is safe for every field. - @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*), - ) => { - $(let $field = $val;)? - // Initialize the field. - // - // SAFETY: The memory at `slot` is uninitialized. - unsafe { ::core::ptr::write(::core::ptr::addr_of_mut!((*$slot).$field), $field) }; - // Create the drop guard: - // - // We only give access to `&DropGuard`, so it cannot be accidentally forgotten. - // - // SAFETY: We forget the guard later when initialization has succeeded. - let $field = &unsafe { - $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field)) - }; - - $crate::try_pin_init!(init_slot: - @data($data), - @slot($slot), - @munch_fields($($rest)*), - ); - }; - (make_initializer: - @slot($slot:ident), - @type_name($t:ident), - @munch_fields($(,)?), - @acc($($acc:tt)*), - ) => { - // Endpoint, nothing more to munch, create the initializer. - // Since we are in the `if false` branch, this will never get executed. We abuse `slot` to - // get the correct type inference here: - unsafe { - ::core::ptr::write($slot, $t { - $($acc)* - }); - } - }; - (make_initializer: - @slot($slot:ident), - @type_name($t:ident), - @munch_fields($field:ident <- $val:expr, $($rest:tt)*), - @acc($($acc:tt)*), - ) => { - $crate::try_pin_init!(make_initializer: - @slot($slot), - @type_name($t), - @munch_fields($($rest)*), - @acc($($acc)* $field: ::core::panic!(),), - ); - }; - (make_initializer: - @slot($slot:ident), - @type_name($t:ident), - @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*), - @acc($($acc:tt)*), - ) => { - $crate::try_pin_init!(make_initializer: - @slot($slot), - @type_name($t), - @munch_fields($($rest)*), - @acc($($acc)* $field: ::core::panic!(),), - ); - }; - (forget_guards: - @munch_fields($(,)?), - ) => { - // Munching finished. - }; - (forget_guards: - @munch_fields($field:ident <- $val:expr, $($rest:tt)*), - ) => { - unsafe { $crate::init::__internal::DropGuard::forget($field) }; - - $crate::try_pin_init!(forget_guards: - @munch_fields($($rest)*), - ); - }; - (forget_guards: - @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*), - ) => { - unsafe { $crate::init::__internal::DropGuard::forget($field) }; - - $crate::try_pin_init!(forget_guards: - @munch_fields($($rest)*), - ); - }; } /// Construct an in-place initializer for `struct`s. @@ -816,11 +643,14 @@ macro_rules! init { ($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? { $($fields:tt)* }) => { - $crate::try_init!( + $crate::__init_internal!( @this($($this)?), @typ($t $(::<$($generics),*>)?), @fields($($fields)*), @error(::core::convert::Infallible), + @data(InitData, /*no use_data*/), + @has_data(HasInitData, __init_data), + @construct_closure(init_from_closure), ) } } @@ -863,199 +693,29 @@ macro_rules! try_init { ($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? { $($fields:tt)* }) => { - $crate::try_init!( + $crate::__init_internal!( @this($($this)?), @typ($t $(::<$($generics),*>)?), @fields($($fields)*), @error($crate::error::Error), + @data(InitData, /*no use_data*/), + @has_data(HasInitData, __init_data), + @construct_closure(init_from_closure), ) }; ($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? { $($fields:tt)* }? $err:ty) => { - $crate::try_init!( + $crate::__init_internal!( @this($($this)?), @typ($t $(::<$($generics),*>)?), @fields($($fields)*), @error($err), + @data(InitData, /*no use_data*/), + @has_data(HasInitData, __init_data), + @construct_closure(init_from_closure), ) }; - ( - @this($($this:ident)?), - @typ($t:ident $(::<$($generics:ty),*>)?), - @fields($($fields:tt)*), - @error($err:ty), - ) => {{ - // We do not want to allow arbitrary returns, so we declare this type as the `Ok` return - // type and shadow it later when we insert the arbitrary user code. That way there will be - // no possibility of returning without `unsafe`. - struct __InitOk; - // Get the init data from the supplied type. - let data = unsafe { - use $crate::init::__internal::HasInitData; - $t$(::<$($generics),*>)?::__init_data() - }; - // Ensure that `data` really is of type `InitData` and help with type inference: - let init = $crate::init::__internal::InitData::make_closure::<_, __InitOk, $err>( - data, - move |slot| { - { - // Shadow the structure so it cannot be used to return early. - struct __InitOk; - // Create the `this` so it can be referenced by the user inside of the - // expressions creating the individual fields. - $(let $this = unsafe { ::core::ptr::NonNull::new_unchecked(slot) };)? - // Initialize every field. - $crate::try_init!(init_slot: - @slot(slot), - @munch_fields($($fields)*,), - ); - // We use unreachable code to ensure that all fields have been mentioned exactly - // once, this struct initializer will still be type-checked and complain with a - // very natural error message if a field is forgotten/mentioned more than once. - #[allow(unreachable_code, clippy::diverging_sub_expression)] - if false { - $crate::try_init!(make_initializer: - @slot(slot), - @type_name($t), - @munch_fields($($fields)*,), - @acc(), - ); - } - // Forget all guards, since initialization was a success. - $crate::try_init!(forget_guards: - @munch_fields($($fields)*,), - ); - } - Ok(__InitOk) - } - ); - let init = move |slot| -> ::core::result::Result<(), $err> { - init(slot).map(|__InitOk| ()) - }; - let init = unsafe { $crate::init::init_from_closure::<_, $err>(init) }; - init - }}; - (init_slot: - @slot($slot:ident), - @munch_fields( $(,)?), - ) => { - // Endpoint of munching, no fields are left. - }; - (init_slot: - @slot($slot:ident), - @munch_fields($field:ident <- $val:expr, $($rest:tt)*), - ) => { - let $field = $val; - // Call the initializer. - // - // SAFETY: `slot` is valid, because we are inside of an initializer closure, we - // return when an error/panic occurs. - unsafe { - $crate::init::Init::__init($field, ::core::ptr::addr_of_mut!((*$slot).$field))?; - } - // Create the drop guard. - // - // We only give access to `&DropGuard`, so it cannot be accidentally forgotten. - // - // SAFETY: We forget the guard later when initialization has succeeded. - let $field = &unsafe { - $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field)) - }; - - $crate::try_init!(init_slot: - @slot($slot), - @munch_fields($($rest)*), - ); - }; - (init_slot: - @slot($slot:ident), - // Direct value init. - @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*), - ) => { - $(let $field = $val;)? - // Call the initializer. - // - // SAFETY: The memory at `slot` is uninitialized. - unsafe { ::core::ptr::write(::core::ptr::addr_of_mut!((*$slot).$field), $field) }; - // Create the drop guard. - // - // We only give access to `&DropGuard`, so it cannot be accidentally forgotten. - // - // SAFETY: We forget the guard later when initialization has succeeded. - let $field = &unsafe { - $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field)) - }; - - $crate::try_init!(init_slot: - @slot($slot), - @munch_fields($($rest)*), - ); - }; - (make_initializer: - @slot($slot:ident), - @type_name($t:ident), - @munch_fields( $(,)?), - @acc($($acc:tt)*), - ) => { - // Endpoint, nothing more to munch, create the initializer. - // Since we are in the `if false` branch, this will never get executed. We abuse `slot` to - // get the correct type inference here: - unsafe { - ::core::ptr::write($slot, $t { - $($acc)* - }); - } - }; - (make_initializer: - @slot($slot:ident), - @type_name($t:ident), - @munch_fields($field:ident <- $val:expr, $($rest:tt)*), - @acc($($acc:tt)*), - ) => { - $crate::try_init!(make_initializer: - @slot($slot), - @type_name($t), - @munch_fields($($rest)*), - @acc($($acc)*$field: ::core::panic!(),), - ); - }; - (make_initializer: - @slot($slot:ident), - @type_name($t:ident), - @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*), - @acc($($acc:tt)*), - ) => { - $crate::try_init!(make_initializer: - @slot($slot), - @type_name($t), - @munch_fields($($rest)*), - @acc($($acc)*$field: ::core::panic!(),), - ); - }; - (forget_guards: - @munch_fields($(,)?), - ) => { - // Munching finished. - }; - (forget_guards: - @munch_fields($field:ident <- $val:expr, $($rest:tt)*), - ) => { - unsafe { $crate::init::__internal::DropGuard::forget($field) }; - - $crate::try_init!(forget_guards: - @munch_fields($($rest)*), - ); - }; - (forget_guards: - @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*), - ) => { - unsafe { $crate::init::__internal::DropGuard::forget($field) }; - - $crate::try_init!(forget_guards: - @munch_fields($($rest)*), - ); - }; } /// A pin-initializer for the type `T`. diff --git a/rust/kernel/init/macros.rs b/rust/kernel/init/macros.rs index 00aa4e956c0a..ad78dd0d9d9e 100644 --- a/rust/kernel/init/macros.rs +++ b/rust/kernel/init/macros.rs @@ -1,10 +1,12 @@ // SPDX-License-Identifier: Apache-2.0 OR MIT //! This module provides the macros that actually implement the proc-macros `pin_data` and -//! `pinned_drop`. +//! `pinned_drop`. It also contains `__init_internal` the implementation of the `{try_}{pin_}init!` +//! macros. //! //! These macros should never be called directly, since they expect their input to be -//! in a certain format which is internal. Use the proc-macros instead. +//! in a certain format which is internal. If used incorrectly, these macros can lead to UB even in +//! safe code! Use the public facing macros instead. //! //! This architecture has been chosen because the kernel does not yet have access to `syn` which //! would make matters a lot easier for implementing these as proc-macros. @@ -980,3 +982,234 @@ macro_rules! __pin_data { } }; } + +/// The internal init macro. Do not call manually! +/// +/// This is called by the `{try_}{pin_}init!` macros with various inputs. +/// +/// This macro has multiple internal call configurations, these are always the very first ident: +/// - nothing: this is the base case and called by the `{try_}{pin_}init!` macros. +/// - `init_slot`: recursively creates the code that initializes all fields in `slot`. +/// - `make_initializer`: recursively create the struct initializer that guarantees that every +/// field has been initialized exactly once. +/// - `forget_guards`: recursively forget the drop guards for every field. +#[doc(hidden)] +#[macro_export] +macro_rules! __init_internal { + ( + @this($($this:ident)?), + @typ($t:ident $(::<$($generics:ty),*>)?), + @fields($($fields:tt)*), + @error($err:ty), + // Either `PinData` or `InitData`, `$use_data` should only be present in the `PinData` + // case. + @data($data:ident, $($use_data:ident)?), + // `HasPinData` or `HasInitData`. + @has_data($has_data:ident, $get_data:ident), + // `pin_init_from_closure` or `init_from_closure`. + @construct_closure($construct_closure:ident), + ) => {{ + // We do not want to allow arbitrary returns, so we declare this type as the `Ok` return + // type and shadow it later when we insert the arbitrary user code. That way there will be + // no possibility of returning without `unsafe`. + struct __InitOk; + // Get the data about fields from the supplied type. + let data = unsafe { + use $crate::init::__internal::$has_data; + $t$(::<$($generics),*>)?::$get_data() + }; + // Ensure that `data` really is of type `$data` and help with type inference: + let init = $crate::init::__internal::$data::make_closure::<_, __InitOk, $err>( + data, + move |slot| { + { + // Shadow the structure so it cannot be used to return early. + struct __InitOk; + // Create the `this` so it can be referenced by the user inside of the + // expressions creating the individual fields. + $(let $this = unsafe { ::core::ptr::NonNull::new_unchecked(slot) };)? + // Initialize every field. + $crate::__init_internal!(init_slot($($use_data)?): + @data(data), + @slot(slot), + @munch_fields($($fields)*,), + ); + // We use unreachable code to ensure that all fields have been mentioned exactly + // once, this struct initializer will still be type-checked and complain with a + // very natural error message if a field is forgotten/mentioned more than once. + #[allow(unreachable_code, clippy::diverging_sub_expression)] + if false { + $crate::__init_internal!(make_initializer: + @slot(slot), + @type_name($t), + @munch_fields($($fields)*,), + @acc(), + ); + } + // Forget all guards, since initialization was a success. + $crate::__init_internal!(forget_guards: + @munch_fields($($fields)*,), + ); + } + Ok(__InitOk) + } + ); + let init = move |slot| -> ::core::result::Result<(), $err> { + init(slot).map(|__InitOk| ()) + }; + let init = unsafe { $crate::init::$construct_closure::<_, $err>(init) }; + init + }}; + (init_slot($($use_data:ident)?): + @data($data:ident), + @slot($slot:ident), + @munch_fields($(,)?), + ) => { + // Endpoint of munching, no fields are left. + }; + (init_slot($use_data:ident): // `use_data` is present, so we use the `data` to init fields. + @data($data:ident), + @slot($slot:ident), + // In-place initialization syntax. + @munch_fields($field:ident <- $val:expr, $($rest:tt)*), + ) => { + let $field = $val; + // Call the initializer. + // + // SAFETY: `slot` is valid, because we are inside of an initializer closure, we + // return when an error/panic occurs. + // We also use the `data` to require the correct trait (`Init` or `PinInit`) for `$field`. + unsafe { $data.$field(::core::ptr::addr_of_mut!((*$slot).$field), $field)? }; + // Create the drop guard. + // + // We only give access to `&DropGuard`, so it cannot be forgotten via safe code. + // + // SAFETY: We forget the guard later when initialization has succeeded. + let $field = &unsafe { + $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field)) + }; + + $crate::__init_internal!(init_slot($use_data): + @data($data), + @slot($slot), + @munch_fields($($rest)*), + ); + }; + (init_slot(): // No `use_data`, so we use `Init::__init` directly. + @data($data:ident), + @slot($slot:ident), + // In-place initialization syntax. + @munch_fields($field:ident <- $val:expr, $($rest:tt)*), + ) => { + let $field = $val; + // Call the initializer. + // + // SAFETY: `slot` is valid, because we are inside of an initializer closure, we + // return when an error/panic occurs. + unsafe { $crate::init::Init::__init($field, ::core::ptr::addr_of_mut!((*$slot).$field))? }; + // Create the drop guard. + // + // We only give access to `&DropGuard`, so it cannot be forgotten via safe code. + // + // SAFETY: We forget the guard later when initialization has succeeded. + let $field = &unsafe { + $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field)) + }; + + $crate::__init_internal!(init_slot(): + @data($data), + @slot($slot), + @munch_fields($($rest)*), + ); + }; + (init_slot($($use_data:ident)?): + @data($data:ident), + @slot($slot:ident), + // Init by-value. + @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*), + ) => { + $(let $field = $val;)? + // Initialize the field. + // + // SAFETY: The memory at `slot` is uninitialized. + unsafe { ::core::ptr::write(::core::ptr::addr_of_mut!((*$slot).$field), $field) }; + // Create the drop guard: + // + // We only give access to `&DropGuard`, so it cannot be accidentally forgotten. + // + // SAFETY: We forget the guard later when initialization has succeeded. + let $field = &unsafe { + $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field)) + }; + + $crate::__init_internal!(init_slot($($use_data)?): + @data($data), + @slot($slot), + @munch_fields($($rest)*), + ); + }; + (make_initializer: + @slot($slot:ident), + @type_name($t:ident), + @munch_fields($(,)?), + @acc($($acc:tt)*), + ) => { + // Endpoint, nothing more to munch, create the initializer. + // Since we are in the `if false` branch, this will never get executed. We abuse `slot` to + // get the correct type inference here: + unsafe { + ::core::ptr::write($slot, $t { + $($acc)* + }); + } + }; + (make_initializer: + @slot($slot:ident), + @type_name($t:ident), + @munch_fields($field:ident <- $val:expr, $($rest:tt)*), + @acc($($acc:tt)*), + ) => { + $crate::__init_internal!(make_initializer: + @slot($slot), + @type_name($t), + @munch_fields($($rest)*), + @acc($($acc)* $field: ::core::panic!(),), + ); + }; + (make_initializer: + @slot($slot:ident), + @type_name($t:ident), + @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*), + @acc($($acc:tt)*), + ) => { + $crate::__init_internal!(make_initializer: + @slot($slot), + @type_name($t), + @munch_fields($($rest)*), + @acc($($acc)* $field: ::core::panic!(),), + ); + }; + (forget_guards: + @munch_fields($(,)?), + ) => { + // Munching finished. + }; + (forget_guards: + @munch_fields($field:ident <- $val:expr, $($rest:tt)*), + ) => { + unsafe { $crate::init::__internal::DropGuard::forget($field) }; + + $crate::__init_internal!(forget_guards: + @munch_fields($($rest)*), + ); + }; + (forget_guards: + @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*), + ) => { + unsafe { $crate::init::__internal::DropGuard::forget($field) }; + + $crate::__init_internal!(forget_guards: + @munch_fields($($rest)*), + ); + }; +} -- cgit v1.2.3 From f8badd150763ae0f9c8482fabe0fdbac81735d34 Mon Sep 17 00:00:00 2001 From: Benno Lossin Date: Mon, 14 Aug 2023 08:46:31 +0000 Subject: rust: init: make `#[pin_data]` compatible with conditional compilation of fields This patch allows one to write ``` #[pin_data] pub struct Foo { #[cfg(CONFIG_BAR)] a: Bar, #[cfg(not(CONFIG_BAR))] a: Baz, } ``` Before, this would result in a compile error, because `#[pin_data]` would generate two functions named `a` for both fields unconditionally. Reviewed-by: Martin Rodriguez Reboredo Reviewed-by: Gary Guo Reviewed-by: Alice Ryhl Signed-off-by: Benno Lossin Link: https://lore.kernel.org/r/20230814084602.25699-3-benno.lossin@proton.me Signed-off-by: Miguel Ojeda --- rust/kernel/init/macros.rs | 2 ++ 1 file changed, 2 insertions(+) (limited to 'rust') diff --git a/rust/kernel/init/macros.rs b/rust/kernel/init/macros.rs index ad78dd0d9d9e..474ed36f84a5 100644 --- a/rust/kernel/init/macros.rs +++ b/rust/kernel/init/macros.rs @@ -962,6 +962,7 @@ macro_rules! __pin_data { where $($whr)* { $( + $(#[$($p_attr)*])* $pvis unsafe fn $p_field( self, slot: *mut $p_type, @@ -971,6 +972,7 @@ macro_rules! __pin_data { } )* $( + $(#[$($attr)*])* $fvis unsafe fn $field( self, slot: *mut $type, -- cgit v1.2.3 From 071cedc84e907f6984b3de3285ec2b077d3c3cdb Mon Sep 17 00:00:00 2001 From: Benno Lossin Date: Mon, 14 Aug 2023 08:46:41 +0000 Subject: rust: add derive macro for `Zeroable` Add a derive proc-macro for the `Zeroable` trait. The macro supports structs where every field implements the `Zeroable` trait. This way `unsafe` implementations can be avoided. The macro is split into two parts: - a proc-macro to parse generics into impl and ty generics, - a declarative macro that expands to the impl block. Suggested-by: Asahi Lina Signed-off-by: Benno Lossin Reviewed-by: Gary Guo Reviewed-by: Martin Rodriguez Reboredo Link: https://lore.kernel.org/r/20230814084602.25699-4-benno.lossin@proton.me [ Added `ignore` to the `lib.rs` example and cleaned trivial nit. ] Signed-off-by: Miguel Ojeda --- rust/kernel/init/macros.rs | 35 ++++++++++++++++++++++ rust/kernel/prelude.rs | 2 +- rust/macros/lib.rs | 20 +++++++++++++ rust/macros/quote.rs | 12 ++++++++ rust/macros/zeroable.rs | 72 ++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 140 insertions(+), 1 deletion(-) create mode 100644 rust/macros/zeroable.rs (limited to 'rust') diff --git a/rust/kernel/init/macros.rs b/rust/kernel/init/macros.rs index 474ed36f84a5..0b0ffbc901a7 100644 --- a/rust/kernel/init/macros.rs +++ b/rust/kernel/init/macros.rs @@ -1215,3 +1215,38 @@ macro_rules! __init_internal { ); }; } + +#[doc(hidden)] +#[macro_export] +macro_rules! __derive_zeroable { + (parse_input: + @sig( + $(#[$($struct_attr:tt)*])* + $vis:vis struct $name:ident + $(where $($whr:tt)*)? + ), + @impl_generics($($impl_generics:tt)*), + @ty_generics($($ty_generics:tt)*), + @body({ + $( + $(#[$($field_attr:tt)*])* + $field:ident : $field_ty:ty + ),* $(,)? + }), + ) => { + // SAFETY: Every field type implements `Zeroable` and padding bytes may be zero. + #[automatically_derived] + unsafe impl<$($impl_generics)*> $crate::init::Zeroable for $name<$($ty_generics)*> + where + $($($whr)*)? + {} + const _: () = { + fn assert_zeroable() {} + fn ensure_zeroable<$($impl_generics)*>() + where $($($whr)*)? + { + $(assert_zeroable::<$field_ty>();)* + } + }; + }; +} diff --git a/rust/kernel/prelude.rs b/rust/kernel/prelude.rs index c28587d68ebc..ae21600970b3 100644 --- a/rust/kernel/prelude.rs +++ b/rust/kernel/prelude.rs @@ -18,7 +18,7 @@ pub use core::pin::Pin; pub use alloc::{boxed::Box, vec::Vec}; #[doc(no_inline)] -pub use macros::{module, pin_data, pinned_drop, vtable}; +pub use macros::{module, pin_data, pinned_drop, vtable, Zeroable}; pub use super::build_assert; diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs index b4bc44c27bd4..c42105c2ff96 100644 --- a/rust/macros/lib.rs +++ b/rust/macros/lib.rs @@ -11,6 +11,7 @@ mod paste; mod pin_data; mod pinned_drop; mod vtable; +mod zeroable; use proc_macro::TokenStream; @@ -343,3 +344,22 @@ pub fn paste(input: TokenStream) -> TokenStream { paste::expand(&mut tokens); tokens.into_iter().collect() } + +/// Derives the [`Zeroable`] trait for the given struct. +/// +/// This can only be used for structs where every field implements the [`Zeroable`] trait. +/// +/// # Examples +/// +/// ```rust,ignore +/// #[derive(Zeroable)] +/// pub struct DriverData { +/// id: i64, +/// buf_ptr: *mut u8, +/// len: usize, +/// } +/// ``` +#[proc_macro_derive(Zeroable)] +pub fn derive_zeroable(input: TokenStream) -> TokenStream { + zeroable::derive(input) +} diff --git a/rust/macros/quote.rs b/rust/macros/quote.rs index dddbb4e6f4cb..33a199e4f176 100644 --- a/rust/macros/quote.rs +++ b/rust/macros/quote.rs @@ -124,6 +124,18 @@ macro_rules! quote_spanned { )); quote_spanned!(@proc $v $span $($tt)*); }; + (@proc $v:ident $span:ident ; $($tt:tt)*) => { + $v.push(::proc_macro::TokenTree::Punct( + ::proc_macro::Punct::new(';', ::proc_macro::Spacing::Alone) + )); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident + $($tt:tt)*) => { + $v.push(::proc_macro::TokenTree::Punct( + ::proc_macro::Punct::new('+', ::proc_macro::Spacing::Alone) + )); + quote_spanned!(@proc $v $span $($tt)*); + }; (@proc $v:ident $span:ident $id:ident $($tt:tt)*) => { $v.push(::proc_macro::TokenTree::Ident(::proc_macro::Ident::new(stringify!($id), $span))); quote_spanned!(@proc $v $span $($tt)*); diff --git a/rust/macros/zeroable.rs b/rust/macros/zeroable.rs new file mode 100644 index 000000000000..0d605c46ab3b --- /dev/null +++ b/rust/macros/zeroable.rs @@ -0,0 +1,72 @@ +// SPDX-License-Identifier: GPL-2.0 + +use crate::helpers::{parse_generics, Generics}; +use proc_macro::{TokenStream, TokenTree}; + +pub(crate) fn derive(input: TokenStream) -> TokenStream { + let ( + Generics { + impl_generics, + ty_generics, + }, + mut rest, + ) = parse_generics(input); + // This should be the body of the struct `{...}`. + let last = rest.pop(); + // Now we insert `Zeroable` as a bound for every generic parameter in `impl_generics`. + let mut new_impl_generics = Vec::with_capacity(impl_generics.len()); + // Are we inside of a generic where we want to add `Zeroable`? + let mut in_generic = !impl_generics.is_empty(); + // Have we already inserted `Zeroable`? + let mut inserted = false; + // Level of `<>` nestings. + let mut nested = 0; + for tt in impl_generics { + match &tt { + // If we find a `,`, then we have finished a generic/constant/lifetime parameter. + TokenTree::Punct(p) if nested == 0 && p.as_char() == ',' => { + if in_generic && !inserted { + new_impl_generics.extend(quote! { : ::kernel::init::Zeroable }); + } + in_generic = true; + inserted = false; + new_impl_generics.push(tt); + } + // If we find `'`, then we are entering a lifetime. + TokenTree::Punct(p) if nested == 0 && p.as_char() == '\'' => { + in_generic = false; + new_impl_generics.push(tt); + } + TokenTree::Punct(p) if nested == 0 && p.as_char() == ':' => { + new_impl_generics.push(tt); + if in_generic { + new_impl_generics.extend(quote! { ::kernel::init::Zeroable + }); + inserted = true; + } + } + TokenTree::Punct(p) if p.as_char() == '<' => { + nested += 1; + new_impl_generics.push(tt); + } + TokenTree::Punct(p) if p.as_char() == '>' => { + assert!(nested > 0); + nested -= 1; + new_impl_generics.push(tt); + } + _ => new_impl_generics.push(tt), + } + } + assert_eq!(nested, 0); + if in_generic && !inserted { + new_impl_generics.extend(quote! { : ::kernel::init::Zeroable }); + } + quote! { + ::kernel::__derive_zeroable!( + parse_input: + @sig(#(#rest)*), + @impl_generics(#(#new_impl_generics)*), + @ty_generics(#(#ty_generics)*), + @body(#last), + ); + } +} -- cgit v1.2.3 From 97de919d574e6a22f0d43a169b96274f1862e770 Mon Sep 17 00:00:00 2001 From: Benno Lossin Date: Mon, 14 Aug 2023 08:46:48 +0000 Subject: rust: init: make guards in the init macros hygienic Use hygienic identifiers for the guards instead of the field names. This makes the init macros feel more like normal struct initializers, since assigning identifiers with the name of a field does not create conflicts. Also change the internals of the guards, no need to make the `forget` function `unsafe`, since users cannot access the guards anyways. Now the guards are carried directly on the stack and have no extra `Cell` field that marks if they have been forgotten or not, instead they are just forgotten via `mem::forget`. Suggested-by: Asahi Lina Reviewed-by: Martin Rodriguez Reboredo Reviewed-by: Alice Ryhl Reviewed-by: Gary Guo Signed-off-by: Benno Lossin Link: https://lore.kernel.org/r/20230814084602.25699-5-benno.lossin@proton.me [ Cleaned a few trivial nits. ] Signed-off-by: Miguel Ojeda --- rust/kernel/init.rs | 1 - rust/kernel/init/__internal.rs | 25 ++------- rust/kernel/init/macros.rs | 116 ++++++++++++++++++----------------------- 3 files changed, 56 insertions(+), 86 deletions(-) (limited to 'rust') diff --git a/rust/kernel/init.rs b/rust/kernel/init.rs index d9a91950cba2..ecf6a4bd0ce4 100644 --- a/rust/kernel/init.rs +++ b/rust/kernel/init.rs @@ -206,7 +206,6 @@ use crate::{ use alloc::boxed::Box; use core::{ alloc::AllocError, - cell::Cell, convert::Infallible, marker::PhantomData, mem::MaybeUninit, diff --git a/rust/kernel/init/__internal.rs b/rust/kernel/init/__internal.rs index 44751fb62b51..7abd1fb65e41 100644 --- a/rust/kernel/init/__internal.rs +++ b/rust/kernel/init/__internal.rs @@ -174,7 +174,6 @@ impl StackInit { /// Can be forgotten to prevent the drop. pub struct DropGuard { ptr: *mut T, - do_drop: Cell, } impl DropGuard { @@ -190,32 +189,16 @@ impl DropGuard { /// - will not be dropped by any other means. #[inline] pub unsafe fn new(ptr: *mut T) -> Self { - Self { - ptr, - do_drop: Cell::new(true), - } - } - - /// Prevents this guard from dropping the supplied pointer. - /// - /// # Safety - /// - /// This function is unsafe in order to prevent safe code from forgetting this guard. It should - /// only be called by the macros in this module. - #[inline] - pub unsafe fn forget(&self) { - self.do_drop.set(false); + Self { ptr } } } impl Drop for DropGuard { #[inline] fn drop(&mut self) { - if self.do_drop.get() { - // SAFETY: A `DropGuard` can only be constructed using the unsafe `new` function - // ensuring that this operation is safe. - unsafe { ptr::drop_in_place(self.ptr) } - } + // SAFETY: A `DropGuard` can only be constructed using the unsafe `new` function + // ensuring that this operation is safe. + unsafe { ptr::drop_in_place(self.ptr) } } } diff --git a/rust/kernel/init/macros.rs b/rust/kernel/init/macros.rs index 0b0ffbc901a7..5063b45970f3 100644 --- a/rust/kernel/init/macros.rs +++ b/rust/kernel/init/macros.rs @@ -994,7 +994,6 @@ macro_rules! __pin_data { /// - `init_slot`: recursively creates the code that initializes all fields in `slot`. /// - `make_initializer`: recursively create the struct initializer that guarantees that every /// field has been initialized exactly once. -/// - `forget_guards`: recursively forget the drop guards for every field. #[doc(hidden)] #[macro_export] macro_rules! __init_internal { @@ -1034,6 +1033,7 @@ macro_rules! __init_internal { $crate::__init_internal!(init_slot($($use_data)?): @data(data), @slot(slot), + @guards(), @munch_fields($($fields)*,), ); // We use unreachable code to ensure that all fields have been mentioned exactly @@ -1048,10 +1048,6 @@ macro_rules! __init_internal { @acc(), ); } - // Forget all guards, since initialization was a success. - $crate::__init_internal!(forget_guards: - @munch_fields($($fields)*,), - ); } Ok(__InitOk) } @@ -1065,13 +1061,17 @@ macro_rules! __init_internal { (init_slot($($use_data:ident)?): @data($data:ident), @slot($slot:ident), + @guards($($guards:ident,)*), @munch_fields($(,)?), ) => { - // Endpoint of munching, no fields are left. + // Endpoint of munching, no fields are left. If execution reaches this point, all fields + // have been initialized. Therefore we can now dismiss the guards by forgetting them. + $(::core::mem::forget($guards);)* }; (init_slot($use_data:ident): // `use_data` is present, so we use the `data` to init fields. @data($data:ident), @slot($slot:ident), + @guards($($guards:ident,)*), // In-place initialization syntax. @munch_fields($field:ident <- $val:expr, $($rest:tt)*), ) => { @@ -1082,24 +1082,28 @@ macro_rules! __init_internal { // return when an error/panic occurs. // We also use the `data` to require the correct trait (`Init` or `PinInit`) for `$field`. unsafe { $data.$field(::core::ptr::addr_of_mut!((*$slot).$field), $field)? }; - // Create the drop guard. - // - // We only give access to `&DropGuard`, so it cannot be forgotten via safe code. + // Create the drop guard: // - // SAFETY: We forget the guard later when initialization has succeeded. - let $field = &unsafe { - $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field)) - }; + // We rely on macro hygiene to make it impossible for users to access this local variable. + // We use `paste!` to create new hygiene for `$field`. + ::kernel::macros::paste! { + // SAFETY: We forget the guard later when initialization has succeeded. + let [<$field>] = unsafe { + $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field)) + }; - $crate::__init_internal!(init_slot($use_data): - @data($data), - @slot($slot), - @munch_fields($($rest)*), - ); + $crate::__init_internal!(init_slot($use_data): + @data($data), + @slot($slot), + @guards([<$field>], $($guards,)*), + @munch_fields($($rest)*), + ); + } }; (init_slot(): // No `use_data`, so we use `Init::__init` directly. @data($data:ident), @slot($slot:ident), + @guards($($guards:ident,)*), // In-place initialization syntax. @munch_fields($field:ident <- $val:expr, $($rest:tt)*), ) => { @@ -1109,24 +1113,28 @@ macro_rules! __init_internal { // SAFETY: `slot` is valid, because we are inside of an initializer closure, we // return when an error/panic occurs. unsafe { $crate::init::Init::__init($field, ::core::ptr::addr_of_mut!((*$slot).$field))? }; - // Create the drop guard. - // - // We only give access to `&DropGuard`, so it cannot be forgotten via safe code. + // Create the drop guard: // - // SAFETY: We forget the guard later when initialization has succeeded. - let $field = &unsafe { - $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field)) - }; + // We rely on macro hygiene to make it impossible for users to access this local variable. + // We use `paste!` to create new hygiene for `$field`. + ::kernel::macros::paste! { + // SAFETY: We forget the guard later when initialization has succeeded. + let [<$field>] = unsafe { + $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field)) + }; - $crate::__init_internal!(init_slot(): - @data($data), - @slot($slot), - @munch_fields($($rest)*), - ); + $crate::__init_internal!(init_slot(): + @data($data), + @slot($slot), + @guards([<$field>], $($guards,)*), + @munch_fields($($rest)*), + ); + } }; (init_slot($($use_data:ident)?): @data($data:ident), @slot($slot:ident), + @guards($($guards:ident,)*), // Init by-value. @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*), ) => { @@ -1137,18 +1145,21 @@ macro_rules! __init_internal { unsafe { ::core::ptr::write(::core::ptr::addr_of_mut!((*$slot).$field), $field) }; // Create the drop guard: // - // We only give access to `&DropGuard`, so it cannot be accidentally forgotten. - // - // SAFETY: We forget the guard later when initialization has succeeded. - let $field = &unsafe { - $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field)) - }; + // We rely on macro hygiene to make it impossible for users to access this local variable. + // We use `paste!` to create new hygiene for `$field`. + ::kernel::macros::paste! { + // SAFETY: We forget the guard later when initialization has succeeded. + let [<$field>] = unsafe { + $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field)) + }; - $crate::__init_internal!(init_slot($($use_data)?): - @data($data), - @slot($slot), - @munch_fields($($rest)*), - ); + $crate::__init_internal!(init_slot($($use_data)?): + @data($data), + @slot($slot), + @guards([<$field>], $($guards,)*), + @munch_fields($($rest)*), + ); + } }; (make_initializer: @slot($slot:ident), @@ -1191,29 +1202,6 @@ macro_rules! __init_internal { @acc($($acc)* $field: ::core::panic!(),), ); }; - (forget_guards: - @munch_fields($(,)?), - ) => { - // Munching finished. - }; - (forget_guards: - @munch_fields($field:ident <- $val:expr, $($rest:tt)*), - ) => { - unsafe { $crate::init::__internal::DropGuard::forget($field) }; - - $crate::__init_internal!(forget_guards: - @munch_fields($($rest)*), - ); - }; - (forget_guards: - @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*), - ) => { - unsafe { $crate::init::__internal::DropGuard::forget($field) }; - - $crate::__init_internal!(forget_guards: - @munch_fields($($rest)*), - ); - }; } #[doc(hidden)] -- cgit v1.2.3 From b9b88be046a92a43d70badb340cac9ffd9695dcb Mon Sep 17 00:00:00 2001 From: Benno Lossin Date: Mon, 14 Aug 2023 08:46:55 +0000 Subject: rust: init: wrap type checking struct initializers in a closure In the implementation of the init macros there is a `if false` statement that type checks the initializer to ensure every field is initialized. Since the next patch has a stack variable to store the struct, the function might allocate too much memory on debug builds. Putting the struct into a closure that is never executed ensures that even in debug builds no stack overflow error is caused. In release builds this was not a problem since the code was optimized away due to the `if false`. Reviewed-by: Martin Rodriguez Reboredo Reviewed-by: Alice Ryhl Reviewed-by: Gary Guo Signed-off-by: Benno Lossin Link: https://lore.kernel.org/r/20230814084602.25699-6-benno.lossin@proton.me Signed-off-by: Miguel Ojeda --- rust/kernel/init/macros.rs | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'rust') diff --git a/rust/kernel/init/macros.rs b/rust/kernel/init/macros.rs index 5063b45970f3..a1ccc978feab 100644 --- a/rust/kernel/init/macros.rs +++ b/rust/kernel/init/macros.rs @@ -1040,14 +1040,14 @@ macro_rules! __init_internal { // once, this struct initializer will still be type-checked and complain with a // very natural error message if a field is forgotten/mentioned more than once. #[allow(unreachable_code, clippy::diverging_sub_expression)] - if false { + let _ = || { $crate::__init_internal!(make_initializer: @slot(slot), @type_name($t), @munch_fields($($fields)*,), @acc(), ); - } + }; } Ok(__InitOk) } @@ -1168,8 +1168,8 @@ macro_rules! __init_internal { @acc($($acc:tt)*), ) => { // Endpoint, nothing more to munch, create the initializer. - // Since we are in the `if false` branch, this will never get executed. We abuse `slot` to - // get the correct type inference here: + // Since we are in the closure that is never called, this will never get executed. + // We abuse `slot` to get the correct type inference here: unsafe { ::core::ptr::write($slot, $t { $($acc)* -- cgit v1.2.3 From 92fd540d62701115b22b1f531c8c86454809931b Mon Sep 17 00:00:00 2001 From: Benno Lossin Date: Mon, 14 Aug 2023 08:47:03 +0000 Subject: rust: init: make initializer values inaccessible after initializing Previously the init macros would create a local variable with the name and hygiene of the field that is being initialized to store the value of the field. This would override any user defined variables. For example: ``` struct Foo { a: usize, b: usize, } let a = 10; let foo = init!(Foo{ a: a + 1, // This creates a local variable named `a`. b: a, // This refers to that variable! }); let foo = Box::init!(foo)?; assert_eq!(foo.a, 11); assert_eq!(foo.b, 11); ``` This patch changes this behavior, so the above code would panic at the last assertion, since `b` would have value 10. Reviewed-by: Martin Rodriguez Reboredo Reviewed-by: Alice Ryhl Reviewed-by: Gary Guo Signed-off-by: Benno Lossin Link: https://lore.kernel.org/r/20230814084602.25699-7-benno.lossin@proton.me Signed-off-by: Miguel Ojeda --- rust/kernel/init/macros.rs | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) (limited to 'rust') diff --git a/rust/kernel/init/macros.rs b/rust/kernel/init/macros.rs index a1ccc978feab..6e6c13b2fe78 100644 --- a/rust/kernel/init/macros.rs +++ b/rust/kernel/init/macros.rs @@ -1075,13 +1075,13 @@ macro_rules! __init_internal { // In-place initialization syntax. @munch_fields($field:ident <- $val:expr, $($rest:tt)*), ) => { - let $field = $val; + let init = $val; // Call the initializer. // // SAFETY: `slot` is valid, because we are inside of an initializer closure, we // return when an error/panic occurs. // We also use the `data` to require the correct trait (`Init` or `PinInit`) for `$field`. - unsafe { $data.$field(::core::ptr::addr_of_mut!((*$slot).$field), $field)? }; + unsafe { $data.$field(::core::ptr::addr_of_mut!((*$slot).$field), init)? }; // Create the drop guard: // // We rely on macro hygiene to make it impossible for users to access this local variable. @@ -1107,12 +1107,12 @@ macro_rules! __init_internal { // In-place initialization syntax. @munch_fields($field:ident <- $val:expr, $($rest:tt)*), ) => { - let $field = $val; + let init = $val; // Call the initializer. // // SAFETY: `slot` is valid, because we are inside of an initializer closure, we // return when an error/panic occurs. - unsafe { $crate::init::Init::__init($field, ::core::ptr::addr_of_mut!((*$slot).$field))? }; + unsafe { $crate::init::Init::__init(init, ::core::ptr::addr_of_mut!((*$slot).$field))? }; // Create the drop guard: // // We rely on macro hygiene to make it impossible for users to access this local variable. @@ -1138,11 +1138,13 @@ macro_rules! __init_internal { // Init by-value. @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*), ) => { - $(let $field = $val;)? - // Initialize the field. - // - // SAFETY: The memory at `slot` is uninitialized. - unsafe { ::core::ptr::write(::core::ptr::addr_of_mut!((*$slot).$field), $field) }; + { + $(let $field = $val;)? + // Initialize the field. + // + // SAFETY: The memory at `slot` is uninitialized. + unsafe { ::core::ptr::write(::core::ptr::addr_of_mut!((*$slot).$field), $field) }; + } // Create the drop guard: // // We rely on macro hygiene to make it impossible for users to access this local variable. -- cgit v1.2.3 From 35e7fca2ff59d9d8f036aba3dcf5c34beb79fdb8 Mon Sep 17 00:00:00 2001 From: Benno Lossin Date: Mon, 14 Aug 2023 08:47:10 +0000 Subject: rust: init: add `..Zeroable::zeroed()` syntax for zeroing all missing fields Add the struct update syntax to the init macros, but only for `..Zeroable::zeroed()`. Adding this at the end of the struct initializer allows one to omit fields from the initializer, these fields will be initialized with 0x00 set to every byte. Only types that implement the `Zeroable` trait can utilize this. Suggested-by: Asahi Lina Reviewed-by: Martin Rodriguez Reboredo Reviewed-by: Alice Ryhl Reviewed-by: Gary Guo Signed-off-by: Benno Lossin Link: https://lore.kernel.org/r/20230814084602.25699-8-benno.lossin@proton.me [ Rebased on `rust-next` and cleaned a few trivial nits. ] Signed-off-by: Miguel Ojeda --- rust/kernel/init.rs | 16 ++++++- rust/kernel/init/macros.rs | 115 ++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 129 insertions(+), 2 deletions(-) (limited to 'rust') diff --git a/rust/kernel/init.rs b/rust/kernel/init.rs index ecf6a4bd0ce4..33f2666d5bae 100644 --- a/rust/kernel/init.rs +++ b/rust/kernel/init.rs @@ -508,14 +508,18 @@ macro_rules! stack_try_pin_init { /// - Fields that you want to initialize in-place have to use `<-` instead of `:`. /// - In front of the initializer you can write `&this in` to have access to a [`NonNull`] /// pointer named `this` inside of the initializer. +/// - Using struct update syntax one can place `..Zeroable::zeroed()` at the very end of the +/// struct, this initializes every field with 0 and then runs all initializers specified in the +/// body. This can only be done if [`Zeroable`] is implemented for the struct. /// /// For instance: /// /// ```rust /// # use kernel::pin_init; -/// # use macros::pin_data; +/// # use macros::{Zeroable, pin_data}; /// # use core::{ptr::addr_of_mut, marker::PhantomPinned}; /// #[pin_data] +/// #[derive(Zeroable)] /// struct Buf { /// // `ptr` points into `buf`. /// ptr: *mut u8, @@ -528,6 +532,10 @@ macro_rules! stack_try_pin_init { /// ptr: unsafe { addr_of_mut!((*this.as_ptr()).buf).cast() }, /// pin: PhantomPinned, /// }); +/// pin_init!(Buf { +/// buf: [1; 64], +/// ..Zeroable::zeroed() +/// }); /// ``` /// /// [`try_pin_init!`]: kernel::try_pin_init @@ -547,6 +555,7 @@ macro_rules! pin_init { @data(PinData, use_data), @has_data(HasPinData, __pin_data), @construct_closure(pin_init_from_closure), + @munch_fields($($fields)*), ) }; } @@ -603,6 +612,7 @@ macro_rules! try_pin_init { @data(PinData, use_data), @has_data(HasPinData, __pin_data), @construct_closure(pin_init_from_closure), + @munch_fields($($fields)*), ) }; ($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? { @@ -616,6 +626,7 @@ macro_rules! try_pin_init { @data(PinData, use_data), @has_data(HasPinData, __pin_data), @construct_closure(pin_init_from_closure), + @munch_fields($($fields)*), ) }; } @@ -650,6 +661,7 @@ macro_rules! init { @data(InitData, /*no use_data*/), @has_data(HasInitData, __init_data), @construct_closure(init_from_closure), + @munch_fields($($fields)*), ) } } @@ -700,6 +712,7 @@ macro_rules! try_init { @data(InitData, /*no use_data*/), @has_data(HasInitData, __init_data), @construct_closure(init_from_closure), + @munch_fields($($fields)*), ) }; ($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? { @@ -713,6 +726,7 @@ macro_rules! try_init { @data(InitData, /*no use_data*/), @has_data(HasInitData, __init_data), @construct_closure(init_from_closure), + @munch_fields($($fields)*), ) }; } diff --git a/rust/kernel/init/macros.rs b/rust/kernel/init/macros.rs index 6e6c13b2fe78..9931666293fa 100644 --- a/rust/kernel/init/macros.rs +++ b/rust/kernel/init/macros.rs @@ -991,6 +991,7 @@ macro_rules! __pin_data { /// /// This macro has multiple internal call configurations, these are always the very first ident: /// - nothing: this is the base case and called by the `{try_}{pin_}init!` macros. +/// - `with_update_parsed`: when the `..Zeroable::zeroed()` syntax has been handled. /// - `init_slot`: recursively creates the code that initializes all fields in `slot`. /// - `make_initializer`: recursively create the struct initializer that guarantees that every /// field has been initialized exactly once. @@ -1009,6 +1010,82 @@ macro_rules! __init_internal { @has_data($has_data:ident, $get_data:ident), // `pin_init_from_closure` or `init_from_closure`. @construct_closure($construct_closure:ident), + @munch_fields(), + ) => { + $crate::__init_internal!(with_update_parsed: + @this($($this)?), + @typ($t $(::<$($generics),*>)? ), + @fields($($fields)*), + @error($err), + @data($data, $($use_data)?), + @has_data($has_data, $get_data), + @construct_closure($construct_closure), + @zeroed(), // Nothing means default behavior. + ) + }; + ( + @this($($this:ident)?), + @typ($t:ident $(::<$($generics:ty),*>)?), + @fields($($fields:tt)*), + @error($err:ty), + // Either `PinData` or `InitData`, `$use_data` should only be present in the `PinData` + // case. + @data($data:ident, $($use_data:ident)?), + // `HasPinData` or `HasInitData`. + @has_data($has_data:ident, $get_data:ident), + // `pin_init_from_closure` or `init_from_closure`. + @construct_closure($construct_closure:ident), + @munch_fields(..Zeroable::zeroed()), + ) => { + $crate::__init_internal!(with_update_parsed: + @this($($this)?), + @typ($t $(::<$($generics),*>)? ), + @fields($($fields)*), + @error($err), + @data($data, $($use_data)?), + @has_data($has_data, $get_data), + @construct_closure($construct_closure), + @zeroed(()), // `()` means zero all fields not mentioned. + ) + }; + ( + @this($($this:ident)?), + @typ($t:ident $(::<$($generics:ty),*>)?), + @fields($($fields:tt)*), + @error($err:ty), + // Either `PinData` or `InitData`, `$use_data` should only be present in the `PinData` + // case. + @data($data:ident, $($use_data:ident)?), + // `HasPinData` or `HasInitData`. + @has_data($has_data:ident, $get_data:ident), + // `pin_init_from_closure` or `init_from_closure`. + @construct_closure($construct_closure:ident), + @munch_fields($ignore:tt $($rest:tt)*), + ) => { + $crate::__init_internal!( + @this($($this)?), + @typ($t $(::<$($generics),*>)? ), + @fields($($fields)*), + @error($err), + @data($data, $($use_data)?), + @has_data($has_data, $get_data), + @construct_closure($construct_closure), + @munch_fields($($rest)*), + ) + }; + (with_update_parsed: + @this($($this:ident)?), + @typ($t:ident $(::<$($generics:ty),*>)?), + @fields($($fields:tt)*), + @error($err:ty), + // Either `PinData` or `InitData`, `$use_data` should only be present in the `PinData` + // case. + @data($data:ident, $($use_data:ident)?), + // `HasPinData` or `HasInitData`. + @has_data($has_data:ident, $get_data:ident), + // `pin_init_from_closure` or `init_from_closure`. + @construct_closure($construct_closure:ident), + @zeroed($($init_zeroed:expr)?), ) => {{ // We do not want to allow arbitrary returns, so we declare this type as the `Ok` return // type and shadow it later when we insert the arbitrary user code. That way there will be @@ -1026,6 +1103,17 @@ macro_rules! __init_internal { { // Shadow the structure so it cannot be used to return early. struct __InitOk; + // If `$init_zeroed` is present we should zero the slot now and not emit an + // error when fields are missing (since they will be zeroed). We also have to + // check that the type actually implements `Zeroable`. + $({ + fn assert_zeroable(_: *mut T) {} + // Ensure that the struct is indeed `Zeroable`. + assert_zeroable(slot); + // SAFETY: The type implements `Zeroable` by the check above. + unsafe { ::core::ptr::write_bytes(slot, 0, 1) }; + $init_zeroed // This will be `()` if set. + })? // Create the `this` so it can be referenced by the user inside of the // expressions creating the individual fields. $(let $this = unsafe { ::core::ptr::NonNull::new_unchecked(slot) };)? @@ -1062,7 +1150,7 @@ macro_rules! __init_internal { @data($data:ident), @slot($slot:ident), @guards($($guards:ident,)*), - @munch_fields($(,)?), + @munch_fields($(..Zeroable::zeroed())? $(,)?), ) => { // Endpoint of munching, no fields are left. If execution reaches this point, all fields // have been initialized. Therefore we can now dismiss the guards by forgetting them. @@ -1163,6 +1251,31 @@ macro_rules! __init_internal { ); } }; + (make_initializer: + @slot($slot:ident), + @type_name($t:ident), + @munch_fields(..Zeroable::zeroed() $(,)?), + @acc($($acc:tt)*), + ) => { + // Endpoint, nothing more to munch, create the initializer. Since the users specified + // `..Zeroable::zeroed()`, the slot will already have been zeroed and all field that have + // not been overwritten are thus zero and initialized. We still check that all fields are + // actually accessible by using the struct update syntax ourselves. + // We are inside of a closure that is never executed and thus we can abuse `slot` to + // get the correct type inference here: + #[allow(unused_assignments)] + unsafe { + let mut zeroed = ::core::mem::zeroed(); + // We have to use type inference here to make zeroed have the correct type. This does + // not get executed, so it has no effect. + ::core::ptr::write($slot, zeroed); + zeroed = ::core::mem::zeroed(); + ::core::ptr::write($slot, $t { + $($acc)* + ..zeroed + }); + } + }; (make_initializer: @slot($slot:ident), @type_name($t:ident), -- cgit v1.2.3 From 9e49439077fe0a9aa062e682193b1f3257b314e2 Mon Sep 17 00:00:00 2001 From: Benno Lossin Date: Mon, 14 Aug 2023 08:47:15 +0000 Subject: rust: init: add functions to create array initializers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add two functions `pin_init_array_from_fn` and `init_array_from_fn` that take a function that generates initializers for `T` from `usize`, the added functions then return an initializer for `[T; N]` where every element is initialized by an element returned from the generator function. Suggested-by: Asahi Lina Reviewed-by: Björn Roy Baron Reviewed-by: Alice Ryhl Reviewed-by: Martin Rodriguez Reboredo Signed-off-by: Benno Lossin Link: https://lore.kernel.org/r/20230814084602.25699-9-benno.lossin@proton.me [ Cleaned a couple trivial nits. ] Signed-off-by: Miguel Ojeda --- rust/kernel/init.rs | 88 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) (limited to 'rust') diff --git a/rust/kernel/init.rs b/rust/kernel/init.rs index 33f2666d5bae..429b485d8825 100644 --- a/rust/kernel/init.rs +++ b/rust/kernel/init.rs @@ -202,6 +202,7 @@ use crate::{ error::{self, Error}, sync::UniqueArc, + types::ScopeGuard, }; use alloc::boxed::Box; use core::{ @@ -867,6 +868,93 @@ pub fn uninit() -> impl Init, E> { unsafe { init_from_closure(|_| Ok(())) } } +/// Initializes an array by initializing each element via the provided initializer. +/// +/// # Examples +/// +/// ```rust +/// use kernel::{error::Error, init::init_array_from_fn}; +/// let array: Box<[usize; 1_000]>= Box::init::(init_array_from_fn(|i| i)).unwrap(); +/// assert_eq!(array.len(), 1_000); +/// ``` +pub fn init_array_from_fn( + mut make_init: impl FnMut(usize) -> I, +) -> impl Init<[T; N], E> +where + I: Init, +{ + let init = move |slot: *mut [T; N]| { + let slot = slot.cast::(); + // Counts the number of initialized elements and when dropped drops that many elements from + // `slot`. + let mut init_count = ScopeGuard::new_with_data(0, |i| { + // We now free every element that has been initialized before: + // SAFETY: The loop initialized exactly the values from 0..i and since we + // return `Err` below, the caller will consider the memory at `slot` as + // uninitialized. + unsafe { ptr::drop_in_place(ptr::slice_from_raw_parts_mut(slot, i)) }; + }); + for i in 0..N { + let init = make_init(i); + // SAFETY: Since 0 <= `i` < N, it is still in bounds of `[T; N]`. + let ptr = unsafe { slot.add(i) }; + // SAFETY: The pointer is derived from `slot` and thus satisfies the `__init` + // requirements. + unsafe { init.__init(ptr) }?; + *init_count += 1; + } + init_count.dismiss(); + Ok(()) + }; + // SAFETY: The initializer above initializes every element of the array. On failure it drops + // any initialized elements and returns `Err`. + unsafe { init_from_closure(init) } +} + +/// Initializes an array by initializing each element via the provided initializer. +/// +/// # Examples +/// +/// ```rust +/// use kernel::{sync::{Arc, Mutex}, init::pin_init_array_from_fn, new_mutex}; +/// let array: Arc<[Mutex; 1_000]>= +/// Arc::pin_init(pin_init_array_from_fn(|i| new_mutex!(i))).unwrap(); +/// assert_eq!(array.len(), 1_000); +/// ``` +pub fn pin_init_array_from_fn( + mut make_init: impl FnMut(usize) -> I, +) -> impl PinInit<[T; N], E> +where + I: PinInit, +{ + let init = move |slot: *mut [T; N]| { + let slot = slot.cast::(); + // Counts the number of initialized elements and when dropped drops that many elements from + // `slot`. + let mut init_count = ScopeGuard::new_with_data(0, |i| { + // We now free every element that has been initialized before: + // SAFETY: The loop initialized exactly the values from 0..i and since we + // return `Err` below, the caller will consider the memory at `slot` as + // uninitialized. + unsafe { ptr::drop_in_place(ptr::slice_from_raw_parts_mut(slot, i)) }; + }); + for i in 0..N { + let init = make_init(i); + // SAFETY: Since 0 <= `i` < N, it is still in bounds of `[T; N]`. + let ptr = unsafe { slot.add(i) }; + // SAFETY: The pointer is derived from `slot` and thus satisfies the `__init` + // requirements. + unsafe { init.__pinned_init(ptr) }?; + *init_count += 1; + } + init_count.dismiss(); + Ok(()) + }; + // SAFETY: The initializer above initializes every element of the array. On failure it drops + // any initialized elements and returns `Err`. + unsafe { pin_init_from_closure(init) } +} + // SAFETY: Every type can be initialized by-value. unsafe impl Init for T { unsafe fn __init(self, slot: *mut T) -> Result<(), E> { -- cgit v1.2.3 From 674b1c7aed6082e1ce329bb3bcb49e7eb9913e79 Mon Sep 17 00:00:00 2001 From: Benno Lossin Date: Mon, 14 Aug 2023 08:47:28 +0000 Subject: rust: init: add support for arbitrary paths in init macros Previously only `ident` and generic types were supported in the `{try_}{pin_}init!` macros. This patch allows arbitrary path fragments, so for example `Foo::Bar` but also very complex paths such as `::Bar::<0, i32>`. Internally this is accomplished by using `path` fragments. Due to some peculiar declarative macro limitations, we have to "forget" certain additional parsing information in the token trees. This is achieved by using the `paste!` proc macro. It does not actually modify the input, since no `[< >]` will be present in the input, so it just strips the information held by declarative macros. For example, if a declarative macro takes `$t:path` as its input, it cannot sensibly propagate this to a macro that takes `$($p:tt)*` as its input, since the `$t` token will only be considered one `tt` token for the second macro. If we first pipe the tokens through `paste!`, then it parses as expected. Suggested-by: Asahi Lina Reviewed-by: Martin Rodriguez Reboredo Reviewed-by: Alice Ryhl Reviewed-by: Gary Guo Signed-off-by: Benno Lossin Link: https://lore.kernel.org/r/20230814084602.25699-10-benno.lossin@proton.me Signed-off-by: Miguel Ojeda --- rust/kernel/init/macros.rs | 54 ++++++++++++++++++++++++++++++---------------- 1 file changed, 35 insertions(+), 19 deletions(-) (limited to 'rust') diff --git a/rust/kernel/init/macros.rs b/rust/kernel/init/macros.rs index 9931666293fa..5f0a0bdb9896 100644 --- a/rust/kernel/init/macros.rs +++ b/rust/kernel/init/macros.rs @@ -1000,7 +1000,7 @@ macro_rules! __pin_data { macro_rules! __init_internal { ( @this($($this:ident)?), - @typ($t:ident $(::<$($generics:ty),*>)?), + @typ($t:path), @fields($($fields:tt)*), @error($err:ty), // Either `PinData` or `InitData`, `$use_data` should only be present in the `PinData` @@ -1014,7 +1014,7 @@ macro_rules! __init_internal { ) => { $crate::__init_internal!(with_update_parsed: @this($($this)?), - @typ($t $(::<$($generics),*>)? ), + @typ($t), @fields($($fields)*), @error($err), @data($data, $($use_data)?), @@ -1025,7 +1025,7 @@ macro_rules! __init_internal { }; ( @this($($this:ident)?), - @typ($t:ident $(::<$($generics:ty),*>)?), + @typ($t:path), @fields($($fields:tt)*), @error($err:ty), // Either `PinData` or `InitData`, `$use_data` should only be present in the `PinData` @@ -1039,7 +1039,7 @@ macro_rules! __init_internal { ) => { $crate::__init_internal!(with_update_parsed: @this($($this)?), - @typ($t $(::<$($generics),*>)? ), + @typ($t), @fields($($fields)*), @error($err), @data($data, $($use_data)?), @@ -1050,7 +1050,7 @@ macro_rules! __init_internal { }; ( @this($($this:ident)?), - @typ($t:ident $(::<$($generics:ty),*>)?), + @typ($t:path), @fields($($fields:tt)*), @error($err:ty), // Either `PinData` or `InitData`, `$use_data` should only be present in the `PinData` @@ -1064,7 +1064,7 @@ macro_rules! __init_internal { ) => { $crate::__init_internal!( @this($($this)?), - @typ($t $(::<$($generics),*>)? ), + @typ($t), @fields($($fields)*), @error($err), @data($data, $($use_data)?), @@ -1075,7 +1075,7 @@ macro_rules! __init_internal { }; (with_update_parsed: @this($($this:ident)?), - @typ($t:ident $(::<$($generics:ty),*>)?), + @typ($t:path), @fields($($fields:tt)*), @error($err:ty), // Either `PinData` or `InitData`, `$use_data` should only be present in the `PinData` @@ -1094,7 +1094,11 @@ macro_rules! __init_internal { // Get the data about fields from the supplied type. let data = unsafe { use $crate::init::__internal::$has_data; - $t$(::<$($generics),*>)?::$get_data() + // Here we abuse `paste!` to retokenize `$t`. Declarative macros have some internal + // information that is associated to already parsed fragments, so a path fragment + // cannot be used in this position. Doing the retokenization results in valid rust + // code. + ::kernel::macros::paste!($t::$get_data()) }; // Ensure that `data` really is of type `$data` and help with type inference: let init = $crate::init::__internal::$data::make_closure::<_, __InitOk, $err>( @@ -1253,7 +1257,7 @@ macro_rules! __init_internal { }; (make_initializer: @slot($slot:ident), - @type_name($t:ident), + @type_name($t:path), @munch_fields(..Zeroable::zeroed() $(,)?), @acc($($acc:tt)*), ) => { @@ -1270,15 +1274,21 @@ macro_rules! __init_internal { // not get executed, so it has no effect. ::core::ptr::write($slot, zeroed); zeroed = ::core::mem::zeroed(); - ::core::ptr::write($slot, $t { - $($acc)* - ..zeroed - }); + // Here we abuse `paste!` to retokenize `$t`. Declarative macros have some internal + // information that is associated to already parsed fragments, so a path fragment + // cannot be used in this position. Doing the retokenization results in valid rust + // code. + ::kernel::macros::paste!( + ::core::ptr::write($slot, $t { + $($acc)* + ..zeroed + }); + ); } }; (make_initializer: @slot($slot:ident), - @type_name($t:ident), + @type_name($t:path), @munch_fields($(,)?), @acc($($acc:tt)*), ) => { @@ -1286,14 +1296,20 @@ macro_rules! __init_internal { // Since we are in the closure that is never called, this will never get executed. // We abuse `slot` to get the correct type inference here: unsafe { - ::core::ptr::write($slot, $t { - $($acc)* - }); + // Here we abuse `paste!` to retokenize `$t`. Declarative macros have some internal + // information that is associated to already parsed fragments, so a path fragment + // cannot be used in this position. Doing the retokenization results in valid rust + // code. + ::kernel::macros::paste!( + ::core::ptr::write($slot, $t { + $($acc)* + }); + ); } }; (make_initializer: @slot($slot:ident), - @type_name($t:ident), + @type_name($t:path), @munch_fields($field:ident <- $val:expr, $($rest:tt)*), @acc($($acc:tt)*), ) => { @@ -1306,7 +1322,7 @@ macro_rules! __init_internal { }; (make_initializer: @slot($slot:ident), - @type_name($t:ident), + @type_name($t:path), @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*), @acc($($acc:tt)*), ) => { -- cgit v1.2.3 From 2e704f1883f5dd2f1380944c7d969c817fcd189e Mon Sep 17 00:00:00 2001 From: Benno Lossin Date: Mon, 14 Aug 2023 08:47:32 +0000 Subject: rust: init: implement `Zeroable` for `UnsafeCell` and `Opaque` `UnsafeCell` and `T` have the same layout so if `T` is `Zeroable` then so should `UnsafeCell` be. This allows using the derive macro for `Zeroable` on types that contain an `UnsafeCell`. Since `Opaque` contains a `MaybeUninit`, all bytes zero is a valid bit pattern for that type. Reviewed-by: Gary Guo Reviewed-by: Martin Rodriguez Reboredo Signed-off-by: Benno Lossin Link: https://lore.kernel.org/r/20230814084602.25699-11-benno.lossin@proton.me Signed-off-by: Miguel Ojeda --- rust/kernel/init.rs | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'rust') diff --git a/rust/kernel/init.rs b/rust/kernel/init.rs index 429b485d8825..0e44b3cc2eed 100644 --- a/rust/kernel/init.rs +++ b/rust/kernel/init.rs @@ -202,11 +202,12 @@ use crate::{ error::{self, Error}, sync::UniqueArc, - types::ScopeGuard, + types::{Opaque, ScopeGuard}, }; use alloc::boxed::Box; use core::{ alloc::AllocError, + cell::UnsafeCell, convert::Infallible, marker::PhantomData, mem::MaybeUninit, @@ -1151,6 +1152,11 @@ impl_zeroable! { // SAFETY: Type is allowed to take any value, including all zeros. {} MaybeUninit, + // SAFETY: Type is allowed to take any value, including all zeros. + {} Opaque, + + // SAFETY: `T: Zeroable` and `UnsafeCell` is `repr(transparent)`. + {} UnsafeCell, // SAFETY: All zeros is equivalent to `None` (option layout optimization guarantee). Option, Option, Option, Option, -- cgit v1.2.3 From 1a8076ac6d83825bedb2050e67db0f2635acbb09 Mon Sep 17 00:00:00 2001 From: Benno Lossin Date: Mon, 14 Aug 2023 08:47:40 +0000 Subject: rust: init: make `PinInit` a supertrait of `Init` Remove the blanket implementation of `PinInit for I where I: Init`. This blanket implementation prevented custom types that implement `PinInit`. Reviewed-by: Martin Rodriguez Reboredo Reviewed-by: Alice Ryhl Reviewed-by: Gary Guo Signed-off-by: Benno Lossin Link: https://lore.kernel.org/r/20230814084602.25699-12-benno.lossin@proton.me Signed-off-by: Miguel Ojeda --- rust/kernel/init.rs | 21 ++++++++------------- rust/kernel/init/__internal.rs | 12 ++++++++++++ 2 files changed, 20 insertions(+), 13 deletions(-) (limited to 'rust') diff --git a/rust/kernel/init.rs b/rust/kernel/init.rs index 0e44b3cc2eed..0f9c8576697e 100644 --- a/rust/kernel/init.rs +++ b/rust/kernel/init.rs @@ -799,7 +799,7 @@ pub unsafe trait PinInit: Sized { /// /// [`Arc`]: crate::sync::Arc #[must_use = "An initializer must be used in order to create its value."] -pub unsafe trait Init: Sized { +pub unsafe trait Init: PinInit { /// Initializes `slot`. /// /// # Safety @@ -810,18 +810,6 @@ pub unsafe trait Init: Sized { unsafe fn __init(self, slot: *mut T) -> Result<(), E>; } -// SAFETY: Every in-place initializer can also be used as a pin-initializer. -unsafe impl PinInit for I -where - I: Init, -{ - unsafe fn __pinned_init(self, slot: *mut T) -> Result<(), E> { - // SAFETY: `__init` meets the same requirements as `__pinned_init`, except that it does not - // require `slot` to not move after init. - unsafe { self.__init(slot) } - } -} - /// Creates a new [`PinInit`] from the given closure. /// /// # Safety @@ -964,6 +952,13 @@ unsafe impl Init for T { } } +// SAFETY: Every type can be initialized by-value. `__pinned_init` calls `__init`. +unsafe impl PinInit for T { + unsafe fn __pinned_init(self, slot: *mut T) -> Result<(), E> { + unsafe { self.__init(slot) } + } +} + /// Smart pointer that can initialize memory in-place. pub trait InPlaceInit: Sized { /// Use the given pin-initializer to pin-initialize a `T` inside of a new smart pointer of this diff --git a/rust/kernel/init/__internal.rs b/rust/kernel/init/__internal.rs index 7abd1fb65e41..12e195061525 100644 --- a/rust/kernel/init/__internal.rs +++ b/rust/kernel/init/__internal.rs @@ -32,6 +32,18 @@ where } } +// SAFETY: While constructing the `InitClosure`, the user promised that it upholds the +// `__pinned_init` invariants. +unsafe impl PinInit for InitClosure +where + F: FnOnce(*mut T) -> Result<(), E>, +{ + #[inline] + unsafe fn __pinned_init(self, slot: *mut T) -> Result<(), E> { + (self.0)(slot) + } +} + /// This trait is only implemented via the `#[pin_data]` proc-macro. It is used to facilitate /// the pin projections within the initializers. /// -- cgit v1.2.3 From 7f8977a7fe6df9cdfe489c641058ca5534ec73eb Mon Sep 17 00:00:00 2001 From: Benno Lossin Date: Mon, 14 Aug 2023 08:47:48 +0000 Subject: rust: init: add `{pin_}chain` functions to `{Pin}Init` The `{pin_}chain` functions extend an initializer: it not only initializes the value, but also executes a closure taking a reference to the initialized value. This allows to do something with a value directly after initialization. Suggested-by: Asahi Lina Reviewed-by: Martin Rodriguez Reboredo Signed-off-by: Benno Lossin Reviewed-by: Alice Ryhl Link: https://lore.kernel.org/r/20230814084602.25699-13-benno.lossin@proton.me [ Cleaned a few trivial nits. ] Signed-off-by: Miguel Ojeda --- rust/kernel/init.rs | 142 +++++++++++++++++++++++++++++++++++++++++ rust/kernel/init/__internal.rs | 2 +- 2 files changed, 143 insertions(+), 1 deletion(-) (limited to 'rust') diff --git a/rust/kernel/init.rs b/rust/kernel/init.rs index 0f9c8576697e..0071b2834b78 100644 --- a/rust/kernel/init.rs +++ b/rust/kernel/init.rs @@ -767,6 +767,79 @@ pub unsafe trait PinInit: Sized { /// deallocate. /// - `slot` will not move until it is dropped, i.e. it will be pinned. unsafe fn __pinned_init(self, slot: *mut T) -> Result<(), E>; + + /// First initializes the value using `self` then calls the function `f` with the initialized + /// value. + /// + /// If `f` returns an error the value is dropped and the initializer will forward the error. + /// + /// # Examples + /// + /// ```rust + /// # #![allow(clippy::disallowed_names)] + /// use kernel::{types::Opaque, init::pin_init_from_closure}; + /// #[repr(C)] + /// struct RawFoo([u8; 16]); + /// extern { + /// fn init_foo(_: *mut RawFoo); + /// } + /// + /// #[pin_data] + /// struct Foo { + /// #[pin] + /// raw: Opaque, + /// } + /// + /// impl Foo { + /// fn setup(self: Pin<&mut Self>) { + /// pr_info!("Setting up foo"); + /// } + /// } + /// + /// let foo = pin_init!(Foo { + /// raw <- unsafe { + /// Opaque::ffi_init(|s| { + /// init_foo(s); + /// }) + /// }, + /// }).pin_chain(|foo| { + /// foo.setup(); + /// Ok(()) + /// }); + /// ``` + fn pin_chain(self, f: F) -> ChainPinInit + where + F: FnOnce(Pin<&mut T>) -> Result<(), E>, + { + ChainPinInit(self, f, PhantomData) + } +} + +/// An initializer returned by [`PinInit::pin_chain`]. +pub struct ChainPinInit(I, F, __internal::Invariant<(E, Box)>); + +// SAFETY: The `__pinned_init` function is implemented such that it +// - returns `Ok(())` on successful initialization, +// - returns `Err(err)` on error and in this case `slot` will be dropped. +// - considers `slot` pinned. +unsafe impl PinInit for ChainPinInit +where + I: PinInit, + F: FnOnce(Pin<&mut T>) -> Result<(), E>, +{ + unsafe fn __pinned_init(self, slot: *mut T) -> Result<(), E> { + // SAFETY: All requirements fulfilled since this function is `__pinned_init`. + unsafe { self.0.__pinned_init(slot)? }; + // SAFETY: The above call initialized `slot` and we still have unique access. + let val = unsafe { &mut *slot }; + // SAFETY: `slot` is considered pinned. + let val = unsafe { Pin::new_unchecked(val) }; + (self.1)(val).map_err(|e| { + // SAFETY: `slot` was initialized above. + unsafe { core::ptr::drop_in_place(slot) }; + e + }) + } } /// An initializer for `T`. @@ -808,6 +881,75 @@ pub unsafe trait Init: PinInit { /// - the caller does not touch `slot` when `Err` is returned, they are only permitted to /// deallocate. unsafe fn __init(self, slot: *mut T) -> Result<(), E>; + + /// First initializes the value using `self` then calls the function `f` with the initialized + /// value. + /// + /// If `f` returns an error the value is dropped and the initializer will forward the error. + /// + /// # Examples + /// + /// ```rust + /// # #![allow(clippy::disallowed_names)] + /// use kernel::{types::Opaque, init::{self, init_from_closure}}; + /// struct Foo { + /// buf: [u8; 1_000_000], + /// } + /// + /// impl Foo { + /// fn setup(&mut self) { + /// pr_info!("Setting up foo"); + /// } + /// } + /// + /// let foo = init!(Foo { + /// buf <- init::zeroed() + /// }).chain(|foo| { + /// foo.setup(); + /// Ok(()) + /// }); + /// ``` + fn chain(self, f: F) -> ChainInit + where + F: FnOnce(&mut T) -> Result<(), E>, + { + ChainInit(self, f, PhantomData) + } +} + +/// An initializer returned by [`Init::chain`]. +pub struct ChainInit(I, F, __internal::Invariant<(E, Box)>); + +// SAFETY: The `__init` function is implemented such that it +// - returns `Ok(())` on successful initialization, +// - returns `Err(err)` on error and in this case `slot` will be dropped. +unsafe impl Init for ChainInit +where + I: Init, + F: FnOnce(&mut T) -> Result<(), E>, +{ + unsafe fn __init(self, slot: *mut T) -> Result<(), E> { + // SAFETY: All requirements fulfilled since this function is `__init`. + unsafe { self.0.__pinned_init(slot)? }; + // SAFETY: The above call initialized `slot` and we still have unique access. + (self.1)(unsafe { &mut *slot }).map_err(|e| { + // SAFETY: `slot` was initialized above. + unsafe { core::ptr::drop_in_place(slot) }; + e + }) + } +} + +// SAFETY: `__pinned_init` behaves exactly the same as `__init`. +unsafe impl PinInit for ChainInit +where + I: Init, + F: FnOnce(&mut T) -> Result<(), E>, +{ + unsafe fn __pinned_init(self, slot: *mut T) -> Result<(), E> { + // SAFETY: `__init` has less strict requirements compared to `__pinned_init`. + unsafe { self.__init(slot) } + } } /// Creates a new [`PinInit`] from the given closure. diff --git a/rust/kernel/init/__internal.rs b/rust/kernel/init/__internal.rs index 12e195061525..db3372619ecd 100644 --- a/rust/kernel/init/__internal.rs +++ b/rust/kernel/init/__internal.rs @@ -13,7 +13,7 @@ use super::*; /// /// [nomicon]: https://doc.rust-lang.org/nomicon/subtyping.html /// [this table]: https://doc.rust-lang.org/nomicon/phantom-data.html#table-of-phantomdata-patterns -type Invariant = PhantomData *mut T>; +pub(super) type Invariant = PhantomData *mut T>; /// This is the module-internal type implementing `PinInit` and `Init`. It is unsafe to create this /// type, since the closure needs to fulfill the same safety requirement as the -- cgit v1.2.3 From 4af84c6a85c63bec24611e46bb3de2c0a6602a51 Mon Sep 17 00:00:00 2001 From: Benno Lossin Date: Mon, 14 Aug 2023 08:47:54 +0000 Subject: rust: init: update expanded macro explanation The previous patches changed the internals of the macros resulting in the example expanded code being outdated. This patch updates the example and only changes documentation. Reviewed-by: Martin Rodriguez Reboredo Signed-off-by: Benno Lossin Link: https://lore.kernel.org/r/20230814084602.25699-14-benno.lossin@proton.me Reviewed-by: Alice Ryhl Signed-off-by: Miguel Ojeda --- rust/kernel/init/macros.rs | 126 +++++++++++++++++++++++++-------------------- 1 file changed, 69 insertions(+), 57 deletions(-) (limited to 'rust') diff --git a/rust/kernel/init/macros.rs b/rust/kernel/init/macros.rs index 5f0a0bdb9896..cb6e61b6c50b 100644 --- a/rust/kernel/init/macros.rs +++ b/rust/kernel/init/macros.rs @@ -45,7 +45,7 @@ //! #[pinned_drop] //! impl PinnedDrop for Foo { //! fn drop(self: Pin<&mut Self>) { -//! println!("{self:p} is getting dropped."); +//! pr_info!("{self:p} is getting dropped."); //! } //! } //! @@ -170,8 +170,10 @@ //! t: T, //! } //! #[doc(hidden)] -//! impl<'__pin, T> -//! ::core::marker::Unpin for Bar where __Unpin<'__pin, T>: ::core::marker::Unpin {} +//! impl<'__pin, T> ::core::marker::Unpin for Bar +//! where +//! __Unpin<'__pin, T>: ::core::marker::Unpin, +//! {} //! // Now we need to ensure that `Bar` does not implement `Drop`, since that would give users //! // access to `&mut self` inside of `drop` even if the struct was pinned. This could lead to //! // UB with only safe code, so we disallow this by giving a trait implementation error using @@ -188,8 +190,9 @@ //! // for safety, but a good sanity check, since no normal code calls `PinnedDrop::drop`. //! #[allow(non_camel_case_types)] //! trait UselessPinnedDropImpl_you_need_to_specify_PinnedDrop {} -//! impl -//! UselessPinnedDropImpl_you_need_to_specify_PinnedDrop for T {} +//! impl< +//! T: ::kernel::init::PinnedDrop, +//! > UselessPinnedDropImpl_you_need_to_specify_PinnedDrop for T {} //! impl UselessPinnedDropImpl_you_need_to_specify_PinnedDrop for Bar {} //! }; //! ``` @@ -219,7 +222,7 @@ //! // return type and shadow it later when we insert the arbitrary user code. That way //! // there will be no possibility of returning without `unsafe`. //! struct __InitOk; -//! // Get the pin-data type from the initialized type. +//! // Get the data about fields from the supplied type. //! // - the function is unsafe, hence the unsafe block //! // - we `use` the `HasPinData` trait in the block, it is only available in that //! // scope. @@ -227,8 +230,7 @@ //! use ::kernel::init::__internal::HasPinData; //! Self::__pin_data() //! }; -//! // Use `data` to help with type inference, the closure supplied will have the type -//! // `FnOnce(*mut Self) -> Result<__InitOk, Infallible>`. +//! // Ensure that `data` really is of type `PinData` and help with type inference: //! let init = ::kernel::init::__internal::PinData::make_closure::< //! _, //! __InitOk, @@ -236,71 +238,75 @@ //! >(data, move |slot| { //! { //! // Shadow the structure so it cannot be used to return early. If a user -//! // tries to write `return Ok(__InitOk)`, then they get a type error, since -//! // that will refer to this struct instead of the one defined above. +//! // tries to write `return Ok(__InitOk)`, then they get a type error, +//! // since that will refer to this struct instead of the one defined +//! // above. //! struct __InitOk; //! // This is the expansion of `t,`, which is syntactic sugar for `t: t,`. -//! unsafe { ::core::ptr::write(::core::addr_of_mut!((*slot).t), t) }; -//! // Since initialization could fail later (not in this case, since the error -//! // type is `Infallible`) we will need to drop this field if there is an -//! // error later. This `DropGuard` will drop the field when it gets dropped -//! // and has not yet been forgotten. We make a reference to it, so users -//! // cannot `mem::forget` it from the initializer, since the name is the same -//! // as the field (including hygiene). -//! let t = &unsafe { -//! ::kernel::init::__internal::DropGuard::new( -//! ::core::addr_of_mut!((*slot).t), -//! ) +//! { +//! unsafe { ::core::ptr::write(::core::addr_of_mut!((*slot).t), t) }; +//! } +//! // Since initialization could fail later (not in this case, since the +//! // error type is `Infallible`) we will need to drop this field if there +//! // is an error later. This `DropGuard` will drop the field when it gets +//! // dropped and has not yet been forgotten. +//! let t = unsafe { +//! ::pinned_init::__internal::DropGuard::new(::core::addr_of_mut!((*slot).t)) //! }; //! // Expansion of `x: 0,`: -//! // Since this can be an arbitrary expression we cannot place it inside of -//! // the `unsafe` block, so we bind it here. -//! let x = 0; -//! unsafe { ::core::ptr::write(::core::addr_of_mut!((*slot).x), x) }; +//! // Since this can be an arbitrary expression we cannot place it inside +//! // of the `unsafe` block, so we bind it here. +//! { +//! let x = 0; +//! unsafe { ::core::ptr::write(::core::addr_of_mut!((*slot).x), x) }; +//! } //! // We again create a `DropGuard`. -//! let x = &unsafe { -//! ::kernel::init::__internal::DropGuard::new( -//! ::core::addr_of_mut!((*slot).x), -//! ) +//! let x = unsafe { +//! ::kernel::init::__internal::DropGuard::new(::core::addr_of_mut!((*slot).x)) //! }; -//! +//! // Since initialization has successfully completed, we can now forget +//! // the guards. This is not `mem::forget`, since we only have +//! // `&DropGuard`. +//! ::core::mem::forget(x); +//! ::core::mem::forget(t); //! // Here we use the type checker to ensure that every field has been //! // initialized exactly once, since this is `if false` it will never get //! // executed, but still type-checked. -//! // Additionally we abuse `slot` to automatically infer the correct type for -//! // the struct. This is also another check that every field is accessible -//! // from this scope. +//! // Additionally we abuse `slot` to automatically infer the correct type +//! // for the struct. This is also another check that every field is +//! // accessible from this scope. //! #[allow(unreachable_code, clippy::diverging_sub_expression)] -//! if false { +//! let _ = || { //! unsafe { //! ::core::ptr::write( //! slot, //! Self { -//! // We only care about typecheck finding every field here, -//! // the expression does not matter, just conjure one using -//! // `panic!()`: +//! // We only care about typecheck finding every field +//! // here, the expression does not matter, just conjure +//! // one using `panic!()`: //! t: ::core::panic!(), //! x: ::core::panic!(), //! }, //! ); //! }; -//! } -//! // Since initialization has successfully completed, we can now forget the -//! // guards. This is not `mem::forget`, since we only have `&DropGuard`. -//! unsafe { ::kernel::init::__internal::DropGuard::forget(t) }; -//! unsafe { ::kernel::init::__internal::DropGuard::forget(x) }; +//! }; //! } //! // We leave the scope above and gain access to the previously shadowed //! // `__InitOk` that we need to return. //! Ok(__InitOk) //! }); //! // Change the return type from `__InitOk` to `()`. -//! let init = move |slot| -> ::core::result::Result<(), ::core::convert::Infallible> { +//! let init = move | +//! slot, +//! | -> ::core::result::Result<(), ::core::convert::Infallible> { //! init(slot).map(|__InitOk| ()) //! }; //! // Construct the initializer. //! let init = unsafe { -//! ::kernel::init::pin_init_from_closure::<_, ::core::convert::Infallible>(init) +//! ::kernel::init::pin_init_from_closure::< +//! _, +//! ::core::convert::Infallible, +//! >(init) //! }; //! init //! } @@ -374,7 +380,10 @@ //! b: Bar, //! } //! #[doc(hidden)] -//! impl<'__pin> ::core::marker::Unpin for Foo where __Unpin<'__pin>: ::core::marker::Unpin {} +//! impl<'__pin> ::core::marker::Unpin for Foo +//! where +//! __Unpin<'__pin>: ::core::marker::Unpin, +//! {} //! // Since we specified `PinnedDrop` as the argument to `#[pin_data]`, we expect `Foo` to //! // implement `PinnedDrop`. Thus we do not need to prevent `Drop` implementations like //! // before, instead we implement `Drop` here and delegate to `PinnedDrop`. @@ -403,7 +412,7 @@ //! #[pinned_drop] //! impl PinnedDrop for Foo { //! fn drop(self: Pin<&mut Self>) { -//! println!("{self:p} is getting dropped."); +//! pr_info!("{self:p} is getting dropped."); //! } //! } //! ``` @@ -414,7 +423,7 @@ //! // `unsafe`, full path and the token parameter are added, everything else stays the same. //! unsafe impl ::kernel::init::PinnedDrop for Foo { //! fn drop(self: Pin<&mut Self>, _: ::kernel::init::__internal::OnlyCallFromDrop) { -//! println!("{self:p} is getting dropped."); +//! pr_info!("{self:p} is getting dropped."); //! } //! } //! ``` @@ -449,18 +458,21 @@ //! >(data, move |slot| { //! { //! struct __InitOk; -//! unsafe { ::core::ptr::write(::core::addr_of_mut!((*slot).a), a) }; -//! let a = &unsafe { +//! { +//! unsafe { ::core::ptr::write(::core::addr_of_mut!((*slot).a), a) }; +//! } +//! let a = unsafe { //! ::kernel::init::__internal::DropGuard::new(::core::addr_of_mut!((*slot).a)) //! }; -//! let b = Bar::new(36); +//! let init = Bar::new(36); //! unsafe { data.b(::core::addr_of_mut!((*slot).b), b)? }; -//! let b = &unsafe { +//! let b = unsafe { //! ::kernel::init::__internal::DropGuard::new(::core::addr_of_mut!((*slot).b)) //! }; -//! +//! ::core::mem::forget(b); +//! ::core::mem::forget(a); //! #[allow(unreachable_code, clippy::diverging_sub_expression)] -//! if false { +//! let _ = || { //! unsafe { //! ::core::ptr::write( //! slot, @@ -470,13 +482,13 @@ //! }, //! ); //! }; -//! } -//! unsafe { ::kernel::init::__internal::DropGuard::forget(a) }; -//! unsafe { ::kernel::init::__internal::DropGuard::forget(b) }; +//! }; //! } //! Ok(__InitOk) //! }); -//! let init = move |slot| -> ::core::result::Result<(), ::core::convert::Infallible> { +//! let init = move | +//! slot, +//! | -> ::core::result::Result<(), ::core::convert::Infallible> { //! init(slot).map(|__InitOk| ()) //! }; //! let init = unsafe { -- cgit v1.2.3