- 05 May, 2024 12 commits
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Miguel Ojeda authored
This is the next upgrade to the Rust toolchain, from 1.77.1 to 1.78.0 (i.e. the latest) [1]. See the upgrade policy [2] and the comments on the first upgrade in commit 3ed03f4d ("rust: upgrade to Rust 1.68.2"). It is much smaller than previous upgrades, since the `alloc` fork was dropped in commit 9d0441ba ("rust: alloc: remove our fork of the `alloc` crate") [3]. # Unstable features There have been no changes to the set of unstable features used in our own code. Therefore, the only unstable features allowed to be used outside the `kernel` crate is still `new_uninit`. However, since we finally dropped our `alloc` fork [3], all the unstable features used by `alloc` (~30 language ones, ~60 library ones) are not a concern anymore. This reduces the maintenance burden, increases the chances of new compiler versions working without changes and gets us closer to the goal of supporting several compiler versions. It also means that, ignoring non-language/library features, we are currently left with just the few language features needed to implement the kernel `Arc`, the `new_uninit` library feature, the `compiler_builtins` marker and the few `no_*` `cfg`s we pass when compiling `core`/`alloc`. Please see [4] for details. # Required changes ## LLVM's data layout Rust 1.77.0 (i.e. the previous upgrade) introduced a check for matching LLVM data layouts [5]. Then, Rust 1.78.0 upgraded LLVM's bundled major version from 17 to 18 [6], which changed the data layout in x86 [7]. Thus update the data layout in our custom target specification for x86 so that the compiler does not complain about the mismatch: error: data-layout for target `target-5559158138856098584`, `e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128`, differs from LLVM target's `x86_64-linux-gnu` default layout, `e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128` In the future, the goal is to drop the custom target specifications. Meanwhile, if we want to support other LLVM versions used in `rustc` (e.g. for LTO), we will need to add some extra logic (e.g. conditional on LLVM's version, or extracting the data layout from an existing built-in target specification). ## `unused_imports` Rust's `unused_imports` lint covers both unused and redundant imports. Now, in 1.78.0, the lint detects more cases of redundant imports [8]. Thus one of the previous patches cleaned them up. ## Clippy's `new_without_default` Clippy now suggests to implement `Default` even when `new()` is `const`, since `Default::default()` may call `const` functions even if it is not `const` itself [9]. Thus one of the previous patches implemented it. # Other changes in Rust Rust 1.78.0 introduced `feature(asm_goto)` [10] [11]. This feature was discussed in the past [12]. Rust 1.78.0 introduced `feature(const_refs_to_static)` [13] to allow referencing statics in constants and extended `feature(const_mut_refs)` to allow raw mutable pointers in constants. Together, this should cover the kernel's `VTABLE` use case. In fact, the implementation [14] in upstream Rust added a test case for it [15]. Rust 1.78.0 with debug assertions enabled (i.e. `-Cdebug-assertions=y`, kernel's `CONFIG_RUST_DEBUG_ASSERTIONS=y`) now always checks all unsafe preconditions, though without a way to opt-out for particular cases [16]. It would be ideal to have a way to selectively disable certain checks per-call site for this one (i.e. not just per check but for particular instances of a check), even if the vast majority of the checks remain in place [17]. Rust 1.78.0 also improved a couple issues we reported when giving feedback for the new `--check-cfg` feature [18] [19]. # `alloc` upgrade and reviewing As mentioned above, compiler upgrades will not update `alloc` anymore, since we dropped our `alloc` fork [3]. Link: https://github.com/rust-lang/rust/blob/stable/RELEASES.md#version-1780-2024-05-02 [1] Link: https://rust-for-linux.com/rust-version-policy [2] Link: https://lore.kernel.org/rust-for-linux/20240328013603.206764-1-wedsonaf@gmail.com/ [3] Link: https://github.com/Rust-for-Linux/linux/issues/2 [4] Link: https://github.com/rust-lang/rust/pull/120062 [5] Link: https://github.com/rust-lang/rust/pull/120055 [6] Link: https://reviews.llvm.org/D86310 [7] Link: https://github.com/rust-lang/rust/pull/117772 [8] Link: https://github.com/rust-lang/rust-clippy/pull/10903 [9] Link: https://github.com/rust-lang/rust/pull/119365 [10] Link: https://github.com/rust-lang/rust/issues/119364 [11] Link: https://lore.kernel.org/rust-for-linux/ZWipTZysC2YL7qsq@Boquns-Mac-mini.home/ [12] Link: https://github.com/rust-lang/rust/issues/119618 [13] Link: https://github.com/rust-lang/rust/pull/120932 [14] Link: https://github.com/rust-lang/rust/pull/120932/files#diff-e6fc1622c46054cd46b1d225c5386c5554564b3b0fa8a03c2dc2d8627a1079d9 [15] Link: https://github.com/rust-lang/rust/issues/120969 [16] Link: https://github.com/Rust-for-Linux/linux/issues/354 [17] Link: https://github.com/rust-lang/rust/pull/121202 [18] Link: https://github.com/rust-lang/rust/pull/121237 [19] Reviewed-by:
Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240401212303.537355-4-ojeda@kernel.org [ Added a few more details and links I mentioned in the list. - Miguel ] Signed-off-by:
Miguel Ojeda <ojeda@kernel.org>
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Miguel Ojeda authored
Rust's `unused_imports` lint covers both unused and redundant imports. In the upcoming 1.78.0, the lint detects more cases of redundant imports [1], e.g.: error: the item `bindings` is imported redundantly --> rust/kernel/print.rs:38:9 | 38 | use crate::bindings; | ^^^^^^^^^^^^^^^ the item `bindings` is already defined by prelude Most cases are `use crate::bindings`, plus a few other items like `Box`. Thus clean them up. Note that, in the `bindings` case, the message "defined by prelude" above means the extern prelude, i.e. the `--extern` flags we pass. Link: https://github.com/rust-lang/rust/pull/117772 [1] Reviewed-by: -
Miguel Ojeda authored
In the upcoming Rust 1.78.0, Clippy suggests to implement `Default` even when `new()` is `const`, since `Default::default()` may call `const` functions even if it is not `const` itself [1]: error: you should consider adding a `Default` implementation for `LockClassKey` --> rust/kernel/sync.rs:31:5 | 31 | / pub const fn new() -> Self { 32 | | Self(Opaque::uninit()) 33 | | } | |_____^ Thus implement it. Link: https://github.com/rust-lang/rust-clippy/pull/10903 [1] Reviewed-by:Benno Lossin <benno.lossin@proton.me> Reviewed-by:
Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20240401212303.537355-2-ojeda@kernel.orgSigned-off-by:
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Dirk Behme authored
Add some basics explained by Miguel in [1] to the documentation. And connect it with some hints where this is implemented in the kernel. Link: https://www.linuxfoundation.org/webinars/rust-for-linux-writing-abstractions-and-drivers [1] Cc: Miguel Ojeda <ojeda@kernel.org> Signed-off-by:
Dirk Behme <dirk.behme@de.bosch.com> Reviewed-by:
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Laura Nao authored
Add section describing how to build and run the Rust kselftest. Signed-off-by:
Laura Nao <laura.nao@collabora.com> Reviewed-by:
Muhammad Usama Anjum <usama.anjum@collabora.com> Reviewed-by:
Valentin Obst <kernel@valentinobst.de> Link: https://lore.kernel.org/r/20240405153841.320459-1-laura.nao@collabora.com [ Formatted paths as inline code literals. - Miguel ] Signed-off-by:
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Nell Shamrell-Harrington authored
Rust doctests implicitly include `kernel::prelude::*`. Removes explicit `kernel::prelude` imports from doctests. Suggested-by:
Nell Shamrell-Harrington <nells@linux.microsoft.com> Reviewed-by:
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Raghav Narang authored
In Rust 1.76.0, the `dbg!()` macro was updated to also format the column number. The reason cited was usage of a few characters worth of horizontal space while allowing direct jumps to the source location. [1] Link: https://github.com/rust-lang/rust/pull/114962 [1] Link: https://github.com/Rust-for-Linux/linux/issues/1065Signed-off-by:
Raghav Narang <dev@raxyte.com> Reviewed-by:
Trevor Gross <tmgross@umich.edu> Reviewed-by:
Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/eba70259-9b10-4bf7-ac4f-d7accf6b8891@smtp-relay.sendinblue.com [ Fixed commit author name and removed spurious newline in message. - Miguel ] Signed-off-by:
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Thorsten Blum authored
s/directly the bindings/the bindings directly/ Signed-off-by:
Thorsten Blum <thorsten.blum@toblux.com> Reviewed-by:
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Benno Lossin authored
The initializers created by the `[try_][pin_]init!` macros utilize the guard pattern to drop already initialized fields, when initialization fails mid-way. These guards are generated to have the same name as the field that they handle. To prevent namespacing issues [1] when the field name is the same as e.g. a constant name, add `__` as a prefix and `_guard` as the suffix. [ Gary says: "Here's the simplified example: ``` macro_rules! f { () => { let a = 1; let _: u32 = a; } } const a: u64 = 1; fn main() { f!(); } ``` The `a` in `f` have a different hygiene so normally it is scoped to the macro expansion and wouldn't escape. Interestingly a constant is still preferred despite the hygiene so constants escaped into the macro, leading to the error." - Miguel ] Signed-off-by: -
Alice Ryhl authored
Decrement the refcount of an `Arc`, but handle the case where it hits zero by taking ownership of the now-unique `Arc`, instead of destroying and deallocating it. This is a dependency of the linked list that Rust Binder uses. The linked list uses this method as part of its `ListArc` abstraction [1]. Boqun Feng has authored the examples. Reviewed-by:
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Alice Ryhl authored
Allows access to a value in an `Arc` that is currently held as a raw pointer due to use of `Arc::into_raw`, without destroying or otherwise consuming that raw pointer. This is a dependency of the linked list that Rust Binder uses. The linked list uses this method when iterating over the linked list [1]. Reviewed-by:
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Boqun Feng authored
To support a potential usage: static foo: Opaque<Foo> = ..; // Or defined in an extern block. ... fn bar() { let ptr = foo.get(); } `Opaque::get` need to be `const`, otherwise compiler will complain because calls on statics are limited to const functions. Also `Opaque::get` should be naturally `const` since it's a composition of two `const` functions: `UnsafeCell::get` and `ptr::cast`. Signed-off-by:Wedson Almeida Filho <walmeida@microsoft.com> Reviewed-by:
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- 16 Apr, 2024 10 commits
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Wedson Almeida Filho authored
With the adoption of `BoxExt` and `VecExt`, we don't need the functions provided by this feature (namely the methods prefixed with `try_` and different allocator per collection instance). We do need `AllocError`, but we define our own as it is a trivial empty struct. Reviewed-by:
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Wedson Almeida Filho authored
This is the last component in the conversion for allocators to take allocation flags as parameters. Reviewed-by:
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Wedson Almeida Filho authored
We also remove the `try_` prefix to align with how `Box` and `Vec` are providing methods now. `init` is temporarily updated with uses of GFP_KERNEL. These will be updated in a subsequent patch to take flags as well. Reviewed-by:
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Wedson Almeida Filho authored
We also rename the methods by removing the `try_` prefix since the names are available due to our usage of the `no_global_oom_handling` config when building the `alloc` crate. Reviewed-by:
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Wedson Almeida Filho authored
Make fallible versions of `new` and `new_uninit` methods available in `Box` even though it doesn't implement them because we build `alloc` with the `no_global_oom_handling` config. They also have an extra `flags` parameter that allows callers to pass flags to the allocator. Signed-off-by:
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Wedson Almeida Filho authored
We'll use them when allocating `Box`, `Arc`, and `UniqueArc` instances, as well as when allocating memory for `Vec` elements. These changes will come in subsequent patches. Reviewed-by:
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Wedson Almeida Filho authored
It is not used anymore as `VecExt` now provides the functionality we depend on. Reviewed-by:
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Wedson Almeida Filho authored
Switch away from our fork of the `alloc` crate. We remove it altogether in the next commit. Signed-off-by:
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Wedson Almeida Filho authored
Make `try_with_capacity`, `try_push`, and `try_extend_from_slice` methods available in `Vec` even though it doesn't implement them. It is implemented with `try_reserve` and `push_within_capacity`. This is in preparation for switching to the upstream `alloc` crate. Reviewed-by:
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Wedson Almeida Filho authored
We will add more to the `alloc` module in subsequent patches (e.g., allocation flags and extension traits). Reviewed-by:
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- 07 Apr, 2024 3 commits
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Benno Lossin authored
The previous two patches made it possible to add `#[pin_data]` on structs with default generic parameter values. This patch makes `Work` use `#[pin_data]` and removes an invocation of `pin_init_from_closure`. This function is intended as a low level manual escape hatch, so it is better to rely on the safe `pin_init!` macro. Signed-off-by:
Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by:
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Benno Lossin authored
Add support for generic parameters defaults in `#[pin_data]` by using the newly introduced `decl_generics` instead of the `impl_generics`. Before this would not compile: #[pin_data] struct Foo<const N: usize = 0> { // ... } because it would be expanded to this: struct Foo<const N: usize = 0> { // ... } const _: () = { struct __ThePinData<const N: usize = 0> { __phantom: ::core::marker::PhantomData<fn(Foo<N>) -> Foo<N>>, } impl<const N: usize = 0> ::core::clone::Clone for __ThePinData<N> { fn clone(&self) -> Self { *self } } // [...] rest of expansion omitted }; The problem is with the `impl<const N: usize = 0>`, since that is invalid Rust syntax. It should not mention the default value at all, since default values only make sense on type definitions. The new `impl_generics` do not contain the default values, thus generating correct Rust code. This is used by the next commit that puts `#[pin_data]` on `kernel::workqueue::Work`. Signed-off-by: -
Benno Lossin authored
The generic parameters on a type definition can specify default values. Currently `parse_generics()` cannot handle this though. For example when parsing the following generics: <T: Clone, const N: usize = 0> The `impl_generics` will be set to `T: Clone, const N: usize = 0` and `ty_generics` will be set to `T, N`. Now using the `impl_generics` on an impl block: impl<$($impl_generics)*> Foo {} will result in invalid Rust code, because default values are only available on type definitions. Therefore add parsing support for generic parameter default values using a new kind of generics called `decl_generics` and change the old behavior of `impl_generics` to not contain the generic parameter default values. Now `Generics` has three fields: - `impl_generics`: the generics with bounds (e.g. `T: Clone, const N: usize`) - `decl_generics`: the generics with bounds and default values (e.g. `T: Clone, const N: usize = 0`) - `ty_generics`: contains the generics without bounds and without default values (e.g. `T, N`) `impl_generics` is designed to be used on `impl<$impl_generics>`, `decl_generics` for the type definition, so `struct Foo<$decl_generics>` and `ty_generics` whenever you use the type, so `Foo<$ty_generics>`. Here is an example that uses all three different types of generics: let (Generics { decl_generics, impl_generics, ty_generics }, rest) = parse_generics(input); quote! { struct Foo<$($decl_generics)*> { // ... } impl<$impl_generics> Foo<$ty_generics> { fn foo() { // ... } } } The next commit contains a fix to the `#[pin_data]` macro making it compatible with generic parameter default values by relying on this new behavior. Signed-off-by:
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- 02 Apr, 2024 3 commits
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Danilo Krummrich authored
Add functions to convert a CString to upper- / lowercase, either in-place or by creating a copy of the original CString. Naming follows the one from the Rust stdlib, where functions starting with 'to' create a copy and functions starting with 'make' perform an in-place conversion. This is required by the Nova project (GSP only Rust successor of Nouveau) to convert stringified enum values (representing different GPU chipsets) to strings in order to generate the corresponding firmware paths. See also [1]. Link: https://rust-for-linux.zulipchat.com/#narrow/stream/288089-General/topic/String.20manipulation.20in.20kernel.20Rust [1] Reviewed-by:
Danilo Krummrich <dakr@redhat.com> Reviewed-by:
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Miguel Ojeda authored
Rust 1.74.0 introduced (unstable) support for the `-Zdebuginfo-compression` flag, thus use it. Note that the releases built by the Rust project (i.e. the ones provided by rustup) do not enable support for zstd in their bundled LLVM (yet, at least), thus the Rust compiler will warn, but the build will proceed: warning: unknown debuginfo compression algorithm zstd - will fall back to uncompressed debuginfo Link: https://github.com/rust-lang/rust/issues/120953 Link: https://github.com/rust-lang/rust/pull/115358Reviewed-by: -
Miguel Ojeda authored
Rust 1.64.0 introduced (unstable) support for the `-Zdwarf-version` flag, which allows to select DWARFv5, thus use it. Link: https://github.com/rust-lang/rust/issues/103057 Link: https://github.com/rust-lang/rust/pull/98350Reviewed-by:
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- 29 Mar, 2024 2 commits
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Miguel Ojeda authored
This is the next upgrade to the Rust toolchain, from 1.76.0 to 1.77.1 (i.e. the latest) [1]. See the upgrade policy [2] and the comments on the first upgrade in commit 3ed03f4d ("rust: upgrade to Rust 1.68.2"). # Unstable features The `offset_of` feature (single-field `offset_of!`) that we were using got stabilized in Rust 1.77.0 [3]. Therefore, now the only unstable features allowed to be used outside the `kernel` crate is `new_uninit`, though other code to be upstreamed may increase the list. Please see [4] for details. # Required changes Rust 1.77.0 merged the `unused_tuple_struct_fields` lint into `dead_code`, thus upgrading it from `allow` to `warn` [5]. In turn, this made `rustc` complain about the `ThisModule`'s pointer field being never read, but the previous patch adds the `as_ptr` method to it, needed by Binder [6], so that we do not need to locally `allow` it. # Other changes Rust 1.77.0 introduces the `--check-cfg` feature [7], for which there is a Call for Testing going on [8]. We were requested to test it and we found it useful [9] -- we will likely enable it in the future. # `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://github.com/rust-lang/rust/blob/stable/RELEASES.md#version-1770-2024-03-21 [1] Link: https://rust-for-linux.com/rust-version-policy [2] Link: https://github.com/rust-lang/rust/pull/118799 [3] Link: https://github.com/Rust-for-Linux/linux/issues/2 [4] Link: https://github.com/rust-lang/rust/pull/118297 [5] Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-2-08ba9197f637@google.com/#Z31rust:kernel:lib.rs [6] Link: https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html [7] Link: https://github.com/rust-lang/rfcs/pull/3013#issuecomment-1936648479 [8] Link: https://github.com/rust-lang/rust/issues/82450#issuecomment-1947462977 [9] Reviewed-by:
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Alice Ryhl authored
This allows you to get a raw pointer to THIS_MODULE for use in unsafe code. The Rust Binder RFC uses it when defining fops for the binderfs component [1]. This doesn't really need to go in now - it could go in together with Rust Binder like how it is sent in the Rust Binder RFC. However, the upcoming 1.77.0 release of the Rust compiler introduces a new warning, and applying this patch now will silence that warning. That allows us to avoid adding the #[allow(dead_code)] annotation seen in [2]. Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-2-08ba9197f637@google.com/ [1] Link: https://lore.kernel.org/all/20240217002717.57507-1-ojeda@kernel.org/ [2] Signed-off-by:
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- 24 Mar, 2024 10 commits
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Linus Torvalds authored
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git://git.kernel.org/pub/scm/linux/kernel/git/efi/efiLinus Torvalds authored
Pull EFI fixes from Ard Biesheuvel: - Fix logic that is supposed to prevent placement of the kernel image below LOAD_PHYSICAL_ADDR - Use the firmware stack in the EFI stub when running in mixed mode - Clear BSS only once when using mixed mode - Check efi.get_variable() function pointer for NULL before trying to call it * tag 'efi-fixes-for-v6.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: efi: fix panic in kdump kernel x86/efistub: Don't clear BSS twice in mixed mode x86/efistub: Call mixed mode boot services on the firmware's stack efi/libstub: fix efi_random_alloc() to allocate memory at alloc_min or higher address
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull x86 fixes from Thomas Gleixner: - Ensure that the encryption mask at boot is properly propagated on 5-level page tables, otherwise the PGD entry is incorrectly set to non-encrypted, which causes system crashes during boot. - Undo the deferred 5-level page table setup as it cannot work with memory encryption enabled. - Prevent inconsistent XFD state on CPU hotplug, where the MSR is reset to the default value but the cached variable is not, so subsequent comparisons might yield the wrong result and as a consequence the result prevents updating the MSR. - Register the local APIC address only once in the MPPARSE enumeration to prevent triggering the related WARN_ONs() in the APIC and topology code. - Handle the case where no APIC is found gracefully by registering a fake APIC in the topology code. That makes all related topology functions work correctly and does not affect the actual APIC driver code at all. - Don't evaluate logical IDs during early boot as the local APIC IDs are not yet enumerated and the invoked function returns an error code. Nothing requires the logical IDs before the final CPUID enumeration takes place, which happens after the enumeration. - Cure the fallout of the per CPU rework on UP which misplaced the copying of boot_cpu_data to per CPU data so that the final update to boot_cpu_data got lost which caused inconsistent state and boot crashes. - Use copy_from_kernel_nofault() in the kprobes setup as there is no guarantee that the address can be safely accessed. - Reorder struct members in struct saved_context to work around another kmemleak false positive - Remove the buggy code which tries to update the E820 kexec table for setup_data as that is never passed to the kexec kernel. - Update the resource control documentation to use the proper units. - Fix a Kconfig warning observed with tinyconfig * tag 'x86-urgent-2024-03-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot/64: Move 5-level paging global variable assignments back x86/boot/64: Apply encryption mask to 5-level pagetable update x86/cpu: Add model number for another Intel Arrow Lake mobile processor x86/fpu: Keep xfd_state in sync with MSR_IA32_XFD Documentation/x86: Document that resctrl bandwidth control units are MiB x86/mpparse: Register APIC address only once x86/topology: Handle the !APIC case gracefully x86/topology: Don't evaluate logical IDs during early boot x86/cpu: Ensure that CPU info updates are propagated on UP kprobes/x86: Use copy_from_kernel_nofault() to read from unsafe address x86/pm: Work around false positive kmemleak report in msr_build_context() x86/kexec: Do not update E820 kexec table for setup_data x86/config: Fix warning for 'make ARCH=x86_64 tinyconfig'
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull scheduler doc clarification from Thomas Gleixner: "A single update for the documentation of the base_slice_ns tunable to clarify that any value which is less than the tick slice has no effect because the scheduler tick is not guaranteed to happen within the set time slice" * tag 'sched-urgent-2024-03-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/doc: Update documentation for base_slice_ns and CONFIG_HZ relation
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git://git.infradead.org/users/hch/dma-mappingLinus Torvalds authored
Pull dma-mapping fixes from Christoph Hellwig: "This has a set of swiotlb alignment fixes for sometimes very long standing bugs from Will. We've been discussion them for a while and they should be solid now" * tag 'dma-mapping-6.9-2024-03-24' of git://git.infradead.org/users/hch/dma-mapping: swiotlb: Reinstate page-alignment for mappings >= PAGE_SIZE iommu/dma: Force swiotlb_max_mapping_size on an untrusted device swiotlb: Fix alignment checks when both allocation and DMA masks are present swiotlb: Honour dma_alloc_coherent() alignment in swiotlb_alloc() swiotlb: Enforce page alignment in swiotlb_alloc() swiotlb: Fix double-allocation of slots due to broken alignment handling
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Oleksandr Tymoshenko authored
Check if get_next_variable() is actually valid pointer before calling it. In kdump kernel this method is set to NULL that causes panic during the kexec-ed kernel boot. Tested with QEMU and OVMF firmware. Fixes: bad267f9 ("efi: verify that variable services are supported") Signed-off-by:
Oleksandr Tymoshenko <ovt@google.com> Signed-off-by:
Ard Biesheuvel <ardb@kernel.org>
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Ard Biesheuvel authored
Clearing BSS should only be done once, at the very beginning. efi_pe_entry() is the entrypoint from the firmware, which may not clear BSS and so it is done explicitly. However, efi_pe_entry() is also used as an entrypoint by the mixed mode startup code, in which case BSS will already have been cleared, and doing it again at this point will corrupt global variables holding the firmware's GDT/IDT and segment selectors. So make the memset() conditional on whether the EFI stub is running in native mode. Fixes: b3810c5a ("x86/efistub: Clear decompressor BSS in native EFI entrypoint") Signed-off-by:
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Ard Biesheuvel authored
Normally, the EFI stub calls into the EFI boot services using the stack that was live when the stub was entered. According to the UEFI spec, this stack needs to be at least 128k in size - this might seem large but all asynchronous processing and event handling in EFI runs from the same stack and so quite a lot of space may be used in practice. In mixed mode, the situation is a bit different: the bootloader calls the 32-bit EFI stub entry point, which calls the decompressor's 32-bit entry point, where the boot stack is set up, using a fixed allocation of 16k. This stack is still in use when the EFI stub is started in 64-bit mode, and so all calls back into the EFI firmware will be using the decompressor's limited boot stack. Due to the placement of the boot stack right after the boot heap, any stack overruns have gone unnoticed. However, commit 5c4feadb0011983b ("x86/decompressor: Move global symbol references to C code") moved the definition of the boot heap into C code, and now the boot stack is placed right at the base of BSS, where any overruns will corrupt the end of the .data section. While it would be possible to work around this by increasing the size of the boot stack, doing so would affect all x86 systems, and mixed mode systems are a tiny (and shrinking) fraction of the x86 installed base. So instead, record the firmware stack pointer value when entering from the 32-bit firmware, and switch to this stack every time a EFI boot service call is made. Cc: <stable@kernel.org> # v6.1+ Signed-off-by: -
Tom Lendacky authored
Commit 63bed966 ("x86/startup_64: Defer assignment of 5-level paging global variables") moved assignment of 5-level global variables to later in the boot in order to avoid having to use RIP relative addressing in order to set them. However, when running with 5-level paging and SME active (mem_encrypt=on), the variables are needed as part of the page table setup needed to encrypt the kernel (using pgd_none(), p4d_offset(), etc.). Since the variables haven't been set, the page table manipulation is done as if 4-level paging is active, causing the system to crash on boot. While only a subset of the assignments that were moved need to be set early, move all of the assignments back into check_la57_support() so that these assignments aren't spread between two locations. Instead of just reverting the fix, this uses the new RIP_REL_REF() macro when assigning the variables. Fixes: 63bed966 ("x86/startup_64: Defer assignment of 5-level paging global variables") Signed-off-by:
Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by:
Ingo Molnar <mingo@kernel.org> Reviewed-by:
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Tom Lendacky authored
When running with 5-level page tables, the kernel mapping PGD entry is updated to point to the P4D table. The assignment uses _PAGE_TABLE_NOENC, which, when SME is active (mem_encrypt=on), results in a page table entry without the encryption mask set, causing the system to crash on boot. Change the assignment to use _PAGE_TABLE instead of _PAGE_TABLE_NOENC so that the encryption mask is set for the PGD entry. Fixes: 533568e0 ("x86/boot/64: Use RIP_REL_REF() to access early_top_pgt[]") Signed-off-by:
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