user/sven/linux.git/rust, branch v6.6.48

rust: kernel: require `Send` for `Module` implementations

2024-05-17T10:01:56Z

[ Upstream commit 323617f649c0966ad5e741e47e27e06d3a680d8f ] The thread that calls the module initialisation code when a module is loaded is not guaranteed [in fact, it is unlikely] to be the same one that calls the module cleanup code on module unload, therefore, `Module` implementations must be `Send` to account for them moving from one thread to another implicitly. Signed-off-by: Wedson Almeida Filho Reviewed-by: Alice Ryhl Reviewed-by: Benno Lossin Cc: stable@vger.kernel.org # 6.8.x: df70d04d5697: rust: phy: implement `Send` for `Registration` Cc: stable@vger.kernel.org Fixes: 247b365dc8dc ("rust: add `kernel` crate") Link: https://lore.kernel.org/r/20240328195457.225001-3-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda Signed-off-by: Sasha Levin

rust: macros: fix soundness issue in `module!` macro

2024-05-17T10:01:56Z

[ Upstream commit 7044dcff8301b29269016ebd17df27c4736140d2 ] The `module!` macro creates glue code that are called by C to initialize the Rust modules using the `Module::init` function. Part of this glue code are the local functions `__init` and `__exit` that are used to initialize/destroy the Rust module. These functions are safe and also visible to the Rust mod in which the `module!` macro is invoked. This means that they can be called by other safe Rust code. But since they contain `unsafe` blocks that rely on only being called at the right time, this is a soundness issue. Wrap these generated functions inside of two private modules, this guarantees that the public functions cannot be called from the outside. Make the safe functions `unsafe` and add SAFETY comments. Cc: stable@vger.kernel.org Reported-by: Björn Roy Baron Closes: https://github.com/Rust-for-Linux/linux/issues/629 Fixes: 1fbde52bde73 ("rust: add `macros` crate") Signed-off-by: Benno Lossin Reviewed-by: Wedson Almeida Filho Link: https://lore.kernel.org/r/20240401185222.12015-1-benno.lossin@proton.me [ Moved `THIS_MODULE` out of the private-in-private modules since it should remain public, as Dirk Behme noticed [1]. Capitalized comments, avoided newline in non-list SAFETY comments and reworded to add Reported-by and newline. ] Link: https://rust-for-linux.zulipchat.com/#narrow/stream/291565-Help/topic/x/near/433512583 [1] Signed-off-by: Miguel Ojeda Signed-off-by: Sasha Levin

rust: module: place generated init_module() function in .init.text

2024-05-17T10:01:55Z

[ Upstream commit 1b6170ff7a203a5e8354f19b7839fe8b897a9c0d ] Currently Rust kernel modules have their init code placed in the `.text` section of the .ko file. I don't think this causes any real problems for Rust modules as long as all code called during initialization lives in `.text`. However, if a Rust `init_module()` function (that lives in `.text`) calls a function marked with `__init` (in C) or `#[link_section = ".init.text"]` (in Rust), then a warning is generated by modpost because that function lives in `.init.text`. For example: WARNING: modpost: fs/bcachefs/bcachefs: section mismatch in reference: init_module+0x6 (section: .text) -> _RNvXCsj7d3tFpT5JS_15bcachefs_moduleNtB2_8BcachefsNtCsjDtqRIL3JAG_6kernel6Module4init (section: .init.text) I ran into this while experimenting with converting the bcachefs kernel module from C to Rust. The module's `init()`, written in Rust, calls C functions like `bch2_vfs_init()` which are placed in `.init.text`. This patch places the macro-generated `init_module()` Rust function in the `.init.text` section. It also marks `init_module()` as unsafe--now it may not be called after module initialization completes because it may be freed already. Note that this is not enough on its own to actually get all the module initialization code in that section. The module author must still add the `#[link_section = ".init.text"]` attribute to the Rust `init()` in the `impl kernel::Module` block in order to then call `__init` functions. However, this patch enables module authors do so, when previously it would not be possible (without warnings). Signed-off-by: Thomas Bertschinger Reviewed-by: Martin Rodriguez Reboredo Reviewed-by: Alice Ryhl Link: https://lore.kernel.org/r/20240206153806.567055-1-tahbertschinger@gmail.com [ Reworded title to add prefix. ] Signed-off-by: Miguel Ojeda Stable-dep-of: 7044dcff8301 ("rust: macros: fix soundness issue in `module!` macro") Signed-off-by: Sasha Levin

rust: remove `params` from `module` macro example

2024-05-02T14:32:42Z

commit 19843452dca40e28d6d3f4793d998b681d505c7f upstream. Remove argument `params` from the `module` macro example, because the macro does not currently support module parameters since it was not sent with the initial merge. Signed-off-by: Aswin Unnikrishnan Reviewed-by: Alice Ryhl Cc: stable@vger.kernel.org Fixes: 1fbde52bde73 ("rust: add `macros` crate") Link: https://lore.kernel.org/r/20240419215015.157258-1-aswinunni01@gmail.com [ Reworded slightly. ] Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman

kbuild: rust: remove unneeded `@rustc_cfg` to avoid ICE

2024-05-02T14:32:42Z

commit 50cfe93b01475ba36878b65d35d812e1bb48ac71 upstream. When KUnit tests are enabled, under very big kernel configurations (e.g. `allyesconfig`), we can trigger a `rustdoc` ICE [1]: RUSTDOC TK rust/kernel/lib.rs error: the compiler unexpectedly panicked. this is a bug. The reason is that this build step has a duplicated `@rustc_cfg` argument, which contains the kernel configuration, and thus a lot of arguments. The factor 2 happens to be enough to reach the ICE. Thus remove the unneeded `@rustc_cfg`. By doing so, we clean up the command and workaround the ICE. The ICE has been fixed in the upcoming Rust 1.79 [2]. Cc: stable@vger.kernel.org Fixes: a66d733da801 ("rust: support running Rust documentation tests as KUnit ones") Link: https://github.com/rust-lang/rust/issues/122722 [1] Link: https://github.com/rust-lang/rust/pull/122840 [2] Reviewed-by: Alice Ryhl Link: https://lore.kernel.org/r/20240422091215.526688-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman

rust: init: remove impl Zeroable for Infallible

2024-05-02T14:32:42Z

commit 49ceae68a0df9a92617a61e9ce8a0efcf6419585 upstream. In Rust, producing an invalid value of any type is immediate undefined behavior (UB); this includes via zeroing memory. Therefore, since an uninhabited type has no valid values, producing any values at all for it is UB. The Rust standard library type `core::convert::Infallible` is uninhabited, by virtue of having been declared as an enum with no cases, which always produces uninhabited types in Rust. The current kernel code allows this UB to be triggered, for example by code like `Box::::init(kernel::init::zeroed())`. Thus, remove the implementation of `Zeroable` for `Infallible`, thereby avoiding the unsoundness (potential for future UB). Cc: stable@vger.kernel.org Fixes: 38cde0bd7b67 ("rust: init: add `Zeroable` trait and `init::zeroed` function") Closes: https://github.com/Rust-for-Linux/pinned-init/pull/13 Signed-off-by: Laine Taffin Altman Reviewed-by: Alice Ryhl Reviewed-by: Boqun Feng Reviewed-by: Benno Lossin Link: https://lore.kernel.org/r/CA160A4E-561E-4918-837E-3DCEBA74F808@me.com [ Reformatted the comment slightly. ] Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman

rust: upgrade to Rust 1.73.0

2024-02-16T18:10:43Z

commit e08ff622c91af997cb89bc47e90a1a383e938bd0 upstream. This is the next upgrade to the Rust toolchain, from 1.72.1 to 1.73.0 (i.e. the latest) [1]. See the upgrade policy [2] 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 [3] for details. # Required changes For the upgrade, the following changes are required: - Allow `internal_features` for `feature(compiler_builtins)` since now Rust warns about using internal compiler and standard library features (similar to how it also warns about incomplete ones) [4]. - A cleanup for a documentation link thanks to a new `rustdoc` lint. See previous commits for details. - A need to make an intra-doc link to a macro explicit, due to a change in behavior in `rustdoc`. See previous commits for details. # `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-1730-2023-10-05 [1] Link: https://rust-for-linux.com/rust-version-policy [2] Link: https://github.com/Rust-for-Linux/linux/issues/2 [3] Link: https://github.com/rust-lang/compiler-team/issues/596 [4] Reviewed-by: Martin Rodriguez Reboredo Reviewed-by: Vincenzo Palazzo Reviewed-by: Alice Ryhl Link: https://lore.kernel.org/r/20231005210556.466856-4-ojeda@kernel.org Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman

rust: print: use explicit link in documentation

2024-02-16T18:10:43Z

commit a53d8cdd5a0aec75ae32badc2d8995c59ea6e3f0 upstream. The future `rustdoc` in the Rust 1.73.0 upgrade requires an explicit link for `pr_info!`: error: unresolved link to `pr_info` --> rust/kernel/print.rs:395:63 | 395 | /// Use only when continuing a previous `pr_*!` macro (e.g. [`pr_info!`]). | ^^^^^^^^ no item named `pr_info` in scope | = note: `macro_rules` named `pr_info` exists in this crate, but it is not in scope at this link's location = note: `-D rustdoc::broken-intra-doc-links` implied by `-D warnings` Thus do so to avoid a broken link while upgrading. Reviewed-by: Alice Ryhl Reviewed-by: Vincenzo Palazzo Reviewed-by: Finn Behrens Reviewed-by: Martin Rodriguez Reboredo Link: https://lore.kernel.org/r/20231005210556.466856-3-ojeda@kernel.org Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman

rust: task: remove redundant explicit link

2024-02-16T18:10:43Z

commit c61bcc278b1924da13fd52edbd46b08a518c11ef upstream. Starting with Rust 1.73.0, `rustdoc` detects redundant explicit links with its new lint `redundant_explicit_links` [1]: error: redundant explicit link target --> rust/kernel/task.rs:85:21 | 85 | /// [`current`](crate::current) macro because it is safe. | --------- ^^^^^^^^^^^^^^ explicit target is redundant | | | because label contains path that resolves to same destination | = note: when a link's destination is not specified, the label is used to resolve intra-doc links = note: `-D rustdoc::redundant-explicit-links` implied by `-D warnings` help: remove explicit link target | 85 | /// [`current`] macro because it is safe. In order to avoid the warning in the compiler upgrade commit, make it an intra-doc link as the tool suggests. Link: https://github.com/rust-lang/rust/pull/113167 [1] Reviewed-by: Finn Behrens Reviewed-by: Alice Ryhl Reviewed-by: Martin Rodriguez Reboredo Reviewed-by: Vincenzo Palazzo Link: https://lore.kernel.org/r/20231005210556.466856-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman

rust: upgrade to Rust 1.72.1

2024-02-16T18:10:43Z

commit ae6df65dabc3f8bd89663d96203963323e266d90 upstream. This is the third upgrade to the Rust toolchain, from 1.71.1 to 1.72.1 (i.e. the latest) [1]. See the upgrade policy [2] 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 [3] for details. # Other improvements Previously, the compiler could incorrectly generate a `.eh_frame` section under `-Cpanic=abort`. We were hitting this bug when debug assertions were enabled (`CONFIG_RUST_DEBUG_ASSERTIONS=y`) [4]: LD .tmp_vmlinux.kallsyms1 ld.lld: error: :(.eh_frame) is being placed in '.eh_frame' Gary fixed the issue in Rust 1.72.0 [5]. # Required changes For the upgrade, the following changes are required: - A call to `Box::from_raw` in `rust/kernel/sync/arc.rs` now requires an explicit `drop()` call. See previous patch for details. # `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-1721-2023-09-19 [1] Link: https://rust-for-linux.com/rust-version-policy [2] Link: https://github.com/Rust-for-Linux/linux/issues/2 [3] Closes: https://github.com/Rust-for-Linux/linux/issues/1012 [4] Link: https://github.com/rust-lang/rust/pull/112403 [5] Reviewed-by: Martin Rodriguez Reboredo Reviewed-by: Gary Guo Reviewed-by: Alice Ryhl Reviewed-by: Björn Roy Baron Link: https://lore.kernel.org/r/20230823160244.188033-3-ojeda@kernel.org [ Used 1.72.1 instead of .0 (no changes in `alloc`) and reworded to mention that we hit the `.eh_frame` bug under debug assertions. ] Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman