user/sven/linux.git/rust, branch v6.6.54

rust: kbuild: fix export of bss symbols

2024-09-12T09:11:32Z

[ Upstream commit b8673d56935c32a4e0a1a0b40951fdd313dbf340 ] Symbols in the bss segment are not currently exported. This is a problem for Rust modules that link against statics, that are resident in the kernel image. Thus export symbols in the bss segment. Fixes: 2f7ab1267dc9 ("Kbuild: add Rust support") Signed-off-by: Andreas Hindborg Reviewed-by: Alice Ryhl Tested-by: Alice Ryhl Reviewed-by: Gary Guo Link: https://lore.kernel.org/r/20240815074519.2684107-2-nmi@metaspace.dk [ Reworded slightly. - Miguel ] Signed-off-by: Miguel Ojeda Signed-off-by: Sasha Levin

rust: Use awk instead of recent xargs

2024-09-12T09:11:32Z

[ Upstream commit 45f97e6385cad6d0e48a27ddcd08793bb4d35851 ] `awk` is already required by the kernel build, and the `xargs` feature used in current Rust detection is not present in all `xargs` (notably, toybox based xargs, used in the Android kernel build). Signed-off-by: Matthew Maurer Reviewed-by: Alice Ryhl Tested-by: Alice Ryhl Reviewed-by: Martin Rodriguez Reboredo Link: https://lore.kernel.org/r/20230928205045.2375899-1-mmaurer@google.com Signed-off-by: Miguel Ojeda Stable-dep-of: b8673d56935c ("rust: kbuild: fix export of bss symbols") Signed-off-by: Sasha Levin

rust: macros: provide correct provenance when constructing THIS_MODULE

2024-09-12T09:11:25Z

commit a5a3c952e82c1ada12bf8c55b73af26f1a454bd2 upstream. Currently while defining `THIS_MODULE` symbol in `module!()`, the pointer used to construct `ThisModule` is derived from an immutable reference of `__this_module`, which means the pointer doesn't have the provenance for writing, and that means any write to that pointer is UB regardless of data races or not. However, the usage of `THIS_MODULE` includes passing this pointer to functions that may write to it (probably in unsafe code), and this will create soundness issues. One way to fix this is using `addr_of_mut!()` but that requires the unstable feature "const_mut_refs". So instead of `addr_of_mut()!`, an extern static `Opaque` is used here: since `Opaque` is transparent to `T`, an extern static `Opaque` will just wrap the C symbol (defined in a C compile unit) in an `Opaque`, which provides a pointer with writable provenance via `Opaque::get()`. This fix the potential UBs because of pointer provenance unmatched. Reported-by: Alice Ryhl Signed-off-by: Boqun Feng Reviewed-by: Alice Ryhl Reviewed-by: Trevor Gross Reviewed-by: Benno Lossin Reviewed-by: Gary Guo Closes: https://rust-for-linux.zulipchat.com/#narrow/stream/x/topic/x/near/465412664 Fixes: 1fbde52bde73 ("rust: add `macros` crate") Cc: stable@vger.kernel.org # 6.6.x: be2ca1e03965: ("rust: types: Make Opaque::get const") Link: https://lore.kernel.org/r/20240828180129.4046355-1-boqun.feng@gmail.com [ Fixed two typos, reworded title. - Miguel ] Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman

rust: types: Make Opaque::get const

2024-09-12T09:11:25Z

commit be2ca1e03965ffb214b6cbda0ffd84daeeb5f214 upstream. To support a potential usage: static foo: Opaque = ..; // 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: Boqun Feng Reviewed-by: Alice Ryhl Reviewed-by: Wedson Almeida Filho Reviewed-by: Benno Lossin Link: https://lore.kernel.org/r/20240401214543.1242286-1-boqun.feng@gmail.com Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman

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