kernel/linux.git/rust, branch v6.19.5

rust: devres: fix race condition due to nesting

2026-02-26T23:01:12+00:00

[ Upstream commit ba268514ea14b44570030e8ed2aef92a38679e85 ] Commit f5d3ef25d238 ("rust: devres: get rid of Devres' inner Arc") did attempt to optimize away the internal reference count of Devres. However, without an internal reference count, we can't support cases where Devres is indirectly nested, resulting into a deadlock. Such indirect nesting easily happens in the following way: A registration object (which is guarded by devres) hold a reference count of an object that holds a device resource guarded by devres itself. For instance a drm::Registration holds a reference of a drm::Device. The drm::Device itself holds a device resource in its private data. When the drm::Registration is dropped by devres, and it happens that it did hold the last reference count of the drm::Device, it also drops the device resource, which is guarded by devres itself. Thus, resulting into a deadlock in the Devres destructor of the device resource, as in the following backtrace. sysrq: Show Blocked State task:rmmod state:D stack:0 pid:1331 tgid:1331 ppid:1330 task_flags:0x400100 flags:0x00000010 Call trace: __switch_to+0x190/0x294 (T) __schedule+0x878/0xf10 schedule+0x4c/0xcc schedule_timeout+0x44/0x118 wait_for_common+0xc0/0x18c wait_for_completion+0x18/0x24 _RINvNtCs4gKlGRWyJ5S_4core3ptr13drop_in_placeINtNtNtCsgzhNYVB7wSz_6kernel4sync3arc3ArcINtNtBN_6devres6DevresmEEECsRdyc7Hyps3_15rust_driver_pci+0x68/0xe8 [rust_driver_pci] _RINvNvNtCsgzhNYVB7wSz_6kernel6devres16register_foreign8callbackINtNtCs4gKlGRWyJ5S_4core3pin3PinINtNtNtB6_5alloc4kbox3BoxINtNtNtB6_4sync3arc3ArcINtB4_6DevresmEENtNtB1A_9allocator7KmallocEEECsRdyc7Hyps3_15rust_driver_pci+0x34/0xc8 [rust_driver_pci] devm_action_release+0x14/0x20 devres_release_all+0xb8/0x118 device_release_driver_internal+0x1c4/0x28c driver_detach+0x94/0xd4 bus_remove_driver+0xdc/0x11c driver_unregister+0x34/0x58 pci_unregister_driver+0x20/0x80 __arm64_sys_delete_module+0x1d8/0x254 invoke_syscall+0x40/0xcc el0_svc_common+0x8c/0xd8 do_el0_svc+0x1c/0x28 el0_svc+0x54/0x1d4 el0t_64_sync_handler+0x84/0x12c el0t_64_sync+0x198/0x19c In order to fix this, re-introduce the internal reference count. Reported-by: Boris Brezillon Closes: https://rust-for-linux.zulipchat.com/#narrow/channel/288089-General/topic/.E2.9C.94.20Deadlock.20caused.20by.20nested.20Devres/with/571242651 Reported-by: Markus Probst Closes: https://rust-for-linux.zulipchat.com/#narrow/channel/288089-General/topic/.E2.9C.94.20Devres.20inside.20Devres.20stuck.20on.20cleanup/with/571239721 Reported-by: Alice Ryhl Closes: https://gitlab.freedesktop.org/panfrost/linux/-/merge_requests/56#note_3282757 Fixes: f5d3ef25d238 ("rust: devres: get rid of Devres' inner Arc") Reviewed-by: Greg Kroah-Hartman Reviewed-by: Alice Ryhl Tested-by: Boris Brezillon Link: https://patch.msgid.link/20260205222529.91465-1-dakr@kernel.org [ Call clone() prior to devm_add_action(). - Danilo ] Signed-off-by: Danilo Krummrich Signed-off-by: Sasha Levin

rust: driver-core: use "kernel vertical" style for imports

2026-02-26T23:01:12+00:00

[ Upstream commit 52563c665b0b0b39f319bee40ecc5e8f25b9050a ] Convert all imports to use "kernel vertical" style. With this, subsequent patches neither introduce unrelated changes nor leave an inconsistent import pattern. While at it, drop unnecessary imports covered by prelude::*. Link: https://docs.kernel.org/rust/coding-guidelines.html#imports Reviewed-by: Greg Kroah-Hartman Link: https://patch.msgid.link/20260105142123.95030-3-dakr@kernel.org Signed-off-by: Danilo Krummrich Stable-dep-of: ba268514ea14 ("rust: devres: fix race condition due to nesting") Signed-off-by: Sasha Levin

rust: task: restrict Task::group_leader() to current

2026-02-26T23:01:08+00:00

[ Upstream commit 105ddfb2d2b3acec7a7d9695463df48733d91e6c ] The Task::group_leader() method currently allows you to access the group_leader() of any task, for example one you hold a refcount to. But this is not safe in general since the group leader could change when a task exits. See for example commit a15f37a40145c ("kernel/sys.c: fix the racy usage of task_lock(tsk->group_leader) in sys_prlimit64() paths"). All existing users of Task::group_leader() call this method on current, which is guaranteed running, so there's not an actual issue in Rust code today. But to prevent code in the future from making this mistake, restrict Task::group_leader() so that it can only be called on current. There are some other cases where accessing task->group_leader is okay. For example it can be safe if you hold tasklist_lock or rcu_read_lock(). However, only supporting current->group_leader is sufficient for all in-tree Rust users of group_leader right now. Safe Rust functionality for accessing it under rcu or while holding tasklist_lock may be added in the future if required by any future Rust module. This patch is a bugfix in that it prevents users of this API from writing incorrect code. It doesn't change behavior of correct code. Link: https://lkml.kernel.org/r/20260107-task-group-leader-v2-1-8fbf816f2a2f@google.com Signed-off-by: Alice Ryhl Fixes: 313c4281bc9d ("rust: add basic `Task`") Reported-by: Oleg Nesterov Closes: https://lore.kernel.org/all/aTLnV-5jlgfk1aRK@redhat.com/ Reviewed-by: Boqun Feng Reviewed-by: Gary Guo Cc: Andreas Hindborg Cc: Benno Lossin Cc: "Björn Roy Baron" Cc: Björn Roy Baron Cc: Christian Brauner Cc: Danilo Krummrich Cc: FUJITA Tomonori Cc: Miguel Ojeda Cc: Panagiotis Foliadis Cc: Shankari Anand Cc: Trevor Gross Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

rust: pwm: Fix potential memory leak on init error

2026-02-26T23:01:01+00:00

[ Upstream commit a2633dc243c35754a0c2270131d8a199c987c9bf ] When initializing a PWM chip using pwmchip_alloc(), the allocated device owns an initial reference that must be released on all error paths. If __pinned_init() were to fail, the allocated pwm_chip would currently leak because the error path returns without calling pwmchip_put(). Fixes: 7b3dce814a15 ("rust: pwm: Add Kconfig and basic data structures") Signed-off-by: Kari Argillander Acked-by: Michal Wilczynski Link: https://patch.msgid.link/20260102-pwm-rust-v2-1-2702ce57d571@gmail.com Signed-off-by: Uwe Kleine-König Signed-off-by: Sasha Levin

Merge tag 'rust-fixes-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

2026-01-31T00:15:59+00:00

Pull Rust fixes from Miguel Ojeda: "Toolchain and infrastructure: - Trigger rebuilds of the newly added 'proc-macro2' crate (and its dependencies) when the Rust compiler version changes - Fix error in '.rsi' targets (macro expanding single targets) under 'O=' pointing to an external (not subdir) folder - Fix off-by-one line number in 'rustdoc' KUnit tests - Add '-fdiagnostics-show-context' to GCC flags skipped by 'bindgen' - Clean objtool warning by adding one more 'noreturn' function - Clean 'libpin_init_internal.{so,dylib}' in 'mrproper' 'kernel' crate: - Fix build error when using expressions in formatting arguments - Mark 'num::Bounded::__new()' as unsafe and clean documentation accordingly - Always inline functions using 'build_assert' with arguments - Fix 'rusttest' build error providing the right 'isize_atomic_repr' type for the host 'macros' crate: - Fix 'rusttest' build error by ignoring example rust-analyzer: - Remove assertion that was not true for distributions like NixOS - Add missing dependency edges and fix editions for 'quote' and sysroot crates to provide correct IDE support DRM Tyr: - Fix build error by adding missing dependency on 'CONFIG_COMMON_CLK' Plus clean a few typos in docs and comments" * tag 'rust-fixes-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (28 commits) rust: num: bounded: clean __new documentation and comments scripts: generate_rust_analyzer: fix resolution of #[pin_data] macros drm/tyr: depend on `COMMON_CLK` to fix build error rust: sync: atomic: Provide stub for `rusttest` 32-bit hosts kbuild: rust: clean libpin_init_internal in mrproper rust: proc-macro2: rebuild if the version text changes rust: num: bounded: add missing comment for always inlined function rust: sync: refcount: always inline functions using build_assert with arguments rust: bits: always inline functions using build_assert with arguments scripts: generate_rust_analyzer: compile sysroot with correct edition scripts: generate_rust_analyzer: compile quote with correct edition scripts: generate_rust_analyzer: quote: treat `core` and `std` as dependencies scripts: generate_rust_analyzer: syn: treat `std` as a dependency scripts: generate_rust_analyzer: remove sysroot assertion rust: kbuild: give `--config-path` to `rustfmt` in `.rsi` target scripts: generate_rust_analyzer: Add pin_init_internal deps scripts: generate_rust_analyzer: Add pin_init -> compiler_builtins dep scripts: generate_rust_analyzer: Add compiler_builtins -> core dep rust: macros: ignore example with module parameters rust: num: bounded: mark __new as unsafe ...

rust: num: bounded: clean __new documentation and comments

2026-01-26T01:53:16+00:00

Following commit 3a1ec424dd9c ("rust: num: bounded: mark __new as unsafe"), remove the redundant paragraph in the documentation of __new now that the Safety section explicitly covers the requirement. Additionally, add an INVARIANT comment inside the function body where the Bounded instance is actually constructed to document that the type invariant is upheld. Suggested-by: Miguel Ojeda Link: https://lore.kernel.org/rust-for-linux/CANiq72mUCUh72BWP4eD1PTDpwdb1ML+Xgfom-Ys6thJooqQPwQ@mail.gmail.com/ Signed-off-by: Shivam Kalra Acked-by: Alexandre Courbot Link: https://patch.msgid.link/20260123132132.53854-1-shivamklr@cock.li [ Reworded slightly. - Miguel ] Signed-off-by: Miguel Ojeda

rust: sync: atomic: Provide stub for `rusttest` 32-bit hosts

2026-01-26T01:18:58+00:00

For arm32, on a x86_64 builder, running the `rusttest` target yields: error[E0080]: evaluation of constant value failed --> rust/kernel/static_assert.rs:37:23 | 37 | const _: () = ::core::assert!($condition $(,$arg)?); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the evaluated program panicked at 'assertion failed: size_of::() == size_of::()', rust/kernel/sync/atomic/predefine.rs:68:1 | ::: rust/kernel/sync/atomic/predefine.rs:68:1 | 68 | static_assert!(size_of::() == size_of::()); | -------------------------------------------------------------------- in this macro invocation | = note: this error originates in the macro `::core::assert` which comes from the expansion of the macro `static_assert` (in Nightly builds, run with -Z macro-backtrace for more info) The reason is that `rusttest` runs on the host, so for e.g. a x86_64 builder `isize` is 64 bits but it is not a `CONFIG_64BIT` build. Fix it by providing a stub for `rusttest` as usual. Fixes: 84c6d36bcaf9 ("rust: sync: atomic: Add Atomic<{usize,isize}>") Cc: stable@vger.kernel.org Reviewed-by: Onur Özkan Acked-by: Boqun Feng Link: https://patch.msgid.link/20260123233432.22703-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda

Merge tag 'driver-core-6.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core

2026-01-24T18:13:22+00:00

Pull driver core fixes from Danilo Krummrich: - Always inline I/O and IRQ methods using build_assert!() to avoid false positive build errors - Do not free the driver's device private data in I2C shutdown() avoiding race conditions that can lead to UAF bugs - Drop the driver's device private data after the driver has been fully unbound from its device to avoid UAF bugs from &Device scopes, such as IRQ callbacks * tag 'driver-core-6.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: rust: driver: drop device private data post unbind rust: driver: add DriverData type to the DriverLayout trait rust: driver: add DEVICE_DRIVER_OFFSET to the DriverLayout trait rust: driver: introduce a DriverLayout trait rust: auxiliary: add Driver::unbind() callback rust: i2c: do not drop device private data on shutdown() rust: irq: always inline functions using build_assert with arguments rust: io: always inline functions using build_assert with arguments

rust: proc-macro2: rebuild if the version text changes

2026-01-23T09:44:27+00:00

The Rust compiler cannot use dependencies built by other versions, e.g.: error[E0514]: found crate `proc_macro2` compiled by an incompatible version of rustc --> rust/quote/ext.rs:5:5 | 5 | use proc_macro2::{TokenStream, TokenTree}; | ^^^^^^^^^^^ | = note: the following crate versions were found: crate `proc_macro2` compiled by rustc 1.92.0 (ded5c06cf 2025-12-08): ./rust/libproc_macro2.rlib = help: please recompile that crate using this compiler (rustc 1.93.0 (254b59607 2026-01-19)) (consider running `cargo clean` first) Thus trigger a rebuild if the version text changes like we do in other top-level cases (e.g. see commit aeb0e24abbeb ("kbuild: rust: replace proc macros dependency on `core.o` with the version text")). The build errors for now are hard to trigger, since we do not yet use the new crates we just introduced (the use cases are coming in the next merge window), but they can still be seen if e.g. one manually removes one of the targets, so fix it already. Fixes: 158a3b72118a ("rust: proc-macro2: enable support in kbuild") Reviewed-by: Alice Ryhl Link: https://patch.msgid.link/20260122054135.138445-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda

rust: num: bounded: add missing comment for always inlined function

2026-01-18T19:40:12+00:00

This code is always inlined to avoid a build error if the error path of `build_assert` cannot be optimized out. Add a comment justifying the `#[inline(always)]` property to avoid it being taken away by mistake. Reviewed-by: Daniel Almeida Signed-off-by: Alexandre Courbot Link: https://patch.msgid.link/20251208-io-build-assert-v3-7-98aded02c1ea@nvidia.com Signed-off-by: Miguel Ojeda