[ Upstream commit 4a5dc632e0b603ec1cbbf87b78de86b4b6359cff ]
Originally, `Atomic::from_ptr()` requires `T` being a `Sync` because I
thought having the ability to do `from_ptr()` meant multiplle
`&Atomic<T>`s shared by different threads, which was identical (or
similar) to multiple `&T`s shared by different threads. Hence `T` was
required to be `Sync`. However this is not true, since `&Atomic<T>` is
not the same at `&T`. Moreover, having this bound makes `Atomic::<*mut
T>::from_ptr()` impossible, which is definitely not intended. Therefore
remove the `T: Sync` bound.
[boqun: Fix title typo spotted by Alice & Gary]
Fixes: 29c32c405e53 ("rust: sync: atomic: Add generic atomics")
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260120115207.55318-2-boqun.feng@gmail.com
Link: https://patch.msgid.link/20260303201701.12204-2-boqun@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c03791085adcd61fa9b766ab303c7d0941d7378d ]
cpufreq_cpu_get() can sleep on PREEMPT_RT in presence of concurrent
writer(s), however amd-pstate depends on fetching the cpudata via the
policy's driver data which necessitates grabbing the reference.
Since schedutil governor can call "cpufreq_driver->update_perf()"
during sched_tick/enqueue/dequeue with rq_lock held and IRQs disabled,
fetching the policy object using the cpufreq_cpu_get() helper in the
scheduler fast-path leads to "BUG: scheduling while atomic" on
PREEMPT_RT [1].
Pass the cached cpufreq policy object in sg_policy to the update_perf()
instead of just the CPU. The CPU can be inferred using "policy->cpu".
The lifetime of cpufreq_policy object outlasts that of the governor and
the cpufreq driver (allocated when the CPU is onlined and only reclaimed
when the CPU is offlined / the CPU device is removed) which makes it
safe to be referenced throughout the governor's lifetime.
Closes:https://lore.kernel.org/all/20250731092316.3191-1-spasswolf@web.de/ [1]
Fixes: 1d215f0319c2 ("cpufreq: amd-pstate: Add fast switch function for AMD P-State")
Reported-by: Bert Karwatzki <spasswolf@web.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Acked-by: Gary Guo <gary@garyguo.net> # Rust
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Reviewed-by: Zhongqiu Han <zhongqiu.han@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260316081849.19368-3-kprateek.nayak@amd.com
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 2e42a17b8f6bc3c0cd69d7556b588011d3ec2394 upstream.
Currently, if `drm_gem_object_init` fails, the object is freed without
any cleanup. Perform the cleanup in that case.
Cc: stable@vger.kernel.org
Fixes: c284d3e42338 ("rust: drm: gem: Add GEM object abstraction")
Signed-off-by: Eliot Courtney <ecourtney@nvidia.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Onur Özkan <work@onurozkan.dev>
Link: https://patch.msgid.link/20260423-fix-gem-1-v1-1-e12e35f7bba9@nvidia.com
[ Move safety comment closer to unsafe block to avoid a clippy warning.
- Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 18fb5f1f0289b8217c0c43d54d12bccc201dd640 upstream.
When DMA_ATTR_NO_KERNEL_MAPPING is passed to dma_alloc_attrs(), the
returned CPU address is not a pointer to the allocated memory but an
opaque handle (e.g. struct page *).
Coherent<T> (or CoherentAllocation<T> respectively) stores this value as
NonNull<T> and exposes methods that dereference it and even modify its
contents.
Remove the flag from the public attrs module such that drivers cannot
pass it to Coherent<T> (or CoherentAllocation<T> respectively) in the
first place.
Instead DMA_ATTR_NO_KERNEL_MAPPING can be supported with an additional
opaque type (e.g. CoherentHandle) which does not provide access to the
allocated memory.
Cc: stable@vger.kernel.org
Fixes: ad2907b4e308 ("rust: add dma coherent allocator abstraction")
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260321172749.592387-1-dakr@kernel.org
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The Rust `Regulator` abstraction uses `NonNull` to wrap the underlying
`struct regulator` pointer. When `CONFIG_REGULATOR` is disabled, the C
stub for `regulator_get` returns `NULL`. `from_err_ptr` does not treat
`NULL` as an error, so it was passed to `NonNull::new_unchecked`,
causing undefined behavior.
Fix this by using a raw pointer `*mut bindings::regulator` instead of
`NonNull`. This allows `inner` to be `NULL` when `CONFIG_REGULATOR` is
disabled, and leverages the C stubs which are designed to handle `NULL`
or are no-ops.
Fixes: 9b614ceada7c ("rust: regulator: add a bare minimum regulator abstraction")
Reported-by: Miguel Ojeda <ojeda@kernel.org>
Closes: https://lore.kernel.org/r/20260322193830.89324-1-ojeda@kernel.org
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Link: https://patch.msgid.link/20260324-regulator-fix-v1-1-a5244afa3c15@google.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Pull Rust fixes from Miguel Ojeda:
"Toolchain and infrastructure:
- Remap paths to avoid absolute ones starting with the upcoming Rust
1.95.0 release. This improves build reproducibility, avoids leaking
the exact path and avoids having the same path appear in two forms
The approach here avoids remapping debug information as well, in
order to avoid breaking tools that used the paths to access source
files, which was the previous attempt that needed to be reverted
- Allow 'unused_features' lint for the upcoming Rust 1.96.0 release.
While well-intentioned, we do not benefit much from the new lint
- Emit dependency information into '$(depfile)' directly to avoid a
temporary '.d' file (it was an old approach)
'kernel' crate:
- 'str' module: fix warning under '!CONFIG_BLOCK' by making
'NullTerminatedFormatter' public
- 'cpufreq' module: suppress false positive Clippy warning
'pin-init' crate:
- Remove '#[disable_initialized_field_access]' attribute which was
unsound. This means removing the support for structs with unaligned
fields (through the 'repr(packed)' attribute), for now
And document the load-bearing fact of field accessors (i.e. that
they are required for soundness)
- Replace shadowed return token by 'unsafe'-to-create token in order
to remain sound in the face of the likely upcoming Type Alias Impl
Trait (TAIT) and the next trait solver in upstream Rust"
* tag 'rust-fixes-7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux:
rust: kbuild: allow `unused_features`
rust: cpufreq: suppress clippy::double_parens in Policy doctest
rust: pin-init: replace shadowed return token by `unsafe`-to-create token
rust: pin-init: internal: init: document load-bearing fact of field accessors
rust: pin-init: internal: init: remove `#[disable_initialized_field_access]`
rust: build: remap path to avoid absolute path
rust: kbuild: emit dep-info into $(depfile) directly
rust: str: make NullTerminatedFormatter public
Core Changes: - Fix safety issue in dma_read! and dma_write!. Driver Changes (Nova Core): - Fix UB in DmaGspMem pointer accessors. - Fix stack overflow in GSP memory allocation. Signed-off-by: Dave Airlie <airlied@redhat.com> From: Alice Ryhl <aliceryhl@google.com> Link: https://patch.msgid.link/abNBSol3CLRCqlkZ@google.com
The kernel fmt! proc macro wraps each format argument as &(arg). Passing a
tuple such as (a, b) produces &((a, b)) after expansion. Clippy flags that
as double_parens, but it is a false positive fixed in Clippy 1.92 [1] [2].
Suppress the warning on the affected doctest function with a reason
attribute so it can be removed once the minimum toolchain moves past 1.92.
[ We may end up deciding to support per-version Clippy lints, in which
case we will need [3].
In the future, if [4] gets fixed, we may be able to use
`Delimiter::None` as Gary suggested in [5].
Link: https://lore.kernel.org/rust-for-linux/20260307170929.153892-1-ojeda@kernel.org/ [3]
Link: https://github.com/rust-lang/rust/issues/67062 [4]
Link: https://lore.kernel.org/rust-for-linux/DGUA5GY2DGYN.3PG0FKLG7GFN1@garyguo.net/ [5]
- Miguel ]
Link: https://github.com/rust-lang/rust-clippy/issues/15852 [1]
Link: https://github.com/rust-lang/rust-clippy/pull/15939 [2]
Suggested-by: Gary Guo <gary@garyguo.net>
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://patch.msgid.link/20260312041934.362840-2-jhubbard@nvidia.com
[ Reworded to replace GitHub-like short link with full URLs in Link tags.
Reworded reason string to match the style of a couple others we have
elsewhere. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Current `dma_read!`, `dma_write!` macros also use a custom
`addr_of!()`-based implementation for projecting pointers, which has
soundness issue as it relies on absence of `Deref` implementation on types.
It also has a soundness issue where it does not protect against unaligned
fields (when `#[repr(packed)]` is used) so it can generate misaligned
accesses.
This commit migrates them to use the general pointer projection
infrastructure, which handles these cases correctly.
As part of migration, the macro is updated to have an improved surface
syntax. The current macro have
dma_read!(a.b.c[d].e.f)
to mean `a.b.c` is a DMA coherent allocation and it should project into it
with `[d].e.f` and do a read, which is confusing as it makes the indexing
operator integral to the macro (so it will break if you have an array of
`CoherentAllocation`, for example).
This also is problematic as we would like to generalize
`CoherentAllocation` from just slices to arbitrary types.
Make the macro expects `dma_read!(path.to.dma, .path.inside.dma)` as the
canonical syntax. The index operator is no longer special and is just one
type of projection (in additional to field projection). Similarly, make
`dma_write!(path.to.dma, .path.inside.dma, value)` become the canonical
syntax for writing.
Another issue of the current macro is that it is always fallible. This
makes sense with existing design of `CoherentAllocation`, but once we
support fixed size arrays with `CoherentAllocation`, it is desirable to
have the ability to perform infallible indexing as well, e.g. doing a `[0]`
index of `[Foo; 2]` is okay and can be checked at build-time, so forcing
falliblity is non-ideal. To capture this, the macro is changed to use
`[idx]` as infallible projection and `[idx]?` as fallible index projection
(those syntax are part of the general projection infra). A benefit of this
is that while individual indexing operation may fail, the overall
read/write operation is not fallible.
Fixes: ad2907b4e308 ("rust: add dma coherent allocator abstraction")
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260302164239.284084-4-gary@kernel.org
[ Capitalize safety comments; slightly improve wording in doc-comments.
- Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Add a generic infrastructure for performing field and index projections on
raw pointers. This will form the basis of performing I/O projections.
Pointers manipulations are intentionally using the safe wrapping variants
instead of the unsafe variants, as the latter requires pointers to be
inside an allocation which is not necessarily true for I/O pointers.
This projection macro protects against rogue `Deref` implementation, which
can causes the projected pointer to be outside the bounds of starting
pointer. This is extremely unlikely and Rust has a lint to catch this, but
is unsoundness regardless. The protection works by inducing type inference
ambiguity when `Deref` is implemented.
This projection macro also stops projecting into unaligned fields (i.e.
fields of `#[repr(packed)]` structs), as misaligned pointers require
special handling. This is implemented by attempting to create reference to
projected field inside a `if false` block. Despite being unreachable, Rust
still checks that they're not unaligned fields.
The projection macro supports both fallible and infallible index
projections. These are described in detail inside the documentation.
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://patch.msgid.link/20260302164239.284084-3-gary@kernel.org
[ * Add intro-doc links where possible,
* Fix typos and slightly improve wording, e.g. "as documentation
describes" -> "as the documentation of [`Self::proj`] describes",
* Add an empty line between regular and safety comments, before
examples, and between logically independent comments,
* Capitalize various safety comments.
- Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>