linux-stable.git/rust/kernel, branch v6.17.4 Linux kernel stable tree cpufreq: Make drivers using CPUFREQ_ETERNAL specify transition latency 2025-10-19T14:37:00+00:00 Rafael J. Wysocki rafael.j.wysocki@intel.com 2025-09-26T10:12:37+00:00 509c344cdfd314b26914b2ccb117e78d7e01eb15 commit f97aef092e199c10a3da96ae79b571edd5362faa upstream. Commit a755d0e2d41b ("cpufreq: Honour transition_latency over transition_delay_us") caused platforms where cpuinfo.transition_latency is CPUFREQ_ETERNAL to get a very large transition latency whereas previously it had been capped at 10 ms (and later at 2 ms). This led to a user-observable regression between 6.6 and 6.12 as described by Shawn: "The dbs sampling_rate was 10000 us on 6.6 and suddently becomes 6442450 us (4294967295 / 1000 * 1.5) on 6.12 for these platforms because the default transition delay was dropped [...]. It slows down dbs governor's reacting to CPU loading change dramatically. Also, as transition_delay_us is used by schedutil governor as rate_limit_us, it shows a negative impact on device idle power consumption, because the device gets slightly less time in the lowest OPP." Evidently, the expectation of the drivers using CPUFREQ_ETERNAL as cpuinfo.transition_latency was that it would be capped by the core, but they may as well return a default transition latency value instead of CPUFREQ_ETERNAL and the core need not do anything with it. Accordingly, introduce CPUFREQ_DEFAULT_TRANSITION_LATENCY_NS and make all of the drivers in question use it instead of CPUFREQ_ETERNAL. Also update the related Rust binding. Fixes: a755d0e2d41b ("cpufreq: Honour transition_latency over transition_delay_us") Closes: https://lore.kernel.org/linux-pm/20250922125929.453444-1-shawnguo2@yeah.net/ Reported-by: Shawn Guo <shawnguo@kernel.org> Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org> Reviewed-by: Jie Zhan <zhanjie9@hisilicon.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: 6.6+ <stable@vger.kernel.org> # 6.6+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://patch.msgid.link/2264949.irdbgypaU6@rafael.j.wysocki [ rjw: Fix typo in new symbol name, drop redundant type cast from Rust binding ] Tested-by: Shawn Guo <shawnguo@kernel.org> # with cpufreq-dt driver Reviewed-by: Qais Yousef <qyousef@layalina.io> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit f97aef092e199c10a3da96ae79b571edd5362faa upstream.

Commit a755d0e2d41b ("cpufreq: Honour transition_latency over
transition_delay_us") caused platforms where cpuinfo.transition_latency
is CPUFREQ_ETERNAL to get a very large transition latency whereas
previously it had been capped at 10 ms (and later at 2 ms).

This led to a user-observable regression between 6.6 and 6.12 as
described by Shawn:

"The dbs sampling_rate was 10000 us on 6.6 and suddently becomes
 6442450 us (4294967295 / 1000 * 1.5) on 6.12 for these platforms
 because the default transition delay was dropped [...].

 It slows down dbs governor's reacting to CPU loading change
 dramatically.  Also, as transition_delay_us is used by schedutil
 governor as rate_limit_us, it shows a negative impact on device
 idle power consumption, because the device gets slightly less time
 in the lowest OPP."

Evidently, the expectation of the drivers using CPUFREQ_ETERNAL as
cpuinfo.transition_latency was that it would be capped by the core,
but they may as well return a default transition latency value instead
of CPUFREQ_ETERNAL and the core need not do anything with it.

Accordingly, introduce CPUFREQ_DEFAULT_TRANSITION_LATENCY_NS and make
all of the drivers in question use it instead of CPUFREQ_ETERNAL.  Also
update the related Rust binding.

Fixes: a755d0e2d41b ("cpufreq: Honour transition_latency over transition_delay_us")
Closes: https://lore.kernel.org/linux-pm/20250922125929.453444-1-shawnguo2@yeah.net/
Reported-by: Shawn Guo <shawnguo@kernel.org>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Reviewed-by: Jie Zhan <zhanjie9@hisilicon.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 6.6+ <stable@vger.kernel.org> # 6.6+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/2264949.irdbgypaU6@rafael.j.wysocki
[ rjw: Fix typo in new symbol name, drop redundant type cast from Rust binding ]
Tested-by: Shawn Guo <shawnguo@kernel.org> # with cpufreq-dt driver
Reviewed-by: Qais Yousef <qyousef@layalina.io>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rust: cpumask: Mark CpumaskVar as transparent 2025-10-15T10:03:19+00:00 Baptiste Lepers baptiste.lepers@gmail.com 2025-08-12T14:42:11+00:00 ffe015e8e3f681ca59694da4e56ab873ebd092e3 [ Upstream commit 23fca458f6ab18927e50c2134fb7b60297f18b4e ] Unsafe code in CpumaskVar's methods assumes that the type has the same layout as `bindings::cpumask_var_t`. This is not guaranteed by the default struct representation in Rust, but requires specifying the `transparent` representation. Fixes: 8961b8cb3099a ("rust: cpumask: Add initial abstractions") Signed-off-by: Baptiste Lepers <baptiste.lepers@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 23fca458f6ab18927e50c2134fb7b60297f18b4e ]

Unsafe code in CpumaskVar's methods assumes that the type has the same
layout as `bindings::cpumask_var_t`. This is not guaranteed by
the default struct representation in Rust, but requires specifying the
`transparent` representation.

Fixes: 8961b8cb3099a ("rust: cpumask: Add initial abstractions")
Signed-off-by: Baptiste Lepers <baptiste.lepers@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
rust: pci: fix incorrect platform reference in PCI driver unbind doc comment 2025-10-12T11:01:55+00:00 Rahul Rameshbabu sergeantsagara@protonmail.com 2025-09-14T03:19:19+00:00 32df3ad0dbfbcd0f201df445ed1a6b6567056685 commit a404d099554d17206d1f283c9a91f0616324f691 upstream. Substitute 'platform' with 'pci'. Fixes: 18ebb25dfa18 ("rust: pci: implement Driver::unbind()") Cc: stable@kernel.org Signed-off-by: Rahul Rameshbabu <sergeantsagara@protonmail.com> Signed-off-by: Danilo Krummrich <dakr@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit a404d099554d17206d1f283c9a91f0616324f691 upstream.

Substitute 'platform' with 'pci'.

Fixes: 18ebb25dfa18 ("rust: pci: implement Driver::unbind()")
Cc: stable@kernel.org
Signed-off-by: Rahul Rameshbabu <sergeantsagara@protonmail.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rust: pci: fix incorrect platform reference in PCI driver probe doc comment 2025-10-12T11:01:55+00:00 Rahul Rameshbabu sergeantsagara@protonmail.com 2025-09-14T03:18:34+00:00 c5828784c5b751bafec401f33eebee1ef44ef479 commit 855318e7c0c4a3e3014c0469dd5bc93a1c0df30c upstream. Substitute 'platform' with 'pci'. Fixes: 1bd8b6b2c5d3 ("rust: pci: add basic PCI device / driver abstractions") Cc: stable@kernel.org Signed-off-by: Rahul Rameshbabu <sergeantsagara@protonmail.com> Signed-off-by: Danilo Krummrich <dakr@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 855318e7c0c4a3e3014c0469dd5bc93a1c0df30c upstream.

Substitute 'platform' with 'pci'.

Fixes: 1bd8b6b2c5d3 ("rust: pci: add basic PCI device / driver abstractions")
Cc: stable@kernel.org
Signed-off-by: Rahul Rameshbabu <sergeantsagara@protonmail.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rust: block: fix `srctree/` links 2025-10-12T11:01:55+00:00 Miguel Ojeda ojeda@kernel.org 2025-07-30T13:07:14+00:00 a7452ec64a263ae6c25bed8e7d46fdaa033bf803 commit 208d7f788e84e80992d7b1c82ff17b620eb1371e upstream. This `srctree/` link pointed to a file with an underscore, but the header used a dash instead. Thus fix it. This cleans a future warning that will check our `srctree/` links. Cc: stable@vger.kernel.org Fixes: 3253aba3408a ("rust: block: introduce `kernel::block::mq` module") Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com> Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 208d7f788e84e80992d7b1c82ff17b620eb1371e upstream.

This `srctree/` link pointed to a file with an underscore, but the header
used a dash instead.

Thus fix it.

This cleans a future warning that will check our `srctree/` links.

Cc: stable@vger.kernel.org
Fixes: 3253aba3408a ("rust: block: introduce `kernel::block::mq` module")
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rust: drm: fix `srctree/` links 2025-10-12T11:01:55+00:00 Miguel Ojeda ojeda@kernel.org 2025-07-30T13:07:15+00:00 e294e1254174ebb184691676f8e51d68dcbb346e commit c2783c7cfefd55b1a5be781679cbee5191c0fd87 upstream. These `srctree/` links pointed inside `linux/`, but they are directly under `drm/`. Thus fix them. This cleans a future warning that will check our `srctree/` links. Cc: stable@vger.kernel.org Fixes: a98a73be9ee9 ("rust: drm: file: Add File abstraction") Fixes: c284d3e42338 ("rust: drm: gem: Add GEM object abstraction") Fixes: 07c9016085f9 ("rust: drm: add driver abstractions") Fixes: 1e4b8896c0f3 ("rust: drm: add device abstraction") Fixes: 9a69570682b1 ("rust: drm: ioctl: Add DRM ioctl abstraction") Acked-by: Danilo Krummrich <dakr@kernel.org> Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com> Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit c2783c7cfefd55b1a5be781679cbee5191c0fd87 upstream.

These `srctree/` links pointed inside `linux/`, but they are directly
under `drm/`.

Thus fix them.

This cleans a future warning that will check our `srctree/` links.

Cc: stable@vger.kernel.org
Fixes: a98a73be9ee9 ("rust: drm: file: Add File abstraction")
Fixes: c284d3e42338 ("rust: drm: gem: Add GEM object abstraction")
Fixes: 07c9016085f9 ("rust: drm: add driver abstractions")
Fixes: 1e4b8896c0f3 ("rust: drm: add device abstraction")
Fixes: 9a69570682b1 ("rust: drm: ioctl: Add DRM ioctl abstraction")
Acked-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Merge tag 'driver-core-6.17-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core 2025-09-13T17:36:06+00:00 Linus Torvalds torvalds@linux-foundation.org 2025-09-13T17:36:06+00:00 b891d11b74b447df6e18104199148e420c985ac1 Pull driver core fixes from Danilo Krummrich: - Fix UAF in cgroup pressure polling by using kernfs_get_active_of() to prevent operations on released file descriptors - Fix unresolved intra-doc link in the documentation of struct Device when CONFIG_DRM != y - Update the DMA Rust MAINTAINERS entry * tag 'driver-core-6.17-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: MAINTAINERS: Update the DMA Rust entry kernfs: Fix UAF in polling when open file is released rust: device: fix unresolved link to drm::Device 
Pull driver core fixes from Danilo Krummrich:

 - Fix UAF in cgroup pressure polling by using kernfs_get_active_of()
   to prevent operations on released file descriptors

 - Fix unresolved intra-doc link in the documentation of struct Device
   when CONFIG_DRM != y

 - Update the DMA Rust MAINTAINERS entry

* tag 'driver-core-6.17-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core:
  MAINTAINERS: Update the DMA Rust entry
  kernfs: Fix UAF in polling when open file is released
  rust: device: fix unresolved link to drm::Device
Merge tag 'rust-fixes-6.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux 2025-09-06T19:33:09+00:00 Linus Torvalds torvalds@linux-foundation.org 2025-09-06T19:33:09+00:00 b236920731dd90c3fba8c227aa0c4dee5351a639 Pull rust fixes from Miguel Ojeda: - Two changes to prepare for the future Rust 1.91.0 release (expected 2025-10-30, currently in nightly): a target specification format change and a renamed, soon-to-be-stabilized 'core' function. * tag 'rust-fixes-6.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: rust: support Rust >= 1.91.0 target spec rust: use the new name Location::file_as_c_str() in Rust >= 1.91.0 
Pull rust fixes from Miguel Ojeda:

 - Two changes to prepare for the future Rust 1.91.0 release (expected
   2025-10-30, currently in nightly): a target specification format
   change and a renamed, soon-to-be-stabilized 'core' function.

* tag 'rust-fixes-6.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux:
  rust: support Rust >= 1.91.0 target spec
  rust: use the new name Location::file_as_c_str() in Rust >= 1.91.0
rust: device: fix unresolved link to drm::Device 2025-09-02T09:16:36+00:00 Danilo Krummrich dakr@kernel.org 2025-08-29T19:57:42+00:00 f1b55db08d527240fbc3b8c84229134a98d8d080 drm::Device is only available when CONFIG_DRM=y, which we have to consider for intra-doc links, otherwise the rustdoc make target produces the following warning. >> warning: unresolved link to `kernel::drm::Device` --> rust/kernel/device.rs:154:22 | 154 | /// [`drm::Device`]: kernel::drm::Device | ^^^^^^^^^^^^^^^^^^^ no item named `drm` in module `kernel` | = note: `#[warn(rustdoc::broken_intra_doc_links)]` on by default Fix this by making the intra-doc link conditional on CONFIG_DRM being enabled. Fixes: d6e26c1ae4a6 ("device: rust: expand documentation for Device") Suggested-by: Alice Ryhl <aliceryhl@google.com> Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202508261644.9LclwUgt-lkp@intel.com/ Reviewed-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20250829195745.31174-1-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org> 
drm::Device is only available when CONFIG_DRM=y, which we have to
consider for intra-doc links, otherwise the rustdoc make target produces
the following warning.

>> warning: unresolved link to `kernel::drm::Device`
   --> rust/kernel/device.rs:154:22
   |
   154 | /// [`drm::Device`]: kernel::drm::Device
   |                      ^^^^^^^^^^^^^^^^^^^ no item named `drm` in module `kernel`
   |
   = note: `#[warn(rustdoc::broken_intra_doc_links)]` on by default

Fix this by making the intra-doc link conditional on CONFIG_DRM being enabled.

Fixes: d6e26c1ae4a6 ("device: rust: expand documentation for Device")
Suggested-by: Alice Ryhl <aliceryhl@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202508261644.9LclwUgt-lkp@intel.com/
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250829195745.31174-1-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
rust: use the new name Location::file_as_c_str() in Rust >= 1.91.0 2025-08-31T21:34:34+00:00 Alice Ryhl aliceryhl@google.com 2025-08-27T13:12:16+00:00 c09461a0d24fba8a847a37a381626141da22d8ee As part of the stabilization of Location::file_with_nul(), it was brought up that the with_nul() suffix usually means something else in Rust APIs, so the API is being renamed prior to stabilization [1]. Thus, use the new name on new rustc versions. Link: https://www.github.com/rust-lang/rust/pull/145928 [1] Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20250827-file_as_c_str-v1-1-d3f5a3916a9c@google.com [ Kept `cfg` separation. Reworded slightly. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org> 
As part of the stabilization of Location::file_with_nul(), it was brought
up that the with_nul() suffix usually means something else in Rust APIs,
so the API is being renamed prior to stabilization [1].

Thus, use the new name on new rustc versions.

Link: https://www.github.com/rust-lang/rust/pull/145928 [1]
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20250827-file_as_c_str-v1-1-d3f5a3916a9c@google.com
[ Kept `cfg` separation. Reworded slightly. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>