lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <68ac0f0ee3c0ebd3d3cc078a6270752778a1b732.1740475625.git.viresh.kumar@linaro.org>
Date: Tue, 25 Feb 2025 15:17:14 +0530
From: Viresh Kumar <viresh.kumar@...aro.org>
To: Yury Norov <yury.norov@...il.com>,
	Rasmus Villemoes <linux@...musvillemoes.dk>,
	Viresh Kumar <viresh.kumar@...aro.org>,
	Miguel Ojeda <ojeda@...nel.org>,
	Alex Gaynor <alex.gaynor@...il.com>,
	Boqun Feng <boqun.feng@...il.com>,
	Gary Guo <gary@...yguo.net>,
	Björn Roy Baron <bjorn3_gh@...tonmail.com>,
	Benno Lossin <benno.lossin@...ton.me>,
	Andreas Hindborg <a.hindborg@...nel.org>,
	Alice Ryhl <aliceryhl@...gle.com>,
	Trevor Gross <tmgross@...ch.edu>
Cc: linux-kernel@...r.kernel.org,
	Danilo Krummrich <dakr@...hat.com>,
	rust-for-linux@...r.kernel.org,
	Vincent Guittot <vincent.guittot@...aro.org>
Subject: [PATCH 1/2] rust: Add initial cpumask abstractions

Add initial Rust abstractions for struct cpumask, covering a subset of
its APIs. Additional APIs can be added as needed.

These abstractions will be used in upcoming Rust support for cpufreq and
OPP frameworks.

Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
---
 rust/kernel/cpumask.rs | 168 +++++++++++++++++++++++++++++++++++++++++
 rust/kernel/lib.rs     |   1 +
 2 files changed, 169 insertions(+)
 create mode 100644 rust/kernel/cpumask.rs

diff --git a/rust/kernel/cpumask.rs b/rust/kernel/cpumask.rs
new file mode 100644
index 000000000000..13864424420b
--- /dev/null
+++ b/rust/kernel/cpumask.rs
@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! CPU mask abstractions.
+//!
+//! C header: [`include/linux/cpumask.h`](srctree/include/linux/cpumask.h)
+
+use crate::{bindings, error::Result, prelude::ENOMEM};
+
+#[cfg(not(CONFIG_CPUMASK_OFFSTACK))]
+use crate::prelude::{KBox, GFP_KERNEL};
+
+#[cfg(CONFIG_CPUMASK_OFFSTACK)]
+use core::ptr;
+
+/// A simple implementation of `struct cpumask` from the C code.
+pub struct Cpumask {
+    ptr: *mut bindings::cpumask,
+    owned: bool,
+}
+
+impl Cpumask {
+    /// Creates cpumask.
+    #[cfg(CONFIG_CPUMASK_OFFSTACK)]
+    fn new_inner(empty: bool) -> Result<Self> {
+        let mut ptr: *mut bindings::cpumask = ptr::null_mut();
+
+        // SAFETY: Depending on the value of `gfp_flags`, this call may sleep. Other than that, it
+        // is always safe to call this method.
+        if !unsafe {
+            if empty {
+                bindings::zalloc_cpumask_var(&mut ptr, bindings::GFP_KERNEL)
+            } else {
+                bindings::alloc_cpumask_var(&mut ptr, bindings::GFP_KERNEL)
+            }
+        } {
+            return Err(ENOMEM);
+        }
+
+        Ok(Self { ptr, owned: true })
+    }
+
+    /// Creates cpumask.
+    #[cfg(not(CONFIG_CPUMASK_OFFSTACK))]
+    fn new_inner(empty: bool) -> Result<Self> {
+        let ptr = KBox::into_raw(KBox::new([bindings::cpumask::default(); 1], GFP_KERNEL)?);
+
+        // SAFETY: Depending on the value of `gfp_flags`, this call may sleep. Other than that, it
+        // is always safe to call this method.
+        if !unsafe {
+            if empty {
+                bindings::zalloc_cpumask_var(ptr, bindings::GFP_KERNEL)
+            } else {
+                bindings::alloc_cpumask_var(ptr, bindings::GFP_KERNEL)
+            }
+        } {
+            return Err(ENOMEM);
+        }
+
+        Ok(Self {
+            ptr: ptr as *mut _,
+            owned: true,
+        })
+    }
+
+    /// Creates empty cpumask.
+    pub fn new() -> Result<Self> {
+        Self::new_inner(true)
+    }
+
+    /// Creates uninitialized cpumask.
+    fn new_uninit() -> Result<Self> {
+        Self::new_inner(false)
+    }
+
+    /// Clones cpumask.
+    pub fn try_clone(&self) -> Result<Self> {
+        let mut cpumask = Self::new_uninit()?;
+
+        self.copy(&mut cpumask);
+        Ok(cpumask)
+    }
+
+    /// Creates a new abstraction instance of an existing `struct cpumask` pointer.
+    ///
+    /// # Safety
+    ///
+    /// Callers must ensure that `ptr` is valid, and non-null.
+    #[cfg(CONFIG_CPUMASK_OFFSTACK)]
+    pub unsafe fn get_cpumask(ptr: &mut *mut bindings::cpumask) -> Self {
+        Self {
+            ptr: *ptr,
+            owned: false,
+        }
+    }
+
+    /// Creates a new abstraction instance of an existing `struct cpumask` pointer.
+    ///
+    /// # Safety
+    ///
+    /// Callers must ensure that `ptr` is valid, and non-null.
+    #[cfg(not(CONFIG_CPUMASK_OFFSTACK))]
+    pub unsafe fn get_cpumask(ptr: &mut bindings::cpumask_var_t) -> Self {
+        Self {
+            ptr: ptr as *mut _,
+            owned: false,
+        }
+    }
+
+    /// Obtain the raw `struct cpumask *`.
+    pub fn as_raw(&mut self) -> *mut bindings::cpumask {
+        self.ptr
+    }
+
+    /// Sets CPU in the cpumask.
+    ///
+    /// Update the cpumask with a single CPU.
+    pub fn set(&mut self, cpu: u32) {
+        // SAFETY: `ptr` is guaranteed to be valid for the lifetime of `self`. And it is safe to
+        // call `cpumask_set_cpus()` for any CPU.
+        unsafe { bindings::cpumask_set_cpu(cpu, self.ptr) };
+    }
+
+    /// Clears CPU in the cpumask.
+    ///
+    /// Update the cpumask with a single CPU.
+    pub fn clear(&mut self, cpu: i32) {
+        // SAFETY: `ptr` is guaranteed to be valid for the lifetime of `self`. And it is safe to
+        // call `cpumask_clear_cpu()` for any CPU.
+        unsafe { bindings::cpumask_clear_cpu(cpu, self.ptr) };
+    }
+
+    /// Sets all CPUs in the cpumask.
+    pub fn set_all(&mut self) {
+        // SAFETY: `ptr` is guaranteed to be valid for the lifetime of `self`. And it is safe to
+        // call `cpumask_setall()`.
+        unsafe { bindings::cpumask_setall(self.ptr) };
+    }
+
+    /// Gets weight of a cpumask.
+    pub fn weight(&self) -> u32 {
+        // SAFETY: `ptr` is guaranteed to be valid for the lifetime of `self`. And it is safe to
+        // call `cpumask_weight()`.
+        unsafe { bindings::cpumask_weight(self.ptr) }
+    }
+
+    /// Copies cpumask.
+    pub fn copy(&self, dstp: &mut Self) {
+        // SAFETY: `ptr` is guaranteed to be valid for the lifetime of `self`. And it is safe to
+        // call `cpumask_copy()`.
+        unsafe { bindings::cpumask_copy(dstp.as_raw(), self.ptr) };
+    }
+}
+
+impl Drop for Cpumask {
+    fn drop(&mut self) {
+        if self.owned {
+            // SAFETY: `ptr` is guaranteed to be valid for the lifetime of `self`. And it is safe
+            // to call `free_cpumask_var()`.
+            unsafe { bindings::free_cpumask_var(self.ptr) }
+
+            #[cfg(not(CONFIG_CPUMASK_OFFSTACK))]
+            // SAFETY: The pointer was earlier initialized from the result of `KBox::into_raw()`.
+            unsafe {
+                drop(KBox::from_raw(self.ptr))
+            };
+        }
+    }
+}
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 496ed32b0911..efbd7be98dab 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -40,6 +40,7 @@
 pub mod block;
 #[doc(hidden)]
 pub mod build_assert;
+pub mod cpumask;
 pub mod cred;
 pub mod device;
 pub mod device_id;
-- 
2.31.1.272.g89b43f80a514


Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ