Merge tag 'linux-cpupower-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux

Merge cpupower utility updates for 6.18-rc1 from Shuah Khan:

"Fixes incorrect return vale in cpupower_write_sysfs() error path
 and passing incorrect size to cpuidle_state_write_file() while
 writing status to disable file in cpuidle_state_disable()."

* tag 'linux-cpupower-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux: (1125 commits)
  tools/cpupower: Fix incorrect size in cpuidle_state_disable()
  tools/cpupower: fix error return value in cpupower_write_sysfs()
  Linux 6.17-rc6
  MAINTAINERS: Input: Drop melfas-mip4 section
  USB: core: remove the move buf action
  MAINTAINERS: Update the DMA Rust entry
  erofs: fix long xattr name prefix placement
  Revert "net: usb: asix: ax88772: drop phylink use in PM to avoid MDIO runtime PM wakeups"
  hsr: hold rcu and dev lock for hsr_get_port_ndev
  hsr: use hsr_for_each_port_rtnl in hsr_port_get_hsr
  hsr: use rtnl lock when iterating over ports
  wifi: nl80211: completely disable per-link stats for now
  net: usb: asix: ax88772: drop phylink use in PM to avoid MDIO runtime PM wakeups
  net: ethtool: fix wrong type used in struct kernel_ethtool_ts_info
  selftests/bpf: Skip timer cases when bpf_timer is not supported
  bpf: Reject bpf_timer for PREEMPT_RT
  libceph: fix invalid accesses to ceph_connection_v1_info
  PM: hibernate: Restrict GFP mask in hibernation_snapshot()
  MAINTAINERS: add Phil as netfilter reviewer
  netfilter: nf_tables: restart set lookup on base_seq change
  ...

2 files changed, 29 insertions, 12 deletions

diff --git a/rust/kernel/alloc/allocator.rs b/rust/kernel/alloc/allocator.rs
index aa2dfa9dca4c..2692cf90c948 100644
--- a/rust/kernel/alloc/allocator.rs
+++ b/rust/kernel/alloc/allocator.rs
@@ -43,17 +43,6 @@ pub struct Vmalloc;
 /// For more details see [self].
 pub struct KVmalloc;
 
-/// Returns a proper size to alloc a new object aligned to `new_layout`'s alignment.
-fn aligned_size(new_layout: Layout) -> usize {
-    // Customized layouts from `Layout::from_size_align()` can have size < align, so pad first.
-    let layout = new_layout.pad_to_align();
-
-    // Note that `layout.size()` (after padding) is guaranteed to be a multiple of `layout.align()`
-    // which together with the slab guarantees means the `krealloc` will return a properly aligned
-    // object (see comments in `kmalloc()` for more information).
-    layout.size()
-}
-
 /// # Invariants
 ///
 /// One of the following: `krealloc`, `vrealloc`, `kvrealloc`.
@@ -88,7 +77,7 @@ impl ReallocFunc {
         old_layout: Layout,
         flags: Flags,
     ) -> Result<NonNull<[u8]>, AllocError> {
-        let size = aligned_size(layout);
+        let size = layout.size();
         let ptr = match ptr {
             Some(ptr) => {
                 if old_layout.size() == 0 {
@@ -123,6 +112,17 @@ impl ReallocFunc {
     }
 }
 
+impl Kmalloc {
+    /// Returns a [`Layout`] that makes [`Kmalloc`] fulfill the requested size and alignment of
+    /// `layout`.
+    pub fn aligned_layout(layout: Layout) -> Layout {
+        // Note that `layout.size()` (after padding) is guaranteed to be a multiple of
+        // `layout.align()` which together with the slab guarantees means that `Kmalloc` will return
+        // a properly aligned object (see comments in `kmalloc()` for more information).
+        layout.pad_to_align()
+    }
+}
+
 // SAFETY: `realloc` delegates to `ReallocFunc::call`, which guarantees that
 // - memory remains valid until it is explicitly freed,
 // - passing a pointer to a valid memory allocation is OK,
@@ -135,6 +135,8 @@ unsafe impl Allocator for Kmalloc {
         old_layout: Layout,
         flags: Flags,
     ) -> Result<NonNull<[u8]>, AllocError> {
+        let layout = Kmalloc::aligned_layout(layout);
+
         // SAFETY: `ReallocFunc::call` has the same safety requirements as `Allocator::realloc`.
         unsafe { ReallocFunc::KREALLOC.call(ptr, layout, old_layout, flags) }
     }
@@ -176,6 +178,10 @@ unsafe impl Allocator for KVmalloc {
         old_layout: Layout,
         flags: Flags,
     ) -> Result<NonNull<[u8]>, AllocError> {
+        // `KVmalloc` may use the `Kmalloc` backend, hence we have to enforce a `Kmalloc`
+        // compatible layout.
+        let layout = Kmalloc::aligned_layout(layout);
+
         // TODO: Support alignments larger than PAGE_SIZE.
         if layout.align() > bindings::PAGE_SIZE {
             pr_warn!("KVmalloc does not support alignments larger than PAGE_SIZE yet.\n");
diff --git a/rust/kernel/alloc/allocator_test.rs b/rust/kernel/alloc/allocator_test.rs
index a3074480bd8d..90dd987d40e4 100644
--- a/rust/kernel/alloc/allocator_test.rs
+++ b/rust/kernel/alloc/allocator_test.rs
@@ -22,6 +22,17 @@ pub type Kmalloc = Cmalloc;
 pub type Vmalloc = Kmalloc;
 pub type KVmalloc = Kmalloc;
 
+impl Cmalloc {
+    /// Returns a [`Layout`] that makes [`Kmalloc`] fulfill the requested size and alignment of
+    /// `layout`.
+    pub fn aligned_layout(layout: Layout) -> Layout {
+        // Note that `layout.size()` (after padding) is guaranteed to be a multiple of
+        // `layout.align()` which together with the slab guarantees means that `Kmalloc` will return
+        // a properly aligned object (see comments in `kmalloc()` for more information).
+        layout.pad_to_align()
+    }
+}
+
 extern "C" {
     #[link_name = "aligned_alloc"]
     fn libc_aligned_alloc(align: usize, size: usize) -> *mut crate::ffi::c_void;