diff options
author | Takashi Iwai <tiwai@suse.de> | 2025-08-29 11:13:09 +0200 |
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committer | Takashi Iwai <tiwai@suse.de> | 2025-08-29 11:13:09 +0200 |
commit | 3e93d5bbcbfc3808f83712c0701f9d4c148cc8ed (patch) | |
tree | 2f1ac64d01ba1938b12d6036fa7161340a9abded /rust/kernel/alloc/allocator.rs | |
parent | 2cbe4ac193ed7172cfd825c0cc46ce4a41be4ba1 (diff) | |
parent | 3e7fd1febc3156d3d98fba229399a13b12d69707 (diff) |
Merge tag 'asoc-fix-v6.17-rc3' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus
ASoC: Fixes for v6.17
The main fixes here are for some of the cleanups done in the core in
this release, we had broken component lookup in the case with a single
bus and DMA controller. Otherwise it's driver specific changes, the
shortlogs for the Intel WCL and rsnd drivers look like minor cleanups
but are actually bugfixes (adding an op needed for correct functionality
and reverting an inappropriate helper usage).
Diffstat (limited to 'rust/kernel/alloc/allocator.rs')
-rw-r--r-- | rust/kernel/alloc/allocator.rs | 30 |
1 files changed, 18 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"); |