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authorLinus Torvalds <torvalds@linux-foundation.org>2025-08-22 18:16:54 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2025-08-22 18:16:54 -0400
commit6debb69041724bae8a8a4d0ac60502754c1cd945 (patch)
treef54687bf2686d44aaaa25ac88588fb6d38d1350d /rust/kernel/alloc/allocator.rs
parent471b25a2fcbb25dccd7c9bece30313f2440a554e (diff)
parenta60f5ee68efd91b4507eacbb40d4024ecf363304 (diff)
Merge tag 'drm-fixes-2025-08-23-1' of https://gitlab.freedesktop.org/drm/kernel
Pull drm fixes from Dave Airlie: "Weekly drm fixes. Looks like things did indeed get busier after rc2, nothing seems too major, but stuff scattered all over the place, amdgpu, xe, i915, hibmc, rust support code, and other small fixes. rust: - drm device memory layout and safety fixes tests: - Endianness fixes gpuvm: - docs warning fix panic: - fix division on 32-bit arm i915: - TypeC DP display Fixes - Silence rpm wakeref asserts on GEN11_GU_MISC_IIR access - Relocate compression repacking WA for JSL/EHL xe: - xe_vm_create fixes - fix vm bind ioctl double free amdgpu: - Replay fixes - SMU14 fix - Null check DC fixes - DCE6 DC fixes - Misc DC fixes bridge: - analogix_dp: devm_drm_bridge_alloc() error handling fix habanalabs: - Memory deallocation fix hibmc: - modesetting black screen fixes - fix UAF on irq - fix leak on i2c failure path nouveau: - memory leak fixes - typos rockchip: - Kconfig fix - register caching fix" * tag 'drm-fixes-2025-08-23-1' of https://gitlab.freedesktop.org/drm/kernel: (49 commits) drm/xe: Fix vm_bind_ioctl double free bug drm/xe: Move ASID allocation and user PT BO tracking into xe_vm_create drm/xe: Assign ioctl xe file handler to vm in xe_vm_create drm/i915/gt: Relocate compression repacking WA for JSL/EHL drm/i915: silence rpm wakeref asserts on GEN11_GU_MISC_IIR access drm/amd/display: Fix DP audio DTO1 clock source on DCE 6. drm/amd/display: Fix fractional fb divider in set_pixel_clock_v3 drm/amd/display: Don't print errors for nonexistent connectors drm/amd/display: Don't warn when missing DCE encoder caps drm/amd/display: Fill display clock and vblank time in dce110_fill_display_configs drm/amd/display: Find first CRTC and its line time in dce110_fill_display_configs drm/amd/display: Adjust DCE 8-10 clock, don't overclock by 15% drm/amd/display: Don't overclock DCE 6 by 15% drm/amd/display: Add null pointer check in mod_hdcp_hdcp1_create_session() drm/amd/display: Fix Xorg desktop unresponsive on Replay panel drm/amd/display: Avoid a NULL pointer dereference drm/amdgpu/swm14: Update power limit logic drm/amd/display: Revert Add HPO encoder support to Replay drm/i915/icl+/tc: Convert AUX powered WARN to a debug message drm/i915/lnl+/tc: Use the cached max lane count value ...
Diffstat (limited to 'rust/kernel/alloc/allocator.rs')
-rw-r--r--rust/kernel/alloc/allocator.rs30
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");