Hi Miguel,
I end up with this series:
(background: https://lore.kernel.org/rust-for-linux/CANiq72=pb18B6NOcXF03d0ctOP8kv2dqnUeNyEuSvuDb=vs-0g@mail.gmail.com/)
Patch #1: introduces the core helper function that help calculate the
correct size for krealloc(), and also use the helper function to fix
`__rust_*` ones, this should be backported to stable kernels hence the
Cc.
Patch #2: use the helper function in KernelAllocator
Patch #3: Bjorn's patch with correct use of the helper function.
I have to add a few more SAFETY comments in these `__rust_*` functions,
which may cause conflict with your 1.71 series.
Since all previous patches get refactored a bit, I dropped all the
Reviewed-bys, appreciate anyone to take a look, thanks!
Regards,
Boqun
Björn Roy Baron (1):
rust: alloc: Add realloc and alloc_zeroed to the GlobalAlloc impl
Boqun Feng (2):
rust: allocator: Prevent mis-aligned allocation
rust: allocator: Use krealloc_aligned() in KernelAllocator::alloc
rust/bindings/bindings_helper.h | 1 +
rust/kernel/allocator.rs | 107 ++++++++++++++++++++++++++------
2 files changed, 90 insertions(+), 18 deletions(-)
--
2.41.0
This fixes the potential issue that when KernelAllocator is used, the
allocation may be mis-aligned due to SLAB's alignment guarantee.
Signed-off-by: Boqun Feng <[email protected]>
---
rust/kernel/allocator.rs | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/rust/kernel/allocator.rs b/rust/kernel/allocator.rs
index fae11d1fdba7..1aec688cf0e0 100644
--- a/rust/kernel/allocator.rs
+++ b/rust/kernel/allocator.rs
@@ -41,9 +41,9 @@ unsafe fn krealloc_aligned(ptr: *mut u8, new_layout: Layout, flags: bindings::gf
unsafe impl GlobalAlloc for KernelAllocator {
unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
- // `krealloc()` is used instead of `kmalloc()` because the latter is
- // an inline function and cannot be bound to as a result.
- unsafe { bindings::krealloc(ptr::null(), layout.size(), bindings::GFP_KERNEL) as *mut u8 }
+ // SAFETY: `ptr::null_mut()` is null and `layout` has a non-zero size by the function safety
+ // requirement.
+ unsafe { krealloc_aligned(ptr::null_mut(), layout, bindings::GFP_KERNEL) }
}
unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) {
--
2.41.0
On Sun, Jul 30, 2023 at 3:29 AM Boqun Feng <[email protected]> wrote:
>
> Patch #1: introduces the core helper function that help calculate the
> correct size for krealloc(), and also use the helper function to fix
> `__rust_*` ones, this should be backported to stable kernels hence the
> Cc.
>
> Patch #2: use the helper function in KernelAllocator
>
> Patch #3: Bjorn's patch with correct use of the helper function.
Looks good to me, thanks a lot!
> I have to add a few more SAFETY comments in these `__rust_*` functions,
> which may cause conflict with your 1.71 series.
No worries.
> Since all previous patches get refactored a bit, I dropped all the
> Reviewed-bys, appreciate anyone to take a look, thanks!
Thanks Boqun!
Cheers,
Miguel
Boqun Feng <[email protected]> writes:
> This fixes the potential issue that when KernelAllocator is used, the
> allocation may be mis-aligned due to SLAB's alignment guarantee.
>
> Signed-off-by: Boqun Feng <[email protected]>
> ---
> rust/kernel/allocator.rs | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/rust/kernel/allocator.rs b/rust/kernel/allocator.rs
> index fae11d1fdba7..1aec688cf0e0 100644
> --- a/rust/kernel/allocator.rs
> +++ b/rust/kernel/allocator.rs
> @@ -41,9 +41,9 @@ unsafe fn krealloc_aligned(ptr: *mut u8, new_layout: Layout, flags: bindings::gf
>
> unsafe impl GlobalAlloc for KernelAllocator {
> unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
> - // `krealloc()` is used instead of `kmalloc()` because the latter is
> - // an inline function and cannot be bound to as a result.
> - unsafe { bindings::krealloc(ptr::null(), layout.size(), bindings::GFP_KERNEL) as *mut u8 }
> + // SAFETY: `ptr::null_mut()` is null and `layout` has a non-zero size by the function safety
> + // requirement.
> + unsafe { krealloc_aligned(ptr::null_mut(), layout, bindings::GFP_KERNEL) }
> }
>
> unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) {
Reviewed-by: Andreas Hindborg <[email protected]>