linux/rust
Boqun Feng f0618c305b rust: allocator: Prevent mis-aligned allocation
commit b3d8aa84bb upstream.

Currently the rust allocator simply passes the size of the type Layout
to krealloc(), and in theory the alignment requirement from the type
Layout may be larger than the guarantee provided by SLAB, which means
the allocated object is mis-aligned.

Fix this by adjusting the allocation size to the nearest power of two,
which SLAB always guarantees a size-aligned allocation. And because Rust
guarantees that the original size must be a multiple of alignment and
the alignment must be a power of two, then the alignment requirement is
satisfied.

Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Co-developed-by: "Andreas Hindborg (Samsung)" <nmi@metaspace.dk>
Signed-off-by: "Andreas Hindborg (Samsung)" <nmi@metaspace.dk>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Cc: stable@vger.kernel.org # v6.1+
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Fixes: 247b365dc8 ("rust: add `kernel` crate")
Link: https://github.com/Rust-for-Linux/linux/issues/974
Link: https://lore.kernel.org/r/20230730012905.643822-2-boqun.feng@gmail.com
[ Applied rewording of comment as discussed in the mailing list. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-11 12:08:18 +02:00
..
alloc rust: adapt alloc crate to the kernel 2022-09-28 08:57:01 +02:00
bindings rust: allocator: Prevent mis-aligned allocation 2023-08-11 12:08:18 +02:00
kernel rust: allocator: Prevent mis-aligned allocation 2023-08-11 12:08:18 +02:00
macros rust: add macros crate 2022-09-28 08:58:00 +02:00
.gitignore Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
bindgen_parameters Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
compiler_builtins.rs rust: add compiler_builtins crate 2022-09-28 08:58:00 +02:00
exports.c rust: export generated symbols 2022-09-28 08:59:52 +02:00
helpers.c
Makefile Kbuild: add Rust support 2022-09-28 09:02:20 +02:00