Re: [PATCH v2 0/2] Take ARCH_KMALLOC_MINALIGN into account for build-time XArray check

Re: [PATCH v2 0/2] Take ARCH_KMALLOC_MINALIGN into account for build-time XArray check

[Thorsten Leemhuis]

On 15.08.25 21:12, Danilo Krummrich wrote:
> On Mon Aug 11, 2025 at 2:31 PM CEST, Alice Ryhl wrote:
>> Alice Ryhl (2):
>>       rust: alloc: specify the minimum alignment of each allocator
> 
>     [ Add helper for ARCH_KMALLOC_MINALIGN; remove cast to usize. - Danilo ]
> 
>>       rust: alloc: take the allocator into account for FOREIGN_ALIGN
> 
> Applied to alloc-next, thanks!

I had a build error with my daily linux-next builds for Fedora (using
the Fedora rawhide config) on arm64 (ppc64le and x86_64 worked fine).
From a quick look it seems it might be due to this series, which 
turned up in -next today:

"""
error[E0428]: the name `ARCH_KMALLOC_MINALIGN` is defined multiple times
      --> /builddir/build/BUILD/kernel-6.17.0-build/kernel-next-20250818/linux-6.17.0-0.0.next.20250818.423.vanilla.fc44.aarch64/rust/bindings/bindings_generated.rs:134545:1
       |
9622   | pub const ARCH_KMALLOC_MINALIGN: u32 = 8;
       | ----------------------------------------- previous definition of the value `ARCH_KMALLOC_MINALIGN` here
...
134545 | pub const ARCH_KMALLOC_MINALIGN: usize = 8;
       | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `ARCH_KMALLOC_MINALIGN` redefined here
       |
       = note: `ARCH_KMALLOC_MINALIGN` must be defined only once in the value namespace of this module

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0428`.
make[2]: *** [rust/Makefile:539: rust/bindings.o] Error 1
make[1]: *** [/builddir/build/BUILD/kernel-6.17.0-build/kernel-next-20250818/linux-6.17.0-0.0.next.20250818.423.vanilla.fc44.aarch64/Makefile:1294: prepare] Error 2
make: *** [Makefile:256: __sub-make] Error 2
"""

Full log:
https://download.copr.fedorainfracloud.org/results/@kernel-vanilla/next/fedora-rawhide-aarch64/09439461-next-next-all/builder-live.log.gz

Ciao, Thorsten

Re: [PATCH v2 0/2] Take ARCH_KMALLOC_MINALIGN into account for build-time XArray check

[Miguel Ojeda]

On Mon, Aug 18, 2025 at 1:09 PM Thorsten Leemhuis <linux@leemhuis.info> wrote:
>
> on arm64 (ppc64le and x86_64 worked fine).

Yeah, it happens in arm, arm64, loongarch64 and riscv64 -- we don't
have powerpc support for Rust upstream yet (we had it originally
out-of-tree, but it never got upstreamed).

Cheers,
Miguel

Re: [PATCH v2 0/2] Take ARCH_KMALLOC_MINALIGN into account for build-time XArray check

[Danilo Krummrich]

On Mon Aug 18, 2025 at 1:09 PM CEST, Thorsten Leemhuis wrote:
> error[E0428]: the name `ARCH_KMALLOC_MINALIGN` is defined multiple times
>       --> /builddir/build/BUILD/kernel-6.17.0-build/kernel-next-20250818/linux-6.17.0-0.0.next.20250818.423.vanilla.fc44.aarch64/rust/bindings/bindings_generated.rs:134545:1
>        |
> 9622   | pub const ARCH_KMALLOC_MINALIGN: u32 = 8;
>        | ----------------------------------------- previous definition of the value `ARCH_KMALLOC_MINALIGN` here
> ...
> 134545 | pub const ARCH_KMALLOC_MINALIGN: usize = 8;
>        | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `ARCH_KMALLOC_MINALIGN` redefined here
>        |
>        = note: `ARCH_KMALLOC_MINALIGN` must be defined only once in the value namespace of this module
>
> error: aborting due to 1 previous error

Thanks for reporting, the diff below should fix it, I'll send a patch soon.

diff --git a/rust/bindgen_parameters b/rust/bindgen_parameters
index 0f96af8b9a7f..02b371b98b39 100644
--- a/rust/bindgen_parameters
+++ b/rust/bindgen_parameters
@@ -34,3 +34,4 @@
 # We use const helpers to aid bindgen, to avoid conflicts when constants are
 # recognized, block generation of the non-helper constants.
 --blocklist-item ARCH_SLAB_MINALIGN
+--blocklist-item ARCH_KMALLOC_MINALIGN