Re: error[E0080]: evaluation panicked: assertion failed: size_of::<isize>() == size_of::<isize_atomic_repr>()

[Nathan Chancellor]

On Mon, Oct 26, 2026 at 01:51:14PM +0100, kernel test robot wrote:
> Hi Nathan,
> 
> FYI, the error/warning still remains.

I think the result of this bisection is wrong. When building at the
parent change (703749b069d5) with this toolchain, there is the error
that this change (eb13a1ff271b) resolves:

  ld.lld: error: undefined symbol: memset
  >>> referenced by getrandom.c:87 (lib/vdso/getrandom.c:87)
  >>>               arch/loongarch/vdso/vgetrandom.o:(__vdso_getrandom)
  make[4]: *** [arch/loongarch/vdso/Makefile:83: arch/loongarch/vdso/vdso.so.dbg] Error 1

If I use LLVM 23.1.4 + rust 1.99.1 to build at the parent change, I can
get the same error reported, so I don't think my change is responsible
for it.

> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   6b4b543fa18757297ac756a6fe6e64f506b7844a
> commit: eb13a1ff271b0d180687eebb30611b0b276d5193 random: vDSO: avoid call to memset() when zeroing reserved parameter
> date:   3 weeks ago
> config: loongarch-randconfig-r2103-20261026 (https://download.01.org/0day-ci/archive/20261026/202610261307.vnC1uCAL-lkp@xxxxxxxxx/config)
> compiler: clang version 24.0.0git (https://github.com/llvm/llvm-project 42d4451d86c175b745d6ea1c4081787994c7259b)
> rustc: rustc 1.96.0 (ac68faa20 2026-05-25)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20261026/202610261307.vnC1uCAL-lkp@xxxxxxxxx/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Fixes: eb13a1ff271b ("random: vDSO: avoid call to memset() when zeroing reserved parameter")
> | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202610261307.vnC1uCAL-lkp@xxxxxxxxx/
> 
> All errors (new ones prefixed by >>):
> 
> >> error[E0080]: evaluation panicked: assertion failed: size_of::<isize>() == size_of::<isize_atomic_repr>()
>    --> rust/kernel/build_assert.rs:112:23
>    |
>    112 |         const _: () = ::core::assert!($condition $(,$arg)?);
>    |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ evaluation of `sync::atomic::predefine::_` failed here
>    |
>    ::: rust/kernel/sync/atomic/predefine.rs:98:1
>    |
>    98 | static_assert!(size_of::<isize>() == size_of::<isize_atomic_repr>());
>    | -------------------------------------------------------------------- in this macro invocation
>    |
>    = note: this error originates in the macro `::core::assert` which comes from the expansion of the macro `static_assert` (in Nightly builds, run with -Z macro-backtrace for more info)
> --
> >> error[E0080]: evaluation panicked: assertion failed: align_of::<isize>() == align_of::<isize_atomic_repr>()
>    --> rust/kernel/build_assert.rs:112:23
>    |
>    112 |         const _: () = ::core::assert!($condition $(,$arg)?);
>    |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ evaluation of `sync::atomic::predefine::_` failed here
>    |
>    ::: rust/kernel/sync/atomic/predefine.rs:99:1
>    |
>    99 | static_assert!(align_of::<isize>() == align_of::<isize_atomic_repr>());
>    | ---------------------------------------------------------------------- in this macro invocation
>    |
>    = note: this error originates in the macro `::core::assert` which comes from the expansion of the macro `static_assert` (in Nightly builds, run with -Z macro-backtrace for more info)
> --
> >> error[E0080]: evaluation panicked: assertion failed: size_of::<usize>() == size_of::<isize_atomic_repr>()
>    --> rust/kernel/build_assert.rs:112:23
>    |
>    112 |         const _: () = ::core::assert!($condition $(,$arg)?);
>    |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ evaluation of `sync::atomic::predefine::_` failed here
>    |
>    ::: rust/kernel/sync/atomic/predefine.rs:100:1
>    |
>    100 | static_assert!(size_of::<usize>() == size_of::<isize_atomic_repr>());
>    | -------------------------------------------------------------------- in this macro invocation
>    |
>    = note: this error originates in the macro `::core::assert` which comes from the expansion of the macro `static_assert` (in Nightly builds, run with -Z macro-backtrace for more info)
> --
> >> error[E0080]: evaluation panicked: assertion failed: align_of::<usize>() == align_of::<isize_atomic_repr>()
>    --> rust/kernel/build_assert.rs:112:23
>    |
>    112 |         const _: () = ::core::assert!($condition $(,$arg)?);
>    |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ evaluation of `sync::atomic::predefine::_` failed here
>    |
>    ::: rust/kernel/sync/atomic/predefine.rs:101:1
>    |
>    101 | static_assert!(align_of::<usize>() == align_of::<isize_atomic_repr>());
>    | ---------------------------------------------------------------------- in this macro invocation
>    |
>    = note: this error originates in the macro `::core::assert` which comes from the expansion of the macro `static_assert` (in Nightly builds, run with -Z macro-backtrace for more info)
> 
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki

-- 
Cheers,
Nathan