[RFC PATCH v3 1/1] arch: arm64: Implement unaligned atomic emulation

[Will Deacon]

On Tue, Sep 29, 2026 at 11:01:38PM -0300, André Almeida wrote:
> Implement support for emulating unaligned atomic operations on arm64.
> User applications that wish to enable support for this should use the
> pctrl() flag `PR_ARM64_UNALIGN_ATOMIC_EMULATE`.
> 
> Signed-off-by: André Almeida <andrealmeid at igalia.com>
> ---
>  arch/arm64/Kconfig                   |   6 +
>  arch/arm64/include/asm/exception.h   |   1 +
>  arch/arm64/include/asm/processor.h   |   5 +
>  arch/arm64/include/asm/rwonce.h      |  14 +-
>  arch/arm64/include/asm/thread_info.h |   1 +
>  arch/arm64/kernel/Makefile           |   3 +-
>  arch/arm64/kernel/process.c          |  15 +
>  arch/arm64/kernel/unaligned_atomic.c | 521 +++++++++++++++++++++++++++
>  arch/arm64/mm/fault.c                |  10 +
>  include/uapi/linux/prctl.h           |   5 +
>  kernel/sys.c                         |   7 +-
>  11 files changed, 579 insertions(+), 9 deletions(-)
>  create mode 100644 arch/arm64/kernel/unaligned_atomic.c

No.

I already explained to you why this doesn't work:

https://lore.kernel.org/r/aV1YnOetDHhKe4hz@willie-the-truck

Will