Re: [PATCH v1 1/2] vdso: Add VDSO_UNALIGNED_PACKED config option for ARMv5

[Arnd Bergmann]

On Mon, Oct 19, 2026, at 22:12, Ian Rogers wrote:
> +
> +config VDSO_UNALIGNED_PACKED
> +	bool
> +	default CPU_32v5
> +	help
> +	  Use packed structs rather than memcpy() in include/vdso/unaligned.h
> +	  for unaligned memory accesses. Enabled on ARMv5 where GCC may emit
> +	  out-of-line memcpy() calls instead of inlining byte accesses.

As explained, I think this misrepresents the problem as Arm specific and
isn't the correct method for -munaligned-access targets on Arm, which
include CPU_32v3, CPU_32v4 and CPU_32v4T along with CPU_32v5.

I still hope we can use a version that just produces the intended code
on both -munaligned-access and -mno-unaligned-access targets like the
old version did.

     Arnd