Re: [PATCH v6 02/21] arm64: Allow mismatched 32-bit EL0 support

[Qais Yousef]

On 05/18/21 10:47, Will Deacon wrote:
> When confronted with a mixture of CPUs, some of which support 32-bit
> applications and others which don't, we quite sensibly treat the system
> as 64-bit only for userspace and prevent execve() of 32-bit binaries.
> 
> Unfortunately, some crazy folks have decided to build systems like this
> with the intention of running 32-bit applications, so relax our
> sanitisation logic to continue to advertise 32-bit support to userspace
> on these systems and track the real 32-bit capable cores in a cpumask
> instead. For now, the default behaviour remains but will be tied to
> a command-line option in a later patch.
> 
> Signed-off-by: Will Deacon <will@xxxxxxxxxx>
> ---
>  arch/arm64/include/asm/cpucaps.h    |   3 +-

Heads up. I just tried to apply this on 5.13-rc2 and it failed because cpucaps.
was removed; it's autogenerated now.

See commit 0c6c2d3615ef: ()"arm64: Generate cpucaps.h")

Cheers

--
Qais Youesf