Re: [RFC PATCH V3 00/43] rv64ilp32_abi: Build CONFIG_64BIT kernel-self with ILP32 ABI

David Hildenbrand
2025-03-25T18:51:54Z

On 25.03.25 13:26, Peter Zijlstra wrote:
> On Tue, Mar 25, 2025 at 08:15:41AM -0400, guoren@kernel.org wrote:
>> From: "Guo Ren (Alibaba DAMO Academy)" <guoren@kernel.org>
>>
>> Since 2001, the CONFIG_64BIT kernel has been built with the LP64 ABI,
>> but this patchset allows the CONFIG_64BIT kernel to use an ILP32 ABI
>
> I'm thinking you're going to be finding a metric ton of assumptions
> about 'unsigned long' being 64bit when 64BIT=y throughout the kernel.
>
> I know of a couple of places where 64BIT will result in different math
> such that a 32bit 'unsigned long' will trivially overflow.
>
> Please, don't do this. This adds a significant maintenance burden on all
> of us.
>

Fully agreed.

--
Cheers,

David / dhildenb