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

From: David Hildenbrand
Date: Tue Mar 25 2025 - 15:02:37 EST


On 25.03.25 13:26, Peter Zijlstra wrote:
On Tue, Mar 25, 2025 at 08:15:41AM -0400, guoren@xxxxxxxxxx wrote:
From: "Guo Ren (Alibaba DAMO Academy)" <guoren@xxxxxxxxxx>

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