Re: [PATCH 4/4] asm-generic/bitsperlong.h: Add sanity checks for __BITS_PER_LONG

From: H. Peter Anvin

Date: Mon Jan 19 2026 - 16:13:09 EST


On 2026-01-19 07:39, Thomas Weißschuh wrote:
>>
>> Do we actually support any compilers which *don't* define __SIZEOF_LONG__?
>
> When building the kernel not. I used this pattern because it is used
> further up in the file. There it makes sense as it is actually a userspace
> header which needs to support all kinds of compilers.
> But this new check is gated behind __KERNEL__ anyways...
> For the next revision I will move it into the regular kernel-internal
> bitsperlong.h. That will be less confusing and still handle the vDSO build,
> due to the way our header hierarchy works.
>

The point is that we can simply do:

#define __BITS_PER_LONG (__SIZEOF_LONG__ << 3)

... and it will always be consistent.

-hpa