Re: git: 97ce8f7d2b8e - main - amd64: define and use STACKALIGN and REDZONE_SZ

From: John Baldwin <jhb_at_FreeBSD.org>
Date: Tue, 17 Feb 2026 19:42:20 UTC
On 2/16/26 21:44, Konstantin Belousov wrote:
> On Mon, Feb 16, 2026 at 05:01:58PM -0800, Enji Cooper (yaneurabeya) wrote:
>>
>>> On Feb 9, 2026, at 9:57 AM, Konstantin Belousov <kib@FreeBSD.org> wrote:
>>>
>>> The branch main has been updated by kib:
>>>
>>> URL: https://cgit.FreeBSD.org/src/commit/?id=97ce8f7d2b8eff42460f60e8c49d9849b58b6e81
>>>
>>> commit 97ce8f7d2b8eff42460f60e8c49d9849b58b6e81
>>> Author:     Konstantin Belousov <kib@FreeBSD.org>
>>> AuthorDate: 2026-02-07 00:36:44 +0000
>>> Commit:     Konstantin Belousov <kib@FreeBSD.org>
>>> CommitDate: 2026-02-09 17:57:00 +0000
>>>
>>>     amd64: define and use STACKALIGN and REDZONE_SZ
>>>
>>>     Reviewed by:    brooks, emaste, jhb
>>>     Sponsored by:   The FreeBSD Foundation
>>>     MFC after:      1 week
>>>     Differential revision:  https://reviews.freebsd.org/D55151
>>
>> Hi kib@!
>> 	It looks like this broke the build with gcc12 on main: https://ci.freebsd.org/job/FreeBSD-main-amd64-gcc14_build/2893/console .
> 
> https://reviews.freebsd.org/D55319
> might be the fix.

I have the same thing at https://reviews.freebsd.org/D55161

Per my comments there, I do think it might break 32-bit kernels, but we probably
don't care about that.  (Namely, if rounddown2() is used on a type larger than
uintptr_t such as trunc_page on a vm_paddr_t on i386, this change truncates the
value).

If we really care, we could use _Generic or the like to only use the uintptr_t
casts for pointer types.

-- 
John Baldwin