linux-kernel - Re: [PATCH 0/5] replace magic numbers in GDT descriptors

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Message-ID: <CAHk-=wgSjQvgXbYkqJuOhL337cESfb-z65889D+-Rc6o5euYwQ@mail.gmail.com>
Date: Tue, 19 Dec 2023 09:33:36 -0800
From: Linus Torvalds <torvalds@...uxfoundation.org>
To: Vegard Nossum <vegard.nossum@...cle.com>
Cc: Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>, 
	Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org, 
	"H. Peter Anvin" <hpa@...or.com>, linux-kernel@...r.kernel.org, 
	Brian Gerst <brgerst@...il.com>, Peter Zijlstra <peterz@...radead.org>
Subject: Re: [PATCH 0/5] replace magic numbers in GDT descriptors

On Tue, 19 Dec 2023 at 07:12, Vegard Nossum <vegard.nossum@...cle.com> wrote:
>
> Vegard Nossum (5):
>   x86: provide new infrastructure for GDT descriptors
>   x86: replace magic numbers in GDT descriptors, part 1
>   x86: replace magic numbers in GDT descriptors, part 2
>   x86: always set A (accessed) flag in GDT descriptors
>   x86: add DB flag to 32-bit percpu GDT entry

All these patches look fine to me, but I will again leave it to the
x86 maintainers whether they want to apply them. But feel free to add
my Ack if y ou do.

The end result does look a *lot* more legible, with something like

   DESC_DATA64 | DESC_USER

instead of just a raw number like 0xc0f3.

So while this is unlikely to be a maintenance burden (since we look at
these things so seldom, and they never really change), I think it's a
nice readability improvement.

The fact that Vegard found two oddities while doing this series just
reinforces that readability issue. Neither of them were bugs, but they
were odd inconsistencies.

               Linus