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From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Wed, 12 Jun 2024 15:25:26 -0700
Message-ID: <CAHk-=wh9_a757XQKJZyuWXM8yEZcSCCqzdnzxxFU3LEQcukxdQ@mail.gmail.com>
Subject: Re: [PATCH 0/7] arm64 / x86-64: low-level code generation issues
To: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Anvin <hpa@zytor.com>, Ingo Molnar <mingo@kernel.org>, Borislav Petkov <bp@alien8.de>, 
	Thomas Gleixner <tglx@linutronix.de>, Rasmus Villemoes <linux@rasmusvillemoes.dk>, 
	Josh Poimboeuf <jpoimboe@kernel.org>, Catalin Marinas <catalin.marinas@arm.com>, 
	Will Deacon <will@kernel.org>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, 
	"the arch/x86 maintainers" <x86@kernel.org>, linux-arm-kernel@lists.infradead.org, 
	linux-arch <linux-arch@vger.kernel.org>
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On Wed, 12 Jun 2024 at 13:02, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
> I'll send out a new version of the arm64 patches with the KCSAN build
> failure fixed (with the simple no-op save/restore functions by making
> KCSAN and SW PAN mutually incompatible), and with the virtual address
> fix you pointed out in the other email.

Actually, unless somebody really wants to see the whole series again,
here's just the diff between the end result of the series.

The actual changes are done in the relevant commits (ie the "asm goto
for get_user()" one for the KCSAN issue, and the "arm64 runtime
constant" commit for the I$ fixup).

Holler if you want to see the full series again.

It might be worth noting that I initially made the arm64 KCSAN support
have a "depend on !ARM64_SW_TTBR0_PAN" condition, but decided that
it's actually better to do it the other way around, and make
ARM64_SW_TTBR0_PAN depend on KCSAN not being enabled.

That way we're basically more eagerly disabling the thing that should
go away, and we're also having the KCSAN code be checked for
allmodconfig builds.

But hey, it's a judgement call.

               Linus

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