linux-kernel - Re: [PATCH 03/15] arm64: kvm: Fix symbol dependency in __hyp_call_panic

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Date:   Thu, 7 May 2020 15:36:17 +0100
From:   David Brazdil <dbrazdil@...gle.com>
To:     Marc Zyngier <maz@...nel.org>
Cc:     David Brazdil <dbrazdil@...gle.com>,
        Catalin Marinas <catalin.marinas@....com>,
        James Morse <james.morse@....com>,
        Julien Thierry <julien.thierry.kdev@...il.com>,
        Suzuki K Poulose <suzuki.poulose@....com>,
        Will Deacon <will@...nel.org>, kvmarm@...ts.cs.columbia.edu,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 03/15] arm64: kvm: Fix symbol dependency in
 __hyp_call_panic_nvhe

Hi Marc,

> 
> What breaks without this constraint? Is it a fix that should go in
> early? Otherwise looks good.

This only becomes an issue when __hyp_call_panic_nvhe() and
__hyp_call_panic_vhe() are moved to separate files, so I don't think it's
necessary to go in early.

Currently the string variable (declared static) is seen by the C compiler as
used by __hyp_call_panic_vhe(). But when split, the variable in the nVHE source
file becomes unused, is dropped by the compiler and the inline assembly's
reference is unresolved. We could then alias __hyp_text___hyp_panic_string back
to the VHE copy, but this is the right way of addressing it.

Thanks for the review,
David