linux-kernel - Re: [RFC PATCH 2/3] x86/boot/compressed: force hidden visibility for all symbol references

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Message-ID: <20200108155700.GA2602122@rani.riverdale.lan>
Date:   Wed, 8 Jan 2020 10:57:00 -0500
From:   Arvind Sankar <nivedita@...m.mit.edu>
To:     Ard Biesheuvel <ard.biesheuvel@...aro.org>
Cc:     Arvind Sankar <nivedita@...m.mit.edu>,
        Ard Biesheuvel <ardb@...nel.org>,
        linux-efi <linux-efi@...r.kernel.org>,
        the arch/x86 maintainers <x86@...nel.org>,
        Andy Lutomirski <luto@...nel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
        Linus Torvalds <torvalds@...ux-foundation.org>
Subject: Re: [RFC PATCH 2/3] x86/boot/compressed: force hidden visibility for
 all symbol references

On Wed, Jan 08, 2020 at 04:47:51PM +0100, Ard Biesheuvel wrote:
> The EFI stub already sets the hidden visibility attribute for the few
> external symbol references that it contains, so it is not needed in
> the context of this series.
> 
> In the future, we can revisit this if we want to get rid of the
> various __pure getter functions, but that requires thorough testing on
> other architectures and toolchains, so I'd prefer to leave that for
> later.

We don't need it for the stub right now, but then this bit in the cover
letter is not yet true, we still need to be careful about libstub code.

> ...we can start using ordinary external symbol references in the EFI
> stub without running the risk of boot regressions.