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From: Will Deacon <will@kernel.org>
To: Marc Zyngier <maz@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu
Subject: Re: [PATCH 06/15] arm64: kvm: Move __smccc_workaround_1_smc to .rodata
Date: Mon, 11 May 2020 11:29:21 +0100	[thread overview]
Message-ID: <20200511102921.GA18310@willie-the-truck> (raw)
In-Reply-To: <20200511110459.1fcf4db7@why>

On Mon, May 11, 2020 at 11:04:59AM +0100, Marc Zyngier wrote:
> On Thu, 30 Apr 2020 15:48:22 +0100
> David Brazdil <dbrazdil@google.com> wrote:
> 
> > This snippet of assembly is used by cpu_errata.c to overwrite parts of KVM hyp
> > vector. It is never directly executed, so move it from .text to .rodata.
> > 
> > Signed-off-by: David Brazdil <dbrazdil@google.com>
> > ---
> >  arch/arm64/kvm/hyp/hyp-entry.S | 6 ++++++
> >  1 file changed, 6 insertions(+)
> > 
> > diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S
> > index 5986e1d78d3f..7e5f386c5c2d 100644
> > --- a/arch/arm64/kvm/hyp/hyp-entry.S
> > +++ b/arch/arm64/kvm/hyp/hyp-entry.S
> > @@ -364,6 +364,11 @@ SYM_CODE_END(__bp_harden_hyp_vecs)
> >  	.popsection
> >  
> >  #ifndef __HYPERVISOR__
> > +	/*
> > +	 * This is not executed directly and is instead copied into the vectors
> > +	 * by install_bp_hardening_cb().
> > +	 */
> > +	.pushsection	.rodata
> >  SYM_CODE_START(__smccc_workaround_1_smc)
> 
> I wonder whether we should keep the SYM_CODE_START() annotation or not.
> It feels weird to say "code" in a rodata section, and the alignment
> doesn't matter as we copy it in place, as you noticed.

The BTI patches hook these, but I don't see that being relevant for a
vector entry as PSTATE.BTYPE is zapped to 0.

Will
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  reply	other threads:[~2020-05-11 10:29 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-30 14:48 [PATCH 00/15] Split off nVHE hyp code David Brazdil
2020-04-30 14:48 ` [PATCH 01/15] arm64: kvm: Unify users of HVC instruction David Brazdil
2020-05-07 14:01   ` Marc Zyngier
2020-05-07 14:36     ` Quentin Perret
2020-05-13 10:30       ` David Brazdil
2020-04-30 14:48 ` [PATCH 02/15] arm64: kvm: Formalize host-hyp hypcall ABI David Brazdil
2020-05-07 13:10   ` Marc Zyngier
2020-05-07 13:33     ` Quentin Perret
2020-05-10 10:16       ` Marc Zyngier
2020-05-13 10:48         ` David Brazdil
2020-04-30 14:48 ` [PATCH 03/15] arm64: kvm: Fix symbol dependency in __hyp_call_panic_nvhe David Brazdil
2020-05-07 13:22   ` Marc Zyngier
2020-05-07 14:36     ` David Brazdil
2020-05-10 11:14       ` Marc Zyngier
2020-04-30 14:48 ` [PATCH 04/15] arm64: kvm: Add build rules for separate nVHE object files David Brazdil
2020-05-07 13:46   ` Marc Zyngier
2020-04-30 14:48 ` [PATCH 05/15] arm64: kvm: Build hyp-entry.S separately for VHE/nVHE David Brazdil
2020-05-07 15:07   ` Marc Zyngier
2020-05-07 15:15     ` Marc Zyngier
2020-04-30 14:48 ` [PATCH 06/15] arm64: kvm: Move __smccc_workaround_1_smc to .rodata David Brazdil
2020-05-11 10:04   ` Marc Zyngier
2020-05-11 10:29     ` Will Deacon [this message]
2020-04-30 14:48 ` [PATCH 07/15] arm64: kvm: Split hyp/tlb.c to VHE/nVHE David Brazdil
2020-04-30 14:48 ` [PATCH 08/15] arm64: kvm: Split hyp/switch.c " David Brazdil
2020-04-30 14:48 ` [PATCH 09/15] arm64: kvm: Split hyp/debug-sr.c " David Brazdil
2020-04-30 14:48 ` [PATCH 10/15] arm64: kvm: Split hyp/sysreg-sr.c " David Brazdil
2020-04-30 14:48 ` [PATCH 11/15] arm64: kvm: Split hyp/timer-sr.c " David Brazdil
2020-04-30 14:48 ` [PATCH 12/15] arm64: kvm: Compile remaining hyp/ files for both VHE/nVHE David Brazdil
2020-04-30 14:48 ` [PATCH 13/15] arm64: kvm: Add comments around __hyp_text_ symbol aliases David Brazdil
2020-04-30 14:48 ` [PATCH 14/15] arm64: kvm: Remove __hyp_text macro, use build rules instead David Brazdil
2020-04-30 14:48 ` [PATCH 15/15] arm64: kvm: Lift instrumentation restrictions on VHE David Brazdil
2020-04-30 17:53 ` [PATCH 00/15] Split off nVHE hyp code Marc Zyngier
2020-04-30 18:57   ` David Brazdil

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