linux-kernel - Re: [PATCH] KVM: arm64: Fix set_id_regs selftest for ASIDBITS becoming unwritable

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <875xnisocy.wl-maz@kernel.org>
Date: Tue, 17 Dec 2024 08:30:37 +0000
From: Marc Zyngier <maz@...nel.org>
To: Mark Brown <broonie@...nel.org>
Cc: Oliver Upton <oliver.upton@...ux.dev>,
	Joey Gouly <joey.gouly@....com>,
	Suzuki K Poulose <suzuki.poulose@....com>,
	Paolo Bonzini <pbonzini@...hat.com>,
	Shuah Khan <shuah@...nel.org>,
	Catalin Marinas <catalin.marinas@....com>,
	Zenghui Yu <yuzenghui@...wei.com>,
	linux-arm-kernel@...ts.infradead.org,
	kvmarm@...ts.linux.dev,
	kvm@...r.kernel.org,
	linux-kselftest@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] KVM: arm64: Fix set_id_regs selftest for ASIDBITS becoming unwritable

On Mon, 16 Dec 2024 19:28:24 +0000,
Mark Brown <broonie@...nel.org> wrote:
> 
> In commit 03c7527e97f7 ("KVM: arm64: Do not allow ID_AA64MMFR0_EL1.ASIDbits
> to be overridden") we made that bitfield in the ID registers unwritable
> however the change neglected to make the corresponding update to set_id_regs
> resulting in it failing:
> 
> # ok 56 ID_AA64MMFR0_EL1_BIGEND
> # ==== Test Assertion Failure ====
> #   aarch64/set_id_regs.c:434: masks[idx] & ftr_bits[j].mask == ftr_bits[j].mask
> #   pid=5566 tid=5566 errno=22 - Invalid argument
> #      1	0x00000000004034a7: test_vm_ftr_id_regs at set_id_regs.c:434
> #      2	0x0000000000401b53: main at set_id_regs.c:684
> #      3	0x0000ffff8e6b7543: ?? ??:0
> #      4	0x0000ffff8e6b7617: ?? ??:0
> #      5	0x0000000000401e6f: _start at ??:?
> #   0 != 0xf0 (masks[idx] & ftr_bits[j].mask != ftr_bits[j].mask)
> not ok 8 selftests: kvm: set_id_regs # exit=254
> 
> Remove ID_AA64MMFR1_EL1.ASIDBITS from the set of bitfields we test for
> writeability.
> 
> Fixes: 03c7527e97f7 ("KVM: arm64: Do not allow ID_AA64MMFR0_EL1.ASIDbits to be overridden")

A patch for a test doesn't fix anything in the kernel.

> Signed-off-by: Mark Brown <broonie@...nel.org>
> ---
>  tools/testing/selftests/kvm/aarch64/set_id_regs.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/kvm/aarch64/set_id_regs.c b/tools/testing/selftests/kvm/aarch64/set_id_regs.c
> index a79b7f18452d2ec336ae623b8aa5c9cf329b6b4e..3a97c160b5fec990aaf8dfaf100a907b913f057c 100644
> --- a/tools/testing/selftests/kvm/aarch64/set_id_regs.c
> +++ b/tools/testing/selftests/kvm/aarch64/set_id_regs.c
> @@ -152,7 +152,6 @@ static const struct reg_ftr_bits ftr_id_aa64mmfr0_el1[] = {
>  	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR0_EL1, BIGENDEL0, 0),
>  	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR0_EL1, SNSMEM, 0),
>  	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR0_EL1, BIGEND, 0),
> -	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR0_EL1, ASIDBITS, 0),
>  	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR0_EL1, PARANGE, 0),
>  	REG_FTR_END,
>  };
> 

With the Fixes: line dropped,

Acked-by: Marc Zyngier <maz@...nel.org>

	M.

-- 
Without deviation from the norm, progress is not possible.