linux-kernel - Re: [PATCH] arm64: paravirt: remove conduit check in has_pv_steal

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: <55b704b7-0a44-8f34-e22f-d60b58db610f@arm.com>
Date:   Fri, 4 Nov 2022 09:13:14 +0000
From:   Steven Price <steven.price@....com>
To:     Usama Arif <usama.arif@...edance.com>,
        linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        kvmarm@...ts.cs.columbia.edu, kvm@...r.kernel.org,
        virtualization@...ts.linux-foundation.org, linux@...linux.org.uk,
        yezengruan@...wei.com, catalin.marinas@....com, will@...nel.org,
        maz@...nel.org, mark.rutland@....com
Cc:     fam.zheng@...edance.com, liangma@...ngbit.com,
        punit.agrawal@...edance.com
Subject: Re: [PATCH] arm64: paravirt: remove conduit check in
 has_pv_steal_clock

On 04/11/2022 06:16, Usama Arif wrote:
> arm_smccc_1_1_invoke() which is called later on in the function
> will return failure if there's no conduit (or pre-SMCCC 1.1),
> hence the check is unnecessary.
> 
> Suggested-by: Steven Price <steven.price@....com>
> Signed-off-by: Usama Arif <usama.arif@...edance.com>

Reviewed-by: Steven Price <steven.price@....com>

> ---
>  arch/arm64/kernel/paravirt.c | 4 ----
>  1 file changed, 4 deletions(-)
> 
> diff --git a/arch/arm64/kernel/paravirt.c b/arch/arm64/kernel/paravirt.c
> index 57c7c211f8c7..aa718d6a9274 100644
> --- a/arch/arm64/kernel/paravirt.c
> +++ b/arch/arm64/kernel/paravirt.c
> @@ -141,10 +141,6 @@ static bool __init has_pv_steal_clock(void)
>  {
>  	struct arm_smccc_res res;
>  
> -	/* To detect the presence of PV time support we require SMCCC 1.1+ */
> -	if (arm_smccc_1_1_get_conduit() == SMCCC_CONDUIT_NONE)
> -		return false;
> -
>  	arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
>  			     ARM_SMCCC_HV_PV_TIME_FEATURES, &res);
>