linux-kernel - Re: [PATCH v2 1/6] x86/bugs: Move the X86_FEATURE_USE

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: <Z7_CwVbA3yyk6iF2@google.com>
Date: Wed, 26 Feb 2025 17:41:21 -0800
From: Sean Christopherson <seanjc@...gle.com>
To: Yosry Ahmed <yosry.ahmed@...ux.dev>
Cc: x86@...nel.org, Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>, 
	Borislav Petkov <bp@...en8.de>, Dave Hansen <dave.hansen@...ux.intel.com>, 
	"H. Peter Anvin" <hpa@...or.com>, Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>, 
	Andy Lutomirski <luto@...nel.org>, Peter Zijlstra <peterz@...radead.org>, 
	Josh Poimboeuf <jpoimboe@...nel.org>, Paolo Bonzini <pbonzini@...hat.com>, 
	Jim Mattson <jmattson@...gle.com>, kvm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 1/6] x86/bugs: Move the X86_FEATURE_USE_IBPB check into callers

On Thu, Feb 27, 2025, Yosry Ahmed wrote:
> indirect_branch_prediction_barrier() only performs the MSR write if
> X86_FEATURE_USE_IBPB is set, using alternative_msr_write(). In
> preparation for removing X86_FEATURE_USE_IBPB, move the feature check
> into the callers so that they can be addressed one-by-one, and use
> X86_FEATURE_IBPB instead to guard the MSR write.
> 
> Signed-off-by: Yosry Ahmed <yosry.ahmed@...ux.dev>
> Acked-by: Josh Poimboeuf <jpoimboe@...nel.org>
> ---

Acked-by: Sean Christopherson <seanjc@...gle.com>