linux-kernel - [patch 1/7] x86/fpu: Remove redundant XCOMP

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20220324134623.408932232@linutronix.de>
Date:   Thu, 24 Mar 2022 14:47:08 +0100 (CET)
From:   Thomas Gleixner <tglx@...utronix.de>
To:     LKML <linux-kernel@...r.kernel.org>
Cc:     x86@...nel.org, "Chang S. Bae" <chang.seok.bae@...el.com>,
        Paolo Bonzini <bonzini@....org>
Subject: [patch 1/7] x86/fpu: Remove redundant XCOMP_BV initialization

fpu_copy_uabi_to_guest_fpstate() initializes the XCOMP_BV field in the
XSAVE header. That's a leftover from the old KVM FPU buffer handling code.

Since d69c1382e1b7 ("x86/kvm: Convert FPU handling to a single swap
buffer") KVM uses the FPU core allocation code, which initializes the
XCOMP_BV field already.

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Cc: Paolo Bonzini <bonzini@....org>
---
 arch/x86/kernel/fpu/core.c |    3 ---
 1 file changed, 3 deletions(-)

--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -415,9 +415,6 @@ int fpu_copy_uabi_to_guest_fpstate(struc
 		xpkru = get_xsave_addr(&kstate->regs.xsave, XFEATURE_PKRU);
 		*vpkru = xpkru->pkru;
 	}
-
-	/* Ensure that XCOMP_BV is set up for XSAVES */
-	xstate_init_xcomp_bv(&kstate->regs.xsave, kstate->xfeatures);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(fpu_copy_uabi_to_guest_fpstate);