linux-kernel - [tip: x86/cpu] x86/fpu: Remove unnecessary CPUID level check

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>] [day] [month] [year] [list]

Message-ID: <173453059585.7135.6447480558100818200.tip-bot2@tip-bot2>
Date: Wed, 18 Dec 2024 14:03:15 -0000
From: "tip-bot2 for Dave Hansen" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: Dave Hansen <dave.hansen@...ux.intel.com>,
 "Chang S. Bae" <chang.seok.bae@...el.com>, x86@...nel.org,
 linux-kernel@...r.kernel.org
Subject: [tip: x86/cpu] x86/fpu: Remove unnecessary CPUID level check

The following commit has been merged into the x86/cpu branch of tip:

Commit-ID:     74ccf55c81c96e0674d7b66bae98dabbce589d57
Gitweb:        https://git.kernel.org/tip/74ccf55c81c96e0674d7b66bae98dabbce589d57
Author:        Dave Hansen <dave.hansen@...ux.intel.com>
AuthorDate:    Fri, 13 Dec 2024 12:50:38 -08:00
Committer:     Dave Hansen <dave.hansen@...ux.intel.com>
CommitterDate: Wed, 18 Dec 2024 05:24:43 -08:00

x86/fpu: Remove unnecessary CPUID level check

The CPUID level dependency table will entirely zap X86_FEATURE_XSAVE
if the CPUID level is too low.  This code is unreachable.  Kill it.

Signed-off-by: Dave Hansen <dave.hansen@...ux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@...ux.intel.com>
Reviewed-by: Chang S. Bae <chang.seok.bae@...el.com>
Link: https://lore.kernel.org/all/20241213205038.6E71F9A4%40davehans-spike.ostc.intel.com
---
 arch/x86/kernel/fpu/xstate.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index bf38b3e..edacd34 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -764,11 +764,6 @@ void __init fpu__init_system_xstate(unsigned int legacy_size)
 		return;
 	}

-	if (boot_cpu_data.cpuid_level < XSTATE_CPUID) {
-		WARN_ON_FPU(1);
-		return;
-	}
-
 	/*
 	 * Find user xstates supported by the processor.
 	 */