From nobody Sat Feb 7 08:53:14 2026 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4010A425CC2; Tue, 20 Jan 2026 12:08:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768910891; cv=none; b=KzZWiMaI6C5Di1iZp2izhQnR9bTovUOO0Sv2KbFZx7pRDXX2EMEUfCJeLdDwOi/AbQi8CIQZR6qIBuWVbF1Fsi/ii9+67MNAM/jaWrdjEyUHYipLH0ImGjlmrdHNweYx9mzJVMtmxx6CzXot85IpeNKVDeEjDtPLEkxPRAJC26U= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768910891; c=relaxed/simple; bh=FMmNcgeD+XtT4L7eTxEYPqrd2SuHvAJx4GtKMHiar5Y=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=YTGjfvpAfQlaXbmd279xCpIqQ138zAwLH2x+vhMV7PrP33C871ZukCJ8uNetuqAiHNN+fWsnMHngi6tYbCdlh/9A+LnXswowLky9BZPesoLPlHChtmVJGcjsf53ZJRqzKjvu0dUCkgbc7QKAjkxqeGtl+X9zaaSGNglosfurYz4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=Nb5VzOaq; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=oiNUuLPz; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="Nb5VzOaq"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="oiNUuLPz" Date: Tue, 20 Jan 2026 12:08:01 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1768910883; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=XOq5y2FS2ZFLMZbpDlgrHEK37UG1yjJ0vShsFNED83M=; b=Nb5VzOaqDJBOXTvHksLPLRDo2o5swRLaZnn6r03TTCd4d0jOi5TsnwirK/4AXrHf3yvgBx RtT2wxWTyJ/iCEqzgvggarQj5z0tMTgUyodBEITxgyh1J2TGS6g9QHke5iiUC77Fo5rUsg QmBmw8y9Hr++dD5USl7Q/+okFIJcyOMYPG0OiTjrnMjnHMvrDmEvighRgkxc967tHfiJR7 9HaJvZKlzV52Ol2HhvlW8EqwyPnLWJ2IYUeBldJAfT/7CZNUedTNUOUQ9b7MQe+UnWNLXj aaumNxRZvKSDOIdmVRHnhLEfiwnahoBaSFfiBSVbdt7GDdVpSnyF6pdoGf6i9w== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1768910883; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=XOq5y2FS2ZFLMZbpDlgrHEK37UG1yjJ0vShsFNED83M=; b=oiNUuLPzB6EUh8dMdAV1cJIA16PDf1Tcf8IqEBpY1jxv/aQUYludKW0mTH2MIeet20bwaO ryAhBnHZAjxUc6CQ== From: "tip-bot2 for Uros Bizjak" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/cleanups] x86/segment: Use MOVL when reading segment registers Cc: Uros Bizjak , "Borislav Petkov (AMD)" , "H. Peter Anvin (Intel)" , Michael Kelley , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20260105090422.6243-1-ubizjak@gmail.com> References: <20260105090422.6243-1-ubizjak@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <176891088183.510.8607818928752445249.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the x86/cleanups branch of tip: Commit-ID: 53ed3d91a141f5c8b3bce45b0004fbbfefe77956 Gitweb: https://git.kernel.org/tip/53ed3d91a141f5c8b3bce45b0004fbbfe= fe77956 Author: Uros Bizjak AuthorDate: Mon, 05 Jan 2026 10:02:32 +01:00 Committer: Borislav Petkov (AMD) CommitterDate: Tue, 20 Jan 2026 12:34:58 +01:00 x86/segment: Use MOVL when reading segment registers Use MOVL when reading segment registers to avoid 0x66 operand-size override insn prefix. The segment value is always 16-bit and gets zero-extended to t= he full 32-bit size. Example: 4e4: 66 8c c0 mov %es,%ax 4e7: 66 89 83 80 0b 00 00 mov %ax,0xb80(%rbx) 4e4: 8c c0 mov %es,%eax 4e6: 66 89 83 80 0b 00 00 mov %ax,0xb80(%rbx) Also, use the %k0 modifier which generates the SImode (signed integer) register name for the target register. [ bp: Extend and clarify commit message. ] Signed-off-by: Uros Bizjak Signed-off-by: Borislav Petkov (AMD) Reviewed-by: H. Peter Anvin (Intel) Tested-by: Michael Kelley Link: https://patch.msgid.link/20260105090422.6243-1-ubizjak@gmail.com --- arch/x86/include/asm/segment.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h index f59ae71..9f5be2b 100644 --- a/arch/x86/include/asm/segment.h +++ b/arch/x86/include/asm/segment.h @@ -348,7 +348,7 @@ static inline void __loadsegment_fs(unsigned short valu= e) * Save a segment register away: */ #define savesegment(seg, value) \ - asm("mov %%" #seg ",%0":"=3Dr" (value) : : "memory") + asm("movl %%" #seg ",%k0" : "=3Dr" (value) : : "memory") =20 #endif /* !__ASSEMBLER__ */ #endif /* __KERNEL__ */