From nobody Wed Dec 24 01:49:43 2025 Received: from mail.alien8.de (mail.alien8.de [65.109.113.108]) (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 CDB59679FD for ; Tue, 30 Jan 2024 11:00:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=65.109.113.108 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706612412; cv=none; b=HRHc1AOuXSDS66+Z4peOyu0SPsHRTQ8GXowLeD/5e/n2HNzIOcCWqNJTELF4gR1K3O95sRVocc53rxMNGpIwZGjoVCkFJZB3awF5isGz4UPyCd+wVOMtNAgu6kG3GXTwpksRObmV+MbyMGYAlDzwfmxe2eZYPraIFt1AnoWNZzo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706612412; c=relaxed/simple; bh=jgeafpJI+MYDNRoPvXNTdDfiHQEnLFcoETk5RR++mSA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cD58jd7RfoI5IKPLJo7avPkl9jF11CHcaugnrZ6LNLpj54vxmrZukwy7vTS7NPX4L9d9WLjjZGO9eIJ4XViQRmkWevL0kXjUzteGVo6ExepDrgMJJrZdCSOTITGDKWt2ZkZof2gwYzS+JnkmxT/qpB8oXHhwoD5/8jNo3azgyNA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=alien8.de; spf=pass smtp.mailfrom=alien8.de; dkim=fail (4096-bit key) header.d=alien8.de header.i=@alien8.de header.b=OTjnlGn6 reason="signature verification failed"; arc=none smtp.client-ip=65.109.113.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=alien8.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=alien8.de Authentication-Results: smtp.subspace.kernel.org; dkim=fail reason="signature verification failed" (4096-bit key) header.d=alien8.de header.i=@alien8.de header.b="OTjnlGn6" Received: from localhost (localhost.localdomain [127.0.0.1]) by mail.alien8.de (SuperMail on ZX Spectrum 128k) with ESMTP id DE99840E01FE; Tue, 30 Jan 2024 11:00:08 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at mail.alien8.de Authentication-Results: mail.alien8.de (amavisd-new); dkim=fail (4096-bit key) reason="fail (body has been altered)" header.d=alien8.de Received: from mail.alien8.de ([127.0.0.1]) by localhost (mail.alien8.de [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id km_ryPGWyPCV; Tue, 30 Jan 2024 11:00:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=alien8; t=1706612406; bh=njqwLfrv56leHkX+AonJAZ0qg8TBI+C0ajpxz+Cn0Oo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OTjnlGn6LgS9QuS49oeJ51uVOHhFXrZOzFkMxaJc5FTZQUM24RJpzByIImRZrdi0x Kp2+1i8t7mAruSVfSzPb690CUJlhdcs0PytNvnek5izutBVARqUTr9MFO1DY9t9RGx +ZZwfdjnAMnzDCcioulTTZlnYSJ/coCMeLjFOTjtxNVnZ0iRCfTsZMSIt35DMeYmm9 fXQE/HHPm1irE+ccxrGeKAZMo1O4Yr65tfwXWjPq6geTE4HTI3vr6Ma7zoZNmIsoqT xLCFrDXpy5SuZlNKNgBVk8Yn16ccb42OeYZsss/J4TEdDvqGR5ue7oICVvUTvFiFbF /JHxZaEqNYU39PUHzb7mLaaOoONCHxYXYv5ijYtlyYzsQAp6Srwbu080o4VwBR30Sh 4Hys7u3OV/Ua4IILMgTSSSFcA+u92rKeCTNGHJ01C/QfR5IIJjK6r5ps4uGVQDZGUC 1KCg4RoWOpkiqMafjgFIHWqmEL1NIRqrCBG/SOO1W8+EUTVtgdCi/eg6p+Rx3x8M8I OMINe6Uev0RagiBQ4WGdhhptBaNEv80IeOucy/5psVL05+ysZD/4RORE5wQ8cookqb 8TZIkv69YgilpOIzZ0YeT3Q662yAeneeLhnWqIRfIs3ALBgHVyl/zFjFgf6ih84Lik CVZJWoo4SLSZNQyLEN/Rq1/A= Received: from zn.tnic (pd953033e.dip0.t-ipconnect.de [217.83.3.62]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature ECDSA (P-256) server-digest SHA256) (No client certificate requested) by mail.alien8.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 867C840E0177; Tue, 30 Jan 2024 11:00:03 +0000 (UTC) From: Borislav Petkov To: X86 ML Cc: Paul Gortmaker , LKML Subject: [PATCH 3/4] x86/alternatives: Optimize optimize_nops() Date: Tue, 30 Jan 2024 11:59:40 +0100 Message-ID: <20240130105941.19707-4-bp@alien8.de> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240130105941.19707-1-bp@alien8.de> References: <20240130105941.19707-1-bp@alien8.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: "Borislav Petkov (AMD)" Return early if NOPs have already been optimized. Signed-off-by: Borislav Petkov (AMD) --- arch/x86/kernel/alternative.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 2dd1c7fe0949..68ee46c379c1 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -233,6 +233,10 @@ static void __init_or_module noinline optimize_nops(co= nst u8 * const instr, u8 * if (insn_is_nop(&insn)) { int nop =3D i; =20 + /* Has the NOP already been optimized? */ + if (i + insn.length =3D=3D len) + return; + next =3D skip_nops(buf, next, len); =20 add_nop(buf + nop, next - nop); --=20 2.43.0