From nobody Fri Dec 19 17:27:07 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 21AA5146010 for ; Sun, 31 Mar 2024 18:01:11 +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=1711908073; cv=none; b=a8mUsc+/xHOBOSOcJltE7SG/tJ/rP8khklktFDqrP+ZntLnSz/XnPiliECmCouZkmS+OSIULI8DMkaj+H3+ejJTu0DiDnU1GsXQanduDqpSDRzMMYuLGhGrBFzQvqWdLe3mcAv8svCy4BGJhYvO8fNfVBwA5DIh96W+Cgpa1sSM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711908073; c=relaxed/simple; bh=IhzTBjgcSUxPoooKAQMtSfyuHxZVHsNUvUQ5FyB2k/w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cQagxF0d4jla9LY+rucff19mIRNg35YxMZTYo4Mph36dI0fOy5kp2UgEB9KOd22zs25YCtFKHpmNR8ntZAyvTmmcuf4ySYr9UH1DHk/Agy8p6hx5r8Yq0KYvaipnf1FcgB02AKDjBXUYXljnUX5JblH1trO9AJR2F4OtWwk/m4E= 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=K9qn3z0c 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="K9qn3z0c" Received: from localhost (localhost.localdomain [127.0.0.1]) by mail.alien8.de (SuperMail on ZX Spectrum 128k) with ESMTP id 58BE540E02A5; Sun, 31 Mar 2024 18:01:10 +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 JgU7a60AfwIv; Sun, 31 Mar 2024 18:01:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=alien8; t=1711908067; bh=ws0VdAWkXbMIBACYGflMkkVS5RnmQ4Ymb+wW5pLwxlI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=K9qn3z0cErgG2fQK0eRAsEk/xh+rtwrfJum4UAEVoGvPQmGtfCgUUz6O2GazczbqA t/GFxksgI+UbutZr/56EglUnmYEnleIv5qnT8EKxSXIatIB4iIrB6dou80ewPlJdkv ZBSW621KvXFBF0iXLRn0KetG7Zv5e1kCmSM5xS00uo9P+whpnv9oDp89QWd2n6MCqI kQFAoeOg8LW42lWka5135uc+IXID8xFibgSA/zSmkU9q+yJkALaIkKcl/WkLoMMeuG Xi89RQ9ew7nQfwA4sIu3i0tKSwElv2PkwdX7QXVxtLOBeGQJiVDeQCJMkJ7MF646RU Dv4Fu0K7yAac6aATtwWdnNZbPoZ8SFqObQKAWyAvHCEGSf9f1rwrj1e05qJRjunJXS gBO1nTJ8l5HFUVyM7YgcMWOLilQR4riiWAF2tIhHQyk8bY2l/kaJtBTELYnBb4bY36 HoOD8EWkcIDGmKikUPpcHQgRx1goIClwdZuP0TLAyQM70k6LLGQnXBUAsy+7cR2/Uk 6t8cmG2U+Drk2lJl4/FnNLLFHAZUZ9x3qwtW4EtBiV1IoEBvpAUIfh3JvrcRXY4Ivq 7eSq0Zo0/Ty0uEIzyJAjiEECSupZ1ag40lpe0uNR2LFL8LLDojwHnf0I60QgaZlWWI heKv3yZ2It2iF+9lsSqWtSns= Received: from zn.tnic (p5de8ecf7.dip0.t-ipconnect.de [93.232.236.247]) (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 220E140E0202; Sun, 31 Mar 2024 18:01:05 +0000 (UTC) From: Borislav Petkov To: X86 ML Cc: LKML Subject: [PATCH v2 3/4] x86/alternatives: Optimize optimize_nops() Date: Sun, 31 Mar 2024 20:00:41 +0200 Message-ID: <20240331180042.13933-4-bp@alien8.de> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240331180042.13933-1-bp@alien8.de> References: <20240331180042.13933-1-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 4b3378c71518..67dd7c371d28 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -233,6 +233,10 @@ static void noinline optimize_nops(const u8 * const in= str, u8 *buf, size_t len) 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