From nobody Sat Nov 23 18:46:56 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=reject dis=none) header.from=citrix.com ARC-Seal: i=1; a=rsa-sha256; t=1701163377; cv=none; d=zohomail.com; s=zohoarc; b=FkbZ+qcYk9TDvrgy1Us3nVwN4zbUPDjC0Tcp53qvdeEFTe/A+A83uYY17fjAC5UK1ghMcKayRkAPomg2kQj93bbaOu6V+SaFWvZ+f663KTOscmJP/v9d0X9lhrjClKdPjWtZzvj0syTSiRyiMv/+J1239lreg+5oFVFY0U1FPsg= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1701163377; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:Subject:To:To:Message-Id:Reply-To; bh=nloFbZsR0n5o1gFMfsRypOwTdPPhgWOtMQCBf1lcPX8=; b=VFc6u2HIJa+QIvVbuzQNvMUTUmoXGyNtCH4hKXWIOw9vRqvnyVuhbJrIutQQQ2y6Rlenq3RBwBjEkp4XEnErEXQUZGYUHQ7YEqXrWU0mzl+09ERKUtD4bpk5Y0ooIz7gnmd2ZLJ4DQIDslv1kL6hJvsmWMmKqh7skdCE01BYqo8= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass header.from= (p=reject dis=none) Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 170116337736153.39377061575942; Tue, 28 Nov 2023 01:22:57 -0800 (PST) Received: from list by lists.xenproject.org with outflank-mailman.642824.1002563 (Exim 4.92) (envelope-from ) id 1r7uIV-0005C3-Dj; Tue, 28 Nov 2023 09:22:27 +0000 Received: by outflank-mailman (output) from mailman id 642824.1002563; Tue, 28 Nov 2023 09:22:27 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1r7uIV-0005At-9F; Tue, 28 Nov 2023 09:22:27 +0000 Received: by outflank-mailman (input) for mailman id 642824; Tue, 28 Nov 2023 09:22:26 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1r7uIU-0004tq-C2 for xen-devel@lists.xenproject.org; Tue, 28 Nov 2023 09:22:26 +0000 Received: from mail-wm1-x32a.google.com (mail-wm1-x32a.google.com [2a00:1450:4864:20::32a]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id a472df4c-8dcf-11ee-98e3-6d05b1d4d9a1; Tue, 28 Nov 2023 10:22:25 +0100 (CET) Received: by mail-wm1-x32a.google.com with SMTP id 5b1f17b1804b1-40b4c2ef58aso4187555e9.0 for ; Tue, 28 Nov 2023 01:22:25 -0800 (PST) Received: from localhost ([213.195.113.99]) by smtp.gmail.com with ESMTPSA id n8-20020a05600c3b8800b0040b398f0585sm14323367wms.9.2023.11.28.01.22.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Nov 2023 01:22:24 -0800 (PST) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: a472df4c-8dcf-11ee-98e3-6d05b1d4d9a1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=citrix.com; s=google; t=1701163345; x=1701768145; darn=lists.xenproject.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=nloFbZsR0n5o1gFMfsRypOwTdPPhgWOtMQCBf1lcPX8=; b=eX4ePTQEiWinhG61NI8NtbC0pSmWTfp4G1zG3TASMY4PNT4MQ1ybL9nLc6OHVw+NkR eBhKvXVKN23VRTwND5PLx9jYXmw43eigkuSu42AvxidIoBkCJnIWP8v01msJ5biTlfaM zJz4MaWKjRBSG741CWN9qSyKj3ZlCUh9MGi/U= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701163345; x=1701768145; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=nloFbZsR0n5o1gFMfsRypOwTdPPhgWOtMQCBf1lcPX8=; b=Zu15x3k9uipQ4EdIaNoh4Is5bJnFyzq2FqMWCkPLETuuDkZO5p/yMJTo6v+P6+sqGl XuqtNFfBAw3+Ej36fo3qu+SivNAH0ro/+rDNFjzBFtu6QGe3DtBBlmbWNxFFqYrY80Yh 6petiGvPkwC/WlXtd7RbRYyWbwlV0eglPZw2NXiD5rWvAGLP2WJVQb6DZUk5u/RuF6I+ x7IpXOXShfyTw01f5oFJOdga3WF5E+ct8XCQ5r+JFrf5HMviJczvNsc1BhcgFfZ1eCGW D76Gxry7XxC0Ehh55reXc7PvaUU97i/uO7Kr2rJH47cuSMU12USv9UgrdE2k0ZWUeueT lhiw== X-Gm-Message-State: AOJu0YzlHDp4qza2KReYyR7hZqtPUpZJ5VThXrdrLWz0l8WAvacaOAoG sbjgPNRcYZJZNXnig+0RxGprw9pu+pc6/umuOjI= X-Google-Smtp-Source: AGHT+IG3Eo5ZvV3iidJ+LL4lIRYVlc0WvPm8MgpcybdntPPVgNd0KKSy77sIYN1+0k2yHT3X4/QGCA== X-Received: by 2002:a05:600c:198a:b0:40b:448b:f711 with SMTP id t10-20020a05600c198a00b0040b448bf711mr4835936wmq.18.1701163345041; Tue, 28 Nov 2023 01:22:25 -0800 (PST) From: Roger Pau Monne To: xen-devel@lists.xenproject.org Cc: Konrad Rzeszutek Wilk , Ross Lagerwall , Roger Pau Monne Subject: [PATCH v2 3/3] livepatch-build-tools: account for section alignment when calculating function size Date: Tue, 28 Nov 2023 10:21:52 +0100 Message-ID: <20231128092152.35039-4-roger.pau@citrix.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231128092152.35039-1-roger.pau@citrix.com> References: <20231128092152.35039-1-roger.pau@citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-ZohoMail-DKIM: pass (identity @citrix.com) X-ZM-MESSAGEID: 1701163378284000003 Forcing function section alignment at the compiler level ensures that enough space is present in the text section so that at least a jump can be encoded= in the old function body to switch to the newly loaded code payload. Modify create-diff-object to account for any section alignment when calcula= ting the size of the old function. When used with a suitable -falign-function compiler parameter on the Xen hypervisor build this ensures that all functions have enough space to accommodate for any control flow instructions plus a jump. Note that while the rounding could be applied to all (text) symbols, it's n= ot required, as the size is only relevant for functions that are live patched,= and hence only do the rounding when calculating the old (previous) function siz= e. Signed-off-by: Roger Pau Monn=C3=A9 --- Changes since v2: - New in this version. --- common.h | 2 ++ create-diff-object.c | 5 +++++ 2 files changed, 7 insertions(+) diff --git a/common.h b/common.h index 0d3e5f1dd3b5..5ff9ef6ca8e9 100644 --- a/common.h +++ b/common.h @@ -37,6 +37,8 @@ extern char *childobj; list_add_tail(&(_new)->list, (_list)); \ } =20 +#define ROUNDUP(x, a) (((x) + (a) - 1) & ~((a) - 1)) + enum loglevel { DEBUG, NORMAL diff --git a/create-diff-object.c b/create-diff-object.c index d0e14e3a62bb..fed360a9aa68 100644 --- a/create-diff-object.c +++ b/create-diff-object.c @@ -2015,6 +2015,11 @@ static void livepatch_create_patches_sections(struct= kpatch_elf *kelf, ERROR("lookup_global_symbol %s", sym->name); } + + /* Take into account section alignment for padding. */ + result.size =3D ROUNDUP(result.size, + sym->sec->sh.sh_addralign); + log_debug("lookup for %s @ 0x%016lx len %lu\n", sym->name, result.value, result.size); =20 --=20 2.43.0