From patchwork Tue Feb 14 19:23:51 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Moon X-Patchwork-Id: 13140767 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 43BD9C6379F for ; Tue, 14 Feb 2023 19:24:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231556AbjBNTYY (ORCPT ); Tue, 14 Feb 2023 14:24:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38954 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229510AbjBNTYY (ORCPT ); Tue, 14 Feb 2023 14:24:24 -0500 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BB6FB1F5E9; Tue, 14 Feb 2023 11:24:22 -0800 (PST) Received: from pps.filterd (m0279869.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 31EDgq5Y032679; Tue, 14 Feb 2023 19:24:08 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=from : to : cc : subject : date : message-id : mime-version : content-type; s=qcppdkim1; bh=1ky1Chlo5Mk7HtdXFf5Se4xDFK0+xw22bu8O3gO0CBY=; b=K1tXUjZHDgTiMzf5aBVXRRsnahlNWN8KySzDMJwchQwQntAZXs6QmBxtLYHykoUw0z1k VZa0cLogZfZL9bvwhizTycpFN1hxNCQ0uMZGW8F/nOZBSmjhN7W1Ovw2WS3L1LDYz61R efouEeYE6CBHAskbg4M4Yhrevqmi1RxJdAe96n9f8O/jYvFEZ/ouR2GJ+vWB2d7tj5aG IG4M93f7DS2o2n6tzEvEP4RwwYjryLl9LYMKQR68kppeAOS1SXJyKmQXAlF0GjuQC/bd kgN2AkaeDYeVJXAM1iq9lNmSh+EQvefV0nEpxiwKpDLji//jgJBDZPuBZ5txVmYPT5x1 VQ== Received: from nalasppmta01.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3nqts7u871-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 14 Feb 2023 19:24:08 +0000 Received: from nalasex01c.na.qualcomm.com (nalasex01c.na.qualcomm.com [10.47.97.35]) by NALASPPMTA01.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 31EJO7Nc006393 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 14 Feb 2023 19:24:07 GMT Received: from hu-johmoo-lv.qualcomm.com (10.49.16.6) by nalasex01c.na.qualcomm.com (10.47.97.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.36; Tue, 14 Feb 2023 11:24:06 -0800 From: John Moon To: Masahiro Yamada , Nathan Chancellor , Nick Desaulniers , "Nicolas Schier" CC: John Moon , , , , Trilok Soni , Bjorn Andersson , Todd Kjos , Matthias Maennich , Giuliano Procida , Jordan Crouse , Subject: [PATCH 1/1] Validating UAPI backwards compatibility Date: Tue, 14 Feb 2023 11:23:51 -0800 Message-ID: <20230214192351.15253-1-quic_johmoo@quicinc.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [10.49.16.6] X-ClientProxiedBy: nalasex01c.na.qualcomm.com (10.47.97.35) To nalasex01c.na.qualcomm.com (10.47.97.35) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: WSg9IxOmODV9rxFH5LvOKVWyz_KoYN23 X-Proofpoint-ORIG-GUID: WSg9IxOmODV9rxFH5LvOKVWyz_KoYN23 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.219,Aquarius:18.0.930,Hydra:6.0.562,FMLib:17.11.170.22 definitions=2023-02-14_13,2023-02-14_01,2023-02-09_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 priorityscore=1501 bulkscore=0 lowpriorityscore=0 suspectscore=0 mlxlogscore=999 mlxscore=0 impostorscore=0 spamscore=0 phishscore=0 clxscore=1015 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2212070000 definitions=main-2302140168 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org While the kernel community has been good at maintaining backwards compatibility with kernel UAPIs, it would be helpful to have a tool to check if a patch introduces changes that break backwards compatibility. To that end, introduce check-uapi.sh: a simple shell script that checks for changes to UAPI headers using libabigail. libabigail is "a framework which aims at helping developers and software distributors to spot some ABI-related issues like interface incompatibility in ELF shared libraries by performing a static analysis of the ELF binaries at hand." The script uses one of libabigail's tools, "abidiff", to compile the changed header before and after the patch to detect any changes. abidiff "compares the ABI of two shared libraries in ELF format. It emits a meaningful report describing the differences between the two ABIs." Signed-off-by: John Moon --- scripts/check-uapi.sh | 240 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 240 insertions(+) create mode 100755 scripts/check-uapi.sh -- 2.17.1 diff --git a/scripts/check-uapi.sh b/scripts/check-uapi.sh new file mode 100755 index 000000000..209c6793a --- /dev/null +++ b/scripts/check-uapi.sh @@ -0,0 +1,240 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0-only + +# Script to check a patch for UAPI stability +set -o errexit + +print_usage() { + name=$(basename "$0") + cat << EOF +$name - check for UAPI header stability across Git commits + +By default, the script will check to make sure the latest commit did +not introduce ABI changes (HEAD^1). You can check against additional +commits/tags with the -r option. + +Usage: $name [-r GIT_REF] + +Options: + -r GIT_REF Compare current version of file to GIT_REF (e.g. -r v6.1) + +Environmental Args: + ABIDIFF Custom path to abidiff binary + ARCH Architecture to build with (e.g. ARCH=arm) + CC C compiler (default is "gcc") + CROSS_COMPILE Cross-compiling toochain prefix +EOF +} + +# Get the file and sanitize it using the headers_install script +get_header() { + local -r ref="$1" + local -r file="$2" + local -r out="$3" + + if [ ! -x "${KERNEL_SRC}/scripts/unifdef" ]; then + if ! make -C "${KERNEL_SRC}/scripts" unifdef; then + echo 'error - failed to build required dependency "scripts/unifdef"' + exit 1 + fi + fi + + mkdir -p "$(dirname "$out")" + ( + cd "$KERNEL_SRC" + git show "${ref}:${file}" > "${out}.in" + scripts/headers_install.sh "${out}.in" "$out" + ) +} + +# Compile the simple test app +do_compile() { + local -r compiler="$1" + local -r inc_dir="$2" + local -r header="$3" + local -r out="$4" + echo "int main(int argc, char **argv) { return 0; }" | \ + "$compiler" -c \ + -o "$out" \ + -x c \ + -O0 \ + -std=c90 \ + -fno-eliminate-unused-debug-types \ + -g \ + "-I$inc_dir" \ + -include "$header" \ + - +} + +# Print to stderr +errlog() { + echo "$@" >&2 +} + +# Grab the list of incompatible headers from the usr/include Makefile +get_no_header_list() { + { + cat "${KERNEL_SRC}/usr/include/Makefile" + # shellcheck disable=SC2016 + printf '\nall:\n\t@echo $(no-header-test)\n' + } | make -C "${KERNEL_SRC}/usr/include" -f - --just-print \ + | grep '^echo' \ + | cut -d ' ' -f 2- +} + +# Check any changed files in this commit for UAPI compatibility +check_changed_files() { + refs_to_check=("$@") + + local passed=0; + local failed=0; + + while read -r status file; do + local -r base=${file/uapi\//} + + # Get the current version of the file and put it in the install dir + get_header "HEAD" "$file" "${tmp_dir}/usr/${base}" + + for ref in "${refs_to_check[@]}"; do + if ! git rev-parse --verify "$ref" > /dev/null 2>&1; then + echo "error - invalid ref \"$ref\"" + exit 1 + fi + + if check_uapi_for_file "$status" "$file" "$ref" "$base"; then + passed=$((passed + 1)) + else + failed=$((failed + 1)) + fi + done + done < <(cd "$KERNEL_SRC" && git show HEAD --name-status --format="" --diff-filter=a -- include/uapi/) + + total=$((passed + failed)) + if [ "$total" -eq 0 ]; then + errlog "No changes to UAPI headers detected" + else + errlog "${passed}/${total} UAPI header file changes are backwards compatible" + fi + + return "$failed" +} + +# Check UAPI compatibility for a given file +check_uapi_for_file() { + local -r status="$1" + local -r file="$2" + local -r ref="$3" + local -r base="$4" + + # shellcheck disable=SC2076 + if [[ " $(get_no_header_list) " =~ " ${base/include\//} " ]]; then + errlog "$file cannot be tested by this script (see usr/include/Makefile)." + return 1 + fi + + if [ "$status" = "D" ]; then + errlog "UAPI header $file was incorrectly removed" + return 1 + fi + + if [ "$status" = "R" ]; then + errlog "UAPI header $file was incorrectly renamed" + return 1 + fi + + # Get the "previous" verison of the API header and put it in the install dir + get_header "$ref" "$file" "${tmp_dir}/usr/${base}.pre" + + compare_abi "${CROSS_COMPILE}${CC:-gcc}" "$file" "$base" "$ref" +} + +# Perform the A/B compilation and compare output ABI +compare_abi() { + local -r compiler="$1" + local -r file="$2" + local -r base="$3" + local -r ref="$4" + + pre_bin="${tmp_dir}/pre.bin" + post_bin="${tmp_dir}/post.bin" + log="${tmp_dir}/log" + + if ! do_compile "$compiler" "${tmp_dir}/usr/include" "${tmp_dir}/usr/${base}.pre" "$pre_bin" 2> "$log"; then + errlog "Couldn't compile current version of UAPI header $file..." + cat "$log" >&2 + return 1 + fi + + if ! do_compile "$compiler" "${tmp_dir}/usr/include" "${tmp_dir}/usr/${base}" "$post_bin" 2> "$log"; then + errlog "Couldn't compile new version of UAPI header $file..." + cat "$log" >&2 + return 1 + fi + + if "$ABIDIFF" --non-reachable-types "$pre_bin" "$post_bin" > "$log"; then + echo "No ABI differences detected in $file (compared to file at $ref)" + else + errlog "!!! ABI differences detected in $file (compared to file at $ref) !!!" + echo >&2 + sed -e '/summary:/d' -e '/changed type/d' -e '/^$/d' -e 's/^/ /g' "$log" >&2 + echo >&2 + return 1 + fi +} + +# Make sure we have the tools we need +check_deps() { + export ABIDIFF="${ABIDIFF:-abidiff}" + + if ! command -v "$ABIDIFF" > /dev/null 2>&1; then + errlog "error - abidiff not found!" + errlog "Please install abigail-tools (version 1.7 or greater)" + errlog "See: https://sourceware.org/libabigail/manual/libabigail-overview.html" + exit 2 + fi + + local -r abidiff_maj=$("$ABIDIFF" --version | cut -d ' ' -f 2 | cut -d '.' -f 1) + local -r abidiff_min=$("$ABIDIFF" --version | cut -d ' ' -f 2 | cut -d '.' -f 1) + if [ "$abidiff_maj" -lt 1 ] || ([ "$abidiff_maj" -eq 1 ] && [ "$abidiff_min" -lt 7 ]); then + errlog "error - installed abidiff version too old: $("$ABIDIFF" --version)" + errlog "Please install abigail-tools (version 1.7 or greater)" + errlog "See: https://sourceware.org/libabigail/manual/libabigail-overview.html" + exit 2 + fi +} + +main() { + refs_to_check=( "HEAD^1" ) + while getopts "hr:" opt; do + case $opt in + h) + print_usage + exit 0 + ;; + r) + refs_to_check+=( "$OPTARG" ) + ;; + esac + done + + check_deps + + tmp_dir=$(mktemp -d) + #trap 'rm -rf $tmp_dir' EXIT + + if [ -z "$KERNEL_SRC" ]; then + KERNEL_SRC="$(realpath "$(dirname "$0")"/..)" + fi + export KERNEL_SRC + + export ARCH + export CC + export CROSS_COMPILE + + if ! check_changed_files "${refs_to_check[@]}"; then + errlog "UAPI header ABI check failed" + exit 1 + fi +} + +main "$@"