testsuite: add generic test script for incremental depmod

Add a test script to test incremental depmod on a real kernel, as an addition
to the normal kmod CI. This script is meant to be run against the installed
kernel on a test system.

This test script compares the results (i.e. the modules.* files generated by
depmod) of incremental depmod with a full depmod run. The expectation is that
the results are always identical.

The script takes a list of module basenames as arguments, the "test modules",
like this:

   test-incremental.sh scsi_mod drm_display_helper

1. The script looks for a kernel module tree in the system it's running on
and copies this tree to the working directory, and runs a full depmod there.
2. It copies the entire tree again, deletes the test modules and all modules
depending on them, and runs full depmod once more.
3. It copies the tree created in 2., re-adds the previously deleted modules,
and runs "depmod --incremental" with the added modules as arguments, and
compares the results with those from step 1.
4. It copies the tree created in 2., re-adds the previously deleted modules,
runs "depmod --incremental --all", and compares the results with those from
step 1.
5. It copies the tree created in 2, runs "depmod --incremental --all", and
compares the results with those from step 2.

If any differences are found in step 3., 4., or 5., the script will report
them.

By default, all operations are done below a temporary directory under /tmp,
so no changes are made to the system. The autodetected parameters should work
on most systems. Otherwise, the script has various options to override them.

Copying this script into meson's build directory requires meson's
"fs.copyfile" feature, which was introduced in meson 0.64. The meson build
must therefore be disabled on Ubuntu 22.04, which still ships meson 0.61.

Signed-off-by: Martin Wilck <[email protected]>

.github/workflows/main.yml

@@ -38,6 +38,11 @@ jobs:
             multilib: 'true'
           - name: 'ubuntu:24.04'
             multilib: 'true'
+        exclude:
+          - build: 'meson'
+            container:
+              name: 'ubuntu:22.04'
+              multilib: 'true'
 
     container:
       image: ${{ matrix.container.name }}

meson.build

@@ -3,7 +3,7 @@ project(
   'c',
   version : '33',
   license : ['LGPLv2.1', 'GPL-2.0-or-later'],
-  meson_version : '>=0.61.0',
+  meson_version : '>=0.64.0',
   default_options : [
     'c_std=gnu11',
     'b_pie=true',

testsuite/meson.build

@@ -2,6 +2,8 @@ if not get_option('tools')
   error('The test suite requires also building the tools')
 endif
 
+fs = import('fs')
+
 build_module_playground = custom_target(
   'build-module-playground',
   command : [
@@ -122,3 +124,5 @@ foreach input : _testsuite
     depends : [exec, internal_kmod_symlinks, create_rootfs, test_override_mods],
   )
 endforeach
+
+test_incremental = fs.copyfile('test-incremental.sh', 'test-incremental.sh')

testsuite/test-incremental.sh

@@ -0,0 +1,305 @@
+#! /bin/bash
+export TIMEFORMAT="elapsed time: %2Rs (%2U user / %2S system)"
+export LC_ALL=C
+
+set -e -E
+trap 'echo $ME: error in $BASH_COMMAND >&2; exit 1' ERR
+
+CLEANUP=:
+trap 'trap - ERR; eval "$CLEANUP"' 0
+
+ME=${0##*/}
+BASEDIR=
+OUTPUTDIR=
+KVER=
+SYMVERS=
+FILESYMS=
+DEPMOD=
+KEEP=
+ERR=0
+: "${DEPMOD_OPTS:=}"
+
+usage() {
+    cat <<EOF
+Usage: $ME [OPTION]... [MODULE]...
+
+MODULE is a module basename such as 'e1000' or 'sd_mod'.
+If no MODULE arguments are given, they are read from stdin.
+
+Options:
+  -d|--depmod=PATH	depmod executable to call (default: autodetected)
+  -b|--basedir=DIR	base directory to look for modules, default: /
+  -o|--outputdir=PATH	output directory, CONTENTS WILL BE OVERWRITTEN
+			default: temporary directory under ${TMPDIR:-/tmp}
+  -k|--kver=VERSION	kernel version to run for
+			default: autodetected from installed kernel
+  -E|--symvers FILE	symvers file for depmod -E (default: autodetected)
+  -F|--filesyms FILE	System.map file for depmod -F (default: autodetected)
+  -K|--keep			do not clean up results
+  -h|--help			print this help
+EOF
+}
+
+OPTIONS=b:k:E:d:o:F:Kh
+LONGOPTS=basedir:,kver:,symvers:,depmod:,outputdir:,filesyms:,keep,help
+# shellcheck disable=SC2207
+ARGS=$(getopt -o "$OPTIONS" -l "$LONGOPTS" -- "$@")
+eval set -- "$ARGS"
+
+while [[ $# -gt 0 ]]; do
+    case $1 in
+	-d|--depmod)
+	    shift
+	    DEPMOD=$1
+	    ;;
+	-b|--basedir)
+	    shift
+	    BASEDIR=$1
+	    ;;
+	-k|--kver)
+	    shift
+	    KVER=$1
+	    ;;
+	-E|--symvers)
+	    shift
+	    SYMVERS=$1
+	    ;;
+	-F|--filesyms)
+	    shift
+	    FILESYMS=$1
+	    ;;
+	-o|--outputdir)
+	    shift
+	    OUTPUTDIR=$1
+	    ;;
+	-K|--keep)
+	    KEEP=y
+	    ;;
+	-h|--help)
+	    usage
+	    exit 0
+	    ;;
+	--)
+	    shift
+	    break
+	    ;;
+    esac
+    shift
+done
+MODULES=("$@")
+
+find_glob() {
+    local files
+
+    # shellcheck disable=SC2206
+    files=($1)
+    case "${files[0]}" in
+	"$1")
+	    ;;
+	*)
+	    echo "${files[0]}"
+	    ;;
+    esac
+}
+
+find_installed_kernel() {
+    local kernel
+    kernel=$(find_glob "$BASEDIR/lib/modules/*/modules.dep")
+    [[ "$kernel" ]] || {
+	echo "$ME: no installed kernel found" >&2
+	return
+    }
+    kernel=${kernel%/*}
+    kernel=${kernel##*/}
+    echo "$ME: found kernel $kernel" >&2
+    echo "$kernel"
+}
+
+find_symvers() {
+    local symvers
+
+    symvers=$(find_glob "$BASEDIR/boot/symvers-$1*")
+    [[ ! "$symvers" ]] || echo "$symvers"
+}
+
+find_filesyms() {
+    local fsyms
+
+    fsyms=$(find_glob "$BASEDIR/boot/System.map-$1*")
+    [[ ! "$fsyms" ]] || echo "$fsyms"
+}
+
+[[ ! "$BASEDIR" ]] || BASEDIR=$(cd "$BASEDIR" && echo "$PWD")
+
+[[ "$DEPMOD" ]] || {
+    for _x in "${0%/*}/../depmod" "${0%/*}/../tools/depmod" \
+		/usr/local/sbin/depmod /sbin/depmod /usr/sbin/depmod; do
+	[[ -f "$_x" && -x "$_x" ]] && {
+	    DEPMOD=$_x
+	    break
+	}
+    done
+}
+
+[[ "$DEPMOD" && -f "$DEPMOD" && -x "$DEPMOD" ]]
+echo "$ME: using DEPMOD=$DEPMOD" >&2
+if [[ "$OUTPUTDIR" ]]; then
+    [[ -d "$OUTPUTDIR" ]] || {
+	mkdir -p "$OUTPUTDIR"
+	# shellcheck disable=SC2016
+	[[ "$KEEP" ]] || CLEANUP='rm -rf "$OUTPUTDIR";'"$CLEANUP"
+    }
+else
+    OUTPUTDIR=$(mktemp -d "${TMPDIR:-/tmp}/$ME.XXXXXX")
+    [[ "$OUTPUTDIR" ]]
+    # shellcheck disable=SC2016
+    [[ "$KEEP" ]] || CLEANUP='rm -rf "$OUTPUTDIR";'"$CLEANUP"
+fi
+
+OUTPUTDIR=$(cd "$OUTPUTDIR" && echo "$PWD")
+
+[[ "$KVER" ]] || KVER=$(find_installed_kernel)
+[[ "$KVER" && -d "$BASEDIR/lib/modules/$KVER" ]]
+
+[[ "$SYMVERS" ]] || SYMVERS=$(find_symvers "$KVER")
+[[ "$FILESYMS" ]] || FILESYMS=$(find_filesyms "$KVER")
+
+[[ ("$SYMVERS" && -f "$SYMVERS") || ("$FILESYMS" && -f "$FILESYMS") ]]
+
+# depmod can't handle compressed symvers
+case $SYMVERS in
+    *.gz)
+	gzip -dc "$SYMVERS" >"${TMPDIR:-/tmp}/symvers-$KVER"
+	SYMVERS="${TMPDIR:-/tmp}/symvers-$KVER"
+	# shellcheck disable=SC2016
+	CLEANUP='rm -f "$SYMVERS";'"$CLEANUP"
+	;;
+esac
+
+[[ ! "$SYMVERS" ]] || FILESYMS=
+echo "$ME: symbols resolved with ${SYMVERS:+-E "$SYMVERS"}${FILESYMS:+-F "$FILESYMS"}" >&2
+
+[[ "${#MODULES[@]}" -gt 0 ]] || {
+    echo "$ME: reading modules from stdin ..." >&2
+    mapfile -t MODULES < <(sed -E 's/\s+/\n/g')
+}
+[[ "${#MODULES[@]}" -gt 0 ]]
+
+find_module() {
+    local f
+    f=$(cd "$2" && find . -name "$1.ko*" -type f -print -quit)
+    echo "${f#./}"
+}
+
+copy_results_to() {
+    rm -rf "${OUTPUTDIR:?}/$1"
+    mkdir -p "$OUTPUTDIR/$1"
+    cp -a "$WORKDIR/lib/modules/$KVER/modules".* "$OUTPUTDIR/$1"
+}
+
+restore_results_from() {
+    cp -a "$OUTPUTDIR/$1/"* "$WORKDIR/lib/modules/$KVER/"
+}
+
+delete_modules() {
+    pushd "$WORKDIR/lib/modules/$KVER" &>/dev/null
+    rm -f "${!EXTRAMODS[@]}"
+    popd &>/dev/null
+}
+
+restore_deleted_modules() {
+    pushd "$CLONEDIR/lib/modules/$KVER" &>/dev/null
+    echo "${!EXTRAMODS[@]}" | sed -E 's/\s+/\n/g' | \
+	cpio -p --link "$WORKDIR/lib/modules/$KVER" 2>/dev/null
+    popd &>/dev/null
+}
+
+check_results_for() {
+    local ref
+    ref=${2:-reference}
+    if diff -ruq "$OUTPUTDIR/$ref" "$OUTPUTDIR/$1"; then
+	echo "$ME: $1: OK" >&2
+    else
+	echo "$ME: depmod output for in $OUTPUTDIR/$1 differs from $OUTPUTDIR/$ref" >&2
+	: $((ERR++))
+    fi
+}
+
+# MODPATHS holds the full module paths relative to the module directory,
+# this is the same format as in modules.dep
+# REGEX will be used to grep modules.dep for any of these paths occurring
+# in the dependency list of some module (DEPENDS below).
+MODPATHS=()
+for x in "${!MODULES[@]}"; do
+    [[ "$x" ]] || continue
+    mp=$(find_module "${MODULES[$x]}" "$BASEDIR/lib/modules/$KVER")
+    if [[ "$mp" ]]; then
+	MODPATHS["$x"]=$mp
+	REGEX="$REGEX|${mp//./\\.}"
+    else
+	echo "$ME: module ${MODULES[$x]} not found" >&2
+    fi
+done
+REGEX=${REGEX#|}
+
+# First, clone the module directory
+CLONEDIR=$OUTPUTDIR/clone
+[[ -f "$CLONEDIR/lib/modules/$KVER/modules.dep" ]] || {
+    rm -rf "$CLONEDIR/lib/modules"
+    mkdir -p "$CLONEDIR/lib/modules"
+    cp -r "$BASEDIR/lib/modules/$KVER" "$CLONEDIR/lib/modules"
+
+    echo "$ME: running depmod over entire tree"
+    time "$DEPMOD" $DEPMOD_OPTS -b "$CLONEDIR" -e ${SYMVERS:+-E "$SYMVERS"} ${FILESYMS:+-F "$FILESYMS"} "$KVER"
+}
+
+# With modules.dep in place, find all modules that depend on MODULES.
+mapfile -t DEPENDS < <(sed -nE 's,:.*\<('"$REGEX"')\>.*$,,p' "$CLONEDIR/lib/modules/$KVER/modules.dep")
+
+# EXTRAMODS holds the paths for MODULES and all their dependencies
+# use associative array to avoid duplicates
+declare -A EXTRAMODS
+for x in "${MODPATHS[@]}" "${DEPENDS[@]}"; do
+    EXTRAMODS["$x"]=1
+done
+
+# Copy clone work dir and save the depmod results in "reference" dir
+WORKDIR=$OUTPUTDIR/work
+rm -rf "$WORKDIR/lib/modules"
+mkdir -p "$WORKDIR/lib/modules"
+cp -rl "$CLONEDIR/lib/modules/$KVER" "$WORKDIR/lib/modules/$KVER"
+copy_results_to reference
+
+# Delete EXTRAMODS, and run depmod again (pretend system state before adding EXTRAMODS)
+# Save results in "orig"
+delete_modules
+echo "$ME: running full depmod after module removal"
+time "$DEPMOD" $DEPMOD_OPTS -b "$WORKDIR" -e ${SYMVERS:+-E "$SYMVERS"} ${FILESYMS:+-F "$FILESYMS"} "$KVER"
+copy_results_to orig
+
+# 1. Restore deleted modules, and run depmod --incremental
+# Save results in "incremental", and compare to "reference"
+restore_deleted_modules
+echo "$ME: running depmod --incremental (${#EXTRAMODS[@]} modules added)"
+time "$DEPMOD" $DEPMOD_OPTS -b "$WORKDIR" -I -e ${SYMVERS:+-E "$SYMVERS"} ${FILESYMS:+-F "$FILESYMS"} "$KVER" "${!EXTRAMODS[@]}"
+copy_results_to incremental
+check_results_for incremental
+
+# 2. Same thing, but with depmod --incremental --all
+# Save results in "incremental-all", and compare to "reference"
+restore_results_from orig
+echo "$ME: running depmod --incremental --all"
+time "$DEPMOD" $DEPMOD_OPTS -b "$WORKDIR" -I -a -e ${SYMVERS:+-E "$SYMVERS"} ${FILESYMS:+-F "$FILESYMS"} "$KVER"
+copy_results_to incremental-all
+check_results_for incremental-all
+
+# 3. Delete modules again, and test depmod --incremental --all for removal
+# Save results in "deleted", and compare to "orig"
+delete_modules
+echo "$ME: running depmod --incremental --all after module removal"
+# this will spit out lots of "module xyz not found" error messages
+time "$DEPMOD" $DEPMOD_OPTS -b "$WORKDIR" -I -a -e ${SYMVERS:+-E "$SYMVERS"} ${FILESYMS:+-F "$FILESYMS"} "$KVER" 2>/dev/null
+copy_results_to deleted
+check_results_for deleted orig
+
+exit "$ERR"