#!/bin/bash
#
# weak-modules - determine which modules are kABI compatible with installed
# kernels and set up the symlinks in /lib/*/weak-updates.
#
unset LANG LC_ALL LC_COLLATE
tmpdir=$(mktemp -td ${0##*/}.XXXXXX)
trap "rm -rf $tmpdir" EXIT
unset ${!changed_modules_*} ${!changed_initramfs_*}
initramfs_prefix="/boot" # can customize here
dracut="/sbin/dracut"
if [ ! -x "$dracut" ]
then
echo "weak-modules: this tool requires a dracut-enabled kernel"
exit 1
fi
# doit:
# A wrapper used whenever we're going to perform a real operation.
doit() {
[ -n "$verbose" ] && echo "$@"
[ -n "$dry_run" ] || "$@"
}
# rpmsort: The sort in coreutils can't sort the RPM list how we want it so we
# instead transform the list into a form it will sort correctly, then sort.
rpmsort() {
local IFS=$' '
REVERSE=""
rpmlist=($(cat))
if [ "-r" == "$1" ];
then
REVERSE="-r"
fi
echo ${rpmlist[@]} | \
sed -e 's/-/../g' | \
sort ${REVERSE} -n -t"." -k1,1 -k2,2 -k3,3 -k4,4 -k5,5 -k6,6 -k7,7 \
-k8,8 -k9,9 -k10,10 | \
sed -e 's/\.\./-/g'
}
# read_modules_list:
# Read in a list of modules from standard input. Convert the filenames into
# absolute paths and compute the kernel release for each module (either using
# the modinfo section or through the absolute path.
read_modules_list() {
local IFS=$'\n'
modules=($(cat))
for ((n = 0; n < ${#modules[@]}; n++)); do
if [ ${modules[n]:0:1} != '/' ]; then
modules[n]="$PWD/${modules[n]}"
fi
if [ -f "${modules[n]}" ]; then
module_krels[n]=$(krel_of_module ${modules[n]})
else
# Try to extract the kernel release from the path
set -- "${modules[n]#*/lib/modules/}"
module_krels[n]=${1%%/*}
fi
done
}
decompress_initramfs() {
local input=$1
local output=$2
# First, check if this is compressed at all
if cpio -i -t < "$input" > /dev/null 2>/dev/null; then
# If this archive contains a file early_cpio, it's a trick. Strip off
# the early cpio archive and try again.
if cpio -i -t < "$input" 2>/dev/null | grep -q '^early_cpio$' ; then
/usr/lib/dracut/skipcpio "$input" > "${tmpdir}/post_early_cpio.img"
decompress_initramfs "${tmpdir}/post_early_cpio.img" "$output"
retval="$?"
rm -f "${tmpdir}/post_early_cpio.img"
return $retval
fi
cp "$input" "$output"
return 0
fi
# Try gzip
if gzip -cd < "$input" > "$output" 2>/dev/null ; then
return 0
fi
# Next try xz
if xz -cd < "$input" > "$output" 2>/dev/null ; then
return 0
fi
echo "Unable to decompress $input: Unknown format" >&2
return 1
}
# List all module files and modprobe configuration that could require a new
# initramfs. The current directory must be the root of the uncompressed
# initramfs. The unsorted list of files is output to stdout.
list_module_files() {
find . -iname \*.ko 2>/dev/null
find etc/modprobe.d usr/lib/modprobe.d -name \*.conf 2>/dev/null
}
# read_old_initramfs:
compare_initramfs_modules() {
local old_initramfs=$1
local new_initramfs=$2
rm -rf "$tmpdir/old_initramfs"
rm -rf "$tmpdir/new_initramfs"
mkdir "$tmpdir/old_initramfs"
mkdir "$tmpdir/new_initramfs"
decompress_initramfs "$old_initramfs" "$tmpdir/old_initramfs.img"
pushd "$tmpdir/old_initramfs" >/dev/null
cpio -i < "$tmpdir/old_initramfs.img" 2>/dev/null
rm "$tmpdir/old_initramfs.img"
n=0; for i in `list_module_files|sort`; do
old_initramfs_modules[n]="$i"
n=$((n+1))
done
popd >/dev/null
decompress_initramfs "$new_initramfs" "$tmpdir/new_initramfs.img"
pushd "$tmpdir/new_initramfs" >/dev/null
cpio -i < "$tmpdir/new_initramfs.img" 2>/dev/null
rm "$tmpdir/new_initramfs.img"
n=0; for i in `list_module_files|sort`; do
new_initramfs_modules[n]="$i"
n=$((n+1))
done
popd >/dev/null
# Compare the length and contents of the arrays
if [ "${#old_initramfs_modules[@]}" == "${#new_initramfs_modules[@]}" -a \
"${old_initramfs_modules[*]}" == "${new_initramfs_modules[*]}" ];
then
# If the file lists are the same, compare each file to find any that changed
for ((n = 0; n < ${#old_initramfs_modules[@]}; n++)); do
if ! cmp "$tmpdir/old_initramfs/${old_initramfs_modules[n]}" \
"$tmpdir/new_initramfs/${new_initramfs_modules[n]}" ; then
return 1
fi
done
else
return 1
fi
return 0
}
# check_initramfs:
# check and possibly also update the initramfs for changed kernels
check_initramfs() {
local kernel=$1
# If there is no initramfs already we will not make one here.
if [ -e "$initramfs_prefix/initramfs-$kernel.img" ];
then
old_initramfs="$initramfs_prefix/initramfs-$kernel.img"
tmp_initramfs="$initramfs_prefix/initramfs-$kernel.tmp"
new_initramfs="$initramfs_prefix/initramfs-$kernel.img"
$dracut -f "$tmp_initramfs" "$kernel"
if ! $(compare_initramfs_modules "$old_initramfs" "$tmp_initramfs");
then
doit mv "$tmp_initramfs" "$new_initramfs"
else
rm -f "$tmp_initramfs"
fi
fi
}
# krel_of_module:
# Compute the kernel release of a module.
krel_of_module() {
declare module=$1
/sbin/modinfo -F vermagic "$module" | awk '{print $1}'
}
# module_is_compatible:
# Determine if a module is compatible with a particular kernel release. Also
# include any symbol deps that might be introduced by other external kmods.
module_is_compatible() {
declare module=$1 krel=$2 module_krel=$(krel_of_module "$module")
if [ ! -e "$tmpdir/all-symvers-$krel-$module_krel" ]; then
# Symbols exported by the "new" kernel
if [ ! -e $tmpdir/symvers-$krel ]; then
# Accept '.' in the symbol name to handle the .TOC. symbol on ppc
if [ -e /boot/symvers-$krel.gz ]; then
zcat /boot/symvers-$krel.gz \
| sed -r -ne 's:^(0x[0]*[0-9a-f]{8}\t[0-9a-zA-Z_.]+)\t.*:\1:p'
fi > $tmpdir/symvers-$krel
fi
# Symbols exported by the add-on modules of the "new" kernel
if [ ! -e "$tmpdir/addon-symvers-$krel" ]; then
if [ -e /lib/modules/$krel/extra ] && \
[ -n "`find /lib/modules/$krel/extra -type f`" ]; then
find /lib/modules/$krel/extra -name '*.ko' \
| xargs nm \
| sed -nre 's:^[0]*([0-9a-f]{8}) A __crc_(.*):0x\1 \2:p'
fi > $tmpdir/addon-symvers-$krel
fi
# Symbols that other add-on modules of the "old" kernel export
# (and that this module may require)
if [ ! -e "$tmpdir/extra-symvers-$module_krel" ]; then
if [ -e /lib/modules/$module_krel/extra ] && \
[ -n "`find /lib/modules/$module_krel/extra -type f`" ]; then
find /lib/modules/$module_krel/extra -name '*.ko' \
| xargs nm \
| sed -nre 's:^[0]*([0-9a-f]{8}) A __crc_(.*):0x\1 \2:p'
fi > $tmpdir/extra-symvers-$module_krel
fi
sort -u $tmpdir/symvers-$krel \
$tmpdir/extra-symvers-$module_krel \
$tmpdir/addon-symvers-$krel \
> "$tmpdir/all-symvers-$krel-$module_krel"
fi
# If the module does not have modversions enabled, $tmpdir/modvers
# will be empty.
/sbin/modprobe --dump-modversions "$module" \
| sed -r -e 's:^(0x[0]*[0-9a-f]{8}\t.*):\1:' \
| sort -u \
> $tmpdir/modvers
# Only include lines of the second file in the output that don't
# match lines in the first file. (The default separator is
# <space>, so we are matching the whole line.)
join -j 1 -v 2 $tmpdir/all-symvers-$krel-$module_krel \
$tmpdir/modvers > $tmpdir/join
if [ ! -s $tmpdir/modvers ]; then
echo "Warning: Module ${module##*/} from kernel $module_krel has no" \
"modversions, so it cannot be reused for kernel $krel" >&2
elif [ -s $tmpdir/join ]; then
[ -n "$verbose" ] &&
echo "Module ${module##*/} from kernel $module_krel is not compatible" \ "with kernel $krel in symbols:" $(sed -e 's:.* ::' $tmpdir/join)
else
[ -n "$verbose" ] &&
echo "Module ${module##*/} from kernel $module_krel is compatible" \
"with kernel $krel"
return 0
fi
return 1
}
usage() {
echo "Usage: ${0##*/} [options] {--add-modules|--remove-modules}"
echo "${0##*/} [options] {--add-kernel|--remove-kernel} {kernel-release}"
cat <<'EOF'
--add-modules
Add a list of modules read from standard input. Create
symlinks in compatible kernel's weak-updates/ directory.
The list of modules is read from standard input.
--remove-modules
Remove compatibility symlinks from weak-updates/ directories
for a list of modules. The list of modules is read from
standard input. Optionally specify --delete-modules to
prevent weak-modules from attempting to locate any
compatible modules to replace those being removed.
--add-kernel
Add compatibility symlinks for all compatible modules to the
specified or running kernel.
--remove-kernel
Remove all compatibility symlinks for the specified or current
kernel.
--no-initramfs
Do not generate an initramfs.
--verbose
Print the commands executed.
--dry-run
Do not create/remove any files.
EOF
exit $1
}
# module_has_changed:
# Mark if an actual change occured that we need to deal with later by calling
# depmod or mkinitramfs against the affected kernel.
module_has_changed() {
declare module=$1 krel=$2
module=${module%.ko}
module=${module##*/}
eval "changed_modules_${krel//[^a-zA-Z0-9]/_}=$krel"
eval "changed_initramfs_${krel//[^a-zA-Z0-9]/_}=$krel"
}
# add_modules:
# Read in a list of modules from stdinput and process them for compatibility
# with installed kernels under /lib/modules.
add_modules() {
read_modules_list || exit 1
if [ ${#modules[@]} -gt 0 ]; then
for krel in $(ls /lib/modules/); do
[ -e "/boot/symvers-$krel.gz" ] || continue
for ((n = 0; n < ${#modules[@]}; n++)); do
module="${modules[n]}"
module_krel="${module_krels[n]}"
case "$module" in
/lib/modules/$krel/*)
# Module was built against this kernel, update initramfs.
module_has_changed $module $krel
continue ;;
esac
# Module my also serve as a weak-update built against another
# kernel. We need to create symlinks for compatible kernels
# under /lib/modules and rerun depmod/dracut for those.
subpath=`echo $module | sed -nre "s:(/usr)?/lib/modules/$module_krel/([^/]*)/(.*):\3:p"`
weak_module="/lib/modules/$krel/weak-updates/${subpath#/}"
if [ -r "$weak_module" ]; then
weak_krel=$(krel_of_module "$weak_module")
if [ "$weak_krel" != "$module_krel" ] &&
[ "$(printf "%s\n" "$weak_krel" "$module_krel" \
| rpmsort | (read input; echo "$input"; \
while read input; do true; done))" = \
"$module_krel" ]; then
# Keep modules from more recent kernels.
[ -n "$verbose" ] && echo \
"Keeping module ${module##*/} from kernel $weak_krel for kernel $krel"
continue
fi
fi
if module_is_compatible $module $krel; then
doit mkdir -p $(dirname $weak_module)
doit ln -sf $module $weak_module
# Module was built against another kernel, update initramfs.
module_has_changed $module $krel
fi
done
done
fi
}
# remove_modules:
# Read in a list of modules from stdinput and process them for removal.
# Parameter is noreplace to delete modules, otherwise link compat.
remove_modules() {
delete_modules=${1:-replace}
read_modules_list || exit 1
if [ ${#modules[@]} -gt 0 ]; then
# Hunt for all known users of this module in /lib/modules, remove them
# and create symlinks to other compatible modules (downgrade) if
# possible, update initramfs for each modified kernel too.
krels=($(ls /lib/modules/ | rpmsort -r))
for krel in "${krels[@]}"; do
[ -e "/boot/symvers-$krel.gz" ] || continue
for ((n = 0; n < ${#modules[@]}; n++)); do
module="${modules[n]}"
module_krel="${module_krels[n]}"
# Module is going to be removed, update initramfs.
module_has_changed $module $krel
subpath="${module#*/lib/modules/$module_krel/extra}"
weak_module="/lib/modules/$krel/weak-updates/${subpath#/}"
if [ "$module" == "`readlink $weak_module`" ]; then
[ -n "$verbose" ] && echo \
"Removing compatible module ${module##*/} from kernel $krel"
doit rm -f "$weak_module"
if [ "replace" == "$delete_modules" ]; then
for krel2 in "${krels[@]}"; do
if [ $krel2 != $krel ]; then
module="/lib/modules/$krel2/extra/${subpath#/}"
[ -e "$module" ] || continue
if module_is_compatible "$module" "$krel"; then
[ -n "$verbose" ] && echo \
"Adding compatible module ${module##*/} from kernel $krel2 instead"
doit ln -s "$module" "$weak_module"
module_has_changed $module $krel
break
fi
fi
done
fi
# Remove the part of the directory beneath weak-updates
( cd "/lib/modules/$krel/weak-updates" && \
doit rmdir --parents --ignore-fail-on-non-empty "$(dirname "${subpath#/}")" )
fi
done
done
fi
}
add_kernel() {
add_krel=${1:-$(uname -r)}
if [ ! -e "/boot/symvers-$add_krel.gz" ]; then
echo "Symvers dump file /boot/symvers-$add_krel.gz" \
"not found" >&2
exit 1
fi
for krel in $(ls /lib/modules/ | rpmsort -r); do
[ "$add_krel" = "$krel" ] && continue
[ -d /lib/modules/$krel/extra ] || continue
for module in $(find /lib/modules/$krel/extra -name '*.ko'); do
subpath="${module#*/lib/modules/$krel/extra}"
weak_module="/lib/modules/$add_krel/weak-updates/${subpath#/}"
[ -e "$weak_module" ] && continue
if module_is_compatible $module $add_krel; then
module_has_changed $module $add_krel
doit mkdir -p $(dirname $weak_module)
doit ln -sf $module $weak_module
fi
done
done
}
remove_kernel() {
remove_krel=${1:-$(uname -r)}
weak_modules="/lib/modules/$remove_krel/weak-updates"
module_has_changed $weak_modules $remove_krel
# Remove everything beneath the weak-updates directory
( cd "$weak_modules" && doit rm -rf * )
}
################################################################################
################################## MAIN GUTS ###################################
################################################################################
options=`getopt -o h --long help,add-modules,remove-modules \
--long add-kernel,remove-kernel \
--long dry-run,no-initramfs,verbose,delete-modules -- "$@"`
[ $? -eq 0 ] || usage 1
eval set -- "$options"
while :; do
case "$1" in
--add-modules)
do_add_modules=1
;;
--remove-modules)
do_remove_modules=1
;;
--add-kernel)
do_add_kernel=1
;;
--remove-kernel)
do_remove_kernel=1
;;
--dry-run)
dry_run=1
;;
--no-initramfs)
no_initramfs=1
;;
--verbose)
verbose=1
;;
--delete-modules)
do_delete_modules=1
;;
-h|--help)
usage 0
;;
--)
shift
break
;;
esac
shift
done
if [ -n "$do_add_modules" ]; then
add_modules
elif [ -n "$do_remove_modules" ]; then
if [ -n "$do_delete_modules" ]; then
remove_modules "noreplace"
else
remove_modules
fi
elif [ -n "$do_add_kernel" ]; then
kernel=${1:-$(uname -r)}
add_kernel $kernel
elif [ -n "$do_remove_kernel" ]; then
kernel=${1:-$(uname -r)}
remove_kernel $kernel
exit 0
else
usage 1
fi
################################################################################
###################### CLEANUP POST ADD/REMOVE MODULE/KERNEL ###################
################################################################################
# run depmod and dracut as needed
for krel in ${!changed_modules_*}; do
krel=${!krel}
doit /sbin/depmod -ae -F /boot/System.map-$krel $krel
done
for krel in ${!changed_initramfs_*}; do
krel=${!krel}
if [ ! -n "$no_initramfs" ]; then
check_initramfs $krel
fi
done