kernel-srpm-macros/find-requires.ksyms
Eugene Syromiatnikov cd7e9e8a2f find-provides.ksyms, find-requires.ksyms: rewrite indirect CRC parsing
Linux commit v5.19-rc1~139^2~2 ("kbuild: link symbol CRCs at final link,
removing CONFIG_MODULE_REL_CRCS") has broken the assumption aobut
the placement of non-absolute CRC symbols in .rodata (and also affects
the architectures that used to have these symbols as absolute);  rewrite
the parsing by utilising "objdump -t" output to figure out
the section(s) where the __crc_* symbols are stored and process
it instead of the hard-coded ".rodata" section.  The change also speeds
up the processing a bit, around 33% on synthetic tests:

    $ time sh -c 'find ./lib/modules/5.14.0-258.el9.ppc64le -name "*.ko.xz" | find-provides.ksyms.old > /dev/null 2> /dev/null'
    sh -c   10.36s user 5.58s system 137% cpu 11.613 total
    $ time sh -c 'find ./lib/modules/5.14.0-258.el9.ppc64le -name "*.ko.xz" | find-provides.ksyms.new > /dev/null 2> /dev/null'
    sh -c   7.82s user 4.59s system 142% cpu 8.686 total
    $ time sh -c 'find ./lib/modules/5.14.0-258.el9.ppc64le -name "*.ko.xz" -exec sh -c "echo {} | find-provides.ksyms.old" \; > /dev/null 2> /dev/null'
    sh -c   11.85s user 6.76s system 129% cpu 14.318 total
    $ time sh -c 'find ./lib/modules/5.14.0-258.el9.ppc64le -name "*.ko.xz" -exec sh -c "echo {} | find-provides.ksyms.new" \; > /dev/null 2> /dev/null'
    sh -c   8.91s user 5.51s system 135% cpu 10.647 total

* find-provides.ksyms: Process "objdump -t" output to get the list
of sections where __crc_* symbol contents are placed;  retrieve
each one with "readelf -R" and supply it to an awk script that cuts
the required part of it for each __crc_* symbol in that section.
* find-requires.ksyms (all_provides): Likewise.

Signed-off-by: Eugene Syromiatnikov <esyr@redhat.com>
Resolves: #2135047
2023-03-07 14:56:55 +01:00

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#! /bin/bash
#
# This script is called during external module building to create dependencies
# both upon the RHEL kernel, and on additional external modules. Symbols that
# cannot be reconciled against those provided by the kernel are assumed to be
# provided by an external module and "ksym" replaces th regular "kernel" dep.
IFS=$'\n'
# Extract all of the symbols provided by this module.
all_provides() {
for module in "$@"; do
tmpfile=""
if [ "x${module%.ko}" = "x${module}" ]; then
tmpfile=$(mktemp -t ${0##*/}.XXXXXX.ko)
proc_bin=
case "${module##*.}" in
zst)
proc_bin=zstd
;;
xz)
proc_bin=xz
;;
bz2)
proc_bin=bzip2
;;
gz)
proc_bin=gzip
;;
esac
[ -n "$proc_bin" ] || continue
"$proc_bin" -d -c - < "$module" > "$tmpfile" || continue
module="$tmpfile"
fi
if nm "$module" | grep -qE '^([0-9a-f]+) A __crc_(.+)' 2> /dev/null; then
nm "$module" \
| awk \
-v 'dep_pfx='"$dep_pfx" \
--non-decimal-data \
'match($0, /^([0-9a-f]+) A __crc_(.+)/, a) { printf("%s(%s) = 0x%08x\n", dep_pfx, a[2], strtonum("0x" a[1])) }'
else
objdump -t "$module" \
| sed -n 's/^[0-9a-f][0-9a-f]* g...... \(.*\) [0-9a-f][0-9a-f]* __crc_.*$/\1/p' \
| sort -u \
| while read sectname; do
[ -n "$sectname" ] || continue
ELFSECTDATA=$(readelf -R .rodata "$module" | awk '/0x/{printf $2$3$4$5}')
if [[ -n $(readelf -h "$module" | grep "little endian") ]]; then
SECTDATA=$(echo $ELFSECTDATA | sed 's/\(..\)\(..\)\(..\)\(..\)/\4\3\2\1/g')
else
SECTDATA=$ELFSECTDATA
fi
objdump -t "$module" \
| awk \
-v 'dep_pfx='"$dep_pfx" \
-v 'sectdata='"$SECTDATA" \
--non-decimal-data \
'match($0, /^([0-9a-f]+) g...... .* [0-9a-f]+ __crc_(.*)$/, a) { printf("%s(%s) = 0x%08s\n", dep_pfx, a[2], substr(sectdata, (strtonum("0x" a[1]) * 2) + 1, 8)) }'
done
fi
[ -z "$tmpfile" ] || rm -f -- "$tmpfile"
done \
| LC_ALL=C sort -k1,1 -u
}
# Extract all of the requirements of this module.
all_requires() {
for module in "$@"; do
set -- $(/sbin/modinfo -F vermagic "$module" | sed -e 's: .*::' -e q)
/sbin/modprobe --dump-modversions "$module" \
| awk --non-decimal-data '
BEGIN { FS = "\t" ; OFS = "\t" }
{printf("%s:0x%08x\n", $2, $1)}' \
| sed -r -e 's:$:\t'"$1"':'
done \
| LC_ALL=C sort -k1,1 -u
}
# Filter out requirements fulfilled by the module itself.
mod_requires() {
LC_ALL=C join -t $'\t' -j 1 -v 1 \
<(all_requires "$@") \
<(all_provides "$@") \
| LC_ALL=C sort -k1,1 -u
}
if ! [ -e /sbin/modinfo -a -e /sbin/modprobe ]; then
cat > /dev/null
exit 0
fi
check_kabi() {
arch=$(uname -m)
kabi_file="/lib/modules/kabi-current/kabi_stablelist_$arch"
# If not installed, output a warning and return (continue)
if [ ! -f "$kabi_file" ]; then
echo "" >&2
echo "********************************************************************************" >&2
echo "*********************** KERNEL ABI COMPATIBILITY WARNING ***********************" >&2
echo "********************************************************************************" >&2
echo "The kernel ABI reference files (provided by "kabi-stablelists") were not found." >&2
echo "No compatibility check was performed. Please install the kABI reference files" >&2
echo "and rebuild if you would like to verify compatibility with kernel ABI." >&2
echo "" >&2
return
fi
unset non_kabi
for symbol in "$@"; do
if ! egrep "^[[:space:]]$symbol\$" $kabi_file >/dev/null; then
non_kabi=("${non_kabi[@]}" "$symbol")
fi
done
if [ ${#non_kabi[@]} -gt 0 ]; then
echo "" >&2
echo "********************************************************************************" >&2
echo "*********************** KERNEL ABI COMPATIBILITY WARNING ***********************" >&2
echo "********************************************************************************" >&2
echo "The following kernel symbols are not guaranteed to remain compatible with" >&2
echo "future kernel updates to this RHEL release:" >&2
echo "" >&2
for symbol in "${non_kabi[@]}"; do
printf "\t$symbol\n" >&2
done
echo "" >&2
echo "Red Hat recommends that you consider using only official kernel ABI symbols" >&2
echo "where possible. Requests for additions to the kernel ABI can be filed with" >&2
echo "your partner or customer representative (component: driver-update-program)." >&2
echo "" >&2
fi
}
modules=($(grep -E '/lib/modules/.+\.ko(\.gz|\.bz2|\.xz|\.zst)?$') "$@")
if [ ${#modules[@]} -gt 0 ]; then
kernel=$(/sbin/modinfo -F vermagic "${modules[0]}" | sed -e 's: .*::' -e q)
# get all that kernel provides
symvers=$(mktemp -t ${0##*/}.XXXXX)
cat /usr/src/kernels/$kernel/Module.symvers | awk '
BEGIN { FS = "\t" ; OFS = "\t" }
{ print $2 ":" $1 }
' \
| sed -r -e 's:$:\t'"$kernel"':' \
| LC_ALL=C sort -k1,1 -u > $symvers
# Symbols matching with the kernel get a "kernel" dependency
mod_req=$(mktemp -t mod_req.XXXXX)
mod_requires "${modules[@]}" > "$mod_req"
LC_ALL=C join -t $'\t' -j 1 $symvers "$mod_req" | LC_ALL=C sort -u \
| awk 'BEGIN { FS = "[\t:]" ; OFS = "\t" } { print "kernel(" $1 ") = " $2 }'
# Symbols from elsewhere get a "ksym" dependency
LC_ALL=C join -t $'\t' -j 1 -v 2 $symvers "$mod_req" | LC_ALL=C sort -u \
| awk 'BEGIN { FS = "[\t:]" ; OFS = "\t" } { print "ksym(" $1 ") = " $2 }'
os_id=$(sed -nr '/^ID[[:space:]]*=/{ s/ID[[:space:]]*=[[:space:]]*//; s/^"(.*)"$/\1/; p }' /etc/os-release)
if [ "rhel" = "$os_id" ]; then
# Check kABI if the kabi-stablelists package is installed
# Do this last so we can try to output this error at the end
kabi_check_symbols=($(LC_ALL=C join -t $'\t' -j 1 $symvers "$mod_req" | LC_ALL=C sort -u \
| awk 'BEGIN { FS = "[\t:]" ; OFS = "\t" } { print $1 }'))
check_kabi "${kabi_check_symbols[@]}"
fi
fi