You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
kernel-srpm-macros/SOURCES/find-provides.ksyms

139 lines
6.0 KiB

#! /bin/bash
IFS=$'\n'
export LC_ALL=C
# Prevent elfutils from trying to download debuginfos
unset DEBUGINFOD_URLS
for module in $(grep -E '/lib/modules/.+\.ko(\.gz|\.bz2|\.xz|\.zst)?$') "$@"; do
dep_pfx="ksym"
# For built-in kmods, "kernel()" syntax is used instead of "ksym()"
printf "%s" "$module" | grep -v "^${RPM_BUILD_ROOT}/\?lib/modules/[1-9][^/]*/kernel" > /dev/null \
|| dep_pfx="kernel"
tmpfile=""
if [ "x${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
# A modversion can be stored as an ELF symbol in various ways:
# - An immediate symbol whose value is available directly; it shows up
# in the nm or objdump -t output, for example:
# $ nm mlx5_core_5.14.x86_64.ko | grep '__crc_' | head -n 3
# 0000000092f175ca A __crc_mlx5_access_reg
# 000000005b88c9f1 A __crc_mlx5_add_flow_rules
# 00000000e7c0ec8a A __crc_mlx5_alloc_bfreg
# $ objdump -t lib/modules/mlx5_core_5.14.x86_64.ko | grep __crc_ | sort -k 5,5 | head -n 3
# 0000000092f175ca g *ABS* 0000000000000000 __crc_mlx5_access_reg
# 000000005b88c9f1 g *ABS* 0000000000000000 __crc_mlx5_add_flow_rules
# 00000000e7c0ec8a g *ABS* 0000000000000000 __crc_mlx5_alloc_bfreg
# $ zgrep mlx5_access_reg ./lib/modules/5.14.0-284.15.1.el9_2.x86_64/symvers.gz
# 0x92f175ca mlx5_access_reg drivers/net/ethernet/mellanox/mlx5/core/mlx5_core EXPORT_SYMBOL_GPL
# This approach was being used on x86 and arm before Linux 5.19,
# for example.
#
# - A globally or locally visible symbol in a read-only (or not;
# sometimes .rodata is not a read-only section, after all, as binutils
# commit binutils-2_33~1385 has revealed (and binutils-2_35~1768 hasn't
# concealed back)) section (historically .rodata, __kcrctab/__kcrctab_gpl
# since Linux v5.19-rc1~139^2~2):
# $ nm mlx5_core_5.14.s390x.ko | grep '__crc_' | head -n 3
# 0000000000002f7c R __crc_mlx5_access_reg
# 0000000000003304 R __crc_mlx5_add_flow_rules
# 0000000000002d2c R __crc_mlx5_alloc_bfreg
# This layout is used on ppc since Linux v4.10-rc7~15^2~1, for example,
# and on all architectures since Linux 5.19. To extract the symbol
# versions in this case, we get the offset and the section name
# from the "objdump -t" output:
# $ objdump -t lib/modules/mlx5_core_5.14.s390x.ko | grep '__crc_' | sort -k 5,5 | head -n 2
# 0000000000002f7c g .rodata 0000000000000000 __crc_mlx5_access_reg
# 0000000000003304 g .rodata 0000000000000000 __crc_mlx5_add_flow_rules
# and the section contents from the "readelf -R" call:
# $ readelf -R .rodata mlx5_core_5.14.s390x.ko
# [... skipped output ...]
# 0x00002f70 6c6f635f 6e6f6465 00000000 ed6560a8 loc_node.....e`.
# ^^^^^^^^
# comparison with the contents
# of lib/modules/5.14.0-284.15.1.el9_2.s390x/symvers.gz corroborates
# its correctness:
# 0xed6560a8 mlx5_access_reg drivers/net/ethernet/mellanox/mlx5/core/mlx5_core EXPORT_SYMBOL_GPL
# As mentioned earlier, for the later kernel versions, __kcrctab{,_gpl}
# sections are used:
# $ objdump -t lib/modules/mlx5_core_6.4.x86_64.ko | grep '__crc_' | sort -k 5,5 | head -n 2
# 0000000000000000 l __kcrctab_gpl 0000000000000000 __crc_mlx5_access_reg
# 0000000000000090 l __kcrctab 0000000000000000 __crc_mlx5_add_flow_rules
# $ readelf -R __kcrctab_gpl mlx5_core_6.4.x86_64.ko
# 0x00000000 38b0d3c3 1840ce35 b99babc7 70b4700c 8....@.5....p.p.
# ^^^^^^^^
# and in lib/modules/6.4.0-0.rc1.20230511git80e62bc8487b.19.eln126.x86_64/symvers.xz
# we see that it is correct (when accounted for the little endianness):
# 0xc3d3b038 mlx5_access_reg drivers/net/ethernet/mellanox/mlx5/core/mlx5_core EXPORT_SYMBOL_GPL
# This data, after some post-processing, can be used in the awk script
# that extracts parts of the section according to the offsets got
# from the "objdump -t" output.
objdump -t "$module" \
| awk \
-v 'dep_pfx='"$dep_pfx" \
-v 'module='"$module" \
--non-decimal-data \
'BEGIN { revbytes = 0 }
function check_endianness( t) {
if (revbytes) return revbytes;
revbytes = -1;
while (("readelf -h \"" module "\"" | getline t) > 0) {
if (match(t, /^ Data: *2\047s complement, little endian$/)) {
revbytes = 1;
break;
}
}
return revbytes;
}
function readsect(name, a, t) {
a = "";
while (("readelf -R \"" name "\" \"" module "\"" | getline t) > 0) {
if (match(t, /^ 0x[0-9a-f]{8}/))
a = a substr(t, 14, 8) substr(t, 23, 8) substr(t, 32, 8) substr(t, 41, 8);
}
if (check_endianness() == 1)
a = gensub(/(..)(..)(..)(..)/, "\\4\\3\\2\\1", "g", a);
sectdata[name] = a;
}
match($0, /^([0-9a-f]+) [gl]...... (.*) [0-9a-f]+ __crc_(.*)$/, a) {
if (a[2] == "*ABS*") {
printf("%s(%s) = 0x%08x\n", dep_pfx, a[3], strtonum("0x" a[1]));
} else {
if (!(a[2] in sectdata)) { readsect(a[2]) }
printf("%s(%s) = 0x%08s\n", dep_pfx, a[3], substr(sectdata[a[2]], (strtonum("0x" a[1]) * 2) + 1, 8))
}
}'
[ -z "$tmpfile" ] || rm -f -- "$tmpfile"
done \
| sort -k1,1 -u