#! /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

    # awk script return code:
    #   0 - absolute __crc_* symbols have been found, output has been
    #       generated;
    #   23 - a non-absolute __crc_* symbold has been found;
    #   42 - no __crc_* symbols have been found.
    nm "$module" \
    | awk \
       -v 'dep_pfx='"$dep_pfx" \
       --non-decimal-data \
       'BEGIN { exit_code = 42 }
       match($0, /^([0-9a-f]+) (.) __crc_(.+)/, a) {
           if (a[2] == "A") {
               printf("%s(%s) = 0x%08x\n", dep_pfx, a[3], strtonum("0x" a[1]));
               exit_code = 0;
           } else {
               exit_code = 23;
               exit;
           }
       }
       END { exit exit_code }'

    [ 23 = "$?" ] && {
        kmod_elf_hdr="$(readelf -h "$module")"
        [ "x$kmod_elf_hdr" = "x${kmod_elf_hdr%Data:*little endian*}" ]
        revbytes="$?"

        objdump -t "$module" \
        | awk \
          -v 'dep_pfx='"$dep_pfx" \
          -v 'module='"$module" \
          -v 'revbytes='"$revbytes" \
          --non-decimal-data \
          '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 (revbytes) { 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] 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