find-provides.ksyms, find-requires.ksyms: avoid calling nm twice

Instead of running the nm output through grep and then running it
through awk again, run it directly through awk, and bail of immediately
if a non-absolute symbol is found.

Also, while we're here, avoid executing the indirect parsing code
if no __crc_* symbols are present at all, which shaves around 8-18% off
of the run time:

    % for i in ./lib/modules/*; do \
        echo "====== $i ====="; \
        diff -u <(find $i | ./find-provides.ksyms.old) <(find $i | ./find-provides.ksyms.new); \
        echo old:; find $i | time ./find-provides.ksyms.old > /dev/null; \
        echo new:; find $i | time ./find-provides.ksyms.new > /dev/null; \
    done
    ====== ./lib/modules/4.18.0-372.57.1.el8_6.s390x =====
    old: ../find-provides.ksyms.old > /dev/null  5.10s user 4.52s system 150% cpu 6.412 total
    new: ../find-provides.ksyms.new > /dev/null  4.41s user 3.48s system 136% cpu 5.764 total
    ====== ./lib/modules/4.18.0-372.57.1.el8_6.x86_64 =====
    old: ../find-provides.ksyms.old > /dev/null  7.80s user 6.19s system 143% cpu 9.740 total
    new: ../find-provides.ksyms.new > /dev/null  6.07s user 3.97s system 124% cpu 8.066 total
    ====== ./lib/modules/5.14.0-284.15.1.el9_2.s390x =====
    old: ../find-provides.ksyms.old > /dev/null  5.87s user 4.35s system 143% cpu 7.113 total
    new: ../find-provides.ksyms.new > /dev/null  5.12s user 3.56s system 132% cpu 6.533 total
    ====== ./lib/modules/5.14.0-284.15.1.el9_2.x86_64 =====
    old: ../find-provides.ksyms.old > /dev/null  8.44s user 6.78s system 144% cpu 10.535 total
    new: ../find-provides.ksyms.new > /dev/null  6.55s user 4.17s system 123% cpu 8.666 total
    ====== ./lib/modules/6.4.0-0.rc1.20230511git80e62bc8487b.19.eln126.s390x =====
    old: ../find-provides.ksyms.old > /dev/null  5.04s user 3.95s system 145% cpu 6.166 total
    new: ../find-provides.ksyms.new > /dev/null  4.64s user 3.17s system 136% cpu 5.719 total
    ====== ./lib/modules/6.4.0-0.rc1.20230511git80e62bc8487b.19.eln126.x86_64 =====
    old: ../find-provides.ksyms.old > /dev/null  8.49s user 5.54s system 139% cpu 10.043 total
    new: ../find-provides.ksyms.new > /dev/null  7.41s user 4.31s system 129% cpu 9.046 total

* find-provides.ksyms: Rewrite the "if nm | grep -q; then nm | awk"
with straight "nm | awk", update the awk script to return the exit code
accordingly, execute indirect symbol parsing only if inderect __crc_*
symbols are present.
* find-requires.ksyms (all_provides): Likewise.

Signed-off-by: Eugene Syromiatnikov <esyr@redhat.com>

find-provides.ksyms

@@ -37,13 +37,28 @@ for module in $(grep -E '/lib/modules/.+\.ko(\.gz|\.bz2|\.xz|\.zst)?$') "$@"; do
         module="$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($0, /^([0-9a-f]+) A __crc_(.+)/, a) { printf("%s(%s) = 0x%08x\n", dep_pfx, a[2], strtonum("0x" a[1])) }'
-    else
+    # awk script return code:
+    #   0 - absolute __crc_* symbols have been found, output has been
+    #       generated;
+    #   23 - a non-absolute __crc_* symbold has been found;
+    #   42 - no __crc_* symbols have been found.
+    nm "$module" \
+    | awk \
+       -v 'dep_pfx='"$dep_pfx" \
+       --non-decimal-data \
+       'BEGIN { exit_code = 42 }
+       match($0, /^([0-9a-f]+) (.) __crc_(.+)/, a) {
+           if (a[2] == "A") {
+               printf("%s(%s) = 0x%08x\n", dep_pfx, a[3], strtonum("0x" a[1]));
+               exit_code = 0;
+           } else {
+               exit_code = 23;
+               exit;
+           }
+       }
+       END { exit exit_code }'
+
+    [ 23 = "$?" ] && {
         objdump -t "$module" \
         | sed -n 's/^[0-9a-f][0-9a-f]* [gl]...... \(.*\)	[0-9a-f][0-9a-f]* __crc_.*$/\1/p' \
         | sort -u \
@@ -71,7 +86,7 @@ for module in $(grep -E '/lib/modules/.+\.ko(\.gz|\.bz2|\.xz|\.zst)?$') "$@"; do
               }
               match($0, /^([0-9a-f]+) [gl]...... (.*)	[0-9a-f]+ __crc_(.*)$/, a) && a[2] == sectname { printf("%s(%s) = 0x%08s\n", dep_pfx, a[3], substr(sectdata, (strtonum("0x" a[1]) * 2) + 1, 8)) }'
         done
-    fi
+    }
 
     [ -z "$tmpfile" ] || rm -f -- "$tmpfile"
 done \

find-requires.ksyms

@@ -39,13 +39,28 @@ all_provides() {
             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($0, /^([0-9a-f]+) A __crc_(.+)/, a) { printf("%s(%s) = 0x%08x\n", dep_pfx, a[2], strtonum("0x" a[1])) }'
-        else
+        # awk script return code:
+        #   0 - absolute __crc_* symbols have been found, output has been
+        #       generated;
+        #   23 - a non-absolute __crc_* symbold has been found;
+        #   42 - no __crc_* symbols have been found.
+        nm "$module" \
+        | awk \
+           -v 'dep_pfx='"$dep_pfx" \
+           --non-decimal-data \
+           'BEGIN { exit_code = 42 }
+           match($0, /^([0-9a-f]+) (.) __crc_(.+)/, a) {
+               if (a[2] == "A") {
+                   printf("%s(%s) = 0x%08x\n", dep_pfx, a[3], strtonum("0x" a[1]));
+                   exit_code = 0;
+               } else {
+                   exit_code = 23;
+                   exit;
+               }
+           }
+           END { exit exit_code }'
+
+        [ 23 = "$?" ] && {
             objdump -t "$module" \
             | sed -n 's/^[0-9a-f][0-9a-f]* [gl]...... \(.*\)	[0-9a-f][0-9a-f]* __crc_.*$/\1/p' \
             | sort -u \
@@ -73,7 +88,7 @@ all_provides() {
                   }
                   match($0, /^([0-9a-f]+) [gl]...... (.*)	[0-9a-f]+ __crc_(.*)$/, a) && a[2] == sectname { printf("%s(%s) = 0x%08s\n", dep_pfx, a[3], substr(sectdata, (strtonum("0x" a[1]) * 2) + 1, 8)) }'
             done
-        fi
+        }
 
         [ -z "$tmpfile" ] || rm -f -- "$tmpfile"
     done \