From 594e5a5a303e499922715ea9481dfa6d6614b321 Mon Sep 17 00:00:00 2001
From: Eugene Syromiatnikov <esyr@redhat.com>
Date: Sun, 5 Feb 2023 01:12:50 +0100
Subject: [PATCH] find-provides.ksyms, find-requires.ksyms: rewrite absolute
 CRC parsing

Avoid running sed on the whole "nm" output and also avoid "sed | awk"
pipe in favor of a single awk call.  Overall, this gives around 20%
speedup on some quick synthetic tests:

    $ time sh -c 'find ./lib/modules/5.14.0-258.el9.x86_64 -name "*.ko.xz" | find-provides.ksyms.old > /dev/null 2> /dev/null'
    sh -c   14.20s user 8.93s system 144% cpu 16.014 total
    $ time sh -c 'find ./lib/modules/5.14.0-258.el9.x86_64 -name "*.ko.xz" | find-provides.ksyms.new > /dev/null 2> /dev/null'
    sh -c   12.01s user 7.46s system 143% cpu 13.567 total
    $ time sh -c 'find ./lib/modules/5.14.0-258.el9.x86_64 -name "*.ko.xz" -exec sh -c "echo {} | find-provides.ksyms.old" \; > /dev/null 2> /dev/null'
    sh -c   16.31s user 10.77s system 134% cpu 20.092 total
    $ time sh -c 'find ./lib/modules/5.14.0-258.el9.x86_64 -name "*.ko.xz" -exec sh -c "echo {} | find-provides.ksyms.new" \; > /dev/null 2> /dev/null'
    sh -c   13.95s user 8.92s system 135% cpu 16.836 total

* find-provides.ksyms: Check presence of absolute __crc_* symbols with
"grep -q" exit code and not presence of sed output;  rewrite awk script to match
the __crc_* symbols instead of preprocessing the nm output with sed.
* find-requires.ksyms: Likewise.

Signed-off-by: Eugene Syromiatnikov <esyr@redhat.com>
Resolves: #2135047
---
 find-provides.ksyms | 10 ++++++----
 find-requires.ksyms |  8 +++++---
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/find-provides.ksyms b/find-provides.ksyms
index 1a9deb5..9402623 100755
--- a/find-provides.ksyms
+++ b/find-provides.ksyms
@@ -34,10 +34,12 @@ for module in $(grep -E '/lib/modules/.+\.ko(\.gz|\.bz2|\.xz|\.zst)?$') "$@"; do
         module="$tmpfile"
     fi
 
-    if [[ -n $(nm $module | sed -r -ne 's:^0*([0-9a-f]+) A __crc_(.+):0x\1 \2:p') ]]; then
-        nm $module \
-        | sed -r -ne 's:^0*([0-9a-f]+) A __crc_(.+):0x\1 \2:p' \
-        | awk --non-decimal-data '{printf("'"${dep_pfx}"'(%s) = 0x%08x\n", $2, $1)}' \
+    if nm "$module" | grep -qE '^([0-9a-f]+) A __crc_(.+)' 2> /dev/null; then
+        nm "$module" \
+        | awk \
+           -v 'dep_pfx='"$dep_pfx" \
+           --non-decimal-data \
+          'match($0, /^([0-9a-f]+) A __crc_(.+)/, a) { printf("%s(%s) = 0x%08x\n", dep_pfx, a[2], strtonum("0x" a[1])) }' \
         | sort -u
     else
         ELFRODATA=$(readelf -R .rodata $module | awk '/0x/{printf $2$3$4$5}')
diff --git a/find-requires.ksyms b/find-requires.ksyms
index 78a2105..ae61906 100755
--- a/find-requires.ksyms
+++ b/find-requires.ksyms
@@ -35,10 +35,12 @@ all_provides() {
             module="$tmpfile"
         fi
 
-        if [[ -n $(nm "$module" | sed -r -ne 's:^0*([0-9a-f]+) A __crc_(.+):0x\1 \2:p') ]]; then
+        if nm "$module" | grep -qE '^([0-9a-f]+) A __crc_(.+)' 2> /dev/null; then
             nm "$module" \
-            | sed -r -ne 's:^0*([0-9a-f]+) A __crc_(.+):0x\1 \2:p' \
-            | awk --non-decimal-data '{printf("%s:0x%08x\n", $2, $1)}'
+            | awk \
+               -v 'dep_pfx='"$dep_pfx" \
+               --non-decimal-data \
+              'match($0, /^([0-9a-f]+) A __crc_(.+)/, a) { printf("%s(%s) = 0x%08x\n", dep_pfx, a[2], strtonum("0x" a[1])) }'
         else
             ELFRODATA=$(readelf -R .rodata "$module" | awk '/0x/{printf $2$3$4$5}')
             if [[ -n $(readelf -h "$module" | grep "little endian") ]]; then