From f264cfbe8a9fa36765c918db9d7074a89eedbcd6 Mon Sep 17 00:00:00 2001
From: Lukas Nykryn <lnykryn@redhat.com>
Date: Mon, 11 Jun 2018 11:07:59 +0200
Subject: [PATCH] dracut.sh: workaround broken read from /proc/modules

RHEL-only (upstream is using libkmod)
Resolves: #1578222
---
 dracut.sh | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/dracut.sh b/dracut.sh
index 873274c0..9dadece0 100755
--- a/dracut.sh
+++ b/dracut.sh
@@ -1145,10 +1145,23 @@ if [[ $hostonly ]]; then
 
     # check /proc/modules
     declare -A host_modules
-    while read m rest; do
-        [ -z "$m" ] && continue
-        host_modules["$m"]=1
-    done </proc/modules
+    declare new_module_found=1
+    declare tmpmodules=$(mktemp --tmpdir="$TMPDIR/" -t proc_modules.XXXXXX)
+    while [[ $new_module_found ]]; do
+        new_module_found=
+        sleep 0.1
+        #reading from procfs can be broken, so copy the file elsewhere
+        cp -f /proc/modules "$tmpmodules"
+        while read m rest; do
+            [ -z "$m" ] && continue
+            [[ ${host_modules["$m"]} ]] && continue
+            host_modules["$m"]=1
+            new_module_found=1
+        done < "$tmpmodules"
+    done
+    rm "$tmpmodules"
+    unset new_module_found
+    unset tmpmodules
 fi
 
 unset m