Merge pull request AFLplusplus#1998 from trail-of-forks/grub-cmdline

afl-persistent-config: Use GRUB_CMDLINE_LINUX instead of GRUB_CMDLINE_LINUX_DEFAULT

afl-persistent-config

@@ -124,17 +124,26 @@ kernel.sched_latency_ns=250000000
 EOF
   }
 
-  grep -E -q '^GRUB_CMDLINE_LINUX_DEFAULT=' /etc/default/grub 2>/dev/null || echo Error: /etc/default/grub with GRUB_CMDLINE_LINUX_DEFAULT is not present, cannot set boot options
-  grep -E -q '^GRUB_CMDLINE_LINUX_DEFAULT=' /etc/default/grub 2>/dev/null && {
-    grep -E '^GRUB_CMDLINE_LINUX_DEFAULT=' /etc/default/grub | grep -E -q 'noibrs pcid nopti' || {
+  grub_try_disable_mitigation () {
+    KEY="$1"
+    if ! grep -E "^$KEY=" /etc/default/grub | grep -E -q 'noibrs pcid nopti'; then
       echo "Configuring performance boot options"
-      LINE=`grep -E '^GRUB_CMDLINE_LINUX_DEFAULT=' /etc/default/grub | sed 's/^GRUB_CMDLINE_LINUX_DEFAULT=//' | tr -d '"'`
+      LINE=`grep -E "^$KEY=" /etc/default/grub | sed "s/^$KEY=//" | tr -d '"'`
       OPTIONS="$LINE ibpb=off ibrs=off kpti=off l1tf=off spec_rstack_overflow=off mds=off no_stf_barrier noibpb noibrs pcid nopti nospec_store_bypass_disable nospectre_v1 nospectre_v2 pcid=on pti=off spec_store_bypass_disable=off spectre_v2=off stf_barrier=off srbds=off noexec=off noexec32=off tsx=on tsx=on tsx_async_abort=off mitigations=off audit=0 hardened_usercopy=off ssbd=force-off"
-      echo Setting boot options in /etc/default/grub to GRUB_CMDLINE_LINUX_DEFAULT=\"$OPTIONS\"
-      sed -i "s|^GRUB_CMDLINE_LINUX_DEFAULT=.*|GRUB_CMDLINE_LINUX_DEFAULT=\"$OPTIONS\"|" /etc/default/grub
-    }
+      echo Setting boot options in /etc/default/grub to $KEY=\"$OPTIONS\"
+      sed -i "s|^$KEY=.*|$KEY=\"$OPTIONS\"|" /etc/default/grub
+    fi
   }
 
+
+  if grep -E -q '^GRUB_CMDLINE_LINUX=' /etc/default/grub || grep -E -q '^GRUB_CMDLINE_LINUX_DEFAULT=' /etc/default/grub; then
+    grub_try_disable_mitigation "GRUB_CMDLINE_LINUX_DEFAULT"
+    # We also overwrite GRUB_CMDLINE_LINUX because some distributions already overwrite GRUB_CMDLINE_LINUX_DEFAULT
+    grub_try_disable_mitigation "GRUB_CMDLINE_LINUX"
+  else
+    echo "Error: /etc/default/grub with GRUB_CMDLINE_LINUX is not present, cannot set boot options"
+  fi
+
   echo
   echo "Reboot and enjoy your fuzzing"
   exit 0