test: don't preload libasan for systemd-remount-fs.service

The `mount` utility has an unexpected behavior when run with libasan,
causing false-positives during the integration testing.

For example, on Arch Linux with LD_PRELOAD pointing to libasan:
```
bash-5.0# mount -o remount,rw -v /
mount: /dev/sda1 mounted on /.
bash-5.0# echo $?
1
```
However:
```
bash-5.0# LD_PRELOAD= mount -o remount,rw -v /
mount: /dev/sda1 mounted on /.
bash-5.0# echo $?
0
```
Further investigation with strace shows a LeakSanitizer error:
```
bash-5.0# strace -s 512 mount -o remount,rw -v /
...
write(2, "==355==LeakSanitizer has encountered a fatal error.\n", 52) = -1 EBADF (Bad file descriptor)
write(2, "ReportFile::Write() can't output requested buffer!\n", 51) = -1 EBADF (Bad file descriptor)
exit_group(1)                           = ?
+++ exited with 1 +++
```

Let's workaround this by clearing the LD_PRELOAD variable for
systemd-remount-fs.service

diff --git a/test/test-functions b/test/test-functions
index 50c6e9690251a6c2b5c2a347ec4e0ce5a99c7799..b269cd35241125a34d68d708354658d556b5b217 100644 (file)
--- a/test/test-functions
+++ b/test/test-functions
@@ -386,6 +386,18 @@ printf "[Service]\nEnvironment=ASAN_OPTIONS=\$DEFAULT_ASAN_OPTIONS:log_path=/sys
 mkdir -p /etc/systemd/system/systemd-hwdb-update.service.d
 printf "[Unit]\nConditionVirtualization=container\n\n[Service]\nTimeoutSec=180s\n" >/etc/systemd/system/systemd-hwdb-update.service.d/env-override.conf
 
+# The 'mount' utility doesn't behave well under libasan, causing unexpected
+# fails during boot and subsequent test results check:
+# bash-5.0# mount -o remount,rw -v /
+# mount: /dev/sda1 mounted on /.
+# bash-5.0# echo \$?
+# 1
+# Let's workaround this by clearing the previously set LD_PRELOAD env variable,
+# so the libasan library is not loaded for this particular service
+REMOUNTFS_CONF_DIR=/etc/systemd/system/systemd-remount-fs.service.d
+mkdir -p "\$REMOUNTFS_CONF_DIR"
+printf "[Service]\nUnsetEnvironment=LD_PRELOAD\n" >"\$REMOUNTFS_CONF_DIR/env.conf"
+
 export ASAN_OPTIONS=\$DEFAULT_ASAN_OPTIONS:log_path=/systemd.asan.log UBSAN_OPTIONS=\$DEFAULT_UBSAN_OPTIONS
 exec  $ROOTLIBDIR/systemd "\$@"
 EOF