Add support for creating a new testing environment in functions.sh

Add the new functions _run_env(), _exit_env(), _init_env() and
_cleanup_env() to run the tests inside a new environment specified with the
TST_ENV environment variable.

A typical structure of a script with tests is:

trap '_report_exit_and_cleanup _cleanup_env cleanup' \
    SIGINT SIGTERM SIGSEGV EXIT

cleanup() {
	<test cleanup>
}

<tests implementations>

_run_env "$TST_KERNEL" "$PWD/$(basename "$0")" "env_var1=$env_var1 ..."

_exit_env "$TST_KERNEL"

_init_env

<tests init>

<tests call>

If TST_ENV is not set or empty, don't create a new testing environment and
perform the cleanup in the current environment. Don't create a new testing
environment also if the script is already executed in a new environment, to
avoid loops. Instead, for cleanup, do it in the new environment and skip it
in the host environment (if the cleanup function is passed to
_cleanup_env()).

Signal to the creator of the environment failures of tests or of the script
itself run in the new environment (if the exit code is 1 ($FAIL) or 99
($HARDFAIL)) with an unclean shutdown of the system.

Add haveged and systemd as dependencies for the tests in ci/fedora.sh,
respectively for initializing the random number generator and for shutting
down the system in the new environment.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

ci/fedora.sh

@@ -45,7 +45,9 @@ yum -y install \
 	vim-common \
 	wget \
 	which \
-	zstd
+	zstd \
+	haveged \
+	systemd
 
 yum -y install docbook5-style-xsl || true
 yum -y install swtpm || true

tests/functions.sh

@@ -271,6 +271,25 @@ _report_exit_and_cleanup() {
   [ $testsfail -gt 0 ] && echo -n "$RED" || echo -n "$NORM"
   echo " FAIL: $testsfail"
   echo "$NORM"
+  # Signal failure to the testing environment creator with an unclean shutdown.
+  if [ -n "$TST_ENV" ] && [ $$ -eq 1 ]; then
+    if [ -z "$(command -v poweroff)" ]; then
+      echo "Warning: cannot properly shutdown system"
+    fi
+
+    # If no test was executed and the script was successful,
+    # do a clean shutdown.
+    if [ $testsfail -eq 0 ] && [ $testspass -eq 0 ] && [ $testsskip -eq 0 ] &&
+       [ $exit_code -ne "$FAIL" ] && [ $exit_code -ne "$HARDFAIL" ]; then
+      poweroff -f
+    fi
+
+    # If tests were executed and no test failed, do a clean shutdown.
+    if { [ $testspass -gt 0 ] || [ $testsskip -gt 0 ]; } &&
+       [ $testsfail -eq 0 ]; then
+      poweroff -f
+    fi
+  fi
   if [ $testsfail -gt 0 ]; then
     exit "$FAIL"
   elif [ $testspass -gt 0 ]; then
@@ -319,3 +338,75 @@ _softhsm_teardown() {
   unset SOFTHSM_SETUP_CONFIGDIR SOFTHSM2_CONF PKCS11_KEYURI \
     EVMCTL_ENGINE OPENSSL_ENGINE OPENSSL_KEYFORM
 }
+
+# Syntax: _run_env <kernel> <init> <additional kernel parameters>
+_run_env() {
+  if [ -z "$TST_ENV" ]; then
+    return
+  fi
+
+  if [ $$ -eq 1 ]; then
+    return
+  fi
+
+  if [ "$TST_ENV" = "um" ]; then
+    expect_pass "$1" rootfstype=hostfs rw init="$2" quiet mem=2048M "$3"
+  else
+    echo $RED"Testing environment $TST_ENV not supported"$NORM
+    exit "$FAIL"
+  fi
+}
+
+# Syntax: _exit_env <kernel>
+_exit_env() {
+  if [ -z "$TST_ENV" ]; then
+    return
+  fi
+
+  if [ $$ -eq 1 ]; then
+    return
+  fi
+
+  exit "$OK"
+}
+
+# Syntax: _init_env
+_init_env() {
+  if [ -z "$TST_ENV" ]; then
+    return
+  fi
+
+  if [ $$ -ne 1 ]; then
+    return
+  fi
+
+  mount -t tmpfs tmpfs /tmp
+  mount -t proc proc /proc
+  mount -t sysfs sysfs /sys
+  mount -t securityfs securityfs /sys/kernel/security
+
+  if [ -n "$(command -v haveged 2> /dev/null)" ]; then
+    $(command -v haveged) -w 1024 &> /dev/null
+  fi
+
+  pushd "$PWD" > /dev/null || exit "$FAIL"
+}
+
+# Syntax: _cleanup_env <cleanup function>
+_cleanup_env() {
+  if [ -z "$TST_ENV" ]; then
+    $1
+    return
+  fi
+
+  if [ $$ -ne 1 ]; then
+    return
+  fi
+
+  $1
+
+  umount /sys/kernel/security
+  umount /sys
+  umount /proc
+  umount /tmp
+}