[PATCH ima-evm-utils v2 4/9] Add support for UML in functions.sh

[Roberto Sassu <roberto.sassu@xxxxxxxxxxxxxxx>]

From: Roberto Sassu <roberto.sassu@xxxxxxxxxx>

Add the new functions _run_user_mode(), _exit_user_mode(),
_init_user_mode() and _cleanup_user_mode() to run the tests inside a system
booted with the UML kernel.

A typical structure of a script with tests is:

trap cleanup SIGINT SIGTERM SIGSEGV EXIT

_cleanup() {
	<test cleanup>
}

cleanup() {
	_cleanup_user_mode _cleanup
	_report_exit_and_cleanup
}

<tests implementations>

_run_user_mode ../linux $PWD/$(basename $0) "env_var1=$env_var1 ..."

_exit_user_mode ../linux

_init_user_mode

<tests init>

<tests call>

If the UML_MODE environment variable is not set to 1, ignore the UML kernel
execution and initialization requests, and perform the cleanup in the
current environment. Ignore the same also if the script is already run in
the UML environment, to avoid loops. Instead, for cleanup, do it only in
the UML environment and skip it in the host environment.

Signal to the host environment failures of tests run in the UML environment
with an unclean shutdown of the UML kernel.

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 environment created by the UML kernel.

Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
---
 ci/fedora.sh       |  4 ++-
 tests/functions.sh | 79 +++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 81 insertions(+), 2 deletions(-)

diff --git a/ci/fedora.sh b/ci/fedora.sh
index e60de7981c60..198034a34e3c 100755
--- a/ci/fedora.sh
+++ b/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
diff --git a/tests/functions.sh b/tests/functions.sh
index 8f6f02dfcd95..98829d94fae1 100755
--- a/tests/functions.sh
+++ b/tests/functions.sh
@@ -267,6 +267,16 @@ _report_exit_and_cleanup() {
   [ $testsfail -gt 0 ] && echo -n "$RED" || echo -n "$NORM"
   echo " FAIL: $testsfail"
   echo "$NORM"
+  # Signal failure to UML caller with an unclean shutdown.
+  if [ -n "$UML_MODE" ] && [ "$UML_MODE" -eq 1 ] && [ $$ -eq 1 ]; then
+    if [ -z "$(which poweroff)" ]; then
+      echo "Warning: cannot properly shutdown system"
+    fi
+
+    if [ $testsfail -eq 0 ]; then
+      poweroff -f
+    fi
+  fi
   if [ $testsfail -gt 0 ]; then
     exit "$FAIL"
   elif [ $testspass -gt 0 ]; then
@@ -312,4 +322,71 @@ _softhsm_teardown() {
   rm -rf "${SOFTHSM_SETUP_CONFIGDIR}"
   unset SOFTHSM_SETUP_CONFIGDIR SOFTHSM2_CONF PKCS11_KEYURI \
     EVMCTL_ENGINE OPENSSL_ENGINE OPENSSL_KEYFORM
-}
\ No newline at end of file
+}
+
+# Syntax: _run_user_mode <UML binary> <init> <additional kernel parameters>
+_run_user_mode() {
+  if [ -z "$UML_MODE" ] || [ "$UML_MODE" -ne 1 ]; then
+    return
+  fi
+
+  if [ $$ -eq 1 ]; then
+    return
+  fi
+
+  expect_pass $1 rootfstype=hostfs rw init=$2 quiet mem=256M $3
+}
+
+# Syntax: _exit_user_mode <UML binary>
+_exit_user_mode() {
+  if [ -z "$UML_MODE" ] || [ "$UML_MODE" -ne 1 ]; then
+    return
+  fi
+
+  if [ $$ -eq 1 ]; then
+    return
+  fi
+
+  if [ -f "$1" ]; then
+    exit $OK
+  fi
+}
+
+# Syntax: _init_user_mode
+_init_user_mode() {
+  if [ -z "$UML_MODE" ] || [ "$UML_MODE" -ne 1 ]; then
+    return
+  fi
+
+  if [ $$ -ne 1 ]; then
+    return
+  fi
+
+  mount -t proc proc /proc
+  mount -t sysfs sysfs /sys
+  mount -t securityfs securityfs /sys/kernel/security
+
+  if [ -n "$(which haveged 2> /dev/null)" ]; then
+    $(which haveged) -w 1024 &> /dev/null
+  fi
+
+  pushd $PWD > /dev/null
+}
+
+# Syntax: _cleanup_user_mode <cleanup function>
+_cleanup_user_mode() {
+  if [ -z "$UML_MODE" ] || [ "$UML_MODE" -ne 1 ]; then
+    $1
+    return
+  fi
+
+  if [ $$ -ne 1 ]; then
+    return
+  fi
+
+  $1
+
+  umount /sys/kernel/security
+  umount /sys
+  umount /proc
+}
-- 
2.25.1