fault-injection: add selftests for cpu and memory hotplug

This adds two selftests

* tools/testing/selftests/cpu-hotplug/on-off-test.sh is testing script
for CPU hotplug

1. Online all hot-pluggable CPUs
2. Offline all hot-pluggable CPUs
3. Online all hot-pluggable CPUs again
4. Exit if cpu-notifier-error-inject.ko is not available
5. Offline all hot-pluggable CPUs in preparation for testing
6. Test CPU hot-add error handling by injecting notifier errors
7. Online all hot-pluggable CPUs in preparation for testing
8. Test CPU hot-remove error handling by injecting notifier errors

* tools/testing/selftests/memory-hotplug/on-off-test.sh is doing the
similar thing for memory hotplug.

1. Online all hot-pluggable memory
2. Offline 10% of hot-pluggable memory
3. Online all hot-pluggable memory again
4. Exit if memory-notifier-error-inject.ko is not available
5. Offline 10% of hot-pluggable memory in preparation for testing
6. Test memory hot-add error handling by injecting notifier errors
7. Online all hot-pluggable memory in preparation for testing
8. Test memory hot-remove error handling by injecting notifier errors

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Greg KH <greg@kroah.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Dave Jones <davej@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 227 insertions, 0 deletions

diff --git a/tools/testing/selftests/cpu-hotplug/Makefile b/tools/testing/selftests/cpu-hotplug/Makefile
new file mode 100644
index 000000000000..7c9c20ff578a
--- /dev/null
+++ b/tools/testing/selftests/cpu-hotplug/Makefile
@@ -0,0 +1,6 @@
+all:
+
+run_tests:
+        ./on-off-test.sh
+
+clean:
diff --git a/tools/testing/selftests/cpu-hotplug/on-off-test.sh b/tools/testing/selftests/cpu-hotplug/on-off-test.sh
new file mode 100644
index 000000000000..bdde7cf428bb
--- /dev/null
+++ b/tools/testing/selftests/cpu-hotplug/on-off-test.sh
@@ -0,0 +1,221 @@
+#!/bin/bash
+
+SYSFS=
+
+prerequisite()
+{
+        msg="skip all tests:"
+
+        if [ $UID != 0 ]; then
+                echo $msg must be run as root >&2
+                exit 0
+        fi
+
+        SYSFS=`mount -t sysfs | head -1 | awk '{ print $3 }'`
+
+        if [ ! -d "$SYSFS" ]; then
+                echo $msg sysfs is not mounted >&2
+                exit 0
+        fi
+
+        if ! ls $SYSFS/devices/system/cpu/cpu* > /dev/null 2>&1; then
+                echo $msg cpu hotplug is not supported >&2
+                exit 0
+        fi
+}
+
+#
+# list all hot-pluggable CPUs
+#
+hotpluggable_cpus()
+{
+        local state=${1:-.\*}
+
+        for cpu in $SYSFS/devices/system/cpu/cpu*; do
+                if [ -f $cpu/online ] && grep -q $state $cpu/online; then
+                        echo ${cpu##/*/cpu}
+                fi
+        done
+}
+
+hotplaggable_offline_cpus()
+{
+        hotpluggable_cpus 0
+}
+
+hotpluggable_online_cpus()
+{
+        hotpluggable_cpus 1
+}
+
+cpu_is_online()
+{
+        grep -q 1 $SYSFS/devices/system/cpu/cpu$1/online
+}
+
+cpu_is_offline()
+{
+        grep -q 0 $SYSFS/devices/system/cpu/cpu$1/online
+}
+
+online_cpu()
+{
+        echo 1 > $SYSFS/devices/system/cpu/cpu$1/online
+}
+
+offline_cpu()
+{
+        echo 0 > $SYSFS/devices/system/cpu/cpu$1/online
+}
+
+online_cpu_expect_success()
+{
+        local cpu=$1
+
+        if ! online_cpu $cpu; then
+                echo $FUNCNAME $cpu: unexpected fail >&2
+        elif ! cpu_is_online $cpu; then
+                echo $FUNCNAME $cpu: unexpected offline >&2
+        fi
+}
+
+online_cpu_expect_fail()
+{
+        local cpu=$1
+
+        if online_cpu $cpu 2> /dev/null; then
+                echo $FUNCNAME $cpu: unexpected success >&2
+        elif ! cpu_is_offline $cpu; then
+                echo $FUNCNAME $cpu: unexpected online >&2
+        fi
+}
+
+offline_cpu_expect_success()
+{
+        local cpu=$1
+
+        if ! offline_cpu $cpu; then
+                echo $FUNCNAME $cpu: unexpected fail >&2
+        elif ! cpu_is_offline $cpu; then
+                echo $FUNCNAME $cpu: unexpected offline >&2
+        fi
+}
+
+offline_cpu_expect_fail()
+{
+        local cpu=$1
+
+        if offline_cpu $cpu 2> /dev/null; then
+                echo $FUNCNAME $cpu: unexpected success >&2
+        elif ! cpu_is_online $cpu; then
+                echo $FUNCNAME $cpu: unexpected offline >&2
+        fi
+}
+
+error=-12
+priority=0
+
+while getopts e:hp: opt; do
+        case $opt in
+        e)
+                error=$OPTARG
+                ;;
+        h)
+                echo "Usage $0 [ -e errno ] [ -p notifier-priority ]"
+                exit
+                ;;
+        p)
+                priority=$OPTARG
+                ;;
+        esac
+done
+
+if ! [ "$error" -ge -4095 -a "$error" -lt 0 ]; then
+        echo "error code must be -4095 <= errno < 0" >&2
+        exit 1
+fi
+
+prerequisite
+
+#
+# Online all hot-pluggable CPUs
+#
+for cpu in `hotplaggable_offline_cpus`; do
+        online_cpu_expect_success $cpu
+done
+
+#
+# Offline all hot-pluggable CPUs
+#
+for cpu in `hotpluggable_online_cpus`; do
+        offline_cpu_expect_success $cpu
+done
+
+#
+# Online all hot-pluggable CPUs again
+#
+for cpu in `hotplaggable_offline_cpus`; do
+        online_cpu_expect_success $cpu
+done
+
+#
+# Test with cpu notifier error injection
+#
+
+DEBUGFS=`mount -t debugfs | head -1 | awk '{ print $3 }'`
+NOTIFIER_ERR_INJECT_DIR=$DEBUGFS/notifier-error-inject/cpu
+
+prerequisite_extra()
+{
+        msg="skip extra tests:"
+
+        /sbin/modprobe -q -r cpu-notifier-error-inject
+        /sbin/modprobe -q cpu-notifier-error-inject priority=$priority
+
+        if [ ! -d "$DEBUGFS" ]; then
+                echo $msg debugfs is not mounted >&2
+                exit 0
+        fi
+
+        if [ ! -d $NOTIFIER_ERR_INJECT_DIR ]; then
+                echo $msg cpu-notifier-error-inject module is not available >&2
+                exit 0
+        fi
+}
+
+prerequisite_extra
+
+#
+# Offline all hot-pluggable CPUs
+#
+echo 0 > $NOTIFIER_ERR_INJECT_DIR/actions/CPU_DOWN_PREPARE/error
+for cpu in `hotpluggable_online_cpus`; do
+        offline_cpu_expect_success $cpu
+done
+
+#
+# Test CPU hot-add error handling (offline => online)
+#
+echo $error > $NOTIFIER_ERR_INJECT_DIR/actions/CPU_UP_PREPARE/error
+for cpu in `hotplaggable_offline_cpus`; do
+        online_cpu_expect_fail $cpu
+done
+
+#
+# Online all hot-pluggable CPUs
+#
+echo 0 > $NOTIFIER_ERR_INJECT_DIR/actions/CPU_UP_PREPARE/error
+for cpu in `hotplaggable_offline_cpus`; do
+        online_cpu_expect_success $cpu
+done
+
+#
+# Test CPU hot-remove error handling (online => offline)
+#
+echo $error > $NOTIFIER_ERR_INJECT_DIR/actions/CPU_DOWN_PREPARE/error
+for cpu in `hotpluggable_online_cpus`; do
+        offline_cpu_expect_fail $cpu
+done
+
+echo 0 > $NOTIFIER_ERR_INJECT_DIR/actions/CPU_DOWN_PREPARE/error
+/sbin/modprobe -q -r cpu-notifier-error-inject