selftests/livepatch: introduce tests
Add a few livepatch modules and simple target modules that the included
regression suite can run tests against:
- basic livepatching (multiple patches, atomic replace)
- pre/post (un)patch callbacks
- shadow variable API
Signed-off-by: Joe Lawrence <[email protected]>
Signed-off-by: Petr Mladek <[email protected]>
Tested-by: Miroslav Benes <[email protected]>
Tested-by: Alice Ferrazzi <[email protected]>
Acked-by: Joe Lawrence <[email protected]>
Acked-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Jiri Kosina <[email protected]>
diff --git a/lib/livepatch/Makefile b/lib/livepatch/Makefile
new file mode 100644
index 0000000..26900dd
--- /dev/null
+++ b/lib/livepatch/Makefile
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for livepatch test code.
+
+obj-$(CONFIG_TEST_LIVEPATCH) += test_klp_atomic_replace.o \
+ test_klp_callbacks_demo.o \
+ test_klp_callbacks_demo2.o \
+ test_klp_callbacks_busy.o \
+ test_klp_callbacks_mod.o \
+ test_klp_livepatch.o \
+ test_klp_shadow_vars.o
+
+# Target modules to be livepatched require CC_FLAGS_FTRACE
+CFLAGS_test_klp_callbacks_busy.o += $(CC_FLAGS_FTRACE)
+CFLAGS_test_klp_callbacks_mod.o += $(CC_FLAGS_FTRACE)
diff --git a/lib/livepatch/test_klp_atomic_replace.c b/lib/livepatch/test_klp_atomic_replace.c
new file mode 100644
index 0000000..5af7093
--- /dev/null
+++ b/lib/livepatch/test_klp_atomic_replace.c
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Joe Lawrence <[email protected]>
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/livepatch.h>
+
+static int replace;
+module_param(replace, int, 0644);
+MODULE_PARM_DESC(replace, "replace (default=0)");
+
+#include <linux/seq_file.h>
+static int livepatch_meminfo_proc_show(struct seq_file *m, void *v)
+{
+ seq_printf(m, "%s: %s\n", THIS_MODULE->name,
+ "this has been live patched");
+ return 0;
+}
+
+static struct klp_func funcs[] = {
+ {
+ .old_name = "meminfo_proc_show",
+ .new_func = livepatch_meminfo_proc_show,
+ }, {}
+};
+
+static struct klp_object objs[] = {
+ {
+ /* name being NULL means vmlinux */
+ .funcs = funcs,
+ }, {}
+};
+
+static struct klp_patch patch = {
+ .mod = THIS_MODULE,
+ .objs = objs,
+ /* set .replace in the init function below for demo purposes */
+};
+
+static int test_klp_atomic_replace_init(void)
+{
+ patch.replace = replace;
+ return klp_enable_patch(&patch);
+}
+
+static void test_klp_atomic_replace_exit(void)
+{
+}
+
+module_init(test_klp_atomic_replace_init);
+module_exit(test_klp_atomic_replace_exit);
+MODULE_LICENSE("GPL");
+MODULE_INFO(livepatch, "Y");
+MODULE_AUTHOR("Joe Lawrence <[email protected]>");
+MODULE_DESCRIPTION("Livepatch test: atomic replace");
diff --git a/lib/livepatch/test_klp_callbacks_busy.c b/lib/livepatch/test_klp_callbacks_busy.c
new file mode 100644
index 0000000..40beddf
--- /dev/null
+++ b/lib/livepatch/test_klp_callbacks_busy.c
@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Joe Lawrence <[email protected]>
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/workqueue.h>
+#include <linux/delay.h>
+
+static int sleep_secs;
+module_param(sleep_secs, int, 0644);
+MODULE_PARM_DESC(sleep_secs, "sleep_secs (default=0)");
+
+static void busymod_work_func(struct work_struct *work);
+static DECLARE_DELAYED_WORK(work, busymod_work_func);
+
+static void busymod_work_func(struct work_struct *work)
+{
+ pr_info("%s, sleeping %d seconds ...\n", __func__, sleep_secs);
+ msleep(sleep_secs * 1000);
+ pr_info("%s exit\n", __func__);
+}
+
+static int test_klp_callbacks_busy_init(void)
+{
+ pr_info("%s\n", __func__);
+ schedule_delayed_work(&work,
+ msecs_to_jiffies(1000 * 0));
+ return 0;
+}
+
+static void test_klp_callbacks_busy_exit(void)
+{
+ cancel_delayed_work_sync(&work);
+ pr_info("%s\n", __func__);
+}
+
+module_init(test_klp_callbacks_busy_init);
+module_exit(test_klp_callbacks_busy_exit);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Joe Lawrence <[email protected]>");
+MODULE_DESCRIPTION("Livepatch test: busy target module");
diff --git a/lib/livepatch/test_klp_callbacks_demo.c b/lib/livepatch/test_klp_callbacks_demo.c
new file mode 100644
index 0000000..3fd8fe1
--- /dev/null
+++ b/lib/livepatch/test_klp_callbacks_demo.c
@@ -0,0 +1,121 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Joe Lawrence <[email protected]>
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/livepatch.h>
+
+static int pre_patch_ret;
+module_param(pre_patch_ret, int, 0644);
+MODULE_PARM_DESC(pre_patch_ret, "pre_patch_ret (default=0)");
+
+static const char *const module_state[] = {
+ [MODULE_STATE_LIVE] = "[MODULE_STATE_LIVE] Normal state",
+ [MODULE_STATE_COMING] = "[MODULE_STATE_COMING] Full formed, running module_init",
+ [MODULE_STATE_GOING] = "[MODULE_STATE_GOING] Going away",
+ [MODULE_STATE_UNFORMED] = "[MODULE_STATE_UNFORMED] Still setting it up",
+};
+
+static void callback_info(const char *callback, struct klp_object *obj)
+{
+ if (obj->mod)
+ pr_info("%s: %s -> %s\n", callback, obj->mod->name,
+ module_state[obj->mod->state]);
+ else
+ pr_info("%s: vmlinux\n", callback);
+}
+
+/* Executed on object patching (ie, patch enablement) */
+static int pre_patch_callback(struct klp_object *obj)
+{
+ callback_info(__func__, obj);
+ return pre_patch_ret;
+}
+
+/* Executed on object unpatching (ie, patch disablement) */
+static void post_patch_callback(struct klp_object *obj)
+{
+ callback_info(__func__, obj);
+}
+
+/* Executed on object unpatching (ie, patch disablement) */
+static void pre_unpatch_callback(struct klp_object *obj)
+{
+ callback_info(__func__, obj);
+}
+
+/* Executed on object unpatching (ie, patch disablement) */
+static void post_unpatch_callback(struct klp_object *obj)
+{
+ callback_info(__func__, obj);
+}
+
+static void patched_work_func(struct work_struct *work)
+{
+ pr_info("%s\n", __func__);
+}
+
+static struct klp_func no_funcs[] = {
+ {}
+};
+
+static struct klp_func busymod_funcs[] = {
+ {
+ .old_name = "busymod_work_func",
+ .new_func = patched_work_func,
+ }, {}
+};
+
+static struct klp_object objs[] = {
+ {
+ .name = NULL, /* vmlinux */
+ .funcs = no_funcs,
+ .callbacks = {
+ .pre_patch = pre_patch_callback,
+ .post_patch = post_patch_callback,
+ .pre_unpatch = pre_unpatch_callback,
+ .post_unpatch = post_unpatch_callback,
+ },
+ }, {
+ .name = "test_klp_callbacks_mod",
+ .funcs = no_funcs,
+ .callbacks = {
+ .pre_patch = pre_patch_callback,
+ .post_patch = post_patch_callback,
+ .pre_unpatch = pre_unpatch_callback,
+ .post_unpatch = post_unpatch_callback,
+ },
+ }, {
+ .name = "test_klp_callbacks_busy",
+ .funcs = busymod_funcs,
+ .callbacks = {
+ .pre_patch = pre_patch_callback,
+ .post_patch = post_patch_callback,
+ .pre_unpatch = pre_unpatch_callback,
+ .post_unpatch = post_unpatch_callback,
+ },
+ }, { }
+};
+
+static struct klp_patch patch = {
+ .mod = THIS_MODULE,
+ .objs = objs,
+};
+
+static int test_klp_callbacks_demo_init(void)
+{
+ return klp_enable_patch(&patch);
+}
+
+static void test_klp_callbacks_demo_exit(void)
+{
+}
+
+module_init(test_klp_callbacks_demo_init);
+module_exit(test_klp_callbacks_demo_exit);
+MODULE_LICENSE("GPL");
+MODULE_INFO(livepatch, "Y");
+MODULE_AUTHOR("Joe Lawrence <[email protected]>");
+MODULE_DESCRIPTION("Livepatch test: livepatch demo");
diff --git a/lib/livepatch/test_klp_callbacks_demo2.c b/lib/livepatch/test_klp_callbacks_demo2.c
new file mode 100644
index 0000000..5417573
--- /dev/null
+++ b/lib/livepatch/test_klp_callbacks_demo2.c
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Joe Lawrence <[email protected]>
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/livepatch.h>
+
+static int replace;
+module_param(replace, int, 0644);
+MODULE_PARM_DESC(replace, "replace (default=0)");
+
+static const char *const module_state[] = {
+ [MODULE_STATE_LIVE] = "[MODULE_STATE_LIVE] Normal state",
+ [MODULE_STATE_COMING] = "[MODULE_STATE_COMING] Full formed, running module_init",
+ [MODULE_STATE_GOING] = "[MODULE_STATE_GOING] Going away",
+ [MODULE_STATE_UNFORMED] = "[MODULE_STATE_UNFORMED] Still setting it up",
+};
+
+static void callback_info(const char *callback, struct klp_object *obj)
+{
+ if (obj->mod)
+ pr_info("%s: %s -> %s\n", callback, obj->mod->name,
+ module_state[obj->mod->state]);
+ else
+ pr_info("%s: vmlinux\n", callback);
+}
+
+/* Executed on object patching (ie, patch enablement) */
+static int pre_patch_callback(struct klp_object *obj)
+{
+ callback_info(__func__, obj);
+ return 0;
+}
+
+/* Executed on object unpatching (ie, patch disablement) */
+static void post_patch_callback(struct klp_object *obj)
+{
+ callback_info(__func__, obj);
+}
+
+/* Executed on object unpatching (ie, patch disablement) */
+static void pre_unpatch_callback(struct klp_object *obj)
+{
+ callback_info(__func__, obj);
+}
+
+/* Executed on object unpatching (ie, patch disablement) */
+static void post_unpatch_callback(struct klp_object *obj)
+{
+ callback_info(__func__, obj);
+}
+
+static struct klp_func no_funcs[] = {
+ { }
+};
+
+static struct klp_object objs[] = {
+ {
+ .name = NULL, /* vmlinux */
+ .funcs = no_funcs,
+ .callbacks = {
+ .pre_patch = pre_patch_callback,
+ .post_patch = post_patch_callback,
+ .pre_unpatch = pre_unpatch_callback,
+ .post_unpatch = post_unpatch_callback,
+ },
+ }, { }
+};
+
+static struct klp_patch patch = {
+ .mod = THIS_MODULE,
+ .objs = objs,
+ /* set .replace in the init function below for demo purposes */
+};
+
+static int test_klp_callbacks_demo2_init(void)
+{
+ patch.replace = replace;
+ return klp_enable_patch(&patch);
+}
+
+static void test_klp_callbacks_demo2_exit(void)
+{
+}
+
+module_init(test_klp_callbacks_demo2_init);
+module_exit(test_klp_callbacks_demo2_exit);
+MODULE_LICENSE("GPL");
+MODULE_INFO(livepatch, "Y");
+MODULE_AUTHOR("Joe Lawrence <[email protected]>");
+MODULE_DESCRIPTION("Livepatch test: livepatch demo2");
diff --git a/lib/livepatch/test_klp_callbacks_mod.c b/lib/livepatch/test_klp_callbacks_mod.c
new file mode 100644
index 0000000..8fbe645
--- /dev/null
+++ b/lib/livepatch/test_klp_callbacks_mod.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Joe Lawrence <[email protected]>
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+
+static int test_klp_callbacks_mod_init(void)
+{
+ pr_info("%s\n", __func__);
+ return 0;
+}
+
+static void test_klp_callbacks_mod_exit(void)
+{
+ pr_info("%s\n", __func__);
+}
+
+module_init(test_klp_callbacks_mod_init);
+module_exit(test_klp_callbacks_mod_exit);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Joe Lawrence <[email protected]>");
+MODULE_DESCRIPTION("Livepatch test: target module");
diff --git a/lib/livepatch/test_klp_livepatch.c b/lib/livepatch/test_klp_livepatch.c
new file mode 100644
index 0000000..aff08199
--- /dev/null
+++ b/lib/livepatch/test_klp_livepatch.c
@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2014 Seth Jennings <[email protected]>
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/livepatch.h>
+
+#include <linux/seq_file.h>
+static int livepatch_cmdline_proc_show(struct seq_file *m, void *v)
+{
+ seq_printf(m, "%s: %s\n", THIS_MODULE->name,
+ "this has been live patched");
+ return 0;
+}
+
+static struct klp_func funcs[] = {
+ {
+ .old_name = "cmdline_proc_show",
+ .new_func = livepatch_cmdline_proc_show,
+ }, { }
+};
+
+static struct klp_object objs[] = {
+ {
+ /* name being NULL means vmlinux */
+ .funcs = funcs,
+ }, { }
+};
+
+static struct klp_patch patch = {
+ .mod = THIS_MODULE,
+ .objs = objs,
+};
+
+static int test_klp_livepatch_init(void)
+{
+ return klp_enable_patch(&patch);
+}
+
+static void test_klp_livepatch_exit(void)
+{
+}
+
+module_init(test_klp_livepatch_init);
+module_exit(test_klp_livepatch_exit);
+MODULE_LICENSE("GPL");
+MODULE_INFO(livepatch, "Y");
+MODULE_AUTHOR("Seth Jennings <[email protected]>");
+MODULE_DESCRIPTION("Livepatch test: livepatch module");
diff --git a/lib/livepatch/test_klp_shadow_vars.c b/lib/livepatch/test_klp_shadow_vars.c
new file mode 100644
index 0000000..02f892f
--- /dev/null
+++ b/lib/livepatch/test_klp_shadow_vars.c
@@ -0,0 +1,236 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Joe Lawrence <[email protected]>
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/livepatch.h>
+#include <linux/slab.h>
+
+/*
+ * Keep a small list of pointers so that we can print address-agnostic
+ * pointer values. Use a rolling integer count to differentiate the values.
+ * Ironically we could have used the shadow variable API to do this, but
+ * let's not lean too heavily on the very code we're testing.
+ */
+static LIST_HEAD(ptr_list);
+struct shadow_ptr {
+ void *ptr;
+ int id;
+ struct list_head list;
+};
+
+static void free_ptr_list(void)
+{
+ struct shadow_ptr *sp, *tmp_sp;
+
+ list_for_each_entry_safe(sp, tmp_sp, &ptr_list, list) {
+ list_del(&sp->list);
+ kfree(sp);
+ }
+}
+
+static int ptr_id(void *ptr)
+{
+ struct shadow_ptr *sp;
+ static int count;
+
+ list_for_each_entry(sp, &ptr_list, list) {
+ if (sp->ptr == ptr)
+ return sp->id;
+ }
+
+ sp = kmalloc(sizeof(*sp), GFP_ATOMIC);
+ if (!sp)
+ return -1;
+ sp->ptr = ptr;
+ sp->id = count++;
+
+ list_add(&sp->list, &ptr_list);
+
+ return sp->id;
+}
+
+/*
+ * Shadow variable wrapper functions that echo the function and arguments
+ * to the kernel log for testing verification. Don't display raw pointers,
+ * but use the ptr_id() value instead.
+ */
+static void *shadow_get(void *obj, unsigned long id)
+{
+ void *ret = klp_shadow_get(obj, id);
+
+ pr_info("klp_%s(obj=PTR%d, id=0x%lx) = PTR%d\n",
+ __func__, ptr_id(obj), id, ptr_id(ret));
+
+ return ret;
+}
+
+static void *shadow_alloc(void *obj, unsigned long id, size_t size,
+ gfp_t gfp_flags, klp_shadow_ctor_t ctor,
+ void *ctor_data)
+{
+ void *ret = klp_shadow_alloc(obj, id, size, gfp_flags, ctor,
+ ctor_data);
+ pr_info("klp_%s(obj=PTR%d, id=0x%lx, size=%zx, gfp_flags=%pGg), ctor=PTR%d, ctor_data=PTR%d = PTR%d\n",
+ __func__, ptr_id(obj), id, size, &gfp_flags, ptr_id(ctor),
+ ptr_id(ctor_data), ptr_id(ret));
+ return ret;
+}
+
+static void *shadow_get_or_alloc(void *obj, unsigned long id, size_t size,
+ gfp_t gfp_flags, klp_shadow_ctor_t ctor,
+ void *ctor_data)
+{
+ void *ret = klp_shadow_get_or_alloc(obj, id, size, gfp_flags, ctor,
+ ctor_data);
+ pr_info("klp_%s(obj=PTR%d, id=0x%lx, size=%zx, gfp_flags=%pGg), ctor=PTR%d, ctor_data=PTR%d = PTR%d\n",
+ __func__, ptr_id(obj), id, size, &gfp_flags, ptr_id(ctor),
+ ptr_id(ctor_data), ptr_id(ret));
+ return ret;
+}
+
+static void shadow_free(void *obj, unsigned long id, klp_shadow_dtor_t dtor)
+{
+ klp_shadow_free(obj, id, dtor);
+ pr_info("klp_%s(obj=PTR%d, id=0x%lx, dtor=PTR%d)\n",
+ __func__, ptr_id(obj), id, ptr_id(dtor));
+}
+
+static void shadow_free_all(unsigned long id, klp_shadow_dtor_t dtor)
+{
+ klp_shadow_free_all(id, dtor);
+ pr_info("klp_%s(id=0x%lx, dtor=PTR%d)\n",
+ __func__, id, ptr_id(dtor));
+}
+
+
+/* Shadow variable constructor - remember simple pointer data */
+static int shadow_ctor(void *obj, void *shadow_data, void *ctor_data)
+{
+ int **shadow_int = shadow_data;
+ *shadow_int = ctor_data;
+ pr_info("%s: PTR%d -> PTR%d\n",
+ __func__, ptr_id(shadow_int), ptr_id(ctor_data));
+
+ return 0;
+}
+
+static void shadow_dtor(void *obj, void *shadow_data)
+{
+ pr_info("%s(obj=PTR%d, shadow_data=PTR%d)\n",
+ __func__, ptr_id(obj), ptr_id(shadow_data));
+}
+
+static int test_klp_shadow_vars_init(void)
+{
+ void *obj = THIS_MODULE;
+ int id = 0x1234;
+ size_t size = sizeof(int *);
+ gfp_t gfp_flags = GFP_KERNEL;
+
+ int var1, var2, var3, var4;
+ int **sv1, **sv2, **sv3, **sv4;
+
+ void *ret;
+
+ ptr_id(NULL);
+ ptr_id(&var1);
+ ptr_id(&var2);
+ ptr_id(&var3);
+ ptr_id(&var4);
+
+ /*
+ * With an empty shadow variable hash table, expect not to find
+ * any matches.
+ */
+ ret = shadow_get(obj, id);
+ if (!ret)
+ pr_info(" got expected NULL result\n");
+
+ /*
+ * Allocate a few shadow variables with different <obj> and <id>.
+ */
+ sv1 = shadow_alloc(obj, id, size, gfp_flags, shadow_ctor, &var1);
+ sv2 = shadow_alloc(obj + 1, id, size, gfp_flags, shadow_ctor, &var2);
+ sv3 = shadow_alloc(obj, id + 1, size, gfp_flags, shadow_ctor, &var3);
+
+ /*
+ * Verify we can find our new shadow variables and that they point
+ * to expected data.
+ */
+ ret = shadow_get(obj, id);
+ if (ret == sv1 && *sv1 == &var1)
+ pr_info(" got expected PTR%d -> PTR%d result\n",
+ ptr_id(sv1), ptr_id(*sv1));
+ ret = shadow_get(obj + 1, id);
+ if (ret == sv2 && *sv2 == &var2)
+ pr_info(" got expected PTR%d -> PTR%d result\n",
+ ptr_id(sv2), ptr_id(*sv2));
+ ret = shadow_get(obj, id + 1);
+ if (ret == sv3 && *sv3 == &var3)
+ pr_info(" got expected PTR%d -> PTR%d result\n",
+ ptr_id(sv3), ptr_id(*sv3));
+
+ /*
+ * Allocate or get a few more, this time with the same <obj>, <id>.
+ * The second invocation should return the same shadow var.
+ */
+ sv4 = shadow_get_or_alloc(obj + 2, id, size, gfp_flags, shadow_ctor, &var4);
+ ret = shadow_get_or_alloc(obj + 2, id, size, gfp_flags, shadow_ctor, &var4);
+ if (ret == sv4 && *sv4 == &var4)
+ pr_info(" got expected PTR%d -> PTR%d result\n",
+ ptr_id(sv4), ptr_id(*sv4));
+
+ /*
+ * Free the <obj=*, id> shadow variables and check that we can no
+ * longer find them.
+ */
+ shadow_free(obj, id, shadow_dtor); /* sv1 */
+ ret = shadow_get(obj, id);
+ if (!ret)
+ pr_info(" got expected NULL result\n");
+
+ shadow_free(obj + 1, id, shadow_dtor); /* sv2 */
+ ret = shadow_get(obj + 1, id);
+ if (!ret)
+ pr_info(" got expected NULL result\n");
+
+ shadow_free(obj + 2, id, shadow_dtor); /* sv4 */
+ ret = shadow_get(obj + 2, id);
+ if (!ret)
+ pr_info(" got expected NULL result\n");
+
+ /*
+ * We should still find an <id+1> variable.
+ */
+ ret = shadow_get(obj, id + 1);
+ if (ret == sv3 && *sv3 == &var3)
+ pr_info(" got expected PTR%d -> PTR%d result\n",
+ ptr_id(sv3), ptr_id(*sv3));
+
+ /*
+ * Free all the <id+1> variables, too.
+ */
+ shadow_free_all(id + 1, shadow_dtor); /* sv3 */
+ ret = shadow_get(obj, id);
+ if (!ret)
+ pr_info(" shadow_get() got expected NULL result\n");
+
+
+ free_ptr_list();
+
+ return 0;
+}
+
+static void test_klp_shadow_vars_exit(void)
+{
+}
+
+module_init(test_klp_shadow_vars_init);
+module_exit(test_klp_shadow_vars_exit);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Joe Lawrence <[email protected]>");
+MODULE_DESCRIPTION("Livepatch test: shadow variables");
