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 <joe.lawrence@redhat.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Tested-by: Miroslav Benes <mbenes@suse.cz>
Tested-by: Alice Ferrazzi <alice.ferrazzi@gmail.com>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 93 insertions, 0 deletions

diff --git a/lib/livepatch/test_klp_callbacks_demo2.c b/lib/livepatch/test_klp_callbacks_demo2.c
new file mode 100644
index 000000000000..5417573e80af
--- /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 <joe.lawrence@redhat.com>
+
+#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 <joe.lawrence@redhat.com>");
+MODULE_DESCRIPTION("Livepatch test: livepatch demo2");