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, 57 insertions, 0 deletions

diff --git a/lib/livepatch/test_klp_atomic_replace.c b/lib/livepatch/test_klp_atomic_replace.c
new file mode 100644
index 000000000000..5af7093ca00c
--- /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 <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)");
+
+#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 <joe.lawrence@redhat.com>");
+MODULE_DESCRIPTION("Livepatch test: atomic replace");