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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/samples/livepatch/livepatch-sample.c
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/samples/livepatch/livepatch-sample.c')
-rw-r--r--kernel/samples/livepatch/livepatch-sample.c91
1 files changed, 91 insertions, 0 deletions
diff --git a/kernel/samples/livepatch/livepatch-sample.c b/kernel/samples/livepatch/livepatch-sample.c
new file mode 100644
index 000000000..fb8c8614e
--- /dev/null
+++ b/kernel/samples/livepatch/livepatch-sample.c
@@ -0,0 +1,91 @@
+/*
+ * livepatch-sample.c - Kernel Live Patching Sample Module
+ *
+ * Copyright (C) 2014 Seth Jennings <sjenning@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/livepatch.h>
+
+/*
+ * This (dumb) live patch overrides the function that prints the
+ * kernel boot cmdline when /proc/cmdline is read.
+ *
+ * Example:
+ *
+ * $ cat /proc/cmdline
+ * <your cmdline>
+ *
+ * $ insmod livepatch-sample.ko
+ * $ cat /proc/cmdline
+ * this has been live patched
+ *
+ * $ echo 0 > /sys/kernel/livepatch/livepatch_sample/enabled
+ * $ cat /proc/cmdline
+ * <your cmdline>
+ */
+
+#include <linux/seq_file.h>
+static int livepatch_cmdline_proc_show(struct seq_file *m, void *v)
+{
+ seq_printf(m, "%s\n", "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 livepatch_init(void)
+{
+ int ret;
+
+ ret = klp_register_patch(&patch);
+ if (ret)
+ return ret;
+ ret = klp_enable_patch(&patch);
+ if (ret) {
+ WARN_ON(klp_unregister_patch(&patch));
+ return ret;
+ }
+ return 0;
+}
+
+static void livepatch_exit(void)
+{
+ WARN_ON(klp_disable_patch(&patch));
+ WARN_ON(klp_unregister_patch(&patch));
+}
+
+module_init(livepatch_init);
+module_exit(livepatch_exit);
+MODULE_LICENSE("GPL");