1 files changed, 17 insertions, 0 deletions

diff --git a/samples/livepatch/livepatch-sample.c b/samples/livepatch/livepatch-sample.c
index e34f871e69b1..629e0dca0887 100644
--- a/samples/livepatch/livepatch-sample.c
+++ b/samples/livepatch/livepatch-sample.c
@@ -17,6 +17,8 @@
  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/livepatch.h>
@@ -69,6 +71,21 @@ static int livepatch_init(void)
 {
         int ret;
 
+        if (!klp_have_reliable_stack() && !patch.immediate) {
+                /*
+                 * WARNING: Be very careful when using 'patch.immediate' in
+                 * your patches.  It's ok to use it for simple patches like
+                 * this, but for more complex patches which change function
+                 * semantics, locking semantics, or data structures, it may not
+                 * be safe.  Use of this option will also prevent removal of
+                 * the patch.
+                 *
+                 * See Documentation/livepatch/livepatch.txt for more details.
+                 */
+                patch.immediate = true;
+                pr_notice("The consistency model isn't supported for your architecture.  Bypassing safety mechanisms and applying the patch immediately.\n");
+        }
+
         ret = klp_register_patch(&patch);
         if (ret)
                 return ret;