Merge branch 'linus' into x86/urgent, to pick up dependent commits

Signed-off-by: Ingo Molnar <[email protected]>

1 files changed, 65 insertions, 11 deletions

diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index de9e45dca70f..3a4656fb7047 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -366,11 +366,6 @@ static int __klp_enable_patch(struct klp_patch *patch)
 	/*
 	 * A reference is taken on the patch module to prevent it from being
 	 * unloaded.
-	 *
-	 * Note: For immediate (no consistency model) patches we don't allow
-	 * patch modules to unload since there is no safe/sane method to
-	 * determine if a thread is still running in the patched code contained
-	 * in the patch module once the ftrace registration is successful.
 	 */
 	if (!try_module_get(patch->mod))
 		return -ENODEV;
@@ -454,6 +449,8 @@ EXPORT_SYMBOL_GPL(klp_enable_patch);
  * /sys/kernel/livepatch/<patch>
  * /sys/kernel/livepatch/<patch>/enabled
  * /sys/kernel/livepatch/<patch>/transition
+ * /sys/kernel/livepatch/<patch>/signal
+ * /sys/kernel/livepatch/<patch>/force
  * /sys/kernel/livepatch/<patch>/<object>
  * /sys/kernel/livepatch/<patch>/<object>/<function,sympos>
  */
@@ -528,11 +525,73 @@ static ssize_t transition_show(struct kobject *kobj,
 			patch == klp_transition_patch);
 }
 
+static ssize_t signal_store(struct kobject *kobj, struct kobj_attribute *attr,
+			    const char *buf, size_t count)
+{
+	struct klp_patch *patch;
+	int ret;
+	bool val;
+
+	ret = kstrtobool(buf, &val);
+	if (ret)
+		return ret;
+
+	if (!val)
+		return count;
+
+	mutex_lock(&klp_mutex);
+
+	patch = container_of(kobj, struct klp_patch, kobj);
+	if (patch != klp_transition_patch) {
+		mutex_unlock(&klp_mutex);
+		return -EINVAL;
+	}
+
+	klp_send_signals();
+
+	mutex_unlock(&klp_mutex);
+
+	return count;
+}
+
+static ssize_t force_store(struct kobject *kobj, struct kobj_attribute *attr,
+			   const char *buf, size_t count)
+{
+	struct klp_patch *patch;
+	int ret;
+	bool val;
+
+	ret = kstrtobool(buf, &val);
+	if (ret)
+		return ret;
+
+	if (!val)
+		return count;
+
+	mutex_lock(&klp_mutex);
+
+	patch = container_of(kobj, struct klp_patch, kobj);
+	if (patch != klp_transition_patch) {
+		mutex_unlock(&klp_mutex);
+		return -EINVAL;
+	}
+
+	klp_force_transition();
+
+	mutex_unlock(&klp_mutex);
+
+	return count;
+}
+
 static struct kobj_attribute enabled_kobj_attr = __ATTR_RW(enabled);
 static struct kobj_attribute transition_kobj_attr = __ATTR_RO(transition);
+static struct kobj_attribute signal_kobj_attr = __ATTR_WO(signal);
+static struct kobj_attribute force_kobj_attr = __ATTR_WO(force);
 static struct attribute *klp_patch_attrs[] = {
 	&enabled_kobj_attr.attr,
 	&transition_kobj_attr.attr,
+	&signal_kobj_attr.attr,
+	&force_kobj_attr.attr,
 	NULL
 };
 
@@ -830,12 +889,7 @@ int klp_register_patch(struct klp_patch *patch)
 	if (!klp_initialized())
 		return -ENODEV;
 
-	/*
-	 * Architectures without reliable stack traces have to set
-	 * patch->immediate because there's currently no way to patch kthreads
-	 * with the consistency model.
-	 */
-	if (!klp_have_reliable_stack() && !patch->immediate) {
+	if (!klp_have_reliable_stack()) {
 		pr_err("This architecture doesn't have support for the livepatch consistency model.\n");
 		return -ENOSYS;
 	}