Re: [PATCH -v2 7/8] jump_label: Add selftest

[Jason Baron <jbaron@akamai.com>]

On 07/28/2015 09:21 AM, Peter Zijlstra wrote:

Hi,

Funny-so I did something similar but its a modules self test
so I think its complementary. I can re-post with a changelog
and some more comments if you think its worthwhile. I have
two modules in order to test actually updating the key
during module load of the second module. It also covers
the 'legacy' interface.

In order to get the !CONFIG_JUMP_LABEL to work I needed,
the following:

diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h
index c033595..27b335a 100644
--- a/include/linux/jump_label.h
+++ b/include/linux/jump_label.h
@@ -183,10 +183,10 @@ static inline int jump_label_apply_nops(struct module *mod)
     return 0;
 }
 
-#define STATIC_KEY_INIT_TRUE ((struct static_key) \
-        { .enabled = ATOMIC_INIT(1) })
-#define STATIC_KEY_INIT_FALSE ((struct static_key) \
-        { .enabled = ATOMIC_INIT(0) })
+#define STATIC_KEY_INIT_TRUE    \
+        { .enabled = ATOMIC_INIT(1) }
+#define STATIC_KEY_INIT_FALSE    \
+        { .enabled = ATOMIC_INIT(0) }
 
 #endif    /* HAVE_JUMP_LABEL */
 

Other than that, everything seems to be working fine for me
with -v2.

We probably should also update Documentation/static-keys.txt.
I can take a stab at that, if needed.

Module selftest is below.

Thanks,

-Jason

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index b908048..d87d7b6 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1835,6 +1835,15 @@ config MEMTEST
             memtest=17, mean do 17 test patterns.
       If you are unsure how to answer this question, answer N.
 
+config TEST_JUMP_LABEL
+    tristate "Test jump label"
+    default n
+    depends on m
+    help
+      Test jump labels.
+
+      If unsure, say N.
+
 source "samples/Kconfig"
 
 source "lib/Kconfig.kgdb"
diff --git a/lib/Makefile b/lib/Makefile
index ff37c8c..ea20293 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -39,6 +39,8 @@ obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o
 obj-$(CONFIG_TEST_LKM) += test_module.o
 obj-$(CONFIG_TEST_RHASHTABLE) += test_rhashtable.o
 obj-$(CONFIG_TEST_USER_COPY) += test_user_copy.o
+obj-$(CONFIG_TEST_JUMP_LABEL) += test_jump_label.o
+obj-$(CONFIG_TEST_JUMP_LABEL) += test_jump_label_base.o
 
 ifeq ($(CONFIG_DEBUG_KOBJECT),y)
 CFLAGS_kobject.o += -DDEBUG
diff --git a/lib/test_jump_label.c b/lib/test_jump_label.c
new file mode 100644
index 0000000..5a5eb86
--- /dev/null
+++ b/lib/test_jump_label.c
@@ -0,0 +1,225 @@
+/*
+ * Kernel module for testing jump labels.
+ *
+ * Copyright 2015 Akamai Technologies Inc. All Rights Reserved
+ *
+ * Authors:
+ *      Jason Baron       <jbaron@akamai.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/jump_label.h>
+
+/* old keys */
+struct static_key old_true_key = STATIC_KEY_INIT_TRUE;
+struct static_key old_false_key = STATIC_KEY_INIT_FALSE;
+
+/* new api */
+DEFINE_STATIC_KEY_TRUE(true_key);
+DEFINE_STATIC_KEY_FALSE(false_key);
+
+/* external */
+extern struct static_key base_old_true_key;
+extern struct static_key base_inv_old_true_key;
+extern struct static_key base_old_false_key;
+extern struct static_key base_inv_old_false_key;
+
+/* new api */
+extern struct static_key_true base_true_key;
+extern struct static_key_true base_inv_true_key;
+extern struct static_key_false base_false_key;
+extern struct static_key_false base_inv_false_key;
+
+
+struct test_branch {
+    bool init_state;
+    struct static_key *key;
+    bool (*test_key)(void);
+};
+
+#define test_key_func(key, branch)    \
+({bool func(void) { return branch(key); } func;    })
+
+static void invert_key(struct static_key *key)
+{
+    if (static_key_enabled(key))
+        static_key_disable(key);
+    else
+        static_key_enable(key);
+}
+
+static void invert_keys(struct test_branch *branches, int size)
+{
+    struct static_key *previous = NULL;
+    int i;
+   
+    for (i = 0; i < size; i++) {
+        if (previous != branches[i].key) {
+            invert_key(branches[i].key);
+            previous = branches[i].key;
+        }
+    }
+}
+
+int verify_branches(struct test_branch *branches, int size, bool invert)
+{
+    int i;
+    bool ret, init;
+
+    for (i = 0; i < size; i++) {
+        ret = static_key_enabled(branches[i].key);
+        init = branches[i].init_state;
+        if (ret != (invert ? !init : init))
+            return -EINVAL;
+        ret = branches[i].test_key();
+        if (static_key_enabled(branches[i].key)) {
+            if (!ret)
+                return -EINVAL;
+        } else {
+            if (ret)
+                return -EINVAL;
+        }
+    }
+    return 0;
+}
+
+static int __init test_jump_label_init(void)
+{
+    int ret;
+    int size;
+
+    struct test_branch jump_label_tests[] = {
+        /* internal keys - old keys */
+        {
+            .init_state = true,
+            .key = &old_true_key,
+            .test_key = test_key_func(&old_true_key, static_key_true),
+        },
+        {
+            .init_state = false,
+            .key = &old_false_key,
+            .test_key = test_key_func(&old_false_key, static_key_false),
+        },
+        /* internal keys - new keys */
+        {
+            .init_state = true,
+            .key = &true_key.key,
+            .test_key = test_key_func(&true_key, static_branch_likely),
+        },
+        {
+            .init_state = true,
+            .key = &true_key.key,
+            .test_key = test_key_func(&true_key, static_branch_unlikely),
+        },
+        {
+            .init_state = false,
+            .key = &false_key.key,
+            .test_key = test_key_func(&false_key, static_branch_likely),
+        },
+        {
+            .init_state = false,
+            .key = &false_key.key,
+            .test_key = test_key_func(&false_key, static_branch_unlikely),
+        },
+        /* external keys - old keys */
+        {
+            .init_state = true,
+            .key = &base_old_true_key,
+            .test_key = test_key_func(&base_old_true_key, static_key_true),
+        },
+        {
+            .init_state = false,
+            .key = &base_inv_old_true_key,
+            .test_key = test_key_func(&base_inv_old_true_key, static_key_true),
+        },
+        {
+            .init_state = false,
+            .key = &base_old_false_key,
+            .test_key = test_key_func(&base_old_false_key, static_key_false),
+        },
+        {
+            .init_state = true,
+            .key = &base_inv_old_false_key,
+            .test_key = test_key_func(&base_inv_old_false_key, static_key_false),
+        },
+        /* external keys - new keys */
+        {
+            .init_state = true,
+            .key = &base_true_key.key,
+            .test_key = test_key_func(&base_true_key, static_branch_likely),
+        },
+        {
+            .init_state = true,
+            .key = &base_true_key.key,
+            .test_key = test_key_func(&base_true_key, static_branch_unlikely),
+        },
+        {
+            .init_state = false,
+            .key = &base_inv_true_key.key,
+            .test_key = test_key_func(&base_inv_true_key, static_branch_likely),
+        },
+        {
+            .init_state = false,
+            .key = &base_inv_true_key.key,
+            .test_key = test_key_func(&base_inv_true_key, static_branch_unlikely),
+        },
+        {
+            .init_state = false,
+            .key = &base_false_key.key,
+            .test_key = test_key_func(&base_false_key, static_branch_likely),
+        },
+        {
+            .init_state = false,
+            .key = &base_false_key.key,
+            .test_key = test_key_func(&base_false_key, static_branch_unlikely),
+        },
+        {
+            .init_state = true,
+            .key = &base_inv_false_key.key,
+            .test_key = test_key_func(&base_inv_false_key, static_branch_likely),
+        },
+        {
+            .init_state = true,
+            .key = &base_inv_false_key.key,
+            .test_key = test_key_func(&base_inv_false_key, static_branch_unlikely),
+        },
+    };
+
+    size = ARRAY_SIZE(jump_label_tests);
+
+    ret = verify_branches(jump_label_tests, size, false);
+    if (ret)
+        goto out;
+
+    invert_keys(jump_label_tests, size);
+    ret = verify_branches(jump_label_tests, size, true);
+    if (ret)
+        goto out;
+
+    invert_keys(jump_label_tests, size);
+    ret = verify_branches(jump_label_tests, size, false);
+    if (ret)
+        goto out;
+    return 0;
+out:
+    return ret;
+}
+
+static void __exit test_jump_label_exit(void)
+{
+}
+
+module_init(test_jump_label_init);
+module_exit(test_jump_label_exit);
+
+MODULE_AUTHOR("Jason Baron <jbaron@akamai.com>");
+MODULE_LICENSE("GPL");
diff --git a/lib/test_jump_label_base.c b/lib/test_jump_label_base.c
new file mode 100644
index 0000000..91aed8e
--- /dev/null
+++ b/lib/test_jump_label_base.c
@@ -0,0 +1,68 @@
+/*
+ * Kernel module for testing jump labels.
+ *
+ * Copyright 2015 Akamai Technologies Inc. All Rights Reserved
+ *
+ * Authors:
+ *      Jason Baron       <jbaron@akamai.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/jump_label.h>
+
+/* old keys */
+struct static_key base_old_true_key = STATIC_KEY_INIT_TRUE;
+EXPORT_SYMBOL_GPL(base_old_true_key);
+struct static_key base_inv_old_true_key = STATIC_KEY_INIT_TRUE;
+EXPORT_SYMBOL_GPL(base_inv_old_true_key);
+struct static_key base_old_false_key = STATIC_KEY_INIT_FALSE;
+EXPORT_SYMBOL_GPL(base_old_false_key);
+struct static_key base_inv_old_false_key = STATIC_KEY_INIT_FALSE;
+EXPORT_SYMBOL_GPL(base_inv_old_false_key);
+
+/* new keys */
+DEFINE_STATIC_KEY_TRUE(base_true_key);
+EXPORT_SYMBOL_GPL(base_true_key);
+DEFINE_STATIC_KEY_TRUE(base_inv_true_key);
+EXPORT_SYMBOL_GPL(base_inv_true_key);
+DEFINE_STATIC_KEY_FALSE(base_false_key);
+EXPORT_SYMBOL_GPL(base_false_key);
+DEFINE_STATIC_KEY_FALSE(base_inv_false_key);
+EXPORT_SYMBOL_GPL(base_inv_false_key);
+
+static void invert_key(struct static_key *key)
+{
+    if (static_key_enabled(key))
+        static_key_disable(key);
+    else
+        static_key_enable(key);
+}
+
+static int __init test_jump_label_base_init(void)
+{
+    invert_key(&base_inv_old_true_key);
+    invert_key(&base_inv_old_false_key);
+    invert_key(&base_inv_true_key.key);
+    invert_key(&base_inv_false_key.key);
+
+    return 0;
+}
+
+static void __exit test_jump_label_base_exit(void)
+{
+}
+
+module_init(test_jump_label_base_init);
+module_exit(test_jump_label_base_exit);
+
+MODULE_AUTHOR("Jason Baron <jbaron@akamai.com>");
+MODULE_LICENSE("GPL");
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 24ae9e8..b8f12e0 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -20,6 +20,7 @@ ifneq (1, $(quicktest))
 TARGETS += timers
 endif
 TARGETS += user
+TARGETS += jumplabel
 TARGETS += vm
 TARGETS += x86
 #Please keep the TARGETS list alphabetically sorted
diff --git a/tools/testing/selftests/jumplabel/Makefile b/tools/testing/selftests/jumplabel/Makefile
new file mode 100644
index 0000000..7526aa5
--- /dev/null
+++ b/tools/testing/selftests/jumplabel/Makefile
@@ -0,0 +1,8 @@
+# Makefile for jump label selftests
+
+# No binaries, but make sure arg-less "make" doesn't trigger "run_tests"
+all:
+
+TEST_PROGS := test_jump_label.sh
+
+include ../lib.mk
diff --git a/tools/testing/selftests/jumplabel/test_jump_label.sh b/tools/testing/selftests/jumplabel/test_jump_label.sh
new file mode 100755
index 0000000..3457e8a
--- /dev/null
+++ b/tools/testing/selftests/jumplabel/test_jump_label.sh
@@ -0,0 +1,16 @@
+#!/bin/sh
+# Runs jump label kernel module tests
+
+if /sbin/modprobe -q test_jump_label_base; then
+    if /sbin/modprobe -q test_jump_label; then
+        echo "jump_label: ok"
+        /sbin/modprobe -q -r test_jump_label
+        /sbin/modprobe -q -r test_jump_label_base
+    else
+        echo "jump_label: [FAIL]"
+        /sbin/modprobe -q -r test_jump_label_base
+    fi
+else
+    echo "jump_label: [FAIL]"
+    exit 1
+fi
-- 
1.8.2.rc2