jump_label: Provide a self-test
authorJason Baron <jbaron@akamai.com>
Thu, 30 Jul 2015 03:59:44 +0000 (03:59 +0000)
committerIngo Molnar <mingo@kernel.org>
Mon, 3 Aug 2015 09:51:11 +0000 (11:51 +0200)
Signed-off-by: Jason Baron <jbaron@akamai.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: benh@kernel.crashing.org
Cc: bp@alien8.de
Cc: davem@davemloft.net
Cc: ddaney@caviumnetworks.com
Cc: heiko.carstens@de.ibm.com
Cc: linux-kernel@vger.kernel.org
Cc: liuj97@gmail.com
Cc: luto@amacapital.net
Cc: michael@ellerman.id.au
Cc: rabin@rab.in
Cc: ralf@linux-mips.org
Cc: rostedt@goodmis.org
Cc: shuahkh@osg.samsung.com
Cc: vbabka@suse.cz
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/0c091ecebd78a879ed8a71835d205a691a75ab4e.1438227999.git.jbaron@akamai.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
lib/Kconfig.debug
lib/Makefile
lib/test_jump_label.c [new file with mode: 0644]
lib/test_jump_label_base.c [new file with mode: 0644]
tools/testing/selftests/Makefile
tools/testing/selftests/jumplabel/Makefile [new file with mode: 0644]
tools/testing/selftests/jumplabel/test_jump_label.sh [new file with mode: 0644]

index e7b5b654ed8d8a6d5a07fe324b14272f513332b9..304e75f832dceb59dab5cdb0fbd8a2e3571bdc08 100644 (file)
@@ -1841,6 +1841,15 @@ 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"
index 6897b527581a8d9fcb65b4a2e01815d3d34498ed..14f6e07e33a823f3e990305e3defaa6c531fb208 100644 (file)
@@ -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 (file)
index 0000000..2fe7413
--- /dev/null
@@ -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 (file)
index 0000000..91aed8e
--- /dev/null
@@ -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");
index 24ae9e829e9aa2e22db0e035b4c1d53d5424cf61..b8f12e0897e6b1debdd3165e4300ccdbf4e26f44 100644 (file)
@@ -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 (file)
index 0000000..7526aa5
--- /dev/null
@@ -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 100644 (file)
index 0000000..3457e8a
--- /dev/null
@@ -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
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