Merge tag 'linux_kselftest-kunit-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull KUnit updates from Shuah Khan:

 - a new feature that adds APIs for managing devices introducing a set
   of helper functions which allow devices (internally a struct
   kunit_device) to be created and managed by KUnit.

   These devices will be automatically unregistered on test exit. These
   helpers can either use a user-provided struct device_driver, or have
   one automatically created and managed by KUnit. In both cases, the
   device lives on a new kunit_bus.

 - changes to switch drm/tests to use kunit devices

 - several fixes and enhancements to attribute feature

 - changes to reorganize deferred action function introducing
   KUNIT_DEFINE_ACTION_WRAPPER

 - new feature adds ability to run tests after boot using debugfs

 - fixes and enhancements to string-stream-test:
     - parse ERR_PTR in string_stream_destroy()
     - unchecked dereference in bug fix in debugfs_print_results()
     - handling errors from alloc_string_stream()
     - NULL-dereference bug fix in kunit_init_suite()

* tag 'linux_kselftest-kunit-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (27 commits)
  kunit: Fix some comments which were mistakenly kerneldoc
  kunit: Protect string comparisons against NULL
  kunit: Add example of kunit_activate_static_stub() with pointer-to-function
  kunit: Allow passing function pointer to kunit_activate_static_stub()
  kunit: Fix NULL-dereference in kunit_init_suite() if suite->log is NULL
  kunit: Reset test->priv after each param iteration
  kunit: Add example for using test->priv
  drm/tests: Switch to kunit devices
  ASoC: topology: Replace fake root_device with kunit_device in tests
  overflow: Replace fake root_device with kunit_device
  fortify: test: Use kunit_device
  kunit: Add APIs for managing devices
  Documentation: Add debugfs docs with run after boot
  kunit: add ability to run tests after boot using debugfs
  kunit: add is_init test attribute
  kunit: add example suite to test init suites
  kunit: add KUNIT_INIT_TABLE to init linker section
  kunit: move KUNIT_TABLE out of INIT_DATA
  kunit: tool: add test for parsing attributes
  kunit: tool: fix parsing of test attributes
  ...

6 files changed, 134 insertions, 15 deletions

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index bae0fe4d499b..5dd3a61d673d 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -370,7 +370,8 @@
 	BRANCH_PROFILE()						\
 	TRACE_PRINTKS()							\
 	BPF_RAW_TP()							\
-	TRACEPOINT_STR()
+	TRACEPOINT_STR()						\
+	KUNIT_TABLE()
 
 /*
  * Data section helpers
@@ -700,7 +701,7 @@
 	EARLYCON_TABLE()						\
 	LSM_TABLE()							\
 	EARLY_LSM_TABLE()						\
-	KUNIT_TABLE()
+	KUNIT_INIT_TABLE()
 
 #define INIT_TEXT							\
 	*(.init.text .init.text.*)					\
@@ -926,6 +927,12 @@
 		. = ALIGN(8);						\
 		BOUNDED_SECTION_POST_LABEL(.kunit_test_suites, __kunit_suites, _start, _end)
 
+/* Alignment must be consistent with (kunit_suite *) in include/kunit/test.h */
+#define KUNIT_INIT_TABLE()						\
+		. = ALIGN(8);						\
+		BOUNDED_SECTION_POST_LABEL(.kunit_init_test_suites, \
+				__kunit_init_suites, _start, _end)
+
 #ifdef CONFIG_BLK_DEV_INITRD
 #define INIT_RAM_FS							\
 	. = ALIGN(4);							\
diff --git a/include/kunit/device.h b/include/kunit/device.h
new file mode 100644
index 000000000000..2450110ad64e
--- /dev/null
+++ b/include/kunit/device.h
@@ -0,0 +1,80 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * KUnit basic device implementation
+ *
+ * Helpers for creating and managing fake devices for KUnit tests.
+ *
+ * Copyright (C) 2023, Google LLC.
+ * Author: David Gow <davidgow@google.com>
+ */
+
+#ifndef _KUNIT_DEVICE_H
+#define _KUNIT_DEVICE_H
+
+#if IS_ENABLED(CONFIG_KUNIT)
+
+#include <kunit/test.h>
+
+struct device;
+struct device_driver;
+
+/**
+ * kunit_driver_create() - Create a struct device_driver attached to the kunit_bus
+ * @test: The test context object.
+ * @name: The name to give the created driver.
+ *
+ * Creates a struct device_driver attached to the kunit_bus, with the name @name.
+ * This driver will automatically be cleaned up on test exit.
+ *
+ * Return: a stub struct device_driver, managed by KUnit, with the name @name.
+ */
+struct device_driver *kunit_driver_create(struct kunit *test, const char *name);
+
+/**
+ * kunit_device_register() - Create a struct device for use in KUnit tests
+ * @test: The test context object.
+ * @name: The name to give the created device.
+ *
+ * Creates a struct kunit_device (which is a struct device) with the given name,
+ * and a corresponding driver. The device and driver will be cleaned up on test
+ * exit, or when kunit_device_unregister is called. See also
+ * kunit_device_register_with_driver, if you wish to provide your own
+ * struct device_driver.
+ *
+ * Return: a pointer to a struct device which will be cleaned up when the test
+ * exits, or an error pointer if the device could not be allocated or registered.
+ */
+struct device *kunit_device_register(struct kunit *test, const char *name);
+
+/**
+ * kunit_device_register_with_driver() - Create a struct device for use in KUnit tests
+ * @test: The test context object.
+ * @name: The name to give the created device.
+ * @drv: The struct device_driver to associate with the device.
+ *
+ * Creates a struct kunit_device (which is a struct device) with the given
+ * name, and driver. The device will be cleaned up on test exit, or when
+ * kunit_device_unregister is called. See also kunit_device_register, if you
+ * wish KUnit to create and manage a driver for you.
+ *
+ * Return: a pointer to a struct device which will be cleaned up when the test
+ * exits, or an error pointer if the device could not be allocated or registered.
+ */
+struct device *kunit_device_register_with_driver(struct kunit *test,
+						 const char *name,
+						 const struct device_driver *drv);
+
+/**
+ * kunit_device_unregister() - Unregister a KUnit-managed device
+ * @test: The test context object which created the device
+ * @dev: The device.
+ *
+ * Unregisters and destroys a struct device which was created with
+ * kunit_device_register or kunit_device_register_with_driver. If KUnit created
+ * a driver, cleans it up as well.
+ */
+void kunit_device_unregister(struct kunit *test, struct device *dev);
+
+#endif
+
+#endif
diff --git a/include/kunit/resource.h b/include/kunit/resource.h
index c7383e90f5c9..4ad69a2642a5 100644
--- a/include/kunit/resource.h
+++ b/include/kunit/resource.h
@@ -391,6 +391,27 @@ void kunit_remove_resource(struct kunit *test, struct kunit_resource *res);
 typedef void (kunit_action_t)(void *);
 
 /**
+ * KUNIT_DEFINE_ACTION_WRAPPER() - Wrap a function for use as a deferred action.
+ *
+ * @wrapper: The name of the new wrapper function define.
+ * @orig: The original function to wrap.
+ * @arg_type: The type of the argument accepted by @orig.
+ *
+ * Defines a wrapper for a function which accepts a single, pointer-sized
+ * argument. This wrapper can then be passed to kunit_add_action() and
+ * similar. This should be used in preference to casting a function
+ * directly to kunit_action_t, as casting function pointers will break
+ * control flow integrity (CFI), leading to crashes.
+ */
+#define KUNIT_DEFINE_ACTION_WRAPPER(wrapper, orig, arg_type)	\
+	static void wrapper(void *in)				\
+	{							\
+		arg_type arg = (arg_type)in;			\
+		orig(arg);					\
+	}
+
+
+/**
  * kunit_add_action() - Call a function when the test ends.
  * @test: Test case to associate the action with.
  * @action: The function to run on test exit
diff --git a/include/kunit/static_stub.h b/include/kunit/static_stub.h
index 85315c80b303..bf940322dfc0 100644
--- a/include/kunit/static_stub.h
+++ b/include/kunit/static_stub.h
@@ -93,7 +93,7 @@ void __kunit_activate_static_stub(struct kunit *test,
  * The redirection can be disabled again with kunit_deactivate_static_stub().
  */
 #define kunit_activate_static_stub(test, real_fn_addr, replacement_addr) do {	\
-	typecheck_fn(typeof(&real_fn_addr), replacement_addr);			\
+	typecheck_fn(typeof(&replacement_addr), real_fn_addr);			\
 	__kunit_activate_static_stub(test, real_fn_addr, replacement_addr);	\
 } while (0)
 
diff --git a/include/kunit/test.h b/include/kunit/test.h
index 20ed9f9275c9..c2ce379c329b 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -253,6 +253,7 @@ struct kunit_suite {
 	struct dentry *debugfs;
 	struct string_stream *log;
 	int suite_init_err;
+	bool is_init;
 };
 
 /* Stores an array of suites, end points one past the end */
@@ -337,6 +338,9 @@ void __kunit_test_suites_exit(struct kunit_suite **suites, int num_suites);
 void kunit_exec_run_tests(struct kunit_suite_set *suite_set, bool builtin);
 void kunit_exec_list_tests(struct kunit_suite_set *suite_set, bool include_attr);
 
+struct kunit_suite_set kunit_merge_suite_sets(struct kunit_suite_set init_suite_set,
+		struct kunit_suite_set suite_set);
+
 #if IS_BUILTIN(CONFIG_KUNIT)
 int kunit_run_all_tests(void);
 #else
@@ -371,6 +375,11 @@ static inline int kunit_run_all_tests(void)
 
 #define kunit_test_suite(suite)	kunit_test_suites(&suite)
 
+#define __kunit_init_test_suites(unique_array, ...)			       \
+	static struct kunit_suite *unique_array[]			       \
+	__aligned(sizeof(struct kunit_suite *))				       \
+	__used __section(".kunit_init_test_suites") = { __VA_ARGS__ }
+
 /**
  * kunit_test_init_section_suites() - used to register one or more &struct
  *				      kunit_suite containing init functions or
@@ -378,21 +387,21 @@ static inline int kunit_run_all_tests(void)
  *
  * @__suites: a statically allocated list of &struct kunit_suite.
  *
- * This functions identically as kunit_test_suites() except that it suppresses
- * modpost warnings for referencing functions marked __init or data marked
- * __initdata; this is OK because currently KUnit only runs tests upon boot
- * during the init phase or upon loading a module during the init phase.
+ * This functions similar to kunit_test_suites() except that it compiles the
+ * list of suites during init phase.
+ *
+ * This macro also suffixes the array and suite declarations it makes with
+ * _probe; so that modpost suppresses warnings about referencing init data
+ * for symbols named in this manner.
  *
- * NOTE TO KUNIT DEVS: If we ever allow KUnit tests to be run after boot, these
- * tests must be excluded.
+ * Note: these init tests are not able to be run after boot so there is no
+ * "run" debugfs file generated for these tests.
  *
- * The only thing this macro does that's different from kunit_test_suites is
- * that it suffixes the array and suite declarations it makes with _probe;
- * modpost suppresses warnings about referencing init data for symbols named in
- * this manner.
+ * Also, do not mark the suite or test case structs with __initdata because
+ * they will be used after the init phase with debugfs.
  */
 #define kunit_test_init_section_suites(__suites...)			\
-	__kunit_test_suites(CONCATENATE(__UNIQUE_ID(array), _probe),	\
+	__kunit_init_test_suites(CONCATENATE(__UNIQUE_ID(array), _probe), \
 			    ##__suites)
 
 #define kunit_test_init_section_suite(suite)	\
@@ -749,7 +758,7 @@ do {									       \
 		.right_text = #right,					       \
 	};								       \
 									       \
-	if (likely(strcmp(__left, __right) op 0))			       \
+	if (likely((__left) && (__right) && (strcmp(__left, __right) op 0)))   \
 		break;							       \
 									       \
 									       \
diff --git a/include/linux/module.h b/include/linux/module.h
index a98e188cf37b..9cd0009bd050 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -540,6 +540,8 @@ struct module {
 	struct static_call_site *static_call_sites;
 #endif
 #if IS_ENABLED(CONFIG_KUNIT)
+	int num_kunit_init_suites;
+	struct kunit_suite **kunit_init_suites;
 	int num_kunit_suites;
 	struct kunit_suite **kunit_suites;
 #endif