Merge tag 'linux-kselftest-kunit-next-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull KUnit updates from Shuah Khan:
 "Several enhancements, fixes, clean-ups, documentation updates,
  improvements to logging and KTAP compliance of KUnit test output:

   - log numbers in decimal and hex

   - parse KTAP compliant test output

   - allow conditionally exposing static symbols to tests when KUNIT is
     enabled

   - make static symbols visible during kunit testing

   - clean-ups to remove unused structure definition"

* tag 'linux-kselftest-kunit-next-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (29 commits)
  Documentation: dev-tools: Clarify requirements for result description
  apparmor: test: make static symbols visible during kunit testing
  kunit: add macro to allow conditionally exposing static symbols to tests
  kunit: tool: make parser preserve whitespace when printing test log
  Documentation: kunit: Fix "How Do I Use This" / "Next Steps" sections
  kunit: tool: don't include KTAP headers and the like in the test log
  kunit: improve KTAP compliance of KUnit test output
  kunit: tool: parse KTAP compliant test output
  mm: slub: test: Use the kunit_get_current_test() function
  kunit: Use the static key when retrieving the current test
  kunit: Provide a static key to check if KUnit is actively running tests
  kunit: tool: make --json do nothing if --raw_ouput is set
  kunit: tool: tweak error message when no KTAP found
  kunit: remove KUNIT_INIT_MEM_ASSERTION macro
  Documentation: kunit: Remove redundant 'tips.rst' page
  Documentation: KUnit: reword description of assertions
  Documentation: KUnit: make usage.rst a superset of tips.rst, remove duplication
  kunit: eliminate KUNIT_INIT_*_ASSERT_STRUCT macros
  kunit: tool: remove redundant file.close() call in unit test
  kunit: tool: unit tests all check parser errors, standardize formatting a bit
  ...

4 files changed, 215 insertions, 63 deletions

diff --git a/include/kunit/assert.h b/include/kunit/assert.h
index ace3de8d1ee7..24c2b9fa61e8 100644
--- a/include/kunit/assert.h
+++ b/include/kunit/assert.h
@@ -91,19 +91,6 @@ void kunit_unary_assert_format(const struct kunit_assert *assert,
 			       struct string_stream *stream);
 
 /**
- * KUNIT_INIT_UNARY_ASSERT_STRUCT() - Initializes &struct kunit_unary_assert.
- * @cond: A string representation of the expression asserted true or false.
- * @expect_true: True if of type KUNIT_{EXPECT|ASSERT}_TRUE, false otherwise.
- *
- * Initializes a &struct kunit_unary_assert. Intended to be used in
- * KUNIT_EXPECT_* and KUNIT_ASSERT_* macros.
- */
-#define KUNIT_INIT_UNARY_ASSERT_STRUCT(cond, expect_true) {		       \
-	.condition = cond,						       \
-	.expected_true = expect_true					       \
-}
-
-/**
  * struct kunit_ptr_not_err_assert - An expectation/assertion that a pointer is
  *	not NULL and not a -errno.
  * @assert: The parent of this type.
@@ -124,20 +111,6 @@ void kunit_ptr_not_err_assert_format(const struct kunit_assert *assert,
 				     struct string_stream *stream);
 
 /**
- * KUNIT_INIT_PTR_NOT_ERR_ASSERT_STRUCT() - Initializes a
- *	&struct kunit_ptr_not_err_assert.
- * @txt: A string representation of the expression passed to the expectation.
- * @val: The actual evaluated pointer value of the expression.
- *
- * Initializes a &struct kunit_ptr_not_err_assert. Intended to be used in
- * KUNIT_EXPECT_* and KUNIT_ASSERT_* macros.
- */
-#define KUNIT_INIT_PTR_NOT_ERR_STRUCT(txt, val) {			       \
-	.text = txt,							       \
-	.value = val							       \
-}
-
-/**
  * struct kunit_binary_assert_text - holds strings for &struct
  *	kunit_binary_assert and friends to try and make the structs smaller.
  * @operation: A string representation of the comparison operator (e.g. "==").
@@ -174,27 +147,6 @@ void kunit_binary_assert_format(const struct kunit_assert *assert,
 				struct string_stream *stream);
 
 /**
- * KUNIT_INIT_BINARY_ASSERT_STRUCT() - Initializes a binary assert like
- *	kunit_binary_assert, kunit_binary_ptr_assert, etc.
- *
- * @text_: Pointer to a kunit_binary_assert_text.
- * @left_val: The actual evaluated value of the expression in the left slot.
- * @right_val: The actual evaluated value of the expression in the right slot.
- *
- * Initializes a binary assert like kunit_binary_assert,
- * kunit_binary_ptr_assert, etc. This relies on these structs having the same
- * fields but with different types for left_val/right_val.
- * This is ultimately used by binary assertion macros like KUNIT_EXPECT_EQ, etc.
- */
-#define KUNIT_INIT_BINARY_ASSERT_STRUCT(text_,				       \
-					left_val,			       \
-					right_val) {			       \
-	.text = text_,							       \
-	.left_value = left_val,						       \
-	.right_value = right_val					       \
-}
-
-/**
  * struct kunit_binary_ptr_assert - An expectation/assertion that compares two
  *	pointer values (for example, KUNIT_EXPECT_PTR_EQ(test, foo, bar)).
  * @assert: The parent of this type.
@@ -240,4 +192,30 @@ void kunit_binary_str_assert_format(const struct kunit_assert *assert,
 				    const struct va_format *message,
 				    struct string_stream *stream);
 
+/**
+ * struct kunit_mem_assert - An expectation/assertion that compares two
+ *	memory blocks.
+ * @assert: The parent of this type.
+ * @text: Holds the textual representations of the operands and comparator.
+ * @left_value: The actual evaluated value of the expression in the left slot.
+ * @right_value: The actual evaluated value of the expression in the right slot.
+ * @size: Size of the memory block analysed in bytes.
+ *
+ * Represents an expectation/assertion that compares two memory blocks. For
+ * example, to expect that the first three bytes of foo is equal to the
+ * first three bytes of bar, you can use the expectation
+ * KUNIT_EXPECT_MEMEQ(test, foo, bar, 3);
+ */
+struct kunit_mem_assert {
+	struct kunit_assert assert;
+	const struct kunit_binary_assert_text *text;
+	const void *left_value;
+	const void *right_value;
+	const size_t size;
+};
+
+void kunit_mem_assert_format(const struct kunit_assert *assert,
+			     const struct va_format *message,
+			     struct string_stream *stream);
+
 #endif /*  _KUNIT_ASSERT_H */
diff --git a/include/kunit/test-bug.h b/include/kunit/test-bug.h
index 5fc58081d511..c1b2e14eab64 100644
--- a/include/kunit/test-bug.h
+++ b/include/kunit/test-bug.h
@@ -9,16 +9,63 @@
 #ifndef _KUNIT_TEST_BUG_H
 #define _KUNIT_TEST_BUG_H
 
-#define kunit_fail_current_test(fmt, ...) \
-	__kunit_fail_current_test(__FILE__, __LINE__, fmt, ##__VA_ARGS__)
-
 #if IS_BUILTIN(CONFIG_KUNIT)
 
+#include <linux/jump_label.h> /* For static branch */
+#include <linux/sched.h>
+
+/* Static key if KUnit is running any tests. */
+DECLARE_STATIC_KEY_FALSE(kunit_running);
+
+/**
+ * kunit_get_current_test() - Return a pointer to the currently running
+ *			      KUnit test.
+ *
+ * If a KUnit test is running in the current task, returns a pointer to its
+ * associated struct kunit. This pointer can then be passed to any KUnit
+ * function or assertion. If no test is running (or a test is running in a
+ * different task), returns NULL.
+ *
+ * This function is safe to call even when KUnit is disabled. If CONFIG_KUNIT
+ * is not enabled, it will compile down to nothing and will return quickly no
+ * test is running.
+ */
+static inline struct kunit *kunit_get_current_test(void)
+{
+	if (!static_branch_unlikely(&kunit_running))
+		return NULL;
+
+	return current->kunit_test;
+}
+
+
+/**
+ * kunit_fail_current_test() - If a KUnit test is running, fail it.
+ *
+ * If a KUnit test is running in the current task, mark that test as failed.
+ *
+ * This macro will only work if KUnit is built-in (though the tests
+ * themselves can be modules). Otherwise, it compiles down to nothing.
+ */
+#define kunit_fail_current_test(fmt, ...) do {					\
+		if (static_branch_unlikely(&kunit_running)) {			\
+			__kunit_fail_current_test(__FILE__, __LINE__,		\
+						  fmt, ##__VA_ARGS__);		\
+		}								\
+	} while (0)
+
+
 extern __printf(3, 4) void __kunit_fail_current_test(const char *file, int line,
 						    const char *fmt, ...);
 
 #else
 
+static inline struct kunit *kunit_get_current_test(void) { return NULL; }
+
+/* We define this with an empty helper function so format string warnings work */
+#define kunit_fail_current_test(fmt, ...) \
+		__kunit_fail_current_test(__FILE__, __LINE__, fmt, ##__VA_ARGS__)
+
 static inline __printf(3, 4) void __kunit_fail_current_test(const char *file, int line,
 							    const char *fmt, ...)
 {
diff --git a/include/kunit/test.h b/include/kunit/test.h
index b1ab6b32216d..87ea90576b50 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -16,6 +16,7 @@
 #include <linux/container_of.h>
 #include <linux/err.h>
 #include <linux/init.h>
+#include <linux/jump_label.h>
 #include <linux/kconfig.h>
 #include <linux/kref.h>
 #include <linux/list.h>
@@ -27,6 +28,9 @@
 
 #include <asm/rwonce.h>
 
+/* Static key: true if any KUnit tests are currently running */
+DECLARE_STATIC_KEY_FALSE(kunit_running);
+
 struct kunit;
 
 /* Size of log associated with test. */
@@ -515,22 +519,25 @@ void kunit_do_failed_assertion(struct kunit *test,
 			     fmt,					       \
 			     ##__VA_ARGS__)
 
+/* Helper to safely pass around an initializer list to other macros. */
+#define KUNIT_INIT_ASSERT(initializers...) { initializers }
+
 #define KUNIT_UNARY_ASSERTION(test,					       \
 			      assert_type,				       \
-			      condition,				       \
-			      expected_true,				       \
+			      condition_,				       \
+			      expected_true_,				       \
 			      fmt,					       \
 			      ...)					       \
 do {									       \
-	if (likely(!!(condition) == !!expected_true))			       \
+	if (likely(!!(condition_) == !!expected_true_))			       \
 		break;							       \
 									       \
 	_KUNIT_FAILED(test,						       \
 		      assert_type,					       \
 		      kunit_unary_assert,				       \
 		      kunit_unary_assert_format,			       \
-		      KUNIT_INIT_UNARY_ASSERT_STRUCT(#condition,	       \
-						     expected_true),	       \
+		      KUNIT_INIT_ASSERT(.condition = #condition_,	       \
+					.expected_true = expected_true_),      \
 		      fmt,						       \
 		      ##__VA_ARGS__);					       \
 } while (0)
@@ -590,9 +597,9 @@ do {									       \
 		      assert_type,					       \
 		      assert_class,					       \
 		      format_func,					       \
-		      KUNIT_INIT_BINARY_ASSERT_STRUCT(&__text,		       \
-						      __left,		       \
-						      __right),		       \
+		      KUNIT_INIT_ASSERT(.text = &__text,		       \
+					.left_value = __left,		       \
+					.right_value = __right),	       \
 		      fmt,						       \
 		      ##__VA_ARGS__);					       \
 } while (0)
@@ -651,9 +658,42 @@ do {									       \
 		      assert_type,					       \
 		      kunit_binary_str_assert,				       \
 		      kunit_binary_str_assert_format,			       \
-		      KUNIT_INIT_BINARY_ASSERT_STRUCT(&__text,		       \
-						      __left,		       \
-						      __right),		       \
+		      KUNIT_INIT_ASSERT(.text = &__text,		       \
+					.left_value = __left,		       \
+					.right_value = __right),	       \
+		      fmt,						       \
+		      ##__VA_ARGS__);					       \
+} while (0)
+
+#define KUNIT_MEM_ASSERTION(test,					       \
+			    assert_type,				       \
+			    left,					       \
+			    op,						       \
+			    right,					       \
+			    size_,					       \
+			    fmt,					       \
+			    ...)					       \
+do {									       \
+	const void *__left = (left);					       \
+	const void *__right = (right);					       \
+	const size_t __size = (size_);					       \
+	static const struct kunit_binary_assert_text __text = {		       \
+		.operation = #op,					       \
+		.left_text = #left,					       \
+		.right_text = #right,					       \
+	};								       \
+									       \
+	if (likely(memcmp(__left, __right, __size) op 0))		       \
+		break;							       \
+									       \
+	_KUNIT_FAILED(test,						       \
+		      assert_type,					       \
+		      kunit_mem_assert,					       \
+		      kunit_mem_assert_format,				       \
+		      KUNIT_INIT_ASSERT(.text = &__text,		       \
+					.left_value = __left,		       \
+					.right_value = __right,		       \
+					.size = __size),		       \
 		      fmt,						       \
 		      ##__VA_ARGS__);					       \
 } while (0)
@@ -673,7 +713,7 @@ do {									       \
 		      assert_type,					       \
 		      kunit_ptr_not_err_assert,				       \
 		      kunit_ptr_not_err_assert_format,			       \
-		      KUNIT_INIT_PTR_NOT_ERR_STRUCT(#ptr, __ptr),	       \
+		      KUNIT_INIT_ASSERT(.text = #ptr, .value = __ptr),	       \
 		      fmt,						       \
 		      ##__VA_ARGS__);					       \
 } while (0)
@@ -929,6 +969,60 @@ do {									       \
 				   ##__VA_ARGS__)
 
 /**
+ * KUNIT_EXPECT_MEMEQ() - Expects that the first @size bytes of @left and @right are equal.
+ * @test: The test context object.
+ * @left: An arbitrary expression that evaluates to the specified size.
+ * @right: An arbitrary expression that evaluates to the specified size.
+ * @size: Number of bytes compared.
+ *
+ * Sets an expectation that the values that @left and @right evaluate to are
+ * equal. This is semantically equivalent to
+ * KUNIT_EXPECT_TRUE(@test, !memcmp((@left), (@right), (@size))). See
+ * KUNIT_EXPECT_TRUE() for more information.
+ *
+ * Although this expectation works for any memory block, it is not recommended
+ * for comparing more structured data, such as structs. This expectation is
+ * recommended for comparing, for example, data arrays.
+ */
+#define KUNIT_EXPECT_MEMEQ(test, left, right, size) \
+	KUNIT_EXPECT_MEMEQ_MSG(test, left, right, size, NULL)
+
+#define KUNIT_EXPECT_MEMEQ_MSG(test, left, right, size, fmt, ...)	       \
+	KUNIT_MEM_ASSERTION(test,					       \
+			    KUNIT_EXPECTATION,				       \
+			    left, ==, right,				       \
+			    size,					       \
+			    fmt,					       \
+			    ##__VA_ARGS__)
+
+/**
+ * KUNIT_EXPECT_MEMNEQ() - Expects that the first @size bytes of @left and @right are not equal.
+ * @test: The test context object.
+ * @left: An arbitrary expression that evaluates to the specified size.
+ * @right: An arbitrary expression that evaluates to the specified size.
+ * @size: Number of bytes compared.
+ *
+ * Sets an expectation that the values that @left and @right evaluate to are
+ * not equal. This is semantically equivalent to
+ * KUNIT_EXPECT_TRUE(@test, memcmp((@left), (@right), (@size))). See
+ * KUNIT_EXPECT_TRUE() for more information.
+ *
+ * Although this expectation works for any memory block, it is not recommended
+ * for comparing more structured data, such as structs. This expectation is
+ * recommended for comparing, for example, data arrays.
+ */
+#define KUNIT_EXPECT_MEMNEQ(test, left, right, size) \
+	KUNIT_EXPECT_MEMNEQ_MSG(test, left, right, size, NULL)
+
+#define KUNIT_EXPECT_MEMNEQ_MSG(test, left, right, size, fmt, ...)	       \
+	KUNIT_MEM_ASSERTION(test,					       \
+			    KUNIT_EXPECTATION,				       \
+			    left, !=, right,				       \
+			    size,					       \
+			    fmt,					       \
+			    ##__VA_ARGS__)
+
+/**
  * KUNIT_EXPECT_NULL() - Expects that @ptr is null.
  * @test: The test context object.
  * @ptr: an arbitrary pointer.
diff --git a/include/kunit/visibility.h b/include/kunit/visibility.h
new file mode 100644
index 000000000000..0dfe35feeec6
--- /dev/null
+++ b/include/kunit/visibility.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * KUnit API to allow symbols to be conditionally visible during KUnit
+ * testing
+ *
+ * Copyright (C) 2022, Google LLC.
+ * Author: Rae Moar <rmoar@google.com>
+ */
+
+#ifndef _KUNIT_VISIBILITY_H
+#define _KUNIT_VISIBILITY_H
+
+#if IS_ENABLED(CONFIG_KUNIT)
+    /**
+     * VISIBLE_IF_KUNIT - A macro that sets symbols to be static if
+     * CONFIG_KUNIT is not enabled. Otherwise if CONFIG_KUNIT is enabled
+     * there is no change to the symbol definition.
+     */
+    #define VISIBLE_IF_KUNIT
+    /**
+     * EXPORT_SYMBOL_IF_KUNIT(symbol) - Exports symbol into
+     * EXPORTED_FOR_KUNIT_TESTING namespace only if CONFIG_KUNIT is
+     * enabled. Must use MODULE_IMPORT_NS(EXPORTED_FOR_KUNIT_TESTING)
+     * in test file in order to use symbols.
+     */
+    #define EXPORT_SYMBOL_IF_KUNIT(symbol) EXPORT_SYMBOL_NS(symbol, \
+	    EXPORTED_FOR_KUNIT_TESTING)
+#else
+    #define VISIBLE_IF_KUNIT static
+    #define EXPORT_SYMBOL_IF_KUNIT(symbol)
+#endif
+
+#endif /* _KUNIT_VISIBILITY_H */