Merge tag 'linux-kselftest-5.5-rc1-kunit' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kselftest KUnit support gtom Shuah Khan:
 "This adds KUnit, a lightweight unit testing and mocking framework for
  the Linux kernel from Brendan Higgins.

  KUnit is not an end-to-end testing framework. It is currently
  supported on UML and sub-systems can write unit tests and run them in
  UML env. KUnit documentation is included in this update.

  In addition, this Kunit update adds 3 new kunit tests:

   - proc sysctl test from Iurii Zaikin

   - the 'list' doubly linked list test from David Gow

   - ext4 tests for decoding extended timestamps from Iurii Zaikin

  In the future KUnit will be linked to Kselftest framework to provide a
  way to trigger KUnit tests from user-space"

* tag 'linux-kselftest-5.5-rc1-kunit' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (23 commits)
  lib/list-test: add a test for the 'list' doubly linked list
  ext4: add kunit test for decoding extended timestamps
  Documentation: kunit: Fix verification command
  kunit: Fix '--build_dir' option
  kunit: fix failure to build without printk
  MAINTAINERS: add proc sysctl KUnit test to PROC SYSCTL section
  kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec()
  MAINTAINERS: add entry for KUnit the unit testing framework
  Documentation: kunit: add documentation for KUnit
  kunit: defconfig: add defconfigs for building KUnit tests
  kunit: tool: add Python wrappers for running KUnit tests
  kunit: test: add tests for KUnit managed resources
  kunit: test: add the concept of assertions
  kunit: test: add tests for kunit test abort
  kunit: test: add support for test abort
  objtool: add kunit_try_catch_throw to the noreturn list
  kunit: test: add initial tests
  lib: enable building KUnit in lib/
  kunit: test: add the concept of expectations
  kunit: test: add assertion printing library
  ...

1 files changed, 217 insertions, 0 deletions

diff --git a/lib/kunit/string-stream.c b/lib/kunit/string-stream.c
new file mode 100644
index 000000000000..e6d17aacca30
--- /dev/null
+++ b/lib/kunit/string-stream.c
@@ -0,0 +1,217 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * C++ stream style string builder used in KUnit for building messages.
+ *
+ * Copyright (C) 2019, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@google.com>
+ */
+
+#include <kunit/string-stream.h>
+#include <kunit/test.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+
+struct string_stream_fragment_alloc_context {
+	struct kunit *test;
+	int len;
+	gfp_t gfp;
+};
+
+static int string_stream_fragment_init(struct kunit_resource *res,
+				       void *context)
+{
+	struct string_stream_fragment_alloc_context *ctx = context;
+	struct string_stream_fragment *frag;
+
+	frag = kunit_kzalloc(ctx->test, sizeof(*frag), ctx->gfp);
+	if (!frag)
+		return -ENOMEM;
+
+	frag->test = ctx->test;
+	frag->fragment = kunit_kmalloc(ctx->test, ctx->len, ctx->gfp);
+	if (!frag->fragment)
+		return -ENOMEM;
+
+	res->allocation = frag;
+
+	return 0;
+}
+
+static void string_stream_fragment_free(struct kunit_resource *res)
+{
+	struct string_stream_fragment *frag = res->allocation;
+
+	list_del(&frag->node);
+	kunit_kfree(frag->test, frag->fragment);
+	kunit_kfree(frag->test, frag);
+}
+
+static struct string_stream_fragment *alloc_string_stream_fragment(
+		struct kunit *test, int len, gfp_t gfp)
+{
+	struct string_stream_fragment_alloc_context context = {
+		.test = test,
+		.len = len,
+		.gfp = gfp
+	};
+
+	return kunit_alloc_resource(test,
+				    string_stream_fragment_init,
+				    string_stream_fragment_free,
+				    gfp,
+				    &context);
+}
+
+static int string_stream_fragment_destroy(struct string_stream_fragment *frag)
+{
+	return kunit_resource_destroy(frag->test,
+				      kunit_resource_instance_match,
+				      string_stream_fragment_free,
+				      frag);
+}
+
+int string_stream_vadd(struct string_stream *stream,
+		       const char *fmt,
+		       va_list args)
+{
+	struct string_stream_fragment *frag_container;
+	int len;
+	va_list args_for_counting;
+
+	/* Make a copy because `vsnprintf` could change it */
+	va_copy(args_for_counting, args);
+
+	/* Need space for null byte. */
+	len = vsnprintf(NULL, 0, fmt, args_for_counting) + 1;
+
+	va_end(args_for_counting);
+
+	frag_container = alloc_string_stream_fragment(stream->test,
+						      len,
+						      stream->gfp);
+	if (!frag_container)
+		return -ENOMEM;
+
+	len = vsnprintf(frag_container->fragment, len, fmt, args);
+	spin_lock(&stream->lock);
+	stream->length += len;
+	list_add_tail(&frag_container->node, &stream->fragments);
+	spin_unlock(&stream->lock);
+
+	return 0;
+}
+
+int string_stream_add(struct string_stream *stream, const char *fmt, ...)
+{
+	va_list args;
+	int result;
+
+	va_start(args, fmt);
+	result = string_stream_vadd(stream, fmt, args);
+	va_end(args);
+
+	return result;
+}
+
+static void string_stream_clear(struct string_stream *stream)
+{
+	struct string_stream_fragment *frag_container, *frag_container_safe;
+
+	spin_lock(&stream->lock);
+	list_for_each_entry_safe(frag_container,
+				 frag_container_safe,
+				 &stream->fragments,
+				 node) {
+		string_stream_fragment_destroy(frag_container);
+	}
+	stream->length = 0;
+	spin_unlock(&stream->lock);
+}
+
+char *string_stream_get_string(struct string_stream *stream)
+{
+	struct string_stream_fragment *frag_container;
+	size_t buf_len = stream->length + 1; /* +1 for null byte. */
+	char *buf;
+
+	buf = kunit_kzalloc(stream->test, buf_len, stream->gfp);
+	if (!buf)
+		return NULL;
+
+	spin_lock(&stream->lock);
+	list_for_each_entry(frag_container, &stream->fragments, node)
+		strlcat(buf, frag_container->fragment, buf_len);
+	spin_unlock(&stream->lock);
+
+	return buf;
+}
+
+int string_stream_append(struct string_stream *stream,
+			 struct string_stream *other)
+{
+	const char *other_content;
+
+	other_content = string_stream_get_string(other);
+
+	if (!other_content)
+		return -ENOMEM;
+
+	return string_stream_add(stream, other_content);
+}
+
+bool string_stream_is_empty(struct string_stream *stream)
+{
+	return list_empty(&stream->fragments);
+}
+
+struct string_stream_alloc_context {
+	struct kunit *test;
+	gfp_t gfp;
+};
+
+static int string_stream_init(struct kunit_resource *res, void *context)
+{
+	struct string_stream *stream;
+	struct string_stream_alloc_context *ctx = context;
+
+	stream = kunit_kzalloc(ctx->test, sizeof(*stream), ctx->gfp);
+	if (!stream)
+		return -ENOMEM;
+
+	res->allocation = stream;
+	stream->gfp = ctx->gfp;
+	stream->test = ctx->test;
+	INIT_LIST_HEAD(&stream->fragments);
+	spin_lock_init(&stream->lock);
+
+	return 0;
+}
+
+static void string_stream_free(struct kunit_resource *res)
+{
+	struct string_stream *stream = res->allocation;
+
+	string_stream_clear(stream);
+}
+
+struct string_stream *alloc_string_stream(struct kunit *test, gfp_t gfp)
+{
+	struct string_stream_alloc_context context = {
+		.test = test,
+		.gfp = gfp
+	};
+
+	return kunit_alloc_resource(test,
+				    string_stream_init,
+				    string_stream_free,
+				    gfp,
+				    &context);
+}
+
+int string_stream_destroy(struct string_stream *stream)
+{
+	return kunit_resource_destroy(stream->test,
+				      kunit_resource_instance_match,
+				      string_stream_free,
+				      stream);
+}