[PATCH v14 02/18] kunit: test: add test resource management API

Brendan Higgins
2019-08-20T23:20:30Z

Create a common API for test managed resources like memory and test
objects. A lot of times a test will want to set up infrastructure to be
used in test cases; this could be anything from just wanting to allocate
some memory to setting up a driver stack; this defines facilities for
creating "test resources" which are managed by the test infrastructure
and are automatically cleaned up at the conclusion of the test.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
---
include/kunit/test.h | 187 +++++++++++++++++++++++++++++++++++++++++++
kunit/test.c | 163 +++++++++++++++++++++++++++++++++++++
2 files changed, 350 insertions(+)

diff --git a/include/kunit/test.h b/include/kunit/test.h
index e0b34acb9ee4e..f264ffe58f008 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -9,8 +9,72 @@
#ifndef _KUNIT_TEST_H
#define _KUNIT_TEST_H

+#include <linux/slab.h>
#include <linux/types.h>

+struct kunit_resource;
+
+typedef int (*kunit_resource_init_t)(struct kunit_resource *, void *);
+typedef void (*kunit_resource_free_t)(struct kunit_resource *);
+
+/**
+ * struct kunit_resource - represents a *test managed resource*
+ * @allocation: for the user to store arbitrary data.
+ * @free: a user supplied function to free the resource. Populated by
+ * kunit_alloc_resource().
+ *
+ * Represents a *test managed resource*, a resource which will automatically be
+ * cleaned up at the end of a test case.
+ *
+ * Example:
+ *
+ * .. code-block:: c
+ *
+ * struct kunit_kmalloc_params {
+ * size_t size;
+ * gfp_t gfp;
+ * };
+ *
+ * static int kunit_kmalloc_init(struct kunit_resource *res, void *context)
+ * {
+ * struct kunit_kmalloc_params *params = context;
+ * res->allocation = kmalloc(params->size, params->gfp);
+ *
+ * if (!res->allocation)
+ * return -ENOMEM;
+ *
+ * return 0;
+ * }
+ *
+ * static void kunit_kmalloc_free(struct kunit_resource *res)
+ * {
+ * kfree(res->allocation);
+ * }
+ *
+ * void *kunit_kmalloc(struct kunit *test, size_t size, gfp_t gfp)
+ * {
+ * struct kunit_kmalloc_params params;
+ * struct kunit_resource *res;
+ *
+ * params.size = size;
+ * params.gfp = gfp;
+ *
+ * res = kunit_alloc_resource(test, kunit_kmalloc_init,
+ * kunit_kmalloc_free, &params);
+ * if (res)
+ * return res->allocation;
+ *
+ * return NULL;
+ * }
+ */
+struct kunit_resource {
+ void *allocation;
+ kunit_resource_free_t free;
+
+ /* private: internal use only. */
+ struct list_head node;
+};
+
struct kunit;

/**
@@ -109,6 +173,13 @@ struct kunit {
* have terminated.
*/
bool success; /* Read only after test_case finishes! */
+ spinlock_t lock; /* Guards all mutable test state. */
+ /*
+ * Because resources is a list that may be updated multiple times (with
+ * new resources) from any thread associated with a test case, we must
+ * protect it with some type of lock.
+ */
+ struct list_head resources; /* Protected by lock. */
};

void kunit_init_test(struct kunit *test, const char *name);
@@ -141,6 +212,122 @@ int kunit_run_tests(struct kunit_suite *suite);
} \
late_initcall(kunit_suite_init##suite)

+/*
+ * Like kunit_alloc_resource() below, but returns the struct kunit_resource
+ * object that contains the allocation. This is mostly for testing purposes.
+ */
+struct kunit_resource *kunit_alloc_and_get_resource(struct kunit *test,
+ kunit_resource_init_t init,
+ kunit_resource_free_t free,
+ gfp_t internal_gfp,
+ void *context);
+
+/**
+ * kunit_alloc_resource() - Allocates a *test managed resource*.
+ * @test: The test context object.
+ * @init: a user supplied function to initialize the resource.
+ * @free: a user supplied function to free the resource.
+ * @internal_gfp: gfp to use for internal allocations, if unsure, use GFP_KERNEL
+ * @context: for the user to pass in arbitrary data to the init function.
+ *
+ * Allocates a *test managed resource*, a resource which will automatically be
+ * cleaned up at the end of a test case. See &struct kunit_resource for an
+ * example.
+ *
+ * NOTE: KUnit needs to allocate memory for each kunit_resource object. You must
+ * specify an @internal_gfp that is compatible with the use context of your
+ * resource.
+ */
+static inline void *kunit_alloc_resource(struct kunit *test,
+ kunit_resource_init_t init,
+ kunit_resource_free_t free,
+ gfp_t internal_gfp,
+ void *context)
+{
+ struct kunit_resource *res;
+
+ res = kunit_alloc_and_get_resource(test, init, free, internal_gfp,
+ context);
+
+ if (res)
+ return res->allocation;
+
+ return NULL;
+}
+
+typedef bool (*kunit_resource_match_t)(struct kunit *test,
+ const void *res,
+ void *match_data);
+
+/**
+ * kunit_resource_instance_match() - Match a resource with the same instance.
+ * @test: Test case to which the resource belongs.
+ * @res: The data stored in kunit_resource->allocation.
+ * @match_data: The resource pointer to match against.
+ *
+ * An instance of kunit_resource_match_t that matches a resource whose
+ * allocation matches @match_data.
+ */
+static inline bool kunit_resource_instance_match(struct kunit *test,
+ const void *res,
+ void *match_data)
+{
+ return res == match_data;
+}
+
+/**
+ * kunit_resource_destroy() - Find a kunit_resource and destroy it.
+ * @test: Test case to which the resource belongs.
+ * @match: Match function. Returns whether a given resource matches @match_data.
+ * @free: Must match free on the kunit_resource to free.
+ * @match_data: Data passed into @match.
+ *
+ * Free the latest kunit_resource of @test for which @free matches the
+ * kunit_resource_free_t associated with the resource and for which @match
+ * returns true.
+ *
+ * RETURNS:
+ * 0 if kunit_resource is found and freed, -ENOENT if not found.
+ */
+int kunit_resource_destroy(struct kunit *test,
+ kunit_resource_match_t match,
+ kunit_resource_free_t free,
+ void *match_data);
+
+/**
+ * kunit_kmalloc() - Like kmalloc() except the allocation is *test managed*.
+ * @test: The test context object.
+ * @size: The size in bytes of the desired memory.
+ * @gfp: flags passed to underlying kmalloc().
+ *
+ * Just like `kmalloc(...)`, except the allocation is managed by the test case
+ * and is automatically cleaned up after the test case concludes. See &struct
+ * kunit_resource for more information.
+ */
+void *kunit_kmalloc(struct kunit *test, size_t size, gfp_t gfp);
+
+/**
+ * kunit_kfree() - Like kfree except for allocations managed by KUnit.
+ * @test: The test case to which the resource belongs.
+ * @ptr: The memory allocation to free.
+ */
+void kunit_kfree(struct kunit *test, const void *ptr);
+
+/**
+ * kunit_kzalloc() - Just like kunit_kmalloc(), but zeroes the allocation.
+ * @test: The test context object.
+ * @size: The size in bytes of the desired memory.
+ * @gfp: flags passed to underlying kmalloc().
+ *
+ * See kzalloc() and kunit_kmalloc() for more information.
+ */
+static inline void *kunit_kzalloc(struct kunit *test, size_t size, gfp_t gfp)
+{
+ return kunit_kmalloc(test, size, gfp | __GFP_ZERO);
+}
+
+void kunit_cleanup(struct kunit *test);
+
void __printf(3, 4) kunit_printk(const char *level,
const struct kunit *test,
const char *fmt, ...);
diff --git a/kunit/test.c b/kunit/test.c
index d3dda359f99b1..68b1037ab74d0 100644
--- a/kunit/test.c
+++ b/kunit/test.c
@@ -122,6 +122,8 @@ static void kunit_print_test_case_ok_not_ok(struct kunit_case *test_case,

void kunit_init_test(struct kunit *test, const char *name)
{
+ spin_lock_init(&test->lock);
+ INIT_LIST_HEAD(&test->resources);
test->name = name;
test->success = true;
}
@@ -153,6 +155,8 @@ static void kunit_run_case(struct kunit_suite *suite,
if (suite->exit)
suite->exit(&test);

+ kunit_cleanup(&test);
+
test_case->success = test.success;
}

@@ -173,6 +177,165 @@ int kunit_run_tests(struct kunit_suite *suite)
return 0;
}

+struct kunit_resource *kunit_alloc_and_get_resource(struct kunit *test,
+ kunit_resource_init_t init,
+ kunit_resource_free_t free,
+ gfp_t internal_gfp,
+ void *context)
+{
+ struct kunit_resource *res;
+ int ret;
+
+ res = kzalloc(sizeof(*res), internal_gfp);
+ if (!res)
+ return NULL;
+
+ ret = init(res, context);
+ if (ret)
+ return NULL;
+
+ res->free = free;
+ spin_lock(&test->lock);
+ list_add_tail(&res->node, &test->resources);
+ spin_unlock(&test->lock);
+
+ return res;
+}
+
+static void kunit_resource_free(struct kunit *test, struct kunit_resource *res)
+{
+ res->free(res);
+ kfree(res);
+}
+
+static struct kunit_resource *kunit_resource_find(struct kunit *test,
+ kunit_resource_match_t match,
+ kunit_resource_free_t free,
+ void *match_data)
+{
+ struct kunit_resource *resource;
+
+ lockdep_assert_held(&test->lock);
+
+ list_for_each_entry_reverse(resource, &test->resources, node) {
+ if (resource->free != free)
+ continue;
+ if (match(test, resource->allocation, match_data))
+ return resource;
+ }
+
+ return NULL;
+}
+
+static struct kunit_resource *kunit_resource_remove(
+ struct kunit *test,
+ kunit_resource_match_t match,
+ kunit_resource_free_t free,
+ void *match_data)
+{
+ struct kunit_resource *resource;
+
+ spin_lock(&test->lock);
+ resource = kunit_resource_find(test, match, free, match_data);
+ if (resource)
+ list_del(&resource->node);
+ spin_unlock(&test->lock);
+
+ return resource;
+}
+
+int kunit_resource_destroy(struct kunit *test,
+ kunit_resource_match_t match,
+ kunit_resource_free_t free,
+ void *match_data)
+{
+ struct kunit_resource *resource;
+
+ resource = kunit_resource_remove(test, match, free, match_data);
+
+ if (!resource)
+ return -ENOENT;
+
+ kunit_resource_free(test, resource);
+ return 0;
+}
+
+struct kunit_kmalloc_params {
+ size_t size;
+ gfp_t gfp;
+};
+
+static int kunit_kmalloc_init(struct kunit_resource *res, void *context)
+{
+ struct kunit_kmalloc_params *params = context;
+
+ res->allocation = kmalloc(params->size, params->gfp);
+ if (!res->allocation)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static void kunit_kmalloc_free(struct kunit_resource *res)
+{
+ kfree(res->allocation);
+}
+
+void *kunit_kmalloc(struct kunit *test, size_t size, gfp_t gfp)
+{
+ struct kunit_kmalloc_params params = {
+ .size = size,
+ .gfp = gfp
+ };
+
+ return kunit_alloc_resource(test,
+ kunit_kmalloc_init,
+ kunit_kmalloc_free,
+ gfp,
+ &params);
+}
+
+void kunit_kfree(struct kunit *test, const void *ptr)
+{
+ int rc;
+
+ rc = kunit_resource_destroy(test,
+ kunit_resource_instance_match,
+ kunit_kmalloc_free,
+ (void *)ptr);
+
+ WARN_ON(rc);
+}
+
+void kunit_cleanup(struct kunit *test)
+{
+ struct kunit_resource *resource;
+
+ /*
+ * test->resources is a stack - each allocation must be freed in the
+ * reverse order from which it was added since one resource may depend
+ * on another for its entire lifetime.
+ * Also, we cannot use the normal list_for_each constructs, even the
+ * safe ones because *arbitrary* nodes may be deleted when
+ * kunit_resource_free is called; the list_for_each_safe variants only
+ * protect against the current node being deleted, not the next.
+ */
+ while (true) {
+ spin_lock(&test->lock);
+ if (list_empty(&test->resources)) {
+ spin_unlock(&test->lock);
+ break;
+ }
+ resource = list_last_entry(&test->resources,
+ struct kunit_resource,
+ node);
+ list_del(&resource->node);
+ spin_unlock(&test->lock);
+
+ kunit_resource_free(test, resource);
+ }
+}
+
void kunit_printk(const char *level,
const struct kunit *test,
const char *fmt, ...)
--
2.23.0.rc1.153.gdeed80330f-goog

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