summaryrefslogtreecommitdiffstats
path: root/include/kunit/resource.h
blob: 4ad69a2642a51cffc3b000f6057f28016a6f3fc3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * KUnit resource API for test managed resources (allocations, etc.).
 *
 * Copyright (C) 2022, Google LLC.
 * Author: Daniel Latypov <dlatypov@google.com>
 */

#ifndef _KUNIT_RESOURCE_H
#define _KUNIT_RESOURCE_H

#include <kunit/test.h>

#include <linux/kref.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/spinlock.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*
 * @data: for the user to store arbitrary data.
 * @name: optional name
 * @free: a user supplied function to free the resource.
 *
 * Represents a *test managed resource*, a resource which will automatically be
 * cleaned up at the end of a test case. This cleanup is performed by the 'free'
 * function. The struct kunit_resource itself is freed automatically with
 * kfree() if it was allocated by KUnit (e.g., by kunit_alloc_resource()), but
 * must be freed by the user otherwise.
 *
 * Resources are reference counted so if a resource is retrieved via
 * kunit_alloc_and_get_resource() or kunit_find_resource(), we need
 * to call kunit_put_resource() to reduce the resource reference count
 * when finished with it.  Note that kunit_alloc_resource() does not require a
 * kunit_resource_put() because it does not retrieve the resource itself.
 *
 * 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->data = kmalloc(params->size, params->gfp);
 *
 *		if (!res->data)
 *			return -ENOMEM;
 *
 *		return 0;
 *	}
 *
 *	static void kunit_kmalloc_free(struct kunit_resource *res)
 *	{
 *		kfree(res->data);
 *	}
 *
 *	void *kunit_kmalloc(struct kunit *test, size_t size, gfp_t gfp)
 *	{
 *		struct kunit_kmalloc_params params;
 *
 *		params.size = size;
 *		params.gfp = gfp;
 *
 *		return kunit_alloc_resource(test, kunit_kmalloc_init,
 *			kunit_kmalloc_free, gfp, &params);
 *	}
 *
 * Resources can also be named, with lookup/removal done on a name
 * basis also.  kunit_add_named_resource(), kunit_find_named_resource()
 * and kunit_destroy_named_resource().  Resource names must be
 * unique within the test instance.
 */
struct kunit_resource {
	void *data;
	const char *name;
	kunit_resource_free_t free;

	/* private: internal use only. */
	struct kref refcount;
	struct list_head node;
	bool should_kfree;
};

/**
 * kunit_get_resource() - Hold resource for use.  Should not need to be used
 *			  by most users as we automatically get resources
 *			  retrieved by kunit_find_resource*().
 * @res: resource
 */
static inline void kunit_get_resource(struct kunit_resource *res)
{
	kref_get(&res->refcount);
}

/*
 * Called when refcount reaches zero via kunit_put_resource();
 * should not be called directly.
 */
static inline void kunit_release_resource(struct kref *kref)
{
	struct kunit_resource *res = container_of(kref, struct kunit_resource,
						  refcount);

	if (res->free)
		res->free(res);

	/* 'res' is valid here, as if should_kfree is set, res->free may not free
	 * 'res' itself, just res->data
	 */
	if (res->should_kfree)
		kfree(res);
}

/**
 * kunit_put_resource() - When caller is done with retrieved resource,
 *			  kunit_put_resource() should be called to drop
 *			  reference count.  The resource list maintains
 *			  a reference count on resources, so if no users
 *			  are utilizing a resource and it is removed from
 *			  the resource list, it will be freed via the
 *			  associated free function (if any).  Only
 *			  needs to be used if we alloc_and_get() or
 *			  find() resource.
 * @res: resource
 */
static inline void kunit_put_resource(struct kunit_resource *res)
{
	kref_put(&res->refcount, kunit_release_resource);
}

/**
 * __kunit_add_resource() - Internal helper to add a resource.
 *
 * res->should_kfree is not initialised.
 * @test: The test context object.
 * @init: a user-supplied function to initialize the result (if needed).  If
 *        none is supplied, the resource data value is simply set to @data.
 *	  If an init function is supplied, @data is passed to it instead.
 * @free: a user-supplied function to free the resource (if needed).
 * @res: The resource.
 * @data: value to pass to init function or set in resource data field.
 */
int __kunit_add_resource(struct kunit *test,
			 kunit_resource_init_t init,
			 kunit_resource_free_t free,
			 struct kunit_resource *res,
			 void *data);

/**
 * kunit_add_resource() - Add a *test managed resource*.
 * @test: The test context object.
 * @init: a user-supplied function to initialize the result (if needed).  If
 *        none is supplied, the resource data value is simply set to @data.
 *	  If an init function is supplied, @data is passed to it instead.
 * @free: a user-supplied function to free the resource (if needed).
 * @res: The resource.
 * @data: value to pass to init function or set in resource data field.
 */
static inline int kunit_add_resource(struct kunit *test,
				     kunit_resource_init_t init,
				     kunit_resource_free_t free,
				     struct kunit_resource *res,
				     void *data)
{
	res->should_kfree = false;
	return __kunit_add_resource(test, init, free, res, data);
}

static inline struct kunit_resource *
kunit_find_named_resource(struct kunit *test, const char *name);

/**
 * kunit_add_named_resource() - Add a named *test managed resource*.
 * @test: The test context object.
 * @init: a user-supplied function to initialize the resource data, if needed.
 * @free: a user-supplied function to free the resource data, if needed.
 * @res: The resource.
 * @name: name to be set for resource.
 * @data: value to pass to init function or set in resource data field.
 */
static inline int kunit_add_named_resource(struct kunit *test,
					   kunit_resource_init_t init,
					   kunit_resource_free_t free,
					   struct kunit_resource *res,
					   const char *name,
					   void *data)
{
	struct kunit_resource *existing;

	if (!name)
		return -EINVAL;

	existing = kunit_find_named_resource(test, name);
	if (existing) {
		kunit_put_resource(existing);
		return -EEXIST;
	}

	res->name = name;
	res->should_kfree = false;

	return __kunit_add_resource(test, init, free, res, data);
}

/**
 * kunit_alloc_and_get_resource() - Allocates and returns 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 (if needed).
 * @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.
 *
 * This is effectively identical to kunit_alloc_resource, but returns the
 * struct kunit_resource pointer, not just the 'data' pointer. It therefore
 * also increments the resource's refcount, so kunit_put_resource() should be
 * called when you've finished with it.
 *
 * Note: KUnit needs to allocate memory for a kunit_resource object. You must
 * specify an @internal_gfp that is compatible with the use context of your
 * resource.
 */
static inline 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;

	res->should_kfree = true;

	ret = __kunit_add_resource(test, init, free, res, context);
	if (!ret) {
		/*
		 * bump refcount for get; kunit_resource_put() should be called
		 * when done.
		 */
		kunit_get_resource(res);
		return res;
	}
	return NULL;
}

/**
 * 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 (if needed).
 * @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 a 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 = kzalloc(sizeof(*res), internal_gfp);
	if (!res)
		return NULL;

	res->should_kfree = true;
	if (!__kunit_add_resource(test, init, free, res, context))
		return res->data;

	return NULL;
}

typedef bool (*kunit_resource_match_t)(struct kunit *test,
				       struct kunit_resource *res,
				       void *match_data);

/**
 * kunit_resource_name_match() - Match a resource with the same name.
 * @test: Test case to which the resource belongs.
 * @res: The resource.
 * @match_name: The name to match against.
 */
static inline bool kunit_resource_name_match(struct kunit *test,
					     struct kunit_resource *res,
					     void *match_name)
{
	return res->name && strcmp(res->name, match_name) == 0;
}

/**
 * kunit_find_resource() - Find a resource using match function/data.
 * @test: Test case to which the resource belongs.
 * @match: match function to be applied to resources/match data.
 * @match_data: data to be used in matching.
 */
static inline struct kunit_resource *
kunit_find_resource(struct kunit *test,
		    kunit_resource_match_t match,
		    void *match_data)
{
	struct kunit_resource *res, *found = NULL;
	unsigned long flags;

	spin_lock_irqsave(&test->lock, flags);

	list_for_each_entry_reverse(res, &test->resources, node) {
		if (match(test, res, (void *)match_data)) {
			found = res;
			kunit_get_resource(found);
			break;
		}
	}

	spin_unlock_irqrestore(&test->lock, flags);

	return found;
}

/**
 * kunit_find_named_resource() - Find a resource using match name.
 * @test: Test case to which the resource belongs.
 * @name: match name.
 */
static inline struct kunit_resource *
kunit_find_named_resource(struct kunit *test,
			  const char *name)
{
	return kunit_find_resource(test, kunit_resource_name_match,
				   (void *)name);
}

/**
 * kunit_destroy_resource() - 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.
 * @match_data: Data passed into @match.
 *
 * RETURNS:
 * 0 if kunit_resource is found and freed, -ENOENT if not found.
 */
int kunit_destroy_resource(struct kunit *test,
			   kunit_resource_match_t match,
			   void *match_data);

static inline int kunit_destroy_named_resource(struct kunit *test,
					       const char *name)
{
	return kunit_destroy_resource(test, kunit_resource_name_match,
				      (void *)name);
}

/**
 * kunit_remove_resource() - remove resource from resource list associated with
 *			     test.
 * @test: The test context object.
 * @res: The resource to be removed.
 *
 * Note that the resource will not be immediately freed since it is likely
 * the caller has a reference to it via alloc_and_get() or find();
 * in this case a final call to kunit_put_resource() is required.
 */
void kunit_remove_resource(struct kunit *test, struct kunit_resource *res);

/* A 'deferred action' function to be used with kunit_add_action. */
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
 * @ctx: Data passed into @func
 *
 * Defer the execution of a function until the test exits, either normally or
 * due to a failure.  @ctx is passed as additional context. All functions
 * registered with kunit_add_action() will execute in the opposite order to that
 * they were registered in.
 *
 * This is useful for cleaning up allocated memory and resources, as these
 * functions are called even if the test aborts early due to, e.g., a failed
 * assertion.
 *
 * See also: devm_add_action() for the devres equivalent.
 *
 * Returns:
 *   0 on success, an error if the action could not be deferred.
 */
int kunit_add_action(struct kunit *test, kunit_action_t *action, void *ctx);

/**
 * kunit_add_action_or_reset() - Call a function when the test ends.
 * @test: Test case to associate the action with.
 * @action: The function to run on test exit
 * @ctx: Data passed into @func
 *
 * Defer the execution of a function until the test exits, either normally or
 * due to a failure.  @ctx is passed as additional context. All functions
 * registered with kunit_add_action() will execute in the opposite order to that
 * they were registered in.
 *
 * This is useful for cleaning up allocated memory and resources, as these
 * functions are called even if the test aborts early due to, e.g., a failed
 * assertion.
 *
 * If the action cannot be created (e.g., due to the system being out of memory),
 * then action(ctx) will be called immediately, and an error will be returned.
 *
 * See also: devm_add_action_or_reset() for the devres equivalent.
 *
 * Returns:
 *   0 on success, an error if the action could not be deferred.
 */
int kunit_add_action_or_reset(struct kunit *test, kunit_action_t *action,
			      void *ctx);

/**
 * kunit_remove_action() - Cancel a matching deferred action.
 * @test: Test case the action is associated with.
 * @action: The deferred function to cancel.
 * @ctx: The context passed to the deferred function to trigger.
 *
 * Prevent an action deferred via kunit_add_action() from executing when the
 * test terminates.
 *
 * If the function/context pair was deferred multiple times, only the most
 * recent one will be cancelled.
 *
 * See also: devm_remove_action() for the devres equivalent.
 */
void kunit_remove_action(struct kunit *test,
			 kunit_action_t *action,
			 void *ctx);

/**
 * kunit_release_action() - Run a matching action call immediately.
 * @test: Test case the action is associated with.
 * @action: The deferred function to trigger.
 * @ctx: The context passed to the deferred function to trigger.
 *
 * Execute a function deferred via kunit_add_action()) immediately, rather than
 * when the test ends.
 *
 * If the function/context pair was deferred multiple times, it will only be
 * executed once here. The most recent deferral will no longer execute when
 * the test ends.
 *
 * kunit_release_action(test, func, ctx);
 * is equivalent to
 * func(ctx);
 * kunit_remove_action(test, func, ctx);
 *
 * See also: devm_release_action() for the devres equivalent.
 */
void kunit_release_action(struct kunit *test,
			  kunit_action_t *action,
			  void *ctx);
#endif /* _KUNIT_RESOURCE_H */