summaryrefslogtreecommitdiff
path: root/drivers/infiniband/core/uverbs_uapi.c
blob: be854628a7c63149c05ed74f9f001a39fb1bc59d (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
// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
/*
 * Copyright (c) 2017, Mellanox Technologies inc.  All rights reserved.
 */
#include <rdma/uverbs_ioctl.h>
#include <rdma/rdma_user_ioctl.h>
#include <linux/bitops.h>
#include "rdma_core.h"
#include "uverbs.h"

static void *uapi_add_elm(struct uverbs_api *uapi, u32 key, size_t alloc_size)
{
	void *elm;
	int rc;

	if (key == UVERBS_API_KEY_ERR)
		return ERR_PTR(-EOVERFLOW);

	elm = kzalloc(alloc_size, GFP_KERNEL);
	rc = radix_tree_insert(&uapi->radix, key, elm);
	if (rc) {
		kfree(elm);
		return ERR_PTR(rc);
	}

	return elm;
}

static int uapi_merge_method(struct uverbs_api *uapi,
			     struct uverbs_api_object *obj_elm, u32 obj_key,
			     const struct uverbs_method_def *method,
			     bool is_driver)
{
	u32 method_key = obj_key | uapi_key_ioctl_method(method->id);
	struct uverbs_api_ioctl_method *method_elm;
	unsigned int i;

	if (!method->attrs)
		return 0;

	method_elm = uapi_add_elm(uapi, method_key, sizeof(*method_elm));
	if (IS_ERR(method_elm)) {
		if (method_elm != ERR_PTR(-EEXIST))
			return PTR_ERR(method_elm);

		/*
		 * This occurs when a driver uses ADD_UVERBS_ATTRIBUTES_SIMPLE
		 */
		if (WARN_ON(method->handler))
			return -EINVAL;
		method_elm = radix_tree_lookup(&uapi->radix, method_key);
		if (WARN_ON(!method_elm))
			return -EINVAL;
	} else {
		WARN_ON(!method->handler);
		rcu_assign_pointer(method_elm->handler, method->handler);
		if (method->handler != uverbs_destroy_def_handler)
			method_elm->driver_method = is_driver;
	}

	for (i = 0; i != method->num_attrs; i++) {
		const struct uverbs_attr_def *attr = (*method->attrs)[i];
		struct uverbs_api_attr *attr_slot;

		if (!attr)
			continue;

		/*
		 * ENUM_IN contains the 'ids' pointer to the driver's .rodata,
		 * so if it is specified by a driver then it always makes this
		 * into a driver method.
		 */
		if (attr->attr.type == UVERBS_ATTR_TYPE_ENUM_IN)
			method_elm->driver_method |= is_driver;

		attr_slot =
			uapi_add_elm(uapi, method_key | uapi_key_attr(attr->id),
				     sizeof(*attr_slot));
		/* Attributes are not allowed to be modified by drivers */
		if (IS_ERR(attr_slot))
			return PTR_ERR(attr_slot);

		attr_slot->spec = attr->attr;
	}

	return 0;
}

static int uapi_merge_tree(struct uverbs_api *uapi,
			   const struct uverbs_object_tree_def *tree,
			   bool is_driver)
{
	unsigned int i, j;
	int rc;

	if (!tree->objects)
		return 0;

	for (i = 0; i != tree->num_objects; i++) {
		const struct uverbs_object_def *obj = (*tree->objects)[i];
		struct uverbs_api_object *obj_elm;
		u32 obj_key;

		if (!obj)
			continue;

		obj_key = uapi_key_obj(obj->id);
		obj_elm = uapi_add_elm(uapi, obj_key, sizeof(*obj_elm));
		if (IS_ERR(obj_elm)) {
			if (obj_elm != ERR_PTR(-EEXIST))
				return PTR_ERR(obj_elm);

			/* This occurs when a driver uses ADD_UVERBS_METHODS */
			if (WARN_ON(obj->type_attrs))
				return -EINVAL;
			obj_elm = radix_tree_lookup(&uapi->radix, obj_key);
			if (WARN_ON(!obj_elm))
				return -EINVAL;
		} else {
			obj_elm->type_attrs = obj->type_attrs;
			if (obj->type_attrs) {
				obj_elm->type_class =
					obj->type_attrs->type_class;
				/*
				 * Today drivers are only permitted to use
				 * idr_class types. They cannot use FD types
				 * because we currently have no way to revoke
				 * the fops pointer after device
				 * disassociation.
				 */
				if (WARN_ON(is_driver &&
					    obj->type_attrs->type_class !=
						    &uverbs_idr_class))
					return -EINVAL;
			}
		}

		if (!obj->methods)
			continue;

		for (j = 0; j != obj->num_methods; j++) {
			const struct uverbs_method_def *method =
				(*obj->methods)[j];
			if (!method)
				continue;

			rc = uapi_merge_method(uapi, obj_elm, obj_key, method,
					       is_driver);
			if (rc)
				return rc;
		}
	}

	return 0;
}

static int
uapi_finalize_ioctl_method(struct uverbs_api *uapi,
			   struct uverbs_api_ioctl_method *method_elm,
			   u32 method_key)
{
	struct radix_tree_iter iter;
	unsigned int num_attrs = 0;
	unsigned int max_bkey = 0;
	bool single_uobj = false;
	void __rcu **slot;

	method_elm->destroy_bkey = UVERBS_API_ATTR_BKEY_LEN;
	radix_tree_for_each_slot (slot, &uapi->radix, &iter,
				  uapi_key_attrs_start(method_key)) {
		struct uverbs_api_attr *elm =
			rcu_dereference_protected(*slot, true);
		u32 attr_key = iter.index & UVERBS_API_ATTR_KEY_MASK;
		u32 attr_bkey = uapi_bkey_attr(attr_key);
		u8 type = elm->spec.type;

		if (uapi_key_attr_to_method(iter.index) !=
		    uapi_key_attr_to_method(method_key))
			break;

		if (elm->spec.mandatory)
			__set_bit(attr_bkey, method_elm->attr_mandatory);

		if (type == UVERBS_ATTR_TYPE_IDR ||
		    type == UVERBS_ATTR_TYPE_FD) {
			u8 access = elm->spec.u.obj.access;

			/*
			 * Verbs specs may only have one NEW/DESTROY, we don't
			 * have the infrastructure to abort multiple NEW's or
			 * cope with multiple DESTROY failure.
			 */
			if (access == UVERBS_ACCESS_NEW ||
			    access == UVERBS_ACCESS_DESTROY) {
				if (WARN_ON(single_uobj))
					return -EINVAL;

				single_uobj = true;
				if (WARN_ON(!elm->spec.mandatory))
					return -EINVAL;
			}

			if (access == UVERBS_ACCESS_DESTROY)
				method_elm->destroy_bkey = attr_bkey;
		}

		max_bkey = max(max_bkey, attr_bkey);
		num_attrs++;
	}

	method_elm->key_bitmap_len = max_bkey + 1;
	WARN_ON(method_elm->key_bitmap_len > UVERBS_API_ATTR_BKEY_LEN);

	uapi_compute_bundle_size(method_elm, num_attrs);
	return 0;
}

static int uapi_finalize(struct uverbs_api *uapi)
{
	struct radix_tree_iter iter;
	void __rcu **slot;
	int rc;

	radix_tree_for_each_slot (slot, &uapi->radix, &iter, 0) {
		struct uverbs_api_ioctl_method *method_elm =
			rcu_dereference_protected(*slot, true);

		if (uapi_key_is_ioctl_method(iter.index)) {
			rc = uapi_finalize_ioctl_method(uapi, method_elm,
							iter.index);
			if (rc)
				return rc;
		}
	}

	return 0;
}

void uverbs_destroy_api(struct uverbs_api *uapi)
{
	struct radix_tree_iter iter;
	void __rcu **slot;

	if (!uapi)
		return;

	radix_tree_for_each_slot (slot, &uapi->radix, &iter, 0) {
		kfree(rcu_dereference_protected(*slot, true));
		radix_tree_iter_delete(&uapi->radix, &iter, slot);
	}
	kfree(uapi);
}

struct uverbs_api *uverbs_alloc_api(
	const struct uverbs_object_tree_def *const *driver_specs,
	enum rdma_driver_id driver_id)
{
	struct uverbs_api *uapi;
	int rc;

	uapi = kzalloc(sizeof(*uapi), GFP_KERNEL);
	if (!uapi)
		return ERR_PTR(-ENOMEM);

	INIT_RADIX_TREE(&uapi->radix, GFP_KERNEL);
	uapi->driver_id = driver_id;

	rc = uapi_merge_tree(uapi, uverbs_default_get_objects(), false);
	if (rc)
		goto err;

	for (; driver_specs && *driver_specs; driver_specs++) {
		rc = uapi_merge_tree(uapi, *driver_specs, true);
		if (rc)
			goto err;
	}

	rc = uapi_finalize(uapi);
	if (rc)
		goto err;

	return uapi;
err:
	if (rc != -ENOMEM)
		pr_err("Setup of uverbs_api failed, kernel parsing tree description is not valid (%d)??\n",
		       rc);

	uverbs_destroy_api(uapi);
	return ERR_PTR(rc);
}

/*
 * The pre version is done before destroying the HW objects, it only blocks
 * off method access. All methods that require the ib_dev or the module data
 * must test one of these assignments prior to continuing.
 */
void uverbs_disassociate_api_pre(struct ib_uverbs_device *uverbs_dev)
{
	struct uverbs_api *uapi = uverbs_dev->uapi;
	struct radix_tree_iter iter;
	void __rcu **slot;

	rcu_assign_pointer(uverbs_dev->ib_dev, NULL);

	radix_tree_for_each_slot (slot, &uapi->radix, &iter, 0) {
		if (uapi_key_is_ioctl_method(iter.index)) {
			struct uverbs_api_ioctl_method *method_elm =
				rcu_dereference_protected(*slot, true);

			if (method_elm->driver_method)
				rcu_assign_pointer(method_elm->handler, NULL);
		}
	}

	synchronize_srcu(&uverbs_dev->disassociate_srcu);
}

/*
 * Called when a driver disassociates from the ib_uverbs_device. The
 * assumption is that the driver module will unload after. Replace everything
 * related to the driver with NULL as a safety measure.
 */
void uverbs_disassociate_api(struct uverbs_api *uapi)
{
	struct radix_tree_iter iter;
	void __rcu **slot;

	radix_tree_for_each_slot (slot, &uapi->radix, &iter, 0) {
		if (uapi_key_is_object(iter.index)) {
			struct uverbs_api_object *object_elm =
				rcu_dereference_protected(*slot, true);

			/*
			 * Some type_attrs are in the driver module. We don't
			 * bother to keep track of which since there should be
			 * no use of this after disassociate.
			 */
			object_elm->type_attrs = NULL;
		} else if (uapi_key_is_attr(iter.index)) {
			struct uverbs_api_attr *elm =
				rcu_dereference_protected(*slot, true);

			if (elm->spec.type == UVERBS_ATTR_TYPE_ENUM_IN)
				elm->spec.u2.enum_def.ids = NULL;
		}
	}
}