1 /*
2  * Copyright (c) 2017, Mellanox Technologies inc.  All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *      - Redistributions of source code must retain the above
15  *        copyright notice, this list of conditions and the following
16  *        disclaimer.
17  *
18  *      - Redistributions in binary form must reproduce the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer in the documentation and/or other materials
21  *        provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  */
32 
33 #ifndef _UVERBS_IOCTL_
34 #define _UVERBS_IOCTL_
35 
36 #include <rdma/uverbs_types.h>
37 #include <linux/uaccess.h>
38 #include <rdma/rdma_user_ioctl.h>
39 #include <rdma/ib_user_ioctl_verbs.h>
40 #include <rdma/ib_user_ioctl_cmds.h>
41 
42 /*
43  * =======================================
44  *	Verbs action specifications
45  * =======================================
46  */
47 
48 enum uverbs_attr_type {
49 	UVERBS_ATTR_TYPE_NA,
50 	UVERBS_ATTR_TYPE_PTR_IN,
51 	UVERBS_ATTR_TYPE_PTR_OUT,
52 	UVERBS_ATTR_TYPE_IDR,
53 	UVERBS_ATTR_TYPE_FD,
54 	UVERBS_ATTR_TYPE_ENUM_IN,
55 };
56 
57 enum uverbs_obj_access {
58 	UVERBS_ACCESS_READ,
59 	UVERBS_ACCESS_WRITE,
60 	UVERBS_ACCESS_NEW,
61 	UVERBS_ACCESS_DESTROY
62 };
63 
64 /* Specification of a single attribute inside the ioctl message */
65 /* good size 16 */
66 struct uverbs_attr_spec {
67 	u8 type;
68 
69 	/*
70 	 * Support extending attributes by length. Allow the user to provide
71 	 * more bytes than ptr.len, but check that everything after is zero'd
72 	 * by the user.
73 	 */
74 	u8 zero_trailing:1;
75 	/*
76 	 * Valid only for PTR_IN. Allocate and copy the data inside
77 	 * the parser
78 	 */
79 	u8 alloc_and_copy:1;
80 	u8 mandatory:1;
81 
82 	union {
83 		struct {
84 			/* Current known size to kernel */
85 			u16 len;
86 			/* User isn't allowed to provide something < min_len */
87 			u16 min_len;
88 		} ptr;
89 
90 		struct {
91 			/*
92 			 * higher bits mean the namespace and lower bits mean
93 			 * the type id within the namespace.
94 			 */
95 			u16 obj_type;
96 			u8 access;
97 		} obj;
98 
99 		struct {
100 			u8 num_elems;
101 		} enum_def;
102 	} u;
103 
104 	/* This weird split of the enum lets us remove some padding */
105 	union {
106 		struct {
107 			/*
108 			 * The enum attribute can select one of the attributes
109 			 * contained in the ids array. Currently only PTR_IN
110 			 * attributes are supported in the ids array.
111 			 */
112 			const struct uverbs_attr_spec *ids;
113 		} enum_def;
114 	} u2;
115 };
116 
117 /*
118  * Information about the API is loaded into a radix tree. For IOCTL we start
119  * with a tuple of:
120  *  object_id, attr_id, method_id
121  *
122  * Which is a 48 bit value, with most of the bits guaranteed to be zero. Based
123  * on the current kernel support this is compressed into 16 bit key for the
124  * radix tree. Since this compression is entirely internal to the kernel the
125  * below limits can be revised if the kernel gains additional data.
126  *
127  * With 64 leafs per node this is a 3 level radix tree.
128  *
129  * The tree encodes multiple types, and uses a scheme where OBJ_ID,0,0 returns
130  * the object slot, and OBJ_ID,METH_ID,0 and returns the method slot.
131  */
132 enum uapi_radix_data {
133 	UVERBS_API_NS_FLAG = 1U << UVERBS_ID_NS_SHIFT,
134 
135 	UVERBS_API_ATTR_KEY_BITS = 6,
136 	UVERBS_API_ATTR_KEY_MASK = GENMASK(UVERBS_API_ATTR_KEY_BITS - 1, 0),
137 	UVERBS_API_ATTR_BKEY_LEN = (1 << UVERBS_API_ATTR_KEY_BITS) - 1,
138 
139 	UVERBS_API_METHOD_KEY_BITS = 5,
140 	UVERBS_API_METHOD_KEY_SHIFT = UVERBS_API_ATTR_KEY_BITS,
141 	UVERBS_API_METHOD_KEY_NUM_CORE = 24,
142 	UVERBS_API_METHOD_KEY_NUM_DRIVER = (1 << UVERBS_API_METHOD_KEY_BITS) -
143 					   UVERBS_API_METHOD_KEY_NUM_CORE,
144 	UVERBS_API_METHOD_KEY_MASK = GENMASK(
145 		UVERBS_API_METHOD_KEY_BITS + UVERBS_API_METHOD_KEY_SHIFT - 1,
146 		UVERBS_API_METHOD_KEY_SHIFT),
147 
148 	UVERBS_API_OBJ_KEY_BITS = 5,
149 	UVERBS_API_OBJ_KEY_SHIFT =
150 		UVERBS_API_METHOD_KEY_BITS + UVERBS_API_METHOD_KEY_SHIFT,
151 	UVERBS_API_OBJ_KEY_NUM_CORE = 24,
152 	UVERBS_API_OBJ_KEY_NUM_DRIVER =
153 		(1 << UVERBS_API_OBJ_KEY_BITS) - UVERBS_API_OBJ_KEY_NUM_CORE,
154 	UVERBS_API_OBJ_KEY_MASK = GENMASK(31, UVERBS_API_OBJ_KEY_SHIFT),
155 
156 	/* This id guaranteed to not exist in the radix tree */
157 	UVERBS_API_KEY_ERR = 0xFFFFFFFF,
158 };
159 
uapi_key_obj(u32 id)160 static inline __attribute_const__ u32 uapi_key_obj(u32 id)
161 {
162 	if (id & UVERBS_API_NS_FLAG) {
163 		id &= ~UVERBS_API_NS_FLAG;
164 		if (id >= UVERBS_API_OBJ_KEY_NUM_DRIVER)
165 			return UVERBS_API_KEY_ERR;
166 		id = id + UVERBS_API_OBJ_KEY_NUM_CORE;
167 	} else {
168 		if (id >= UVERBS_API_OBJ_KEY_NUM_CORE)
169 			return UVERBS_API_KEY_ERR;
170 	}
171 
172 	return id << UVERBS_API_OBJ_KEY_SHIFT;
173 }
174 
uapi_key_is_object(u32 key)175 static inline __attribute_const__ bool uapi_key_is_object(u32 key)
176 {
177 	return (key & ~UVERBS_API_OBJ_KEY_MASK) == 0;
178 }
179 
uapi_key_ioctl_method(u32 id)180 static inline __attribute_const__ u32 uapi_key_ioctl_method(u32 id)
181 {
182 	if (id & UVERBS_API_NS_FLAG) {
183 		id &= ~UVERBS_API_NS_FLAG;
184 		if (id >= UVERBS_API_METHOD_KEY_NUM_DRIVER)
185 			return UVERBS_API_KEY_ERR;
186 		id = id + UVERBS_API_METHOD_KEY_NUM_CORE;
187 	} else {
188 		id++;
189 		if (id >= UVERBS_API_METHOD_KEY_NUM_CORE)
190 			return UVERBS_API_KEY_ERR;
191 	}
192 
193 	return id << UVERBS_API_METHOD_KEY_SHIFT;
194 }
195 
uapi_key_attr_to_method(u32 attr_key)196 static inline __attribute_const__ u32 uapi_key_attr_to_method(u32 attr_key)
197 {
198 	return attr_key &
199 	       (UVERBS_API_OBJ_KEY_MASK | UVERBS_API_METHOD_KEY_MASK);
200 }
201 
uapi_key_is_ioctl_method(u32 key)202 static inline __attribute_const__ bool uapi_key_is_ioctl_method(u32 key)
203 {
204 	return (key & UVERBS_API_METHOD_KEY_MASK) != 0 &&
205 	       (key & UVERBS_API_ATTR_KEY_MASK) == 0;
206 }
207 
uapi_key_attrs_start(u32 ioctl_method_key)208 static inline __attribute_const__ u32 uapi_key_attrs_start(u32 ioctl_method_key)
209 {
210 	/* 0 is the method slot itself */
211 	return ioctl_method_key + 1;
212 }
213 
uapi_key_attr(u32 id)214 static inline __attribute_const__ u32 uapi_key_attr(u32 id)
215 {
216 	/*
217 	 * The attr is designed to fit in the typical single radix tree node
218 	 * of 64 entries. Since allmost all methods have driver attributes we
219 	 * organize things so that the driver and core attributes interleave to
220 	 * reduce the length of the attributes array in typical cases.
221 	 */
222 	if (id & UVERBS_API_NS_FLAG) {
223 		id &= ~UVERBS_API_NS_FLAG;
224 		id++;
225 		if (id >= 1 << (UVERBS_API_ATTR_KEY_BITS - 1))
226 			return UVERBS_API_KEY_ERR;
227 		id = (id << 1) | 0;
228 	} else {
229 		if (id >= 1 << (UVERBS_API_ATTR_KEY_BITS - 1))
230 			return UVERBS_API_KEY_ERR;
231 		id = (id << 1) | 1;
232 	}
233 
234 	return id;
235 }
236 
uapi_key_is_attr(u32 key)237 static inline __attribute_const__ bool uapi_key_is_attr(u32 key)
238 {
239 	return (key & UVERBS_API_METHOD_KEY_MASK) != 0 &&
240 	       (key & UVERBS_API_ATTR_KEY_MASK) != 0;
241 }
242 
243 /*
244  * This returns a value in the range [0 to UVERBS_API_ATTR_BKEY_LEN),
245  * basically it undoes the reservation of 0 in the ID numbering. attr_key
246  * must already be masked with UVERBS_API_ATTR_KEY_MASK, or be the output of
247  * uapi_key_attr().
248  */
uapi_bkey_attr(u32 attr_key)249 static inline __attribute_const__ u32 uapi_bkey_attr(u32 attr_key)
250 {
251 	return attr_key - 1;
252 }
253 
254 /*
255  * =======================================
256  *	Verbs definitions
257  * =======================================
258  */
259 
260 struct uverbs_attr_def {
261 	u16                           id;
262 	struct uverbs_attr_spec       attr;
263 };
264 
265 struct uverbs_method_def {
266 	u16                                  id;
267 	/* Combination of bits from enum UVERBS_ACTION_FLAG_XXXX */
268 	u32				     flags;
269 	size_t				     num_attrs;
270 	const struct uverbs_attr_def * const (*attrs)[];
271 	int (*handler)(struct ib_uverbs_file *ufile,
272 		       struct uverbs_attr_bundle *ctx);
273 };
274 
275 struct uverbs_object_def {
276 	u16					 id;
277 	const struct uverbs_obj_type	        *type_attrs;
278 	size_t				         num_methods;
279 	const struct uverbs_method_def * const (*methods)[];
280 };
281 
282 struct uverbs_object_tree_def {
283 	size_t					 num_objects;
284 	const struct uverbs_object_def * const (*objects)[];
285 };
286 
287 /*
288  * =======================================
289  *	Attribute Specifications
290  * =======================================
291  */
292 
293 #define UVERBS_ATTR_SIZE(_min_len, _len)			\
294 	.u.ptr.min_len = _min_len, .u.ptr.len = _len
295 
296 #define UVERBS_ATTR_NO_DATA() UVERBS_ATTR_SIZE(0, 0)
297 
298 /*
299  * Specifies a uapi structure that cannot be extended. The user must always
300  * supply the whole structure and nothing more. The structure must be declared
301  * in a header under include/uapi/rdma.
302  */
303 #define UVERBS_ATTR_TYPE(_type)					\
304 	.u.ptr.min_len = sizeof(_type), .u.ptr.len = sizeof(_type)
305 /*
306  * Specifies a uapi structure where the user must provide at least up to
307  * member 'last'.  Anything after last and up until the end of the structure
308  * can be non-zero, anything longer than the end of the structure must be
309  * zero. The structure must be declared in a header under include/uapi/rdma.
310  */
311 #define UVERBS_ATTR_STRUCT(_type, _last)                                       \
312 	.zero_trailing = 1,                                                    \
313 	UVERBS_ATTR_SIZE(((uintptr_t)(&((_type *)0)->_last + 1)),              \
314 			 sizeof(_type))
315 /*
316  * Specifies at least min_len bytes must be passed in, but the amount can be
317  * larger, up to the protocol maximum size. No check for zeroing is done.
318  */
319 #define UVERBS_ATTR_MIN_SIZE(_min_len) UVERBS_ATTR_SIZE(_min_len, USHRT_MAX)
320 
321 /* Must be used in the '...' of any UVERBS_ATTR */
322 #define UA_ALLOC_AND_COPY .alloc_and_copy = 1
323 #define UA_MANDATORY .mandatory = 1
324 #define UA_OPTIONAL .mandatory = 0
325 
326 #define UVERBS_ATTR_IDR(_attr_id, _idr_type, _access, ...)                     \
327 	(&(const struct uverbs_attr_def){                                      \
328 		.id = _attr_id,                                                \
329 		.attr = { .type = UVERBS_ATTR_TYPE_IDR,                        \
330 			  .u.obj.obj_type = _idr_type,                         \
331 			  .u.obj.access = _access,                             \
332 			  __VA_ARGS__ } })
333 
334 #define UVERBS_ATTR_FD(_attr_id, _fd_type, _access, ...)                       \
335 	(&(const struct uverbs_attr_def){                                      \
336 		.id = (_attr_id) +                                             \
337 		      BUILD_BUG_ON_ZERO((_access) != UVERBS_ACCESS_NEW &&      \
338 					(_access) != UVERBS_ACCESS_READ),      \
339 		.attr = { .type = UVERBS_ATTR_TYPE_FD,                         \
340 			  .u.obj.obj_type = _fd_type,                          \
341 			  .u.obj.access = _access,                             \
342 			  __VA_ARGS__ } })
343 
344 #define UVERBS_ATTR_PTR_IN(_attr_id, _type, ...)                               \
345 	(&(const struct uverbs_attr_def){                                      \
346 		.id = _attr_id,                                                \
347 		.attr = { .type = UVERBS_ATTR_TYPE_PTR_IN,                     \
348 			  _type,                                               \
349 			  __VA_ARGS__ } })
350 
351 #define UVERBS_ATTR_PTR_OUT(_attr_id, _type, ...)                              \
352 	(&(const struct uverbs_attr_def){                                      \
353 		.id = _attr_id,                                                \
354 		.attr = { .type = UVERBS_ATTR_TYPE_PTR_OUT,                    \
355 			  _type,                                               \
356 			  __VA_ARGS__ } })
357 
358 /* _enum_arry should be a 'static const union uverbs_attr_spec[]' */
359 #define UVERBS_ATTR_ENUM_IN(_attr_id, _enum_arr, ...)                          \
360 	(&(const struct uverbs_attr_def){                                      \
361 		.id = _attr_id,                                                \
362 		.attr = { .type = UVERBS_ATTR_TYPE_ENUM_IN,                    \
363 			  .u2.enum_def.ids = _enum_arr,                        \
364 			  .u.enum_def.num_elems = ARRAY_SIZE(_enum_arr),       \
365 			  __VA_ARGS__ },                                       \
366 	})
367 
368 /*
369  * An input value that is a bitwise combination of values of _enum_type.
370  * This permits the flag value to be passed as either a u32 or u64, it must
371  * be retrieved via uverbs_get_flag().
372  */
373 #define UVERBS_ATTR_FLAGS_IN(_attr_id, _enum_type, ...)                        \
374 	UVERBS_ATTR_PTR_IN(                                                    \
375 		_attr_id,                                                      \
376 		UVERBS_ATTR_SIZE(sizeof(u32) + BUILD_BUG_ON_ZERO(              \
377 						       !sizeof(_enum_type *)), \
378 				 sizeof(u64)),                                 \
379 		__VA_ARGS__)
380 
381 /*
382  * This spec is used in order to pass information to the hardware driver in a
383  * legacy way. Every verb that could get driver specific data should get this
384  * spec.
385  */
386 #define UVERBS_ATTR_UHW()                                                      \
387 	UVERBS_ATTR_PTR_IN(UVERBS_ATTR_UHW_IN,                                 \
388 			   UVERBS_ATTR_MIN_SIZE(0),			       \
389 			   UA_OPTIONAL),				       \
390 	UVERBS_ATTR_PTR_OUT(UVERBS_ATTR_UHW_OUT,                               \
391 			    UVERBS_ATTR_MIN_SIZE(0),			       \
392 			    UA_OPTIONAL)
393 
394 /*
395  * =======================================
396  *	Declaration helpers
397  * =======================================
398  */
399 
400 #define DECLARE_UVERBS_OBJECT_TREE(_name, ...)                                 \
401 	static const struct uverbs_object_def *const _name##_ptr[] = {         \
402 		__VA_ARGS__,                                                   \
403 	};                                                                     \
404 	static const struct uverbs_object_tree_def _name = {                   \
405 		.num_objects = ARRAY_SIZE(_name##_ptr),                        \
406 		.objects = &_name##_ptr,                                       \
407 	}
408 
409 /* =================================================
410  *              Parsing infrastructure
411  * =================================================
412  */
413 
414 
415 struct uverbs_ptr_attr {
416 	/*
417 	 * If UVERBS_ATTR_SPEC_F_ALLOC_AND_COPY is set then the 'ptr' is
418 	 * used.
419 	 */
420 	union {
421 		void *ptr;
422 		u64 data;
423 	};
424 	u16		len;
425 	u16		uattr_idx;
426 	u8		enum_id;
427 };
428 
429 struct uverbs_obj_attr {
430 	struct ib_uobject		*uobject;
431 	const struct uverbs_api_attr	*attr_elm;
432 };
433 
434 struct uverbs_attr {
435 	union {
436 		struct uverbs_ptr_attr	ptr_attr;
437 		struct uverbs_obj_attr	obj_attr;
438 	};
439 };
440 
441 struct uverbs_attr_bundle {
442 	struct ib_uverbs_file *ufile;
443 	DECLARE_BITMAP(attr_present, UVERBS_API_ATTR_BKEY_LEN);
444 	struct uverbs_attr attrs[];
445 };
446 
uverbs_attr_is_valid(const struct uverbs_attr_bundle * attrs_bundle,unsigned int idx)447 static inline bool uverbs_attr_is_valid(const struct uverbs_attr_bundle *attrs_bundle,
448 					unsigned int idx)
449 {
450 	return test_bit(uapi_bkey_attr(uapi_key_attr(idx)),
451 			attrs_bundle->attr_present);
452 }
453 
454 #define IS_UVERBS_COPY_ERR(_ret)		((_ret) && (_ret) != -ENOENT)
455 
uverbs_attr_get(const struct uverbs_attr_bundle * attrs_bundle,u16 idx)456 static inline const struct uverbs_attr *uverbs_attr_get(const struct uverbs_attr_bundle *attrs_bundle,
457 							u16 idx)
458 {
459 	if (!uverbs_attr_is_valid(attrs_bundle, idx))
460 		return ERR_PTR(-ENOENT);
461 
462 	return &attrs_bundle->attrs[uapi_bkey_attr(uapi_key_attr(idx))];
463 }
464 
uverbs_attr_get_enum_id(const struct uverbs_attr_bundle * attrs_bundle,u16 idx)465 static inline int uverbs_attr_get_enum_id(const struct uverbs_attr_bundle *attrs_bundle,
466 					  u16 idx)
467 {
468 	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
469 
470 	if (IS_ERR(attr))
471 		return PTR_ERR(attr);
472 
473 	return attr->ptr_attr.enum_id;
474 }
475 
uverbs_attr_get_obj(const struct uverbs_attr_bundle * attrs_bundle,u16 idx)476 static inline void *uverbs_attr_get_obj(const struct uverbs_attr_bundle *attrs_bundle,
477 					u16 idx)
478 {
479 	const struct uverbs_attr *attr;
480 
481 	attr = uverbs_attr_get(attrs_bundle, idx);
482 	if (IS_ERR(attr))
483 		return ERR_CAST(attr);
484 
485 	return attr->obj_attr.uobject->object;
486 }
487 
uverbs_attr_get_uobject(const struct uverbs_attr_bundle * attrs_bundle,u16 idx)488 static inline struct ib_uobject *uverbs_attr_get_uobject(const struct uverbs_attr_bundle *attrs_bundle,
489 							 u16 idx)
490 {
491 	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
492 
493 	if (IS_ERR(attr))
494 		return ERR_CAST(attr);
495 
496 	return attr->obj_attr.uobject;
497 }
498 
499 static inline int
uverbs_attr_get_len(const struct uverbs_attr_bundle * attrs_bundle,u16 idx)500 uverbs_attr_get_len(const struct uverbs_attr_bundle *attrs_bundle, u16 idx)
501 {
502 	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
503 
504 	if (IS_ERR(attr))
505 		return PTR_ERR(attr);
506 
507 	return attr->ptr_attr.len;
508 }
509 
uverbs_attr_ptr_is_inline(const struct uverbs_attr * attr)510 static inline bool uverbs_attr_ptr_is_inline(const struct uverbs_attr *attr)
511 {
512 	return attr->ptr_attr.len <= sizeof(attr->ptr_attr.data);
513 }
514 
uverbs_attr_get_alloced_ptr(const struct uverbs_attr_bundle * attrs_bundle,u16 idx)515 static inline void *uverbs_attr_get_alloced_ptr(
516 	const struct uverbs_attr_bundle *attrs_bundle, u16 idx)
517 {
518 	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
519 
520 	if (IS_ERR(attr))
521 		return (void *)attr;
522 
523 	return uverbs_attr_ptr_is_inline(attr) ? (void *)&attr->ptr_attr.data :
524 						 attr->ptr_attr.ptr;
525 }
526 
_uverbs_copy_from(void * to,const struct uverbs_attr_bundle * attrs_bundle,size_t idx,size_t size)527 static inline int _uverbs_copy_from(void *to,
528 				    const struct uverbs_attr_bundle *attrs_bundle,
529 				    size_t idx,
530 				    size_t size)
531 {
532 	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
533 
534 	if (IS_ERR(attr))
535 		return PTR_ERR(attr);
536 
537 	/*
538 	 * Validation ensures attr->ptr_attr.len >= size. If the caller is
539 	 * using UVERBS_ATTR_SPEC_F_MIN_SZ_OR_ZERO then it must call
540 	 * uverbs_copy_from_or_zero.
541 	 */
542 	if (unlikely(size < attr->ptr_attr.len))
543 		return -EINVAL;
544 
545 	if (uverbs_attr_ptr_is_inline(attr))
546 		memcpy(to, &attr->ptr_attr.data, attr->ptr_attr.len);
547 	else if (copy_from_user(to, u64_to_user_ptr(attr->ptr_attr.data),
548 				attr->ptr_attr.len))
549 		return -EFAULT;
550 
551 	return 0;
552 }
553 
_uverbs_copy_from_or_zero(void * to,const struct uverbs_attr_bundle * attrs_bundle,size_t idx,size_t size)554 static inline int _uverbs_copy_from_or_zero(void *to,
555 					    const struct uverbs_attr_bundle *attrs_bundle,
556 					    size_t idx,
557 					    size_t size)
558 {
559 	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
560 	size_t min_size;
561 
562 	if (IS_ERR(attr))
563 		return PTR_ERR(attr);
564 
565 	min_size = min_t(size_t, size, attr->ptr_attr.len);
566 
567 	if (uverbs_attr_ptr_is_inline(attr))
568 		memcpy(to, &attr->ptr_attr.data, min_size);
569 	else if (copy_from_user(to, u64_to_user_ptr(attr->ptr_attr.data),
570 				min_size))
571 		return -EFAULT;
572 
573 	if (size > min_size)
574 		memset(to + min_size, 0, size - min_size);
575 
576 	return 0;
577 }
578 
579 #define uverbs_copy_from(to, attrs_bundle, idx)				      \
580 	_uverbs_copy_from(to, attrs_bundle, idx, sizeof(*to))
581 
582 #define uverbs_copy_from_or_zero(to, attrs_bundle, idx)			      \
583 	_uverbs_copy_from_or_zero(to, attrs_bundle, idx, sizeof(*to))
584 
585 #if IS_ENABLED(CONFIG_INFINIBAND_USER_ACCESS)
586 int uverbs_get_flags64(u64 *to, const struct uverbs_attr_bundle *attrs_bundle,
587 		       size_t idx, u64 allowed_bits);
588 int uverbs_get_flags32(u32 *to, const struct uverbs_attr_bundle *attrs_bundle,
589 		       size_t idx, u64 allowed_bits);
590 int uverbs_copy_to(const struct uverbs_attr_bundle *attrs_bundle, size_t idx,
591 		   const void *from, size_t size);
592 __malloc void *_uverbs_alloc(struct uverbs_attr_bundle *bundle, size_t size,
593 			     gfp_t flags);
594 
uverbs_alloc(struct uverbs_attr_bundle * bundle,size_t size)595 static inline __malloc void *uverbs_alloc(struct uverbs_attr_bundle *bundle,
596 					  size_t size)
597 {
598 	return _uverbs_alloc(bundle, size, GFP_KERNEL);
599 }
600 
uverbs_zalloc(struct uverbs_attr_bundle * bundle,size_t size)601 static inline __malloc void *uverbs_zalloc(struct uverbs_attr_bundle *bundle,
602 					   size_t size)
603 {
604 	return _uverbs_alloc(bundle, size, GFP_KERNEL | __GFP_ZERO);
605 }
606 #else
607 static inline int
uverbs_get_flags64(u64 * to,const struct uverbs_attr_bundle * attrs_bundle,size_t idx,u64 allowed_bits)608 uverbs_get_flags64(u64 *to, const struct uverbs_attr_bundle *attrs_bundle,
609 		   size_t idx, u64 allowed_bits)
610 {
611 	return -EINVAL;
612 }
613 static inline int
uverbs_get_flags32(u32 * to,const struct uverbs_attr_bundle * attrs_bundle,size_t idx,u64 allowed_bits)614 uverbs_get_flags32(u32 *to, const struct uverbs_attr_bundle *attrs_bundle,
615 		   size_t idx, u64 allowed_bits)
616 {
617 	return -EINVAL;
618 }
uverbs_copy_to(const struct uverbs_attr_bundle * attrs_bundle,size_t idx,const void * from,size_t size)619 static inline int uverbs_copy_to(const struct uverbs_attr_bundle *attrs_bundle,
620 				 size_t idx, const void *from, size_t size)
621 {
622 	return -EINVAL;
623 }
uverbs_alloc(struct uverbs_attr_bundle * bundle,size_t size)624 static inline __malloc void *uverbs_alloc(struct uverbs_attr_bundle *bundle,
625 					  size_t size)
626 {
627 	return ERR_PTR(-EINVAL);
628 }
uverbs_zalloc(struct uverbs_attr_bundle * bundle,size_t size)629 static inline __malloc void *uverbs_zalloc(struct uverbs_attr_bundle *bundle,
630 					   size_t size)
631 {
632 	return ERR_PTR(-EINVAL);
633 }
634 #endif
635 
636 #endif
637