linux-stable/include/rdma/uverbs_ioctl.h
Jason Gunthorpe 4b3dd2bbf0 IB/uverbs: Provide implementation private memory for the uverbs_attr_bundle
This already existed as the anonymous 'ctx' structure, but this was not
really a useful form. Hoist this struct into bundle_priv and rework the
internal things to use it instead.

Move a bunch of the processing internal state into the priv and reduce the
excessive use of function arguments.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
2018-08-10 16:06:24 -06:00

745 lines
23 KiB
C

/*
* Copyright (c) 2017, Mellanox Technologies inc. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#ifndef _UVERBS_IOCTL_
#define _UVERBS_IOCTL_
#include <rdma/uverbs_types.h>
#include <linux/uaccess.h>
#include <rdma/rdma_user_ioctl.h>
#include <rdma/ib_user_ioctl_verbs.h>
#include <rdma/ib_user_ioctl_cmds.h>
/*
* =======================================
* Verbs action specifications
* =======================================
*/
enum uverbs_attr_type {
UVERBS_ATTR_TYPE_NA,
UVERBS_ATTR_TYPE_PTR_IN,
UVERBS_ATTR_TYPE_PTR_OUT,
UVERBS_ATTR_TYPE_IDR,
UVERBS_ATTR_TYPE_FD,
UVERBS_ATTR_TYPE_ENUM_IN,
};
enum uverbs_obj_access {
UVERBS_ACCESS_READ,
UVERBS_ACCESS_WRITE,
UVERBS_ACCESS_NEW,
UVERBS_ACCESS_DESTROY
};
/* Specification of a single attribute inside the ioctl message */
/* good size 16 */
struct uverbs_attr_spec {
u8 type;
/*
* Support extending attributes by length. Allow the user to provide
* more bytes than ptr.len, but check that everything after is zero'd
* by the user.
*/
u8 zero_trailing:1;
/*
* Valid only for PTR_IN. Allocate and copy the data inside
* the parser
*/
u8 alloc_and_copy:1;
u8 mandatory:1;
union {
struct {
/* Current known size to kernel */
u16 len;
/* User isn't allowed to provide something < min_len */
u16 min_len;
} ptr;
struct {
/*
* higher bits mean the namespace and lower bits mean
* the type id within the namespace.
*/
u16 obj_type;
u8 access;
} obj;
struct {
u8 num_elems;
} enum_def;
} u;
/* This weird split of the enum lets us remove some padding */
union {
struct {
/*
* The enum attribute can select one of the attributes
* contained in the ids array. Currently only PTR_IN
* attributes are supported in the ids array.
*/
const struct uverbs_attr_spec *ids;
} enum_def;
} u2;
};
struct uverbs_attr_spec_hash {
size_t num_attrs;
unsigned long *mandatory_attrs_bitmask;
struct uverbs_attr_spec attrs[0];
};
struct uverbs_attr_bundle;
struct ib_uverbs_file;
struct uverbs_method_spec {
/* Combination of bits from enum UVERBS_ACTION_FLAG_XXXX */
u32 flags;
size_t num_buckets;
size_t num_child_attrs;
int (*handler)(struct ib_uverbs_file *ufile,
struct uverbs_attr_bundle *ctx);
struct uverbs_attr_spec_hash *attr_buckets[0];
};
struct uverbs_method_spec_hash {
size_t num_methods;
struct uverbs_method_spec *methods[0];
};
struct uverbs_object_spec {
const struct uverbs_obj_type *type_attrs;
size_t num_buckets;
struct uverbs_method_spec_hash *method_buckets[0];
};
struct uverbs_object_spec_hash {
size_t num_objects;
struct uverbs_object_spec *objects[0];
};
struct uverbs_root_spec {
size_t num_buckets;
struct uverbs_object_spec_hash *object_buckets[0];
};
/*
* Information about the API is loaded into a radix tree. For IOCTL we start
* with a tuple of:
* object_id, attr_id, method_id
*
* Which is a 48 bit value, with most of the bits guaranteed to be zero. Based
* on the current kernel support this is compressed into 16 bit key for the
* radix tree. Since this compression is entirely internal to the kernel the
* below limits can be revised if the kernel gains additional data.
*
* With 64 leafs per node this is a 3 level radix tree.
*
* The tree encodes multiple types, and uses a scheme where OBJ_ID,0,0 returns
* the object slot, and OBJ_ID,METH_ID,0 and returns the method slot.
*/
enum uapi_radix_data {
UVERBS_API_NS_FLAG = 1U << UVERBS_ID_NS_SHIFT,
UVERBS_API_ATTR_KEY_BITS = 6,
UVERBS_API_ATTR_KEY_MASK = GENMASK(UVERBS_API_ATTR_KEY_BITS - 1, 0),
UVERBS_API_ATTR_BKEY_LEN = (1 << UVERBS_API_ATTR_KEY_BITS) - 1,
UVERBS_API_METHOD_KEY_BITS = 5,
UVERBS_API_METHOD_KEY_SHIFT = UVERBS_API_ATTR_KEY_BITS,
UVERBS_API_METHOD_KEY_NUM_CORE = 24,
UVERBS_API_METHOD_KEY_NUM_DRIVER = (1 << UVERBS_API_METHOD_KEY_BITS) -
UVERBS_API_METHOD_KEY_NUM_CORE,
UVERBS_API_METHOD_KEY_MASK = GENMASK(
UVERBS_API_METHOD_KEY_BITS + UVERBS_API_METHOD_KEY_SHIFT - 1,
UVERBS_API_METHOD_KEY_SHIFT),
UVERBS_API_OBJ_KEY_BITS = 5,
UVERBS_API_OBJ_KEY_SHIFT =
UVERBS_API_METHOD_KEY_BITS + UVERBS_API_METHOD_KEY_SHIFT,
UVERBS_API_OBJ_KEY_NUM_CORE = 24,
UVERBS_API_OBJ_KEY_NUM_DRIVER =
(1 << UVERBS_API_OBJ_KEY_BITS) - UVERBS_API_OBJ_KEY_NUM_CORE,
UVERBS_API_OBJ_KEY_MASK = GENMASK(31, UVERBS_API_OBJ_KEY_SHIFT),
/* This id guaranteed to not exist in the radix tree */
UVERBS_API_KEY_ERR = 0xFFFFFFFF,
};
static inline __attribute_const__ u32 uapi_key_obj(u32 id)
{
if (id & UVERBS_API_NS_FLAG) {
id &= ~UVERBS_API_NS_FLAG;
if (id >= UVERBS_API_OBJ_KEY_NUM_DRIVER)
return UVERBS_API_KEY_ERR;
id = id + UVERBS_API_OBJ_KEY_NUM_CORE;
} else {
if (id >= UVERBS_API_OBJ_KEY_NUM_CORE)
return UVERBS_API_KEY_ERR;
}
return id << UVERBS_API_OBJ_KEY_SHIFT;
}
static inline __attribute_const__ bool uapi_key_is_object(u32 key)
{
return (key & ~UVERBS_API_OBJ_KEY_MASK) == 0;
}
static inline __attribute_const__ u32 uapi_key_ioctl_method(u32 id)
{
if (id & UVERBS_API_NS_FLAG) {
id &= ~UVERBS_API_NS_FLAG;
if (id >= UVERBS_API_METHOD_KEY_NUM_DRIVER)
return UVERBS_API_KEY_ERR;
id = id + UVERBS_API_METHOD_KEY_NUM_CORE;
} else {
id++;
if (id >= UVERBS_API_METHOD_KEY_NUM_CORE)
return UVERBS_API_KEY_ERR;
}
return id << UVERBS_API_METHOD_KEY_SHIFT;
}
static inline __attribute_const__ u32 uapi_key_attr_to_method(u32 attr_key)
{
return attr_key &
(UVERBS_API_OBJ_KEY_MASK | UVERBS_API_METHOD_KEY_MASK);
}
static inline __attribute_const__ bool uapi_key_is_ioctl_method(u32 key)
{
return (key & UVERBS_API_METHOD_KEY_MASK) != 0 &&
(key & UVERBS_API_ATTR_KEY_MASK) == 0;
}
static inline __attribute_const__ u32 uapi_key_attrs_start(u32 ioctl_method_key)
{
/* 0 is the method slot itself */
return ioctl_method_key + 1;
}
static inline __attribute_const__ u32 uapi_key_attr(u32 id)
{
/*
* The attr is designed to fit in the typical single radix tree node
* of 64 entries. Since allmost all methods have driver attributes we
* organize things so that the driver and core attributes interleave to
* reduce the length of the attributes array in typical cases.
*/
if (id & UVERBS_API_NS_FLAG) {
id &= ~UVERBS_API_NS_FLAG;
id++;
if (id >= 1 << (UVERBS_API_ATTR_KEY_BITS - 1))
return UVERBS_API_KEY_ERR;
id = (id << 1) | 0;
} else {
if (id >= 1 << (UVERBS_API_ATTR_KEY_BITS - 1))
return UVERBS_API_KEY_ERR;
id = (id << 1) | 1;
}
return id;
}
static inline __attribute_const__ bool uapi_key_is_attr(u32 key)
{
return (key & UVERBS_API_METHOD_KEY_MASK) != 0 &&
(key & UVERBS_API_ATTR_KEY_MASK) != 0;
}
/*
* This returns a value in the range [0 to UVERBS_API_ATTR_BKEY_LEN),
* basically it undoes the reservation of 0 in the ID numbering. attr_key
* must already be masked with UVERBS_API_ATTR_KEY_MASK, or be the output of
* uapi_key_attr().
*/
static inline __attribute_const__ u32 uapi_bkey_attr(u32 attr_key)
{
return attr_key - 1;
}
/*
* =======================================
* Verbs definitions
* =======================================
*/
struct uverbs_attr_def {
u16 id;
struct uverbs_attr_spec attr;
};
struct uverbs_method_def {
u16 id;
/* Combination of bits from enum UVERBS_ACTION_FLAG_XXXX */
u32 flags;
size_t num_attrs;
const struct uverbs_attr_def * const (*attrs)[];
int (*handler)(struct ib_uverbs_file *ufile,
struct uverbs_attr_bundle *ctx);
};
struct uverbs_object_def {
u16 id;
const struct uverbs_obj_type *type_attrs;
size_t num_methods;
const struct uverbs_method_def * const (*methods)[];
};
struct uverbs_object_tree_def {
size_t num_objects;
const struct uverbs_object_def * const (*objects)[];
};
/*
* =======================================
* Attribute Specifications
* =======================================
*/
#define UVERBS_ATTR_SIZE(_min_len, _len) \
.u.ptr.min_len = _min_len, .u.ptr.len = _len
#define UVERBS_ATTR_NO_DATA() UVERBS_ATTR_SIZE(0, 0)
/*
* Specifies a uapi structure that cannot be extended. The user must always
* supply the whole structure and nothing more. The structure must be declared
* in a header under include/uapi/rdma.
*/
#define UVERBS_ATTR_TYPE(_type) \
.u.ptr.min_len = sizeof(_type), .u.ptr.len = sizeof(_type)
/*
* Specifies a uapi structure where the user must provide at least up to
* member 'last'. Anything after last and up until the end of the structure
* can be non-zero, anything longer than the end of the structure must be
* zero. The structure must be declared in a header under include/uapi/rdma.
*/
#define UVERBS_ATTR_STRUCT(_type, _last) \
.zero_trailing = 1, \
UVERBS_ATTR_SIZE(((uintptr_t)(&((_type *)0)->_last + 1)), \
sizeof(_type))
/*
* Specifies at least min_len bytes must be passed in, but the amount can be
* larger, up to the protocol maximum size. No check for zeroing is done.
*/
#define UVERBS_ATTR_MIN_SIZE(_min_len) UVERBS_ATTR_SIZE(_min_len, USHRT_MAX)
/* Must be used in the '...' of any UVERBS_ATTR */
#define UA_ALLOC_AND_COPY .alloc_and_copy = 1
#define UA_MANDATORY .mandatory = 1
#define UA_OPTIONAL .mandatory = 0
#define UVERBS_ATTR_IDR(_attr_id, _idr_type, _access, ...) \
(&(const struct uverbs_attr_def){ \
.id = _attr_id, \
.attr = { .type = UVERBS_ATTR_TYPE_IDR, \
.u.obj.obj_type = _idr_type, \
.u.obj.access = _access, \
__VA_ARGS__ } })
#define UVERBS_ATTR_FD(_attr_id, _fd_type, _access, ...) \
(&(const struct uverbs_attr_def){ \
.id = (_attr_id) + \
BUILD_BUG_ON_ZERO((_access) != UVERBS_ACCESS_NEW && \
(_access) != UVERBS_ACCESS_READ), \
.attr = { .type = UVERBS_ATTR_TYPE_FD, \
.u.obj.obj_type = _fd_type, \
.u.obj.access = _access, \
__VA_ARGS__ } })
#define UVERBS_ATTR_PTR_IN(_attr_id, _type, ...) \
(&(const struct uverbs_attr_def){ \
.id = _attr_id, \
.attr = { .type = UVERBS_ATTR_TYPE_PTR_IN, \
_type, \
__VA_ARGS__ } })
#define UVERBS_ATTR_PTR_OUT(_attr_id, _type, ...) \
(&(const struct uverbs_attr_def){ \
.id = _attr_id, \
.attr = { .type = UVERBS_ATTR_TYPE_PTR_OUT, \
_type, \
__VA_ARGS__ } })
/* _enum_arry should be a 'static const union uverbs_attr_spec[]' */
#define UVERBS_ATTR_ENUM_IN(_attr_id, _enum_arr, ...) \
(&(const struct uverbs_attr_def){ \
.id = _attr_id, \
.attr = { .type = UVERBS_ATTR_TYPE_ENUM_IN, \
.u2.enum_def.ids = _enum_arr, \
.u.enum_def.num_elems = ARRAY_SIZE(_enum_arr), \
__VA_ARGS__ }, \
})
/*
* An input value that is a bitwise combination of values of _enum_type.
* This permits the flag value to be passed as either a u32 or u64, it must
* be retrieved via uverbs_get_flag().
*/
#define UVERBS_ATTR_FLAGS_IN(_attr_id, _enum_type, ...) \
UVERBS_ATTR_PTR_IN( \
_attr_id, \
UVERBS_ATTR_SIZE(sizeof(u32) + BUILD_BUG_ON_ZERO( \
!sizeof(_enum_type *)), \
sizeof(u64)), \
__VA_ARGS__)
/*
* This spec is used in order to pass information to the hardware driver in a
* legacy way. Every verb that could get driver specific data should get this
* spec.
*/
#define UVERBS_ATTR_UHW() \
UVERBS_ATTR_PTR_IN(UVERBS_ATTR_UHW_IN, \
UVERBS_ATTR_MIN_SIZE(0), \
UA_OPTIONAL), \
UVERBS_ATTR_PTR_OUT(UVERBS_ATTR_UHW_OUT, \
UVERBS_ATTR_MIN_SIZE(0), \
UA_OPTIONAL)
/*
* =======================================
* Declaration helpers
* =======================================
*/
#define DECLARE_UVERBS_OBJECT_TREE(_name, ...) \
static const struct uverbs_object_def *const _name##_ptr[] = { \
__VA_ARGS__, \
}; \
static const struct uverbs_object_tree_def _name = { \
.num_objects = ARRAY_SIZE(_name##_ptr), \
.objects = &_name##_ptr, \
}
/* =================================================
* Parsing infrastructure
* =================================================
*/
struct uverbs_ptr_attr {
/*
* If UVERBS_ATTR_SPEC_F_ALLOC_AND_COPY is set then the 'ptr' is
* used.
*/
union {
void *ptr;
u64 data;
};
u16 len;
/* Combination of bits from enum UVERBS_ATTR_F_XXXX */
u16 flags;
u8 enum_id;
};
struct uverbs_obj_attr {
struct ib_uobject *uobject;
};
struct uverbs_attr {
/*
* pointer to the user-space given attribute, in order to write the
* new uobject's id or update flags.
*/
struct ib_uverbs_attr __user *uattr;
union {
struct uverbs_ptr_attr ptr_attr;
struct uverbs_obj_attr obj_attr;
};
};
struct uverbs_attr_bundle_hash {
/* if bit i is set, it means attrs[i] contains valid information */
unsigned long *valid_bitmap;
size_t num_attrs;
/*
* arrays of attributes, each element corresponds to the specification
* of the attribute in the same index.
*/
struct uverbs_attr *attrs;
};
struct uverbs_attr_bundle {
struct ib_uverbs_file *ufile;
size_t num_buckets;
struct uverbs_attr_bundle_hash hash[];
};
static inline bool uverbs_attr_is_valid_in_hash(const struct uverbs_attr_bundle_hash *attrs_hash,
unsigned int idx)
{
return test_bit(idx, attrs_hash->valid_bitmap);
}
static inline bool uverbs_attr_is_valid(const struct uverbs_attr_bundle *attrs_bundle,
unsigned int idx)
{
u16 idx_bucket = idx >> UVERBS_ID_NS_SHIFT;
if (attrs_bundle->num_buckets <= idx_bucket)
return false;
return uverbs_attr_is_valid_in_hash(&attrs_bundle->hash[idx_bucket],
idx & ~UVERBS_ID_NS_MASK);
}
#define IS_UVERBS_COPY_ERR(_ret) ((_ret) && (_ret) != -ENOENT)
static inline const struct uverbs_attr *uverbs_attr_get(const struct uverbs_attr_bundle *attrs_bundle,
u16 idx)
{
u16 idx_bucket = idx >> UVERBS_ID_NS_SHIFT;
if (!uverbs_attr_is_valid(attrs_bundle, idx))
return ERR_PTR(-ENOENT);
return &attrs_bundle->hash[idx_bucket].attrs[idx & ~UVERBS_ID_NS_MASK];
}
static inline int uverbs_attr_get_enum_id(const struct uverbs_attr_bundle *attrs_bundle,
u16 idx)
{
const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
if (IS_ERR(attr))
return PTR_ERR(attr);
return attr->ptr_attr.enum_id;
}
static inline void *uverbs_attr_get_obj(const struct uverbs_attr_bundle *attrs_bundle,
u16 idx)
{
const struct uverbs_attr *attr;
attr = uverbs_attr_get(attrs_bundle, idx);
if (IS_ERR(attr))
return ERR_CAST(attr);
return attr->obj_attr.uobject->object;
}
static inline struct ib_uobject *uverbs_attr_get_uobject(const struct uverbs_attr_bundle *attrs_bundle,
u16 idx)
{
const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
if (IS_ERR(attr))
return ERR_CAST(attr);
return attr->obj_attr.uobject;
}
static inline int
uverbs_attr_get_len(const struct uverbs_attr_bundle *attrs_bundle, u16 idx)
{
const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
if (IS_ERR(attr))
return PTR_ERR(attr);
return attr->ptr_attr.len;
}
static inline int uverbs_copy_to(const struct uverbs_attr_bundle *attrs_bundle,
size_t idx, const void *from, size_t size)
{
const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
u16 flags;
size_t min_size;
if (IS_ERR(attr))
return PTR_ERR(attr);
min_size = min_t(size_t, attr->ptr_attr.len, size);
if (copy_to_user(u64_to_user_ptr(attr->ptr_attr.data), from, min_size))
return -EFAULT;
flags = attr->ptr_attr.flags | UVERBS_ATTR_F_VALID_OUTPUT;
if (put_user(flags, &attr->uattr->flags))
return -EFAULT;
return 0;
}
static inline bool uverbs_attr_ptr_is_inline(const struct uverbs_attr *attr)
{
return attr->ptr_attr.len <= sizeof(attr->ptr_attr.data);
}
static inline void *uverbs_attr_get_alloced_ptr(
const struct uverbs_attr_bundle *attrs_bundle, u16 idx)
{
const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
if (IS_ERR(attr))
return (void *)attr;
return uverbs_attr_ptr_is_inline(attr) ? (void *)&attr->ptr_attr.data :
attr->ptr_attr.ptr;
}
static inline int _uverbs_copy_from(void *to,
const struct uverbs_attr_bundle *attrs_bundle,
size_t idx,
size_t size)
{
const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
if (IS_ERR(attr))
return PTR_ERR(attr);
/*
* Validation ensures attr->ptr_attr.len >= size. If the caller is
* using UVERBS_ATTR_SPEC_F_MIN_SZ_OR_ZERO then it must call
* uverbs_copy_from_or_zero.
*/
if (unlikely(size < attr->ptr_attr.len))
return -EINVAL;
if (uverbs_attr_ptr_is_inline(attr))
memcpy(to, &attr->ptr_attr.data, attr->ptr_attr.len);
else if (copy_from_user(to, u64_to_user_ptr(attr->ptr_attr.data),
attr->ptr_attr.len))
return -EFAULT;
return 0;
}
static inline int _uverbs_copy_from_or_zero(void *to,
const struct uverbs_attr_bundle *attrs_bundle,
size_t idx,
size_t size)
{
const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
size_t min_size;
if (IS_ERR(attr))
return PTR_ERR(attr);
min_size = min_t(size_t, size, attr->ptr_attr.len);
if (uverbs_attr_ptr_is_inline(attr))
memcpy(to, &attr->ptr_attr.data, min_size);
else if (copy_from_user(to, u64_to_user_ptr(attr->ptr_attr.data),
min_size))
return -EFAULT;
if (size > min_size)
memset(to + min_size, 0, size - min_size);
return 0;
}
#define uverbs_copy_from(to, attrs_bundle, idx) \
_uverbs_copy_from(to, attrs_bundle, idx, sizeof(*to))
#define uverbs_copy_from_or_zero(to, attrs_bundle, idx) \
_uverbs_copy_from_or_zero(to, attrs_bundle, idx, sizeof(*to))
#if IS_ENABLED(CONFIG_INFINIBAND_USER_ACCESS)
int uverbs_get_flags64(u64 *to, const struct uverbs_attr_bundle *attrs_bundle,
size_t idx, u64 allowed_bits);
int uverbs_get_flags32(u32 *to, const struct uverbs_attr_bundle *attrs_bundle,
size_t idx, u64 allowed_bits);
#else
static inline int
uverbs_get_flags64(u64 *to, const struct uverbs_attr_bundle *attrs_bundle,
size_t idx, u64 allowed_bits)
{
return -EINVAL;
}
static inline int
uverbs_get_flags32(u32 *to, const struct uverbs_attr_bundle *attrs_bundle,
size_t idx, u64 allowed_bits)
{
return -EINVAL;
}
#endif
/* =================================================
* Definitions -> Specs infrastructure
* =================================================
*/
/*
* uverbs_alloc_spec_tree - Merges different common and driver specific feature
* into one parsing tree that every uverbs command will be parsed upon.
*
* @num_trees: Number of trees in the array @trees.
* @trees: Array of pointers to tree root definitions to merge. Each such tree
* possibly contains objects, methods and attributes definitions.
*
* Returns:
* uverbs_root_spec *: The root of the merged parsing tree.
* On error, we return an error code. Error is checked via IS_ERR.
*
* The following merges could take place:
* a. Two trees representing the same method with different handler
* -> We take the handler of the tree that its handler != NULL
* and its index in the trees array is greater. The incentive for that
* is that developers are expected to first merge common trees and then
* merge trees that gives specialized the behaviour.
* b. Two trees representing the same object with different
* type_attrs (struct uverbs_obj_type):
* -> We take the type_attrs of the tree that its type_attr != NULL
* and its index in the trees array is greater. This could be used
* in order to override the free function, allocation size, etc.
* c. Two trees representing the same method attribute (same id but possibly
* different attributes):
* -> ERROR (-ENOENT), we believe that's not the programmer's intent.
*
* An object without any methods is considered invalid and will abort the
* function with -ENOENT error.
*/
#if IS_ENABLED(CONFIG_INFINIBAND_USER_ACCESS)
struct uverbs_root_spec *uverbs_alloc_spec_tree(unsigned int num_trees,
const struct uverbs_object_tree_def **trees);
void uverbs_free_spec_tree(struct uverbs_root_spec *root);
#else
static inline struct uverbs_root_spec *uverbs_alloc_spec_tree(unsigned int num_trees,
const struct uverbs_object_tree_def **trees)
{
return NULL;
}
static inline void uverbs_free_spec_tree(struct uverbs_root_spec *root)
{
}
#endif
#endif