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linux/include/rdma/uverbs_ioctl.h
Mark Bloch 0953fffec9 RDMA/uverbs: Add UVERBS_ATTR_CONST_IN to the specs language 
This makes it clear and safe to access constants passed in from user
space. We define a consistent ABI of u64 for all constants, and verify
that the data passed in can be represented by the type the user supplies.

The expectation is this will always be used with an enum declaring the
constant values, and the user will use the enum type as input to the
accessor.

To retrieve the attribute value we introduce two helper calls - one
standard which may fail if attribute is not valid and one where caller can
provide a default value which will be used in case the attribute is not
valid (useful when attribute is optional).

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Ariel Levkovich <lariel@mellanox.com>
Signed-off-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
2018-09-05 15:14:58 -06:00

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/*
* 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;
};
/*
* 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 member in the enum _enum_type. */
#define UVERBS_ATTR_CONST_IN(_attr_id, _enum_type, ...) \
UVERBS_ATTR_PTR_IN( \
_attr_id, \
UVERBS_ATTR_SIZE( \
sizeof(u64) + BUILD_BUG_ON_ZERO(!sizeof(_enum_type)), \
sizeof(u64)), \
__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;
u16 uattr_idx;
u8 enum_id;
};
struct uverbs_obj_attr {
struct ib_uobject *uobject;
const struct uverbs_api_attr *attr_elm;
};
struct uverbs_attr {
union {
struct uverbs_ptr_attr ptr_attr;
struct uverbs_obj_attr obj_attr;
};
};
struct uverbs_attr_bundle {
struct ib_uverbs_file *ufile;
DECLARE_BITMAP(attr_present, UVERBS_API_ATTR_BKEY_LEN);
struct uverbs_attr attrs[];
};
static inline bool uverbs_attr_is_valid(const struct uverbs_attr_bundle *attrs_bundle,
unsigned int idx)
{
return test_bit(uapi_bkey_attr(uapi_key_attr(idx)),
attrs_bundle->attr_present);
}
#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)
{
if (!uverbs_attr_is_valid(attrs_bundle, idx))
return ERR_PTR(-ENOENT);
return &attrs_bundle->attrs[uapi_bkey_attr(uapi_key_attr(idx))];
}
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 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);
int uverbs_copy_to(const struct uverbs_attr_bundle *attrs_bundle, size_t idx,
const void *from, size_t size);
__malloc void *_uverbs_alloc(struct uverbs_attr_bundle *bundle, size_t size,
gfp_t flags);
static inline __malloc void *uverbs_alloc(struct uverbs_attr_bundle *bundle,
size_t size)
{
return _uverbs_alloc(bundle, size, GFP_KERNEL);
}
static inline __malloc void *uverbs_zalloc(struct uverbs_attr_bundle *bundle,
size_t size)
{
return _uverbs_alloc(bundle, size, GFP_KERNEL | __GFP_ZERO);
}
int _uverbs_get_const(s64 *to, const struct uverbs_attr_bundle *attrs_bundle,
size_t idx, s64 lower_bound, u64 upper_bound,
s64 *def_val);
#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;
}
static inline int uverbs_copy_to(const struct uverbs_attr_bundle *attrs_bundle,
size_t idx, const void *from, size_t size)
{
return -EINVAL;
}
static inline __malloc void *uverbs_alloc(struct uverbs_attr_bundle *bundle,
size_t size)
{
return ERR_PTR(-EINVAL);
}
static inline __malloc void *uverbs_zalloc(struct uverbs_attr_bundle *bundle,
size_t size)
{
return ERR_PTR(-EINVAL);
}
static inline int
_uverbs_get_const(s64 *to, const struct uverbs_attr_bundle *attrs_bundle,
size_t idx, s64 lower_bound, u64 upper_bound,
s64 *def_val)
{
return -EINVAL;
}
#endif
#define uverbs_get_const(_to, _attrs_bundle, _idx) \
({ \
s64 _val; \
int _ret = _uverbs_get_const(&_val, _attrs_bundle, _idx, \
type_min(typeof(*_to)), \
type_max(typeof(*_to)), NULL); \
(*_to) = _val; \
_ret; \
})
#define uverbs_get_const_default(_to, _attrs_bundle, _idx, _default) \
({ \
s64 _val; \
s64 _def_val = _default; \
int _ret = \
_uverbs_get_const(&_val, _attrs_bundle, _idx, \
type_min(typeof(*_to)), \
type_max(typeof(*_to)), &_def_val); \
(*_to) = _val; \
_ret; \
})
#endif
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