swh:1:snp:49cd9498d6cccc5e78252c27dcb645bcf7bf0c91
Tip revision: b9bbe6ed63b2b9f2c9ee5cbd0f2c946a2723f4ce authored by Linus Torvalds on 17 May 2020, 23:48:37 UTC
Linux 5.7-rc6
Linux 5.7-rc6
Tip revision: b9bbe6e
uverbs_ioctl.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.
*/
#include <rdma/rdma_user_ioctl.h>
#include <rdma/uverbs_ioctl.h>
#include "rdma_core.h"
#include "uverbs.h"
struct bundle_alloc_head {
struct bundle_alloc_head *next;
u8 data[];
};
struct bundle_priv {
/* Must be first */
struct bundle_alloc_head alloc_head;
struct bundle_alloc_head *allocated_mem;
size_t internal_avail;
size_t internal_used;
struct radix_tree_root *radix;
const struct uverbs_api_ioctl_method *method_elm;
void __rcu **radix_slots;
unsigned long radix_slots_len;
u32 method_key;
struct ib_uverbs_attr __user *user_attrs;
struct ib_uverbs_attr *uattrs;
DECLARE_BITMAP(uobj_finalize, UVERBS_API_ATTR_BKEY_LEN);
DECLARE_BITMAP(spec_finalize, UVERBS_API_ATTR_BKEY_LEN);
/*
* Must be last. bundle ends in a flex array which overlaps
* internal_buffer.
*/
struct uverbs_attr_bundle bundle;
u64 internal_buffer[32];
};
/*
* Each method has an absolute minimum amount of memory it needs to allocate,
* precompute that amount and determine if the onstack memory can be used or
* if allocation is need.
*/
void uapi_compute_bundle_size(struct uverbs_api_ioctl_method *method_elm,
unsigned int num_attrs)
{
struct bundle_priv *pbundle;
size_t bundle_size =
offsetof(struct bundle_priv, internal_buffer) +
sizeof(*pbundle->bundle.attrs) * method_elm->key_bitmap_len +
sizeof(*pbundle->uattrs) * num_attrs;
method_elm->use_stack = bundle_size <= sizeof(*pbundle);
method_elm->bundle_size =
ALIGN(bundle_size + 256, sizeof(*pbundle->internal_buffer));
/* Do not want order-2 allocations for this. */
WARN_ON_ONCE(method_elm->bundle_size > PAGE_SIZE);
}
/**
* uverbs_alloc() - Quickly allocate memory for use with a bundle
* @bundle: The bundle
* @size: Number of bytes to allocate
* @flags: Allocator flags
*
* The bundle allocator is intended for allocations that are connected with
* processing the system call related to the bundle. The allocated memory is
* always freed once the system call completes, and cannot be freed any other
* way.
*
* This tries to use a small pool of pre-allocated memory for performance.
*/
__malloc void *_uverbs_alloc(struct uverbs_attr_bundle *bundle, size_t size,
gfp_t flags)
{
struct bundle_priv *pbundle =
container_of(bundle, struct bundle_priv, bundle);
size_t new_used;
void *res;
if (check_add_overflow(size, pbundle->internal_used, &new_used))
return ERR_PTR(-EOVERFLOW);
if (new_used > pbundle->internal_avail) {
struct bundle_alloc_head *buf;
buf = kvmalloc(struct_size(buf, data, size), flags);
if (!buf)
return ERR_PTR(-ENOMEM);
buf->next = pbundle->allocated_mem;
pbundle->allocated_mem = buf;
return buf->data;
}
res = (void *)pbundle->internal_buffer + pbundle->internal_used;
pbundle->internal_used =
ALIGN(new_used, sizeof(*pbundle->internal_buffer));
if (want_init_on_alloc(flags))
memset(res, 0, size);
return res;
}
EXPORT_SYMBOL(_uverbs_alloc);
static bool uverbs_is_attr_cleared(const struct ib_uverbs_attr *uattr,
u16 len)
{
if (uattr->len > sizeof(((struct ib_uverbs_attr *)0)->data))
return ib_is_buffer_cleared(u64_to_user_ptr(uattr->data) + len,
uattr->len - len);
return !memchr_inv((const void *)&uattr->data + len,
0, uattr->len - len);
}
static int uverbs_set_output(const struct uverbs_attr_bundle *bundle,
const struct uverbs_attr *attr)
{
struct bundle_priv *pbundle =
container_of(bundle, struct bundle_priv, bundle);
u16 flags;
flags = pbundle->uattrs[attr->ptr_attr.uattr_idx].flags |
UVERBS_ATTR_F_VALID_OUTPUT;
if (put_user(flags,
&pbundle->user_attrs[attr->ptr_attr.uattr_idx].flags))
return -EFAULT;
return 0;
}
static int uverbs_process_idrs_array(struct bundle_priv *pbundle,
const struct uverbs_api_attr *attr_uapi,
struct uverbs_objs_arr_attr *attr,
struct ib_uverbs_attr *uattr,
u32 attr_bkey)
{
const struct uverbs_attr_spec *spec = &attr_uapi->spec;
size_t array_len;
u32 *idr_vals;
int ret = 0;
size_t i;
if (uattr->attr_data.reserved)
return -EINVAL;
if (uattr->len % sizeof(u32))
return -EINVAL;
array_len = uattr->len / sizeof(u32);
if (array_len < spec->u2.objs_arr.min_len ||
array_len > spec->u2.objs_arr.max_len)
return -EINVAL;
attr->uobjects =
uverbs_alloc(&pbundle->bundle,
array_size(array_len, sizeof(*attr->uobjects)));
if (IS_ERR(attr->uobjects))
return PTR_ERR(attr->uobjects);
/*
* Since idr is 4B and *uobjects is >= 4B, we can use attr->uobjects
* to store idrs array and avoid additional memory allocation. The
* idrs array is offset to the end of the uobjects array so we will be
* able to read idr and replace with a pointer.
*/
idr_vals = (u32 *)(attr->uobjects + array_len) - array_len;
if (uattr->len > sizeof(uattr->data)) {
ret = copy_from_user(idr_vals, u64_to_user_ptr(uattr->data),
uattr->len);
if (ret)
return -EFAULT;
} else {
memcpy(idr_vals, &uattr->data, uattr->len);
}
for (i = 0; i != array_len; i++) {
attr->uobjects[i] = uverbs_get_uobject_from_file(
spec->u2.objs_arr.obj_type, spec->u2.objs_arr.access,
idr_vals[i], &pbundle->bundle);
if (IS_ERR(attr->uobjects[i])) {
ret = PTR_ERR(attr->uobjects[i]);
break;
}
}
attr->len = i;
__set_bit(attr_bkey, pbundle->spec_finalize);
return ret;
}
static void uverbs_free_idrs_array(const struct uverbs_api_attr *attr_uapi,
struct uverbs_objs_arr_attr *attr,
bool commit,
struct uverbs_attr_bundle *attrs)
{
const struct uverbs_attr_spec *spec = &attr_uapi->spec;
size_t i;
for (i = 0; i != attr->len; i++)
uverbs_finalize_object(attr->uobjects[i],
spec->u2.objs_arr.access, commit, attrs);
}
static int uverbs_process_attr(struct bundle_priv *pbundle,
const struct uverbs_api_attr *attr_uapi,
struct ib_uverbs_attr *uattr, u32 attr_bkey)
{
const struct uverbs_attr_spec *spec = &attr_uapi->spec;
struct uverbs_attr *e = &pbundle->bundle.attrs[attr_bkey];
const struct uverbs_attr_spec *val_spec = spec;
struct uverbs_obj_attr *o_attr;
switch (spec->type) {
case UVERBS_ATTR_TYPE_ENUM_IN:
if (uattr->attr_data.enum_data.elem_id >= spec->u.enum_def.num_elems)
return -EOPNOTSUPP;
if (uattr->attr_data.enum_data.reserved)
return -EINVAL;
val_spec = &spec->u2.enum_def.ids[uattr->attr_data.enum_data.elem_id];
/* Currently we only support PTR_IN based enums */
if (val_spec->type != UVERBS_ATTR_TYPE_PTR_IN)
return -EOPNOTSUPP;
e->ptr_attr.enum_id = uattr->attr_data.enum_data.elem_id;
/* fall through */
case UVERBS_ATTR_TYPE_PTR_IN:
/* Ensure that any data provided by userspace beyond the known
* struct is zero. Userspace that knows how to use some future
* longer struct will fail here if used with an old kernel and
* non-zero content, making ABI compat/discovery simpler.
*/
if (uattr->len > val_spec->u.ptr.len &&
val_spec->zero_trailing &&
!uverbs_is_attr_cleared(uattr, val_spec->u.ptr.len))
return -EOPNOTSUPP;
/* fall through */
case UVERBS_ATTR_TYPE_PTR_OUT:
if (uattr->len < val_spec->u.ptr.min_len ||
(!val_spec->zero_trailing &&
uattr->len > val_spec->u.ptr.len))
return -EINVAL;
if (spec->type != UVERBS_ATTR_TYPE_ENUM_IN &&
uattr->attr_data.reserved)
return -EINVAL;
e->ptr_attr.uattr_idx = uattr - pbundle->uattrs;
e->ptr_attr.len = uattr->len;
if (val_spec->alloc_and_copy && !uverbs_attr_ptr_is_inline(e)) {
void *p;
p = uverbs_alloc(&pbundle->bundle, uattr->len);
if (IS_ERR(p))
return PTR_ERR(p);
e->ptr_attr.ptr = p;
if (copy_from_user(p, u64_to_user_ptr(uattr->data),
uattr->len))
return -EFAULT;
} else {
e->ptr_attr.data = uattr->data;
}
break;
case UVERBS_ATTR_TYPE_IDR:
case UVERBS_ATTR_TYPE_FD:
if (uattr->attr_data.reserved)
return -EINVAL;
if (uattr->len != 0)
return -EINVAL;
o_attr = &e->obj_attr;
o_attr->attr_elm = attr_uapi;
/*
* The type of uattr->data is u64 for UVERBS_ATTR_TYPE_IDR and
* s64 for UVERBS_ATTR_TYPE_FD. We can cast the u64 to s64
* here without caring about truncation as we know that the
* IDR implementation today rejects negative IDs
*/
o_attr->uobject = uverbs_get_uobject_from_file(
spec->u.obj.obj_type, spec->u.obj.access,
uattr->data_s64, &pbundle->bundle);
if (IS_ERR(o_attr->uobject))
return PTR_ERR(o_attr->uobject);
__set_bit(attr_bkey, pbundle->uobj_finalize);
if (spec->u.obj.access == UVERBS_ACCESS_NEW) {
unsigned int uattr_idx = uattr - pbundle->uattrs;
s64 id = o_attr->uobject->id;
/* Copy the allocated id to the user-space */
if (put_user(id, &pbundle->user_attrs[uattr_idx].data))
return -EFAULT;
}
break;
case UVERBS_ATTR_TYPE_IDRS_ARRAY:
return uverbs_process_idrs_array(pbundle, attr_uapi,
&e->objs_arr_attr, uattr,
attr_bkey);
default:
return -EOPNOTSUPP;
}
return 0;
}
/*
* We search the radix tree with the method prefix and now we want to fast
* search the suffix bits to get a particular attribute pointer. It is not
* totally clear to me if this breaks the radix tree encasulation or not, but
* it uses the iter data to determine if the method iter points at the same
* chunk that will store the attribute, if so it just derefs it directly. By
* construction in most kernel configs the method and attrs will all fit in a
* single radix chunk, so in most cases this will have no search. Other cases
* this falls back to a full search.
*/
static void __rcu **uapi_get_attr_for_method(struct bundle_priv *pbundle,
u32 attr_key)
{
void __rcu **slot;
if (likely(attr_key < pbundle->radix_slots_len)) {
void *entry;
slot = pbundle->radix_slots + attr_key;
entry = rcu_dereference_raw(*slot);
if (likely(!radix_tree_is_internal_node(entry) && entry))
return slot;
}
return radix_tree_lookup_slot(pbundle->radix,
pbundle->method_key | attr_key);
}
static int uverbs_set_attr(struct bundle_priv *pbundle,
struct ib_uverbs_attr *uattr)
{
u32 attr_key = uapi_key_attr(uattr->attr_id);
u32 attr_bkey = uapi_bkey_attr(attr_key);
const struct uverbs_api_attr *attr;
void __rcu **slot;
int ret;
slot = uapi_get_attr_for_method(pbundle, attr_key);
if (!slot) {
/*
* Kernel does not support the attribute but user-space says it
* is mandatory
*/
if (uattr->flags & UVERBS_ATTR_F_MANDATORY)
return -EPROTONOSUPPORT;
return 0;
}
attr = rcu_dereference_protected(*slot, true);
/* Reject duplicate attributes from user-space */
if (test_bit(attr_bkey, pbundle->bundle.attr_present))
return -EINVAL;
ret = uverbs_process_attr(pbundle, attr, uattr, attr_bkey);
if (ret)
return ret;
__set_bit(attr_bkey, pbundle->bundle.attr_present);
return 0;
}
static int ib_uverbs_run_method(struct bundle_priv *pbundle,
unsigned int num_attrs)
{
int (*handler)(struct uverbs_attr_bundle *attrs);
size_t uattrs_size = array_size(sizeof(*pbundle->uattrs), num_attrs);
unsigned int destroy_bkey = pbundle->method_elm->destroy_bkey;
unsigned int i;
int ret;
/* See uverbs_disassociate_api() */
handler = srcu_dereference(
pbundle->method_elm->handler,
&pbundle->bundle.ufile->device->disassociate_srcu);
if (!handler)
return -EIO;
pbundle->uattrs = uverbs_alloc(&pbundle->bundle, uattrs_size);
if (IS_ERR(pbundle->uattrs))
return PTR_ERR(pbundle->uattrs);
if (copy_from_user(pbundle->uattrs, pbundle->user_attrs, uattrs_size))
return -EFAULT;
for (i = 0; i != num_attrs; i++) {
ret = uverbs_set_attr(pbundle, &pbundle->uattrs[i]);
if (unlikely(ret))
return ret;
}
/* User space did not provide all the mandatory attributes */
if (unlikely(!bitmap_subset(pbundle->method_elm->attr_mandatory,
pbundle->bundle.attr_present,
pbundle->method_elm->key_bitmap_len)))
return -EINVAL;
if (pbundle->method_elm->has_udata)
uverbs_fill_udata(&pbundle->bundle,
&pbundle->bundle.driver_udata,
UVERBS_ATTR_UHW_IN, UVERBS_ATTR_UHW_OUT);
else
pbundle->bundle.driver_udata = (struct ib_udata){};
if (destroy_bkey != UVERBS_API_ATTR_BKEY_LEN) {
struct uverbs_obj_attr *destroy_attr =
&pbundle->bundle.attrs[destroy_bkey].obj_attr;
ret = uobj_destroy(destroy_attr->uobject, &pbundle->bundle);
if (ret)
return ret;
__clear_bit(destroy_bkey, pbundle->uobj_finalize);
ret = handler(&pbundle->bundle);
uobj_put_destroy(destroy_attr->uobject);
} else {
ret = handler(&pbundle->bundle);
}
/*
* Until the drivers are revised to use the bundle directly we have to
* assume that the driver wrote to its UHW_OUT and flag userspace
* appropriately.
*/
if (!ret && pbundle->method_elm->has_udata) {
const struct uverbs_attr *attr =
uverbs_attr_get(&pbundle->bundle, UVERBS_ATTR_UHW_OUT);
if (!IS_ERR(attr))
ret = uverbs_set_output(&pbundle->bundle, attr);
}
/*
* EPROTONOSUPPORT is ONLY to be returned if the ioctl framework can
* not invoke the method because the request is not supported. No
* other cases should return this code.
*/
if (WARN_ON_ONCE(ret == -EPROTONOSUPPORT))
return -EINVAL;
return ret;
}
static void bundle_destroy(struct bundle_priv *pbundle, bool commit)
{
unsigned int key_bitmap_len = pbundle->method_elm->key_bitmap_len;
struct bundle_alloc_head *memblock;
unsigned int i;
/* fast path for simple uobjects */
i = -1;
while ((i = find_next_bit(pbundle->uobj_finalize, key_bitmap_len,
i + 1)) < key_bitmap_len) {
struct uverbs_attr *attr = &pbundle->bundle.attrs[i];
uverbs_finalize_object(
attr->obj_attr.uobject,
attr->obj_attr.attr_elm->spec.u.obj.access, commit,
&pbundle->bundle);
}
i = -1;
while ((i = find_next_bit(pbundle->spec_finalize, key_bitmap_len,
i + 1)) < key_bitmap_len) {
struct uverbs_attr *attr = &pbundle->bundle.attrs[i];
const struct uverbs_api_attr *attr_uapi;
void __rcu **slot;
slot = uapi_get_attr_for_method(
pbundle,
pbundle->method_key | uapi_bkey_to_key_attr(i));
if (WARN_ON(!slot))
continue;
attr_uapi = rcu_dereference_protected(*slot, true);
if (attr_uapi->spec.type == UVERBS_ATTR_TYPE_IDRS_ARRAY) {
uverbs_free_idrs_array(attr_uapi, &attr->objs_arr_attr,
commit, &pbundle->bundle);
}
}
for (memblock = pbundle->allocated_mem; memblock;) {
struct bundle_alloc_head *tmp = memblock;
memblock = memblock->next;
kvfree(tmp);
}
}
static int ib_uverbs_cmd_verbs(struct ib_uverbs_file *ufile,
struct ib_uverbs_ioctl_hdr *hdr,
struct ib_uverbs_attr __user *user_attrs)
{
const struct uverbs_api_ioctl_method *method_elm;
struct uverbs_api *uapi = ufile->device->uapi;
struct radix_tree_iter attrs_iter;
struct bundle_priv *pbundle;
struct bundle_priv onstack;
void __rcu **slot;
int ret;
if (unlikely(hdr->driver_id != uapi->driver_id))
return -EINVAL;
slot = radix_tree_iter_lookup(
&uapi->radix, &attrs_iter,
uapi_key_obj(hdr->object_id) |
uapi_key_ioctl_method(hdr->method_id));
if (unlikely(!slot))
return -EPROTONOSUPPORT;
method_elm = rcu_dereference_protected(*slot, true);
if (!method_elm->use_stack) {
pbundle = kmalloc(method_elm->bundle_size, GFP_KERNEL);
if (!pbundle)
return -ENOMEM;
pbundle->internal_avail =
method_elm->bundle_size -
offsetof(struct bundle_priv, internal_buffer);
pbundle->alloc_head.next = NULL;
pbundle->allocated_mem = &pbundle->alloc_head;
} else {
pbundle = &onstack;
pbundle->internal_avail = sizeof(pbundle->internal_buffer);
pbundle->allocated_mem = NULL;
}
/* Space for the pbundle->bundle.attrs flex array */
pbundle->method_elm = method_elm;
pbundle->method_key = attrs_iter.index;
pbundle->bundle.ufile = ufile;
pbundle->bundle.context = NULL; /* only valid if bundle has uobject */
pbundle->radix = &uapi->radix;
pbundle->radix_slots = slot;
pbundle->radix_slots_len = radix_tree_chunk_size(&attrs_iter);
pbundle->user_attrs = user_attrs;
pbundle->internal_used = ALIGN(pbundle->method_elm->key_bitmap_len *
sizeof(*pbundle->bundle.attrs),
sizeof(*pbundle->internal_buffer));
memset(pbundle->bundle.attr_present, 0,
sizeof(pbundle->bundle.attr_present));
memset(pbundle->uobj_finalize, 0, sizeof(pbundle->uobj_finalize));
memset(pbundle->spec_finalize, 0, sizeof(pbundle->spec_finalize));
ret = ib_uverbs_run_method(pbundle, hdr->num_attrs);
bundle_destroy(pbundle, ret == 0);
return ret;
}
long ib_uverbs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct ib_uverbs_file *file = filp->private_data;
struct ib_uverbs_ioctl_hdr __user *user_hdr =
(struct ib_uverbs_ioctl_hdr __user *)arg;
struct ib_uverbs_ioctl_hdr hdr;
int srcu_key;
int err;
if (unlikely(cmd != RDMA_VERBS_IOCTL))
return -ENOIOCTLCMD;
err = copy_from_user(&hdr, user_hdr, sizeof(hdr));
if (err)
return -EFAULT;
if (hdr.length > PAGE_SIZE ||
hdr.length != struct_size(&hdr, attrs, hdr.num_attrs))
return -EINVAL;
if (hdr.reserved1 || hdr.reserved2)
return -EPROTONOSUPPORT;
srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
err = ib_uverbs_cmd_verbs(file, &hdr, user_hdr->attrs);
srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
return err;
}
int uverbs_get_flags64(u64 *to, const struct uverbs_attr_bundle *attrs_bundle,
size_t idx, u64 allowed_bits)
{
const struct uverbs_attr *attr;
u64 flags;
attr = uverbs_attr_get(attrs_bundle, idx);
/* Missing attribute means 0 flags */
if (IS_ERR(attr)) {
*to = 0;
return 0;
}
/*
* New userspace code should use 8 bytes to pass flags, but we
* transparently support old userspaces that were using 4 bytes as
* well.
*/
if (attr->ptr_attr.len == 8)
flags = attr->ptr_attr.data;
else if (attr->ptr_attr.len == 4)
flags = *(u32 *)&attr->ptr_attr.data;
else
return -EINVAL;
if (flags & ~allowed_bits)
return -EINVAL;
*to = flags;
return 0;
}
EXPORT_SYMBOL(uverbs_get_flags64);
int uverbs_get_flags32(u32 *to, const struct uverbs_attr_bundle *attrs_bundle,
size_t idx, u64 allowed_bits)
{
u64 flags;
int ret;
ret = uverbs_get_flags64(&flags, attrs_bundle, idx, allowed_bits);
if (ret)
return ret;
if (flags > U32_MAX)
return -EINVAL;
*to = flags;
return 0;
}
EXPORT_SYMBOL(uverbs_get_flags32);
/*
* Fill a ib_udata struct (core or uhw) using the given attribute IDs.
* This is primarily used to convert the UVERBS_ATTR_UHW() into the
* ib_udata format used by the drivers.
*/
void uverbs_fill_udata(struct uverbs_attr_bundle *bundle,
struct ib_udata *udata, unsigned int attr_in,
unsigned int attr_out)
{
struct bundle_priv *pbundle =
container_of(bundle, struct bundle_priv, bundle);
const struct uverbs_attr *in =
uverbs_attr_get(&pbundle->bundle, attr_in);
const struct uverbs_attr *out =
uverbs_attr_get(&pbundle->bundle, attr_out);
if (!IS_ERR(in)) {
udata->inlen = in->ptr_attr.len;
if (uverbs_attr_ptr_is_inline(in))
udata->inbuf =
&pbundle->user_attrs[in->ptr_attr.uattr_idx]
.data;
else
udata->inbuf = u64_to_user_ptr(in->ptr_attr.data);
} else {
udata->inbuf = NULL;
udata->inlen = 0;
}
if (!IS_ERR(out)) {
udata->outbuf = u64_to_user_ptr(out->ptr_attr.data);
udata->outlen = out->ptr_attr.len;
} else {
udata->outbuf = NULL;
udata->outlen = 0;
}
}
int uverbs_copy_to(const struct uverbs_attr_bundle *bundle, size_t idx,
const void *from, size_t size)
{
const struct uverbs_attr *attr = uverbs_attr_get(bundle, idx);
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;
return uverbs_set_output(bundle, attr);
}
EXPORT_SYMBOL(uverbs_copy_to);
/*
* This is only used if the caller has directly used copy_to_use to write the
* data. It signals to user space that the buffer is filled in.
*/
int uverbs_output_written(const struct uverbs_attr_bundle *bundle, size_t idx)
{
const struct uverbs_attr *attr = uverbs_attr_get(bundle, idx);
if (IS_ERR(attr))
return PTR_ERR(attr);
return uverbs_set_output(bundle, attr);
}
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)
{
const struct uverbs_attr *attr;
attr = uverbs_attr_get(attrs_bundle, idx);
if (IS_ERR(attr)) {
if ((PTR_ERR(attr) != -ENOENT) || !def_val)
return PTR_ERR(attr);
*to = *def_val;
} else {
*to = attr->ptr_attr.data;
}
if (*to < lower_bound || (*to > 0 && (u64)*to > upper_bound))
return -EINVAL;
return 0;
}
EXPORT_SYMBOL(_uverbs_get_const);
int uverbs_copy_to_struct_or_zero(const struct uverbs_attr_bundle *bundle,
size_t idx, const void *from, size_t size)
{
const struct uverbs_attr *attr = uverbs_attr_get(bundle, idx);
if (IS_ERR(attr))
return PTR_ERR(attr);
if (size < attr->ptr_attr.len) {
if (clear_user(u64_to_user_ptr(attr->ptr_attr.data) + size,
attr->ptr_attr.len - size))
return -EFAULT;
}
return uverbs_copy_to(bundle, idx, from, size);
}