// SPDX-License-Identifier: GPL-2.0-only
|
#include <linux/export.h>
|
#include <linux/slab.h>
|
#include <linux/regset.h>
|
|
static int __regset_get(struct task_struct *target,
|
const struct user_regset *regset,
|
unsigned int size,
|
void **data)
|
{
|
void *p = *data, *to_free = NULL;
|
int res;
|
|
if (!regset->regset_get)
|
return -EOPNOTSUPP;
|
if (size > regset->n * regset->size)
|
size = regset->n * regset->size;
|
if (!p) {
|
to_free = p = kzalloc(size, GFP_KERNEL);
|
if (!p)
|
return -ENOMEM;
|
}
|
res = regset->regset_get(target, regset,
|
(struct membuf){.p = p, .left = size});
|
if (res < 0) {
|
kfree(to_free);
|
return res;
|
}
|
*data = p;
|
return size - res;
|
}
|
|
int regset_get(struct task_struct *target,
|
const struct user_regset *regset,
|
unsigned int size,
|
void *data)
|
{
|
return __regset_get(target, regset, size, &data);
|
}
|
EXPORT_SYMBOL(regset_get);
|
|
int regset_get_alloc(struct task_struct *target,
|
const struct user_regset *regset,
|
unsigned int size,
|
void **data)
|
{
|
*data = NULL;
|
return __regset_get(target, regset, size, data);
|
}
|
EXPORT_SYMBOL(regset_get_alloc);
|
|
/**
|
* copy_regset_to_user - fetch a thread's user_regset data into user memory
|
* @target: thread to be examined
|
* @view: &struct user_regset_view describing user thread machine state
|
* @setno: index in @view->regsets
|
* @offset: offset into the regset data, in bytes
|
* @size: amount of data to copy, in bytes
|
* @data: user-mode pointer to copy into
|
*/
|
int copy_regset_to_user(struct task_struct *target,
|
const struct user_regset_view *view,
|
unsigned int setno,
|
unsigned int offset, unsigned int size,
|
void __user *data)
|
{
|
const struct user_regset *regset = &view->regsets[setno];
|
void *buf;
|
int ret;
|
|
ret = regset_get_alloc(target, regset, size, &buf);
|
if (ret > 0)
|
ret = copy_to_user(data, buf, ret) ? -EFAULT : 0;
|
kfree(buf);
|
return ret;
|
}
|
