| 1 | |
| 2 | #include <linux/export.h>
|
| 3 | #include <linux/slab.h>
|
| 4 | #include <linux/regset.h>
|
| 5 |
|
| 6 | static int __regset_get(struct task_struct *target,
|
| 7 | const struct user_regset *regset,
|
| 8 | unsigned int size,
|
| 9 | void **data)
|
| 10 | {
|
| 11 | void *p = *data, *to_free = NULL;
|
| 12 | int res;
|
| 13 |
|
| 14 | if (!regset->regset_get)
|
| 15 | return -EOPNOTSUPP;
|
| 16 | if (size > regset->n * regset->size)
|
| 17 | size = regset->n * regset->size;
|
| 18 | if (!p) {
|
| 19 | to_free = p = kvzalloc(size, GFP_KERNEL);
|
| 20 | if (!p)
|
| 21 | return -ENOMEM;
|
| 22 | }
|
| 23 | res = regset->regset_get(target, regset,
|
| 24 | (struct membuf){.p = p, .left = size});
|
| 25 | if (res < 0) {
|
| 26 | kvfree(to_free);
|
| 27 | return res;
|
| 28 | }
|
| 29 | *data = p;
|
| 30 | return size - res;
|
| 31 | }
|
| 32 |
|
| 33 | int regset_get(struct task_struct *target,
|
| 34 | const struct user_regset *regset,
|
| 35 | unsigned int size,
|
| 36 | void *data)
|
| 37 | {
|
| 38 | return __regset_get(target, regset, size, &data);
|
| 39 | }
|
| 40 | EXPORT_SYMBOL(regset_get);
|
| 41 |
|
| 42 | int regset_get_alloc(struct task_struct *target,
|
| 43 | const struct user_regset *regset,
|
| 44 | unsigned int size,
|
| 45 | void **data)
|
| 46 | {
|
| 47 | *data = NULL;
|
| 48 | return __regset_get(target, regset, size, data);
|
| 49 | }
|
| 50 | EXPORT_SYMBOL(regset_get_alloc);
|
| 51 |
|
| 52 | |
| 53 | * copy_regset_to_user - fetch a thread's user_regset data into user memory
|
| 54 | * @target: thread to be examined
|
| 55 | * @view: &struct user_regset_view describing user thread machine state
|
| 56 | * @setno: index in @view->regsets
|
| 57 | * @offset: offset into the regset data, in bytes
|
| 58 | * @size: amount of data to copy, in bytes
|
| 59 | * @data: user-mode pointer to copy into
|
| 60 |
|
| 61 | int copy_regset_to_user(struct task_struct *target,
|
| 62 | const struct user_regset_view *view,
|
| 63 | unsigned int setno,
|
| 64 | unsigned int offset, unsigned int size,
|
| 65 | void __user *data)
|
| 66 | {
|
| 67 | const struct user_regset *regset = &view->regsets[setno];
|
| 68 | void *buf;
|
| 69 | int ret;
|
| 70 |
|
| 71 | ret = regset_get_alloc(target, regset, size, &buf);
|
| 72 | if (ret > 0)
|
| 73 | ret = copy_to_user(data, buf, ret) ? -EFAULT : 0;
|
| 74 | kvfree(buf);
|
| 75 | return ret;
|
| 76 | }
|