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