forked from Minki/linux
dc12d7968f
Turn copy_regset_to_user() into regset_get_alloc() + copy_to_user(). Now all ->get() calls have a kernel buffer as destination. Note that we'd already eliminated the callers of copy_regset_to_user() with non-zero offset; now that argument is simply unused. Uninlined, while we are at it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
81 lines
2.0 KiB
C
81 lines
2.0 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->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->get(target, regset, 0, size, p, NULL);
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if (unlikely(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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if (regset->get_size) { // arm64-only kludge, will go away
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unsigned max_size = regset->get_size(target, regset);
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if (size > max_size)
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size = max_size;
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}
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return size;
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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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