// 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 = kvzalloc(size, GFP_KERNEL); if (!p) return -ENOMEM; } res = regset->regset_get(target, regset, (struct membuf){.p = p, .left = size}); if (res < 0) { kvfree(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; kvfree(buf); return ret; }