1 // SPDX-License-Identifier: GPL-2.0-or-later
42 #define DATALEN_MSG	((size_t)PAGE_SIZE-sizeof(struct msg_msg))
43 #define DATALEN_SEG	((size_t)PAGE_SIZE-sizeof(struct msg_msgseg))
57 static struct msg_msg *alloc_msg(size_t len)  in alloc_msg()  argument
63 	alen = min(len, DATALEN_MSG);  in alloc_msg()
68 	msg->next = NULL;  in alloc_msg()
69 	msg->security = NULL;  in alloc_msg()
71 	len -= alen;  in alloc_msg()
72 	pseg = &msg->next;  in alloc_msg()
73 	while (len > 0) {  in alloc_msg()
78 		alen = min(len, DATALEN_SEG);  in alloc_msg()
83 		seg->next = NULL;  in alloc_msg()
84 		pseg = &seg->next;  in alloc_msg()
85 		len -= alen;  in alloc_msg()
95 struct msg_msg *load_msg(const void __user *src, size_t len)  in load_msg()  argument
99 	int err = -EFAULT;  in load_msg()
102 	msg = alloc_msg(len);  in load_msg()
104 		return ERR_PTR(-ENOMEM);  in load_msg()
106 	alen = min(len, DATALEN_MSG);  in load_msg()
110 	for (seg = msg->next; seg != NULL; seg = seg->next) {  in load_msg()
111 		len -= alen;  in load_msg()
113 		alen = min(len, DATALEN_SEG);  in load_msg()
132 	size_t len = src->m_ts;  in copy_msg()  local
135 	if (src->m_ts > dst->m_ts)  in copy_msg()
136 		return ERR_PTR(-EINVAL);  in copy_msg()
138 	alen = min(len, DATALEN_MSG);  in copy_msg()
141 	for (dst_pseg = dst->next, src_pseg = src->next;  in copy_msg()
143 	     dst_pseg = dst_pseg->next, src_pseg = src_pseg->next) {  in copy_msg()
145 		len -= alen;  in copy_msg()
146 		alen = min(len, DATALEN_SEG);  in copy_msg()
150 	dst->m_type = src->m_type;  in copy_msg()
151 	dst->m_ts = src->m_ts;  in copy_msg()
158 	return ERR_PTR(-ENOSYS);  in copy_msg()
161 int store_msg(void __user *dest, struct msg_msg *msg, size_t len)  in store_msg()  argument
166 	alen = min(len, DATALEN_MSG);  in store_msg()
168 		return -1;  in store_msg()
170 	for (seg = msg->next; seg != NULL; seg = seg->next) {  in store_msg()
171 		len -= alen;  in store_msg()
173 		alen = min(len, DATALEN_SEG);  in store_msg()
175 			return -1;  in store_msg()
186 	seg = msg->next;  in free_msg()
189 		struct msg_msgseg *tmp = seg->next;  in free_msg()