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1/*
2 * linux/ipc/msgutil.c
3 * Copyright (C) 1999, 2004 Manfred Spraul
4 *
5 * This file is released under GNU General Public Licence version 2 or
6 * (at your option) any later version.
7 *
8 * See the file COPYING for more details.
9 */
10
11#include <linux/spinlock.h>
12#include <linux/init.h>
13#include <linux/security.h>
14#include <linux/slab.h>
15#include <linux/ipc.h>
16#include <linux/msg.h>
17#include <linux/ipc_namespace.h>
18#include <linux/utsname.h>
19#include <linux/proc_ns.h>
20#include <linux/uaccess.h>
21
22#include "util.h"
23
24DEFINE_SPINLOCK(mq_lock);
25
26/*
27 * The next 2 defines are here bc this is the only file
28 * compiled when either CONFIG_SYSVIPC and CONFIG_POSIX_MQUEUE
29 * and not CONFIG_IPC_NS.
30 */
31struct ipc_namespace init_ipc_ns = {
32 .count = ATOMIC_INIT(1),
33 .user_ns = &init_user_ns,
34 .proc_inum = PROC_IPC_INIT_INO,
35};
36
37atomic_t nr_ipc_ns = ATOMIC_INIT(1);
38
39struct msg_msgseg {
40 struct msg_msgseg *next;
41 /* the next part of the message follows immediately */
42};
43
44#define DATALEN_MSG ((size_t)PAGE_SIZE-sizeof(struct msg_msg))
45#define DATALEN_SEG ((size_t)PAGE_SIZE-sizeof(struct msg_msgseg))
46
47
48static struct msg_msg *alloc_msg(size_t len)
49{
50 struct msg_msg *msg;
51 struct msg_msgseg **pseg;
52 size_t alen;
53
54 alen = min(len, DATALEN_MSG);
55 msg = kmalloc(sizeof(*msg) + alen, GFP_KERNEL);
56 if (msg == NULL)
57 return NULL;
58
59 msg->next = NULL;
60 msg->security = NULL;
61
62 len -= alen;
63 pseg = &msg->next;
64 while (len > 0) {
65 struct msg_msgseg *seg;
66 alen = min(len, DATALEN_SEG);
67 seg = kmalloc(sizeof(*seg) + alen, GFP_KERNEL);
68 if (seg == NULL)
69 goto out_err;
70 *pseg = seg;
71 seg->next = NULL;
72 pseg = &seg->next;
73 len -= alen;
74 }
75
76 return msg;
77
78out_err:
79 free_msg(msg);
80 return NULL;
81}
82
83struct msg_msg *load_msg(const void __user *src, size_t len)
84{
85 struct msg_msg *msg;
86 struct msg_msgseg *seg;
87 int err = -EFAULT;
88 size_t alen;
89
90 msg = alloc_msg(len);
91 if (msg == NULL)
92 return ERR_PTR(-ENOMEM);
93
94 alen = min(len, DATALEN_MSG);
95 if (copy_from_user(msg + 1, src, alen))
96 goto out_err;
97
98 for (seg = msg->next; seg != NULL; seg = seg->next) {
99 len -= alen;
100 src = (char __user *)src + alen;
101 alen = min(len, DATALEN_SEG);
102 if (copy_from_user(seg + 1, src, alen))
103 goto out_err;
104 }
105
106 err = security_msg_msg_alloc(msg);
107 if (err)
108 goto out_err;
109
110 return msg;
111
112out_err:
113 free_msg(msg);
114 return ERR_PTR(err);
115}
116#ifdef CONFIG_CHECKPOINT_RESTORE
117struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
118{
119 struct msg_msgseg *dst_pseg, *src_pseg;
120 size_t len = src->m_ts;
121 size_t alen;
122
123 BUG_ON(dst == NULL);
124 if (src->m_ts > dst->m_ts)
125 return ERR_PTR(-EINVAL);
126
127 alen = min(len, DATALEN_MSG);
128 memcpy(dst + 1, src + 1, alen);
129
130 for (dst_pseg = dst->next, src_pseg = src->next;
131 src_pseg != NULL;
132 dst_pseg = dst_pseg->next, src_pseg = src_pseg->next) {
133
134 len -= alen;
135 alen = min(len, DATALEN_SEG);
136 memcpy(dst_pseg + 1, src_pseg + 1, alen);
137 }
138
139 dst->m_type = src->m_type;
140 dst->m_ts = src->m_ts;
141
142 return dst;
143}
144#else
145struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
146{
147 return ERR_PTR(-ENOSYS);
148}
149#endif
150int store_msg(void __user *dest, struct msg_msg *msg, size_t len)
151{
152 size_t alen;
153 struct msg_msgseg *seg;
154
155 alen = min(len, DATALEN_MSG);
156 if (copy_to_user(dest, msg + 1, alen))
157 return -1;
158
159 for (seg = msg->next; seg != NULL; seg = seg->next) {
160 len -= alen;
161 dest = (char __user *)dest + alen;
162 alen = min(len, DATALEN_SEG);
163 if (copy_to_user(dest, seg + 1, alen))
164 return -1;
165 }
166 return 0;
167}
168
169void free_msg(struct msg_msg *msg)
170{
171 struct msg_msgseg *seg;
172
173 security_msg_msg_free(msg);
174
175 seg = msg->next;
176 kfree(msg);
177 while (seg != NULL) {
178 struct msg_msgseg *tmp = seg->next;
179 kfree(seg);
180 seg = tmp;
181 }
182}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * linux/ipc/msgutil.c
4 * Copyright (C) 1999, 2004 Manfred Spraul
5 */
6
7#include <linux/spinlock.h>
8#include <linux/init.h>
9#include <linux/security.h>
10#include <linux/slab.h>
11#include <linux/ipc.h>
12#include <linux/msg.h>
13#include <linux/ipc_namespace.h>
14#include <linux/utsname.h>
15#include <linux/proc_ns.h>
16#include <linux/uaccess.h>
17#include <linux/sched.h>
18
19#include "util.h"
20
21DEFINE_SPINLOCK(mq_lock);
22
23/*
24 * The next 2 defines are here bc this is the only file
25 * compiled when either CONFIG_SYSVIPC and CONFIG_POSIX_MQUEUE
26 * and not CONFIG_IPC_NS.
27 */
28struct ipc_namespace init_ipc_ns = {
29 .ns.count = REFCOUNT_INIT(1),
30 .user_ns = &init_user_ns,
31 .ns.inum = PROC_IPC_INIT_INO,
32#ifdef CONFIG_IPC_NS
33 .ns.ops = &ipcns_operations,
34#endif
35};
36
37struct msg_msgseg {
38 struct msg_msgseg *next;
39 /* the next part of the message follows immediately */
40};
41
42#define DATALEN_MSG ((size_t)PAGE_SIZE-sizeof(struct msg_msg))
43#define DATALEN_SEG ((size_t)PAGE_SIZE-sizeof(struct msg_msgseg))
44
45static kmem_buckets *msg_buckets __ro_after_init;
46
47static int __init init_msg_buckets(void)
48{
49 msg_buckets = kmem_buckets_create("msg_msg", SLAB_ACCOUNT,
50 sizeof(struct msg_msg),
51 DATALEN_MSG, NULL);
52
53 return 0;
54}
55subsys_initcall(init_msg_buckets);
56
57static struct msg_msg *alloc_msg(size_t len)
58{
59 struct msg_msg *msg;
60 struct msg_msgseg **pseg;
61 size_t alen;
62
63 alen = min(len, DATALEN_MSG);
64 msg = kmem_buckets_alloc(msg_buckets, sizeof(*msg) + alen, GFP_KERNEL);
65 if (msg == NULL)
66 return NULL;
67
68 msg->next = NULL;
69 msg->security = NULL;
70
71 len -= alen;
72 pseg = &msg->next;
73 while (len > 0) {
74 struct msg_msgseg *seg;
75
76 cond_resched();
77
78 alen = min(len, DATALEN_SEG);
79 seg = kmalloc(sizeof(*seg) + alen, GFP_KERNEL_ACCOUNT);
80 if (seg == NULL)
81 goto out_err;
82 *pseg = seg;
83 seg->next = NULL;
84 pseg = &seg->next;
85 len -= alen;
86 }
87
88 return msg;
89
90out_err:
91 free_msg(msg);
92 return NULL;
93}
94
95struct msg_msg *load_msg(const void __user *src, size_t len)
96{
97 struct msg_msg *msg;
98 struct msg_msgseg *seg;
99 int err = -EFAULT;
100 size_t alen;
101
102 msg = alloc_msg(len);
103 if (msg == NULL)
104 return ERR_PTR(-ENOMEM);
105
106 alen = min(len, DATALEN_MSG);
107 if (copy_from_user(msg + 1, src, alen))
108 goto out_err;
109
110 for (seg = msg->next; seg != NULL; seg = seg->next) {
111 len -= alen;
112 src = (char __user *)src + alen;
113 alen = min(len, DATALEN_SEG);
114 if (copy_from_user(seg + 1, src, alen))
115 goto out_err;
116 }
117
118 err = security_msg_msg_alloc(msg);
119 if (err)
120 goto out_err;
121
122 return msg;
123
124out_err:
125 free_msg(msg);
126 return ERR_PTR(err);
127}
128#ifdef CONFIG_CHECKPOINT_RESTORE
129struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
130{
131 struct msg_msgseg *dst_pseg, *src_pseg;
132 size_t len = src->m_ts;
133 size_t alen;
134
135 if (src->m_ts > dst->m_ts)
136 return ERR_PTR(-EINVAL);
137
138 alen = min(len, DATALEN_MSG);
139 memcpy(dst + 1, src + 1, alen);
140
141 for (dst_pseg = dst->next, src_pseg = src->next;
142 src_pseg != NULL;
143 dst_pseg = dst_pseg->next, src_pseg = src_pseg->next) {
144
145 len -= alen;
146 alen = min(len, DATALEN_SEG);
147 memcpy(dst_pseg + 1, src_pseg + 1, alen);
148 }
149
150 dst->m_type = src->m_type;
151 dst->m_ts = src->m_ts;
152
153 return dst;
154}
155#else
156struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
157{
158 return ERR_PTR(-ENOSYS);
159}
160#endif
161int store_msg(void __user *dest, struct msg_msg *msg, size_t len)
162{
163 size_t alen;
164 struct msg_msgseg *seg;
165
166 alen = min(len, DATALEN_MSG);
167 if (copy_to_user(dest, msg + 1, alen))
168 return -1;
169
170 for (seg = msg->next; seg != NULL; seg = seg->next) {
171 len -= alen;
172 dest = (char __user *)dest + alen;
173 alen = min(len, DATALEN_SEG);
174 if (copy_to_user(dest, seg + 1, alen))
175 return -1;
176 }
177 return 0;
178}
179
180void free_msg(struct msg_msg *msg)
181{
182 struct msg_msgseg *seg;
183
184 security_msg_msg_free(msg);
185
186 seg = msg->next;
187 kfree(msg);
188 while (seg != NULL) {
189 struct msg_msgseg *tmp = seg->next;
190
191 cond_resched();
192 kfree(seg);
193 seg = tmp;
194 }
195}