1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2007
4 *
5 * Author: Eric Biederman <ebiederm@xmision.com>
6 */
7
8 #include <linux/module.h>
9 #include <linux/ipc.h>
10 #include <linux/nsproxy.h>
11 #include <linux/sysctl.h>
12 #include <linux/uaccess.h>
13 #include <linux/ipc_namespace.h>
14 #include <linux/msg.h>
15 #include "util.h"
16
get_ipc(struct ctl_table * table)17 static void *get_ipc(struct ctl_table *table)
18 {
19 char *which = table->data;
20 struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
21 which = (which - (char *)&init_ipc_ns) + (char *)ipc_ns;
22 return which;
23 }
24
25 #ifdef CONFIG_PROC_SYSCTL
proc_ipc_dointvec(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)26 static int proc_ipc_dointvec(struct ctl_table *table, int write,
27 void *buffer, size_t *lenp, loff_t *ppos)
28 {
29 struct ctl_table ipc_table;
30
31 memcpy(&ipc_table, table, sizeof(ipc_table));
32 ipc_table.data = get_ipc(table);
33
34 return proc_dointvec(&ipc_table, write, buffer, lenp, ppos);
35 }
36
proc_ipc_dointvec_minmax(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)37 static int proc_ipc_dointvec_minmax(struct ctl_table *table, int write,
38 void *buffer, size_t *lenp, loff_t *ppos)
39 {
40 struct ctl_table ipc_table;
41
42 memcpy(&ipc_table, table, sizeof(ipc_table));
43 ipc_table.data = get_ipc(table);
44
45 return proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
46 }
47
proc_ipc_dointvec_minmax_orphans(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)48 static int proc_ipc_dointvec_minmax_orphans(struct ctl_table *table, int write,
49 void *buffer, size_t *lenp, loff_t *ppos)
50 {
51 struct ipc_namespace *ns = current->nsproxy->ipc_ns;
52 int err = proc_ipc_dointvec_minmax(table, write, buffer, lenp, ppos);
53
54 if (err < 0)
55 return err;
56 if (ns->shm_rmid_forced)
57 shm_destroy_orphaned(ns);
58 return err;
59 }
60
proc_ipc_doulongvec_minmax(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)61 static int proc_ipc_doulongvec_minmax(struct ctl_table *table, int write,
62 void *buffer, size_t *lenp, loff_t *ppos)
63 {
64 struct ctl_table ipc_table;
65 memcpy(&ipc_table, table, sizeof(ipc_table));
66 ipc_table.data = get_ipc(table);
67
68 return proc_doulongvec_minmax(&ipc_table, write, buffer,
69 lenp, ppos);
70 }
71
proc_ipc_auto_msgmni(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)72 static int proc_ipc_auto_msgmni(struct ctl_table *table, int write,
73 void *buffer, size_t *lenp, loff_t *ppos)
74 {
75 struct ctl_table ipc_table;
76 int dummy = 0;
77
78 memcpy(&ipc_table, table, sizeof(ipc_table));
79 ipc_table.data = &dummy;
80
81 if (write)
82 pr_info_once("writing to auto_msgmni has no effect");
83
84 return proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
85 }
86
proc_ipc_sem_dointvec(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)87 static int proc_ipc_sem_dointvec(struct ctl_table *table, int write,
88 void *buffer, size_t *lenp, loff_t *ppos)
89 {
90 int ret, semmni;
91 struct ipc_namespace *ns = current->nsproxy->ipc_ns;
92
93 semmni = ns->sem_ctls[3];
94 ret = proc_ipc_dointvec(table, write, buffer, lenp, ppos);
95
96 if (!ret)
97 ret = sem_check_semmni(current->nsproxy->ipc_ns);
98
99 /*
100 * Reset the semmni value if an error happens.
101 */
102 if (ret)
103 ns->sem_ctls[3] = semmni;
104 return ret;
105 }
106
107 #else
108 #define proc_ipc_doulongvec_minmax NULL
109 #define proc_ipc_dointvec NULL
110 #define proc_ipc_dointvec_minmax NULL
111 #define proc_ipc_dointvec_minmax_orphans NULL
112 #define proc_ipc_auto_msgmni NULL
113 #define proc_ipc_sem_dointvec NULL
114 #endif
115
116 int ipc_mni = IPCMNI;
117 int ipc_mni_shift = IPCMNI_SHIFT;
118 int ipc_min_cycle = RADIX_TREE_MAP_SIZE;
119
120 static struct ctl_table ipc_kern_table[] = {
121 {
122 .procname = "shmmax",
123 .data = &init_ipc_ns.shm_ctlmax,
124 .maxlen = sizeof(init_ipc_ns.shm_ctlmax),
125 .mode = 0644,
126 .proc_handler = proc_ipc_doulongvec_minmax,
127 },
128 {
129 .procname = "shmall",
130 .data = &init_ipc_ns.shm_ctlall,
131 .maxlen = sizeof(init_ipc_ns.shm_ctlall),
132 .mode = 0644,
133 .proc_handler = proc_ipc_doulongvec_minmax,
134 },
135 {
136 .procname = "shmmni",
137 .data = &init_ipc_ns.shm_ctlmni,
138 .maxlen = sizeof(init_ipc_ns.shm_ctlmni),
139 .mode = 0644,
140 .proc_handler = proc_ipc_dointvec_minmax,
141 .extra1 = SYSCTL_ZERO,
142 .extra2 = &ipc_mni,
143 },
144 {
145 .procname = "shm_rmid_forced",
146 .data = &init_ipc_ns.shm_rmid_forced,
147 .maxlen = sizeof(init_ipc_ns.shm_rmid_forced),
148 .mode = 0644,
149 .proc_handler = proc_ipc_dointvec_minmax_orphans,
150 .extra1 = SYSCTL_ZERO,
151 .extra2 = SYSCTL_ONE,
152 },
153 {
154 .procname = "msgmax",
155 .data = &init_ipc_ns.msg_ctlmax,
156 .maxlen = sizeof(init_ipc_ns.msg_ctlmax),
157 .mode = 0644,
158 .proc_handler = proc_ipc_dointvec_minmax,
159 .extra1 = SYSCTL_ZERO,
160 .extra2 = SYSCTL_INT_MAX,
161 },
162 {
163 .procname = "msgmni",
164 .data = &init_ipc_ns.msg_ctlmni,
165 .maxlen = sizeof(init_ipc_ns.msg_ctlmni),
166 .mode = 0644,
167 .proc_handler = proc_ipc_dointvec_minmax,
168 .extra1 = SYSCTL_ZERO,
169 .extra2 = &ipc_mni,
170 },
171 {
172 .procname = "auto_msgmni",
173 .data = NULL,
174 .maxlen = sizeof(int),
175 .mode = 0644,
176 .proc_handler = proc_ipc_auto_msgmni,
177 .extra1 = SYSCTL_ZERO,
178 .extra2 = SYSCTL_ONE,
179 },
180 {
181 .procname = "msgmnb",
182 .data = &init_ipc_ns.msg_ctlmnb,
183 .maxlen = sizeof(init_ipc_ns.msg_ctlmnb),
184 .mode = 0644,
185 .proc_handler = proc_ipc_dointvec_minmax,
186 .extra1 = SYSCTL_ZERO,
187 .extra2 = SYSCTL_INT_MAX,
188 },
189 {
190 .procname = "sem",
191 .data = &init_ipc_ns.sem_ctls,
192 .maxlen = 4*sizeof(int),
193 .mode = 0644,
194 .proc_handler = proc_ipc_sem_dointvec,
195 },
196 #ifdef CONFIG_CHECKPOINT_RESTORE
197 {
198 .procname = "sem_next_id",
199 .data = &init_ipc_ns.ids[IPC_SEM_IDS].next_id,
200 .maxlen = sizeof(init_ipc_ns.ids[IPC_SEM_IDS].next_id),
201 .mode = 0644,
202 .proc_handler = proc_ipc_dointvec_minmax,
203 .extra1 = SYSCTL_ZERO,
204 .extra2 = SYSCTL_INT_MAX,
205 },
206 {
207 .procname = "msg_next_id",
208 .data = &init_ipc_ns.ids[IPC_MSG_IDS].next_id,
209 .maxlen = sizeof(init_ipc_ns.ids[IPC_MSG_IDS].next_id),
210 .mode = 0644,
211 .proc_handler = proc_ipc_dointvec_minmax,
212 .extra1 = SYSCTL_ZERO,
213 .extra2 = SYSCTL_INT_MAX,
214 },
215 {
216 .procname = "shm_next_id",
217 .data = &init_ipc_ns.ids[IPC_SHM_IDS].next_id,
218 .maxlen = sizeof(init_ipc_ns.ids[IPC_SHM_IDS].next_id),
219 .mode = 0644,
220 .proc_handler = proc_ipc_dointvec_minmax,
221 .extra1 = SYSCTL_ZERO,
222 .extra2 = SYSCTL_INT_MAX,
223 },
224 #endif
225 {}
226 };
227
228 static struct ctl_table ipc_root_table[] = {
229 {
230 .procname = "kernel",
231 .mode = 0555,
232 .child = ipc_kern_table,
233 },
234 {}
235 };
236
ipc_sysctl_init(void)237 static int __init ipc_sysctl_init(void)
238 {
239 register_sysctl_table(ipc_root_table);
240 return 0;
241 }
242
243 device_initcall(ipc_sysctl_init);
244
ipc_mni_extend(char * str)245 static int __init ipc_mni_extend(char *str)
246 {
247 ipc_mni = IPCMNI_EXTEND;
248 ipc_mni_shift = IPCMNI_EXTEND_SHIFT;
249 ipc_min_cycle = IPCMNI_EXTEND_MIN_CYCLE;
250 pr_info("IPCMNI extended to %d.\n", ipc_mni);
251 return 0;
252 }
253 early_param("ipcmni_extend", ipc_mni_extend);
254