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Merge tag 'mips_5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux
[thirdparty/linux.git] / ipc / ipc_sysctl.c
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
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
26 static int proc_ipc_dointvec(struct ctl_table *table, int write,
27 void __user *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
37 static int proc_ipc_dointvec_minmax(struct ctl_table *table, int write,
38 void __user *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
48 static int proc_ipc_dointvec_minmax_orphans(struct ctl_table *table, int write,
49 void __user *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
61 static int proc_ipc_doulongvec_minmax(struct ctl_table *table, int write,
62 void __user *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
72 static int proc_ipc_auto_msgmni(struct ctl_table *table, int write,
73 void __user *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
87 static int proc_ipc_sem_dointvec(struct ctl_table *table, int write,
88 void __user *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 static int zero;
117 static int one = 1;
118 static int int_max = INT_MAX;
119 int ipc_mni = IPCMNI;
120 int ipc_mni_shift = IPCMNI_SHIFT;
121 int ipc_min_cycle = RADIX_TREE_MAP_SIZE;
122
123 static struct ctl_table ipc_kern_table[] = {
124 {
125 .procname = "shmmax",
126 .data = &init_ipc_ns.shm_ctlmax,
127 .maxlen = sizeof(init_ipc_ns.shm_ctlmax),
128 .mode = 0644,
129 .proc_handler = proc_ipc_doulongvec_minmax,
130 },
131 {
132 .procname = "shmall",
133 .data = &init_ipc_ns.shm_ctlall,
134 .maxlen = sizeof(init_ipc_ns.shm_ctlall),
135 .mode = 0644,
136 .proc_handler = proc_ipc_doulongvec_minmax,
137 },
138 {
139 .procname = "shmmni",
140 .data = &init_ipc_ns.shm_ctlmni,
141 .maxlen = sizeof(init_ipc_ns.shm_ctlmni),
142 .mode = 0644,
143 .proc_handler = proc_ipc_dointvec_minmax,
144 .extra1 = &zero,
145 .extra2 = &ipc_mni,
146 },
147 {
148 .procname = "shm_rmid_forced",
149 .data = &init_ipc_ns.shm_rmid_forced,
150 .maxlen = sizeof(init_ipc_ns.shm_rmid_forced),
151 .mode = 0644,
152 .proc_handler = proc_ipc_dointvec_minmax_orphans,
153 .extra1 = &zero,
154 .extra2 = &one,
155 },
156 {
157 .procname = "msgmax",
158 .data = &init_ipc_ns.msg_ctlmax,
159 .maxlen = sizeof(init_ipc_ns.msg_ctlmax),
160 .mode = 0644,
161 .proc_handler = proc_ipc_dointvec_minmax,
162 .extra1 = &zero,
163 .extra2 = &int_max,
164 },
165 {
166 .procname = "msgmni",
167 .data = &init_ipc_ns.msg_ctlmni,
168 .maxlen = sizeof(init_ipc_ns.msg_ctlmni),
169 .mode = 0644,
170 .proc_handler = proc_ipc_dointvec_minmax,
171 .extra1 = &zero,
172 .extra2 = &ipc_mni,
173 },
174 {
175 .procname = "auto_msgmni",
176 .data = NULL,
177 .maxlen = sizeof(int),
178 .mode = 0644,
179 .proc_handler = proc_ipc_auto_msgmni,
180 .extra1 = &zero,
181 .extra2 = &one,
182 },
183 {
184 .procname = "msgmnb",
185 .data = &init_ipc_ns.msg_ctlmnb,
186 .maxlen = sizeof(init_ipc_ns.msg_ctlmnb),
187 .mode = 0644,
188 .proc_handler = proc_ipc_dointvec_minmax,
189 .extra1 = &zero,
190 .extra2 = &int_max,
191 },
192 {
193 .procname = "sem",
194 .data = &init_ipc_ns.sem_ctls,
195 .maxlen = 4*sizeof(int),
196 .mode = 0644,
197 .proc_handler = proc_ipc_sem_dointvec,
198 },
199 #ifdef CONFIG_CHECKPOINT_RESTORE
200 {
201 .procname = "sem_next_id",
202 .data = &init_ipc_ns.ids[IPC_SEM_IDS].next_id,
203 .maxlen = sizeof(init_ipc_ns.ids[IPC_SEM_IDS].next_id),
204 .mode = 0644,
205 .proc_handler = proc_ipc_dointvec_minmax,
206 .extra1 = &zero,
207 .extra2 = &int_max,
208 },
209 {
210 .procname = "msg_next_id",
211 .data = &init_ipc_ns.ids[IPC_MSG_IDS].next_id,
212 .maxlen = sizeof(init_ipc_ns.ids[IPC_MSG_IDS].next_id),
213 .mode = 0644,
214 .proc_handler = proc_ipc_dointvec_minmax,
215 .extra1 = &zero,
216 .extra2 = &int_max,
217 },
218 {
219 .procname = "shm_next_id",
220 .data = &init_ipc_ns.ids[IPC_SHM_IDS].next_id,
221 .maxlen = sizeof(init_ipc_ns.ids[IPC_SHM_IDS].next_id),
222 .mode = 0644,
223 .proc_handler = proc_ipc_dointvec_minmax,
224 .extra1 = &zero,
225 .extra2 = &int_max,
226 },
227 #endif
228 {}
229 };
230
231 static struct ctl_table ipc_root_table[] = {
232 {
233 .procname = "kernel",
234 .mode = 0555,
235 .child = ipc_kern_table,
236 },
237 {}
238 };
239
240 static int __init ipc_sysctl_init(void)
241 {
242 register_sysctl_table(ipc_root_table);
243 return 0;
244 }
245
246 device_initcall(ipc_sysctl_init);
247
248 static int __init ipc_mni_extend(char *str)
249 {
250 ipc_mni = IPCMNI_EXTEND;
251 ipc_mni_shift = IPCMNI_EXTEND_SHIFT;
252 ipc_min_cycle = IPCMNI_EXTEND_MIN_CYCLE;
253 pr_info("IPCMNI extended to %d.\n", ipc_mni);
254 return 0;
255 }
256 early_param("ipcmni_extend", ipc_mni_extend);