projects/linux·blob v5.13 · refs

253 lines · 6.1 KiB

1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2007
4 *
5 * Author: Eric Biederman <[email protected]>
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
17static 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
26static 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
37static 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
48static 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
61static 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
72static 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
87static 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
116int ipc_mni = IPCMNI;
117int ipc_mni_shift = IPCMNI_SHIFT;
118int ipc_min_cycle = RADIX_TREE_MAP_SIZE;
119
120static 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
228static struct ctl_table ipc_root_table[] = {
229 {
230 .procname = "kernel",
231 .mode = 0555,
232 .child = ipc_kern_table,
233 },
234 {}
235};
236
237static int __init ipc_sysctl_init(void)
238{
239 register_sysctl_table(ipc_root_table);
240 return 0;
241}
242
243device_initcall(ipc_sysctl_init);
244
245static 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}
253early_param("ipcmni_extend", ipc_mni_extend);