Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/upstream-linus
[linux-btrfs-devel.git] / ipc / ipc_sysctl.c
blob00fba2bab87d8019739e4645f98e21559688dcbe
1 /*
2 * Copyright (C) 2007
4 * Author: Eric Biederman <ebiederm@xmision.com>
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation, version 2 of the
9 * License.
12 #include <linux/module.h>
13 #include <linux/ipc.h>
14 #include <linux/nsproxy.h>
15 #include <linux/sysctl.h>
16 #include <linux/uaccess.h>
17 #include <linux/ipc_namespace.h>
18 #include <linux/msg.h>
19 #include "util.h"
21 static void *get_ipc(ctl_table *table)
23 char *which = table->data;
24 struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
25 which = (which - (char *)&init_ipc_ns) + (char *)ipc_ns;
26 return which;
29 #ifdef CONFIG_PROC_SYSCTL
30 static int proc_ipc_dointvec(ctl_table *table, int write,
31 void __user *buffer, size_t *lenp, loff_t *ppos)
33 struct ctl_table ipc_table;
35 memcpy(&ipc_table, table, sizeof(ipc_table));
36 ipc_table.data = get_ipc(table);
38 return proc_dointvec(&ipc_table, write, buffer, lenp, ppos);
41 static int proc_ipc_dointvec_minmax(ctl_table *table, int write,
42 void __user *buffer, size_t *lenp, loff_t *ppos)
44 struct ctl_table ipc_table;
46 memcpy(&ipc_table, table, sizeof(ipc_table));
47 ipc_table.data = get_ipc(table);
49 return proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
52 static int proc_ipc_dointvec_minmax_orphans(ctl_table *table, int write,
53 void __user *buffer, size_t *lenp, loff_t *ppos)
55 struct ipc_namespace *ns = current->nsproxy->ipc_ns;
56 int err = proc_ipc_dointvec_minmax(table, write, buffer, lenp, ppos);
58 if (err < 0)
59 return err;
60 if (ns->shm_rmid_forced)
61 shm_destroy_orphaned(ns);
62 return err;
65 static int proc_ipc_callback_dointvec(ctl_table *table, int write,
66 void __user *buffer, size_t *lenp, loff_t *ppos)
68 struct ctl_table ipc_table;
69 size_t lenp_bef = *lenp;
70 int rc;
72 memcpy(&ipc_table, table, sizeof(ipc_table));
73 ipc_table.data = get_ipc(table);
75 rc = proc_dointvec(&ipc_table, write, buffer, lenp, ppos);
77 if (write && !rc && lenp_bef == *lenp)
79 * Tunable has successfully been changed by hand. Disable its
80 * automatic adjustment. This simply requires unregistering
81 * the notifiers that trigger recalculation.
83 unregister_ipcns_notifier(current->nsproxy->ipc_ns);
85 return rc;
88 static int proc_ipc_doulongvec_minmax(ctl_table *table, int write,
89 void __user *buffer, size_t *lenp, loff_t *ppos)
91 struct ctl_table ipc_table;
92 memcpy(&ipc_table, table, sizeof(ipc_table));
93 ipc_table.data = get_ipc(table);
95 return proc_doulongvec_minmax(&ipc_table, write, buffer,
96 lenp, ppos);
100 * Routine that is called when the file "auto_msgmni" has successfully been
101 * written.
102 * Two values are allowed:
103 * 0: unregister msgmni's callback routine from the ipc namespace notifier
104 * chain. This means that msgmni won't be recomputed anymore upon memory
105 * add/remove or ipc namespace creation/removal.
106 * 1: register back the callback routine.
108 static void ipc_auto_callback(int val)
110 if (!val)
111 unregister_ipcns_notifier(current->nsproxy->ipc_ns);
112 else {
114 * Re-enable automatic recomputing only if not already
115 * enabled.
117 recompute_msgmni(current->nsproxy->ipc_ns);
118 cond_register_ipcns_notifier(current->nsproxy->ipc_ns);
122 static int proc_ipcauto_dointvec_minmax(ctl_table *table, int write,
123 void __user *buffer, size_t *lenp, loff_t *ppos)
125 struct ctl_table ipc_table;
126 size_t lenp_bef = *lenp;
127 int oldval;
128 int rc;
130 memcpy(&ipc_table, table, sizeof(ipc_table));
131 ipc_table.data = get_ipc(table);
132 oldval = *((int *)(ipc_table.data));
134 rc = proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
136 if (write && !rc && lenp_bef == *lenp) {
137 int newval = *((int *)(ipc_table.data));
139 * The file "auto_msgmni" has correctly been set.
140 * React by (un)registering the corresponding tunable, if the
141 * value has changed.
143 if (newval != oldval)
144 ipc_auto_callback(newval);
147 return rc;
150 #else
151 #define proc_ipc_doulongvec_minmax NULL
152 #define proc_ipc_dointvec NULL
153 #define proc_ipc_dointvec_minmax NULL
154 #define proc_ipc_dointvec_minmax_orphans NULL
155 #define proc_ipc_callback_dointvec NULL
156 #define proc_ipcauto_dointvec_minmax NULL
157 #endif
159 static int zero;
160 static int one = 1;
162 static struct ctl_table ipc_kern_table[] = {
164 .procname = "shmmax",
165 .data = &init_ipc_ns.shm_ctlmax,
166 .maxlen = sizeof (init_ipc_ns.shm_ctlmax),
167 .mode = 0644,
168 .proc_handler = proc_ipc_doulongvec_minmax,
171 .procname = "shmall",
172 .data = &init_ipc_ns.shm_ctlall,
173 .maxlen = sizeof (init_ipc_ns.shm_ctlall),
174 .mode = 0644,
175 .proc_handler = proc_ipc_doulongvec_minmax,
178 .procname = "shmmni",
179 .data = &init_ipc_ns.shm_ctlmni,
180 .maxlen = sizeof (init_ipc_ns.shm_ctlmni),
181 .mode = 0644,
182 .proc_handler = proc_ipc_dointvec,
185 .procname = "shm_rmid_forced",
186 .data = &init_ipc_ns.shm_rmid_forced,
187 .maxlen = sizeof(init_ipc_ns.shm_rmid_forced),
188 .mode = 0644,
189 .proc_handler = proc_ipc_dointvec_minmax_orphans,
190 .extra1 = &zero,
191 .extra2 = &one,
194 .procname = "msgmax",
195 .data = &init_ipc_ns.msg_ctlmax,
196 .maxlen = sizeof (init_ipc_ns.msg_ctlmax),
197 .mode = 0644,
198 .proc_handler = proc_ipc_dointvec,
201 .procname = "msgmni",
202 .data = &init_ipc_ns.msg_ctlmni,
203 .maxlen = sizeof (init_ipc_ns.msg_ctlmni),
204 .mode = 0644,
205 .proc_handler = proc_ipc_callback_dointvec,
208 .procname = "msgmnb",
209 .data = &init_ipc_ns.msg_ctlmnb,
210 .maxlen = sizeof (init_ipc_ns.msg_ctlmnb),
211 .mode = 0644,
212 .proc_handler = proc_ipc_dointvec,
215 .procname = "sem",
216 .data = &init_ipc_ns.sem_ctls,
217 .maxlen = 4*sizeof (int),
218 .mode = 0644,
219 .proc_handler = proc_ipc_dointvec,
222 .procname = "auto_msgmni",
223 .data = &init_ipc_ns.auto_msgmni,
224 .maxlen = sizeof(int),
225 .mode = 0644,
226 .proc_handler = proc_ipcauto_dointvec_minmax,
227 .extra1 = &zero,
228 .extra2 = &one,
233 static struct ctl_table ipc_root_table[] = {
235 .procname = "kernel",
236 .mode = 0555,
237 .child = ipc_kern_table,
242 static int __init ipc_sysctl_init(void)
244 register_sysctl_table(ipc_root_table);
245 return 0;
248 __initcall(ipc_sysctl_init);