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-rw-r--r--ipc/ipc_sysctl.c43
1 files changed, 41 insertions, 2 deletions
diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c
index 7f4235bed51..d12ff5cd2a0 100644
--- a/ipc/ipc_sysctl.c
+++ b/ipc/ipc_sysctl.c
@@ -35,6 +35,24 @@ static int proc_ipc_dointvec(ctl_table *table, int write, struct file *filp,
return proc_dointvec(&ipc_table, write, filp, buffer, lenp, ppos);
}
+static int proc_ipc_callback_dointvec(ctl_table *table, int write,
+ struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ size_t lenp_bef = *lenp;
+ int rc;
+
+ rc = proc_ipc_dointvec(table, write, filp, buffer, lenp, ppos);
+
+ if (write && !rc && lenp_bef == *lenp)
+ /*
+ * Tunable has successfully been changed from userland:
+ * disable its automatic recomputing.
+ */
+ unregister_ipcns_notifier(current->nsproxy->ipc_ns);
+
+ return rc;
+}
+
static int proc_ipc_doulongvec_minmax(ctl_table *table, int write,
struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos)
{
@@ -49,6 +67,7 @@ static int proc_ipc_doulongvec_minmax(ctl_table *table, int write,
#else
#define proc_ipc_doulongvec_minmax NULL
#define proc_ipc_dointvec NULL
+#define proc_ipc_callback_dointvec NULL
#endif
#ifdef CONFIG_SYSCTL_SYSCALL
@@ -90,8 +109,28 @@ static int sysctl_ipc_data(ctl_table *table, int __user *name, int nlen,
}
return 1;
}
+
+static int sysctl_ipc_registered_data(ctl_table *table, int __user *name,
+ int nlen, void __user *oldval, size_t __user *oldlenp,
+ void __user *newval, size_t newlen)
+{
+ int rc;
+
+ rc = sysctl_ipc_data(table, name, nlen, oldval, oldlenp, newval,
+ newlen);
+
+ if (newval && newlen && rc > 0)
+ /*
+ * Tunable has successfully been changed from userland:
+ * disable its automatic recomputing.
+ */
+ unregister_ipcns_notifier(current->nsproxy->ipc_ns);
+
+ return rc;
+}
#else
#define sysctl_ipc_data NULL
+#define sysctl_ipc_registered_data NULL
#endif
static struct ctl_table ipc_kern_table[] = {
@@ -137,8 +176,8 @@ static struct ctl_table ipc_kern_table[] = {
.data = &init_ipc_ns.msg_ctlmni,
.maxlen = sizeof (init_ipc_ns.msg_ctlmni),
.mode = 0644,
- .proc_handler = proc_ipc_dointvec,
- .strategy = sysctl_ipc_data,
+ .proc_handler = proc_ipc_callback_dointvec,
+ .strategy = sysctl_ipc_registered_data,
},
{
.ctl_name = KERN_MSGMNB,