[PATCH] sysctl: move utsname sysctls to their own file

[firefly-linux-kernel-4.4.55.git] / kernel / utsname_sysctl.c

diff --git a/kernel/utsname_sysctl.c b/kernel/utsname_sysctl.c
new file mode 100644 (file)
index 0000000..324aa13
--- /dev/null
+++ b/kernel/utsname_sysctl.c
@@ -0,0 +1,146 @@
+/*
+ *  Copyright (C) 2007
+ *
+ *  Author: Eric Biederman <ebiederm@xmision.com>
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License as
+ *  published by the Free Software Foundation, version 2 of the
+ *  License.
+ */
+
+#include <linux/module.h>
+#include <linux/uts.h>
+#include <linux/utsname.h>
+#include <linux/version.h>
+#include <linux/sysctl.h>
+
+static void *get_uts(ctl_table *table, int write)
+{
+       char *which = table->data;
+#ifdef CONFIG_UTS_NS
+       struct uts_namespace *uts_ns = current->nsproxy->uts_ns;
+       which = (which - (char *)&init_uts_ns) + (char *)uts_ns;
+#endif
+       if (!write)
+               down_read(&uts_sem);
+       else
+               down_write(&uts_sem);
+       return which;
+}
+
+static void put_uts(ctl_table *table, int write, void *which)
+{
+       if (!write)
+               up_read(&uts_sem);
+       else
+               up_write(&uts_sem);
+}
+
+#ifdef CONFIG_PROC_FS
+/*
+ *     Special case of dostring for the UTS structure. This has locks
+ *     to observe. Should this be in kernel/sys.c ????
+ */
+static int proc_do_uts_string(ctl_table *table, int write, struct file *filp,
+                 void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+       struct ctl_table uts_table;
+       int r;
+       memcpy(&uts_table, table, sizeof(uts_table));
+       uts_table.data = get_uts(table, write);
+       r = proc_dostring(&uts_table,write,filp,buffer,lenp, ppos);
+       put_uts(table, write, uts_table.data);
+       return r;
+}
+#else
+#define proc_do_uts_string NULL
+#endif
+
+
+#ifdef CONFIG_SYSCTL_SYSCALL
+/* The generic string strategy routine: */
+static int sysctl_uts_string(ctl_table *table, int __user *name, int nlen,
+                 void __user *oldval, size_t __user *oldlenp,
+                 void __user *newval, size_t newlen)
+{
+       struct ctl_table uts_table;
+       int r, write;
+       write = newval && newlen;
+       memcpy(&uts_table, table, sizeof(uts_table));
+       uts_table.data = get_uts(table, write);
+       r = sysctl_string(&uts_table, name, nlen,
+               oldval, oldlenp, newval, newlen);
+       put_uts(table, write, uts_table.data);
+       return r;
+}
+#else
+#define sysctl_uts_string NULL
+#endif
+
+static struct ctl_table uts_kern_table[] = {
+       {
+               .ctl_name       = KERN_OSTYPE,
+               .procname       = "ostype",
+               .data           = init_uts_ns.name.sysname,
+               .maxlen         = sizeof(init_uts_ns.name.sysname),
+               .mode           = 0444,
+               .proc_handler   = proc_do_uts_string,
+               .strategy       = sysctl_uts_string,
+       },
+       {
+               .ctl_name       = KERN_OSRELEASE,
+               .procname       = "osrelease",
+               .data           = init_uts_ns.name.release,
+               .maxlen         = sizeof(init_uts_ns.name.release),
+               .mode           = 0444,
+               .proc_handler   = proc_do_uts_string,
+               .strategy       = sysctl_uts_string,
+       },
+       {
+               .ctl_name       = KERN_VERSION,
+               .procname       = "version",
+               .data           = init_uts_ns.name.version,
+               .maxlen         = sizeof(init_uts_ns.name.version),
+               .mode           = 0444,
+               .proc_handler   = proc_do_uts_string,
+               .strategy       = sysctl_uts_string,
+       },
+       {
+               .ctl_name       = KERN_NODENAME,
+               .procname       = "hostname",
+               .data           = init_uts_ns.name.nodename,
+               .maxlen         = sizeof(init_uts_ns.name.nodename),
+               .mode           = 0644,
+               .proc_handler   = proc_do_uts_string,
+               .strategy       = sysctl_uts_string,
+       },
+       {
+               .ctl_name       = KERN_DOMAINNAME,
+               .procname       = "domainname",
+               .data           = init_uts_ns.name.domainname,
+               .maxlen         = sizeof(init_uts_ns.name.domainname),
+               .mode           = 0644,
+               .proc_handler   = proc_do_uts_string,
+               .strategy       = sysctl_uts_string,
+       },
+       {}
+};
+
+static struct ctl_table uts_root_table[] = {
+       {
+               .ctl_name       = CTL_KERN,
+               .procname       = "kernel",
+               .mode           = 0555,
+               .child          = uts_kern_table,
+       },
+       {}
+};
+
+static int __init utsname_sysctl_init(void)
+{
+       register_sysctl_table(uts_root_table, 0);
+       return 0;
+}
+
+__initcall(utsname_sysctl_init);