[PATCH 50/59] sysctl: Move utsname sysctls to their own file

Eric W. Biederman
2007-01-16T16:55:09Z

This is just a simple cleanup to keep kernel/sysctl.c
from getting to crowded with special cases, and by
keeping all of the utsname logic to together it makes
the code a little more readable.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
kernel/Makefile | 1 +
kernel/sysctl.c | 115 -------------------------------------
kernel/utsname_sysctl.c | 146 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 147 insertions(+), 115 deletions(-)

diff --git a/kernel/Makefile b/kernel/Makefile
index 14f4d45..d286c44 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -48,6 +48,7 @@ obj-$(CONFIG_SECCOMP) += seccomp.o
obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o
obj-$(CONFIG_RELAY) += relay.o
obj-$(CONFIG_UTS_NS) += utsname.o
+obj-$(CONFIG_SYSCTL) += utsname_sysctl.o
obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 7420761..a8c0a03 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -135,13 +135,6 @@ static int parse_table(int __user *, int, void __user *, size_t __user *,
void __user *, size_t, ctl_table *);
#endif

-static int proc_do_uts_string(ctl_table *table, int write, struct file *filp,
- void __user *buffer, size_t *lenp, loff_t *ppos);
-
-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);
-
#ifdef CONFIG_SYSVIPC
static int sysctl_ipc_data(ctl_table *table, int __user *name, int nlen,
void __user *oldval, size_t __user *oldlenp,
@@ -174,27 +167,6 @@ extern ctl_table inotify_table[];
int sysctl_legacy_va_layout;
#endif

-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_SYSVIPC
static void *get_ipc(ctl_table *table, int write)
@@ -275,51 +247,6 @@ static ctl_table root_table[] = {

static ctl_table 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,
- },
- {
.ctl_name = KERN_PANIC,
.procname = "panic",
.data = &panic_timeout,
@@ -1746,21 +1673,6 @@ int proc_dostring(ctl_table *table, int write, struct file *filp,
buffer, lenp, ppos);
}

-/*
- * 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)
-{
- int r;
- void *which;
- which = get_uts(table, write);
- r = _proc_do_string(which, table->maxlen,write,filp,buffer,lenp, ppos);
- put_uts(table, write, which);
- return r;
-}

static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
int *valp,
@@ -2379,12 +2291,6 @@ int proc_dostring(ctl_table *table, int write, struct file *filp,
return -ENOSYS;
}

-static int proc_do_uts_string(ctl_table *table, int write, struct file *filp,
- void __user *buffer, size_t *lenp, loff_t *ppos)
-{
- return -ENOSYS;
-}
-
#ifdef CONFIG_SYSVIPC
static int proc_do_ipc_string(ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos)
@@ -2602,21 +2508,6 @@ int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
}

-/* 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;
-}

#ifdef CONFIG_SYSVIPC
/* The generic sysctl ipc data routine. */
@@ -2723,12 +2614,6 @@ int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
return -ENOSYS;
}

-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)
-{
- return -ENOSYS;
-}
static int sysctl_ipc_data(ctl_table *table, int __user *name, int nlen,
void __user *oldval, size_t __user *oldlenp,
void __user *newval, size_t newlen)
diff --git a/kernel/utsname_sysctl.c b/kernel/utsname_sysctl.c
new file mode 100644
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);
--
1.4.4.1.g278f