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	Put get/get_uts() into CONFIG_PROC_SYSCTL code block as they are used only when CONFIG_PROC_SYSCTL is enabled. Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
		
			
				
	
	
		
			138 lines
		
	
	
	
		
			3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			138 lines
		
	
	
	
		
			3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 *  Copyright (C) 2007
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 *
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 *  Author: Eric Biederman <ebiederm@xmision.com>
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 *
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 *  This program is free software; you can redistribute it and/or
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 *  modify it under the terms of the GNU General Public License as
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 *  published by the Free Software Foundation, version 2 of the
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 *  License.
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 */
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#include <linux/export.h>
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#include <linux/uts.h>
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#include <linux/utsname.h>
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#include <linux/sysctl.h>
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#include <linux/wait.h>
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#ifdef CONFIG_PROC_SYSCTL
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static void *get_uts(ctl_table *table, int write)
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{
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	char *which = table->data;
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	struct uts_namespace *uts_ns;
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	uts_ns = current->nsproxy->uts_ns;
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	which = (which - (char *)&init_uts_ns) + (char *)uts_ns;
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	if (!write)
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		down_read(&uts_sem);
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	else
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		down_write(&uts_sem);
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	return which;
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}
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static void put_uts(ctl_table *table, int write, void *which)
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{
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	if (!write)
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		up_read(&uts_sem);
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	else
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		up_write(&uts_sem);
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}
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/*
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 *	Special case of dostring for the UTS structure. This has locks
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 *	to observe. Should this be in kernel/sys.c ????
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 */
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static int proc_do_uts_string(ctl_table *table, int write,
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		  void __user *buffer, size_t *lenp, loff_t *ppos)
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{
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	struct ctl_table uts_table;
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	int r;
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	memcpy(&uts_table, table, sizeof(uts_table));
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	uts_table.data = get_uts(table, write);
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	r = proc_dostring(&uts_table,write,buffer,lenp, ppos);
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	put_uts(table, write, uts_table.data);
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	if (write)
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		proc_sys_poll_notify(table->poll);
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	return r;
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}
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#else
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#define proc_do_uts_string NULL
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#endif
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static DEFINE_CTL_TABLE_POLL(hostname_poll);
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static DEFINE_CTL_TABLE_POLL(domainname_poll);
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static struct ctl_table uts_kern_table[] = {
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	{
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		.procname	= "ostype",
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		.data		= init_uts_ns.name.sysname,
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		.maxlen		= sizeof(init_uts_ns.name.sysname),
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		.mode		= 0444,
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		.proc_handler	= proc_do_uts_string,
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	},
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	{
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		.procname	= "osrelease",
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		.data		= init_uts_ns.name.release,
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		.maxlen		= sizeof(init_uts_ns.name.release),
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		.mode		= 0444,
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		.proc_handler	= proc_do_uts_string,
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	},
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	{
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		.procname	= "version",
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		.data		= init_uts_ns.name.version,
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		.maxlen		= sizeof(init_uts_ns.name.version),
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		.mode		= 0444,
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		.proc_handler	= proc_do_uts_string,
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	},
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	{
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		.procname	= "hostname",
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		.data		= init_uts_ns.name.nodename,
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		.maxlen		= sizeof(init_uts_ns.name.nodename),
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		.mode		= 0644,
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		.proc_handler	= proc_do_uts_string,
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		.poll		= &hostname_poll,
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	},
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	{
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		.procname	= "domainname",
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		.data		= init_uts_ns.name.domainname,
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		.maxlen		= sizeof(init_uts_ns.name.domainname),
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		.mode		= 0644,
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		.proc_handler	= proc_do_uts_string,
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		.poll		= &domainname_poll,
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	},
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	{}
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};
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static struct ctl_table uts_root_table[] = {
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	{
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		.procname	= "kernel",
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		.mode		= 0555,
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		.child		= uts_kern_table,
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	},
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	{}
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};
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#ifdef CONFIG_PROC_SYSCTL
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/*
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 * Notify userspace about a change in a certain entry of uts_kern_table,
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 * identified by the parameter proc.
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 */
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void uts_proc_notify(enum uts_proc proc)
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{
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	struct ctl_table *table = &uts_kern_table[proc];
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	proc_sys_poll_notify(table->poll);
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}
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#endif
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static int __init utsname_sysctl_init(void)
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{
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	register_sysctl_table(uts_root_table);
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	return 0;
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}
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__initcall(utsname_sysctl_init);
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