uml: host_info tidying

Move the host_info string from util.c to um_arch.c, where it is
actually initialized and used.  Also document its lack of locking.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/um/include/os.h

@@ -273,7 +273,7 @@ extern void stack_protections(unsigned long address);
 extern void task_protections(unsigned long address);
 extern int raw(int fd);
 extern void setup_machinename(char *machine_out);
-extern void setup_hostinfo(void);
+extern void setup_hostinfo(char *buf, int len);
 extern int setjmp_wrapper(void (*proc)(void *, void *), ...);
 
 /* time.c */

arch/um/include/user_util.h

@@ -36,8 +36,6 @@ extern unsigned long end_vm;
 extern unsigned long start_vm;
 extern unsigned long long highmem;
 
-extern char host_info[];
-
 extern unsigned long _stext, _etext, _sdata, _edata, __bss_start, _end;
 extern unsigned long _unprotected_end;
 extern unsigned long brk_start;

arch/um/kernel/um_arch.c

@@ -17,6 +17,7 @@
 #include "linux/seq_file.h"
 #include "linux/delay.h"
 #include "linux/module.h"
+#include "linux/utsname.h"
 #include "asm/page.h"
 #include "asm/pgtable.h"
 #include "asm/ptrace.h"
@@ -67,6 +68,9 @@ unsigned long thread_saved_pc(struct task_struct *task)
 					      task));
 }
 
+/* Changed in setup_arch, which is called in early boot */
+static char host_info[(__NEW_UTS_LEN + 1) * 5];
+
 static int show_cpuinfo(struct seq_file *m, void *v)
 {
 	int index = 0;
@@ -482,7 +486,7 @@ void __init setup_arch(char **cmdline_p)
 	paging_init();
 	strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
 	*cmdline_p = command_line;
-	setup_hostinfo();
+	setup_hostinfo(host_info, sizeof host_info);
 }
 
 void __init check_bugs(void)

arch/um/os-Linux/util.c

@@ -96,15 +96,13 @@ void setup_machinename(char *machine_out)
 	strcpy(machine_out, host.machine);
 }
 
-char host_info[(_UTSNAME_LENGTH + 1) * 4 + _UTSNAME_NODENAME_LENGTH + 1];
-
-void setup_hostinfo(void)
+void setup_hostinfo(char *buf, int len)
 {
 	struct utsname host;
 
 	uname(&host);
-	sprintf(host_info, "%s %s %s %s %s", host.sysname, host.nodename,
-		host.release, host.version, host.machine);
+	snprintf(buf, len, "%s %s %s %s %s", host.sysname, host.nodename,
+		 host.release, host.version, host.machine);
 }
 
 int setjmp_wrapper(void (*proc)(void *, void *), ...)