Mark arguments to certain syscalls as being const

Mark arguments to certain system calls as being const where they should be but
aren't.  The list includes:

 (*) The filename arguments of various stat syscalls, execve(), various utimes
     syscalls and some mount syscalls.

 (*) The filename arguments of some syscall helpers relating to the above.

 (*) The buffer argument of various write syscalls.

Signed-off-by: David Howells <[email protected]>
Acked-by: David S. Miller <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

arch/um/kernel/exec.c

@@ -44,7 +44,7 @@ void start_thread(struct pt_regs *regs, unsigned long eip, unsigned long esp)
 	PT_REGS_SP(regs) = esp;
 }
 
-static long execve1(char *file, char __user * __user *argv,
+static long execve1(const char *file, char __user * __user *argv,
 		    char __user *__user *env)
 {
 	long error;
@@ -61,7 +61,7 @@ static long execve1(char *file, char __user * __user *argv,
 	return error;
 }
 
-long um_execve(char *file, char __user *__user *argv, char __user *__user *env)
+long um_execve(const char *file, char __user *__user *argv, char __user *__user *env)
 {
 	long err;
 
@@ -71,7 +71,7 @@ long um_execve(char *file, char __user *__user *argv, char __user *__user *env)
 	return err;
 }
 
-long sys_execve(char __user *file, char __user *__user *argv,
+long sys_execve(const char __user *file, char __user *__user *argv,
 		char __user *__user *env)
 {
 	long error;

arch/um/kernel/internal.h

@@ -1 +1 @@
-extern long um_execve(char *file, char __user *__user *argv, char __user *__user *env);
+extern long um_execve(const char *file, char __user *__user *argv, char __user *__user *env);

arch/um/kernel/syscall.c

@@ -58,7 +58,7 @@ int kernel_execve(const char *filename, char *const argv[], char *const envp[])
 
 	fs = get_fs();
 	set_fs(KERNEL_DS);
-	ret = um_execve((char *)filename, (char __user *__user *)argv,
+	ret = um_execve(filename, (char __user *__user *)argv,
 			(char __user *__user *) envp);
 	set_fs(fs);