[PATCH] nommu systems can't support /proc/<pid>/maps

So stub it out, similar to /proc/<pid>/wchan for !CONFIG_KALLSYMS

fs/proc/array.c

@@ -513,8 +513,9 @@ static int proc_pid_maps_get_line (char *buf, struct vm_area_struct *map)
 	return len;
 }
 
-ssize_t proc_pid_read_maps (struct task_struct *task, struct file * file, char * buf,
-			  size_t count, loff_t *ppos)
+#ifdef CONFIG_MMU
+ssize_t proc_pid_read_maps(struct task_struct *task, struct file *file,
+			   char *buf, size_t count, loff_t *ppos)
 {
 	struct mm_struct *mm;
 	struct vm_area_struct * map;
@@ -597,3 +598,4 @@ ssize_t proc_pid_read_maps (struct task_struct *task, struct file * file, char *
 out:
 	return retval;
 }
+#endif /* CONFIG_MMU */

fs/proc/base.c

@@ -75,7 +75,9 @@ static struct pid_entry base_stuff[] = {
   E(PROC_PID_CMDLINE,	"cmdline",	S_IFREG|S_IRUGO),
   E(PROC_PID_STAT,	"stat",		S_IFREG|S_IRUGO),
   E(PROC_PID_STATM,	"statm",	S_IFREG|S_IRUGO),
+#ifdef CONFIG_MMU
   E(PROC_PID_MAPS,	"maps",		S_IFREG|S_IRUGO),
+#endif
   E(PROC_PID_MEM,	"mem",		S_IFREG|S_IRUSR|S_IWUSR),
   E(PROC_PID_CWD,	"cwd",		S_IFLNK|S_IRWXUGO),
   E(PROC_PID_ROOT,	"root",		S_IFLNK|S_IRWXUGO),
@@ -98,7 +100,6 @@ static inline int proc_type(struct inode *inode)
 	return PROC_I(inode)->type;
 }
 
-ssize_t proc_pid_read_maps(struct task_struct*,struct file*,char*,size_t,loff_t*);
 int proc_pid_stat(struct task_struct*,char*);
 int proc_pid_status(struct task_struct*,char*);
 int proc_pid_statm(struct task_struct*,char*);
@@ -321,6 +322,9 @@ static int proc_permission(struct inode *inode, int mask)
 	return proc_check_root(inode);
 }
 
+#ifdef CONFIG_MMU
+extern ssize_t proc_pid_read_maps(struct task_struct *, struct file *,
+				  char *, size_t, loff_t *);
 static ssize_t pid_maps_read(struct file * file, char * buf,
 			      size_t count, loff_t *ppos)
 {
@@ -335,6 +339,7 @@ static ssize_t pid_maps_read(struct file * file, char * buf,
 static struct file_operations proc_maps_operations = {
 	.read		= pid_maps_read,
 };
+#endif /* CONFIG_MMU */
 
 extern struct seq_operations mounts_op;
 static int mounts_open(struct inode *inode, struct file *file)
@@ -1023,10 +1028,11 @@ static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
 			inode->i_fop = &proc_info_file_operations;
 			ei->op.proc_read = proc_pid_statm;
 			break;
+#ifdef CONFIG_MMU
 		case PROC_PID_MAPS:
 			inode->i_fop = &proc_maps_operations;
 			break;
-
+#endif
 		case PROC_PID_MEM:
 			inode->i_op = &proc_mem_inode_operations;
 			inode->i_fop = &proc_mem_operations;