2007-10-12 Martin Hunt <hunt@redhat.com>

	* transport.c (_stp_ask_for_symbols): Don't ask for
	transport_info yet.  Need to wait until symbols are
	received.
	(_stp_work_queue): Rename _stp_ready_q to _stp_ctl_ready_q.
	* procfs.c: Create a ".symbols" channel and use it for
	STP_MODULE and STP_SYMBOLS. Rename "cmd" channel to ".cmd".
	* control.c: Ditto.

1 files changed, 250 insertions, 49 deletions

diff --git a/runtime/transport/procfs.c b/runtime/transport/procfs.c
index be672825..88740847 100644
--- a/runtime/transport/procfs.c
+++ b/runtime/transport/procfs.c
@@ -12,10 +12,12 @@
 #define STP_DEFAULT_BUFFERS 256
 static int _stp_current_buffers = STP_DEFAULT_BUFFERS;
 
-static struct list_head _stp_ready_q;
+static struct list_head _stp_ctl_ready_q;
+static struct list_head _stp_sym_ready_q;
 static struct list_head _stp_pool_q;
 spinlock_t _stp_pool_lock = SPIN_LOCK_UNLOCKED;
-spinlock_t _stp_ready_lock = SPIN_LOCK_UNLOCKED;
+spinlock_t _stp_ctl_ready_lock = SPIN_LOCK_UNLOCKED;
+spinlock_t _stp_sym_ready_lock = SPIN_LOCK_UNLOCKED;
 
 #ifdef STP_BULKMODE
 extern int _stp_relay_flushing;
@@ -63,11 +65,10 @@ static struct file_operations _stp_proc_fops = {
 };
 #endif /* STP_BULKMODE */
 
-static ssize_t _stp_ctl_write_cmd (struct file *file, const char __user *buf,
+static ssize_t _stp_sym_write_cmd (struct file *file, const char __user *buf,
 				    size_t count, loff_t *ppos)
 {
 	int type;
-	static int started = 0, initialized = 0;
 
 	if (count < sizeof(int))
 		return 0;
@@ -75,7 +76,7 @@ static ssize_t _stp_ctl_write_cmd (struct file *file, const char __user *buf,
 	if (get_user(type, (int __user *)buf))
 		return -EFAULT;
 
-	//printk ("_stp_proc_write_cmd. count:%d type:%d\n", count, type);
+	kbug ("count:%d type:%d\n", (int)count, type);
 
 	if (type == STP_SYMBOLS) {
 		count -= sizeof(long);
@@ -86,8 +87,45 @@ static ssize_t _stp_ctl_write_cmd (struct file *file, const char __user *buf,
 	}
 
 	switch (type) {
+	case STP_SYMBOLS:
+		
+		if (count)
+			count = _stp_do_symbols(buf, count);
+		break;
+	case STP_MODULE:
+		if (count)
+			count = _stp_do_module(buf, count);
+		else {
+			/* count == 0 indicates end of initial modules list */
+			_stp_ctl_send(STP_TRANSPORT, NULL, 0);			
+		}
+		break;
+	default:
+		errk ("invalid symbol command type %d\n", type);
+		return -EINVAL;
+	}
+
+	return count;
+}
+static ssize_t _stp_ctl_write_cmd (struct file *file, const char __user *buf,
+				    size_t count, loff_t *ppos)
+{
+	int type;
+	static int started = 0;
+
+	if (count < sizeof(int))
+		return 0;
+
+	if (get_user(type, (int __user *)buf))
+		return -EFAULT;
+
+	// kbug ("count:%d type:%d\n", count, type);
+
+	count -= sizeof(int);
+	buf += sizeof(int);
+
+	switch (type) {
 	case STP_START:
-	{
 		if (started == 0) {
 			struct _stp_msg_start st;
 			if (count < sizeof(st))
@@ -98,20 +136,6 @@ static ssize_t _stp_ctl_write_cmd (struct file *file, const char __user *buf,
 			started = 1;
 		}
 		break;
-	}
-
-	case STP_SYMBOLS:
-		if (initialized == 0 && count && current->pid == _stp_init_pid)
-			count = _stp_do_symbols(buf, count);
-		break;
-	case STP_MODULE:
-		if (initialized == 0 && current->pid == _stp_init_pid) {
-			if (count)
-				count = _stp_do_module(buf, count);
-			else
-				initialized = 1;
-		}
-		break;
 	case STP_EXIT:
 		_stp_exit_flag = 1;
 		break;
@@ -131,6 +155,52 @@ struct _stp_buffer {
 };
 
 static DECLARE_WAIT_QUEUE_HEAD(_stp_ctl_wq);
+static DECLARE_WAIT_QUEUE_HEAD(_stp_sym_wq);
+
+#ifdef DEBUG
+static void _stp_ctl_write_dbug (int type, void *data, int len)
+{
+	char buf[64];
+	switch (type) {
+	case STP_REALTIME_DATA:
+		break;
+	case STP_START:
+		printk("_stp_ctl_write: sending STP_START\n");
+		break;
+	case STP_EXIT:
+		printk("_stp_ctl_write: sending STP_EXIT\n");
+		break;
+	case STP_OOB_DATA:
+		snprintf(buf, sizeof(buf), "%s", (char *)data); 
+		printk("_stp_ctl_write: sending %d bytes of STP_OOB_DATA: %s\n", len, buf);
+		break;
+	case STP_SYSTEM:
+		snprintf(buf, sizeof(buf), "%s", (char *)data); 
+		printk("_stp_ctl_write: sending STP_SYSTEM: %s\n", buf);
+		break;
+	case STP_TRANSPORT:
+		printk("_stp_ctl_write: sending STP_TRANSPORT\n");
+		break;
+	default:
+		printk("_stp_ctl_write: ERROR: unknown message type: %d\n", type);
+		break;
+	}
+}
+static void _stp_sym_write_dbug (int type, void *data, int len)
+{
+	switch (type) {
+	case STP_SYMBOLS:
+		printk("_stp_sym_write: sending STP_SYMBOLS\n");
+		break;
+	case STP_MODULE:
+		printk("_stp_sym_write: sending STP_MODULE\n");
+		break;
+	default:
+		printk("_stp_sym_write: ERROR: unknown message type: %d\n", type);
+		break;
+	}
+}
+#endif
 
 static int _stp_ctl_write (int type, void *data, int len)
 {
@@ -138,27 +208,31 @@ static int _stp_ctl_write (int type, void *data, int len)
 	unsigned long flags;
 	unsigned numtrylock;
 
+#ifdef DEBUG
+	_stp_ctl_write_dbug(type, data, len);
+#endif
+
 #define WRITE_AGG
 #ifdef WRITE_AGG
 
 	numtrylock = 0;
-	while (!spin_trylock_irqsave (&_stp_ready_lock, flags) && (++numtrylock < MAXTRYLOCK)) 
+	while (!spin_trylock_irqsave (&_stp_ctl_ready_lock, flags) && (++numtrylock < MAXTRYLOCK)) 
 		ndelay (TRYLOCKDELAY);
 	if (unlikely (numtrylock >= MAXTRYLOCK))
 		return 0;
 
-	if (!list_empty(&_stp_ready_q)) {
-		bptr = (struct _stp_buffer *)_stp_ready_q.prev;
+	if (!list_empty(&_stp_ctl_ready_q)) {
+		bptr = (struct _stp_buffer *)_stp_ctl_ready_q.prev;
 		if (bptr->len + len <= STP_BUFFER_SIZE 
 		    && type == STP_REALTIME_DATA 
 		    && bptr->type == STP_REALTIME_DATA) {
 			memcpy (bptr->buf + bptr->len, data, len);
 			bptr->len += len;
-			spin_unlock_irqrestore(&_stp_ready_lock, flags);
+			spin_unlock_irqrestore(&_stp_ctl_ready_lock, flags);
 			return len;
 		}
 	}
-	spin_unlock_irqrestore(&_stp_ready_lock, flags);
+	spin_unlock_irqrestore(&_stp_ctl_ready_lock, flags);
 #endif
 
 	/* make sure we won't overflow the buffer */
@@ -171,8 +245,9 @@ static int _stp_ctl_write (int type, void *data, int len)
 	if (unlikely (numtrylock >= MAXTRYLOCK))
 		return 0;
 
-	if (list_empty(&_stp_pool_q)) {
+	if (unlikely(list_empty(&_stp_pool_q))) {
 		spin_unlock_irqrestore(&_stp_pool_lock, flags);
+		dbug("_stp_pool_q empty\n");
 		return -1;
 	}
 
@@ -187,12 +262,54 @@ static int _stp_ctl_write (int type, void *data, int len)
 	
 	/* put it on the pool of ready buffers */
 	numtrylock = 0;
-	while (!spin_trylock_irqsave (&_stp_ready_lock, flags) && (++numtrylock < MAXTRYLOCK)) 
+	while (!spin_trylock_irqsave (&_stp_ctl_ready_lock, flags) && (++numtrylock < MAXTRYLOCK)) 
 		ndelay (TRYLOCKDELAY);
+
 	if (unlikely (numtrylock >= MAXTRYLOCK))
 		return 0;
-	list_add_tail(&bptr->list, &_stp_ready_q);
-	spin_unlock_irqrestore(&_stp_ready_lock, flags);
+
+	list_add_tail(&bptr->list, &_stp_ctl_ready_q);
+	spin_unlock_irqrestore(&_stp_ctl_ready_lock, flags);
+
+	return len;
+}
+
+static int _stp_sym_write (int type, void *data, unsigned len)
+{
+	struct _stp_buffer *bptr;
+	unsigned long flags;
+
+#ifdef DEBUG
+	_stp_sym_write_dbug(type, data, len);
+#endif
+
+	/* make sure we won't overflow the buffer */
+	if (unlikely(len > STP_BUFFER_SIZE))
+		return 0;
+
+	spin_lock_irqsave (&_stp_pool_lock, flags);
+	if (unlikely(list_empty(&_stp_pool_q))) {
+		spin_unlock_irqrestore(&_stp_pool_lock, flags); 
+		dbug("_stp_pool_q empty\n");
+		return -1;
+	}
+
+	/* get the next buffer from the pool */
+	bptr = (struct _stp_buffer *)_stp_pool_q.next;
+	list_del_init(&bptr->list);
+	spin_unlock_irqrestore(&_stp_pool_lock, flags);
+
+	bptr->type = type;
+	memcpy(bptr->buf, data, len);
+	bptr->len = len;
+
+	/* put it on the pool of ready buffers */
+	spin_lock_irqsave (&_stp_sym_ready_lock, flags);
+	list_add_tail(&bptr->list, &_stp_sym_ready_q);
+	spin_unlock_irqrestore(&_stp_sym_ready_lock, flags);
+
+	/* OK, it's queued. Now signal any waiters. */
+	wake_up_interruptible(&_stp_sym_wq);
 
 	return len;
 }
@@ -201,45 +318,89 @@ static int _stp_ctl_write (int type, void *data, int len)
 static int _stp_ctl_send (int type, void *data, int len)
 {
 	int err, trylimit = 50;
-	kbug("ctl_send: type=%d len=%d\n", type, len);
-	while ((err = _stp_ctl_write(type, data, len)) < 0 && trylimit--)
-		msleep (5);
-	kbug("returning %d\n", err);
+	if (unlikely(type == STP_SYMBOLS || type == STP_MODULE)) {
+		while ((err = _stp_sym_write(type, data, len)) < 0 && trylimit--)
+			msleep (5);
+	} else {
+		while ((err = _stp_ctl_write(type, data, len)) < 0 && trylimit--)
+			msleep (5);
+	}
 	return err;
 }
 
 static ssize_t
-_stp_ctl_read_cmd (struct file *file, char __user *buf, size_t count, loff_t *ppos)
+_stp_sym_read_cmd (struct file *file, char __user *buf, size_t count, loff_t *ppos)
 {
 	struct _stp_buffer *bptr;
 	int len;
 	unsigned long flags;
 
-	/* FIXME FIXME FIXME. assuming count is large enough to hold buffer!! */
+	/* wait for nonempty ready queue */
+	spin_lock_irqsave(&_stp_sym_ready_lock, flags);
+	while (list_empty(&_stp_sym_ready_q)) {
+		spin_unlock_irqrestore(&_stp_sym_ready_lock, flags);
+		if (file->f_flags & O_NONBLOCK)
+			return -EAGAIN;
+		if (wait_event_interruptible(_stp_sym_wq, !list_empty(&_stp_sym_ready_q)))
+			return -ERESTARTSYS;
+		spin_lock_irqsave(&_stp_sym_ready_lock, flags);
+	}
+  
+	/* get the next buffer off the ready list */
+	bptr = (struct _stp_buffer *)_stp_sym_ready_q.next;
+	list_del_init(&bptr->list);
+	spin_unlock_irqrestore(&_stp_sym_ready_lock, flags);
+
+	/* write it out */
+	len = bptr->len + 4;
+	if (len > count || copy_to_user(buf, &bptr->type, len)) {
+		/* now what?  We took it off the queue then failed to send it */
+		/* we can't put it back on the queue because it will likely be out-of-order */
+		/* fortunately this should never happen */
+		/* FIXME need to mark this as a transport failure */
+		errk("Supplied buffer too small. count:%d len:%d\n", (int)count, len);
+		return -EFAULT;
+	}
+
+	/* put it on the pool of free buffers */
+	spin_lock_irqsave(&_stp_pool_lock, flags);
+	list_add_tail(&bptr->list, &_stp_pool_q);
+	spin_unlock_irqrestore(&_stp_pool_lock, flags);
+
+	return len;
+}
+
+static ssize_t
+_stp_ctl_read_cmd (struct file *file, char __user *buf, size_t count, loff_t *ppos)
+{
+	struct _stp_buffer *bptr;
+	int len;
+	unsigned long flags;
 
 	/* wait for nonempty ready queue */
-	spin_lock_irqsave(&_stp_ready_lock, flags);
-	while (list_empty(&_stp_ready_q)) {
-		spin_unlock_irqrestore(&_stp_ready_lock, flags);
+	spin_lock_irqsave(&_stp_ctl_ready_lock, flags);
+	while (list_empty(&_stp_ctl_ready_q)) {
+		spin_unlock_irqrestore(&_stp_ctl_ready_lock, flags);
 		if (file->f_flags & O_NONBLOCK)
 			return -EAGAIN;
-		if (wait_event_interruptible(_stp_ctl_wq, !list_empty(&_stp_ready_q)))
+		if (wait_event_interruptible(_stp_ctl_wq, !list_empty(&_stp_ctl_ready_q)))
 			return -ERESTARTSYS;
-		spin_lock_irqsave(&_stp_ready_lock, flags);
+		spin_lock_irqsave(&_stp_ctl_ready_lock, flags);
 	}
   
 	/* get the next buffer off the ready list */
-	bptr = (struct _stp_buffer *)_stp_ready_q.next;
+	bptr = (struct _stp_buffer *)_stp_ctl_ready_q.next;
 	list_del_init(&bptr->list);
-	spin_unlock_irqrestore(&_stp_ready_lock, flags);
+	spin_unlock_irqrestore(&_stp_ctl_ready_lock, flags);
 
 	/* write it out */
 	len = bptr->len + 4;
-	if (copy_to_user(buf, &bptr->type, len)) {
+	if (len > count || copy_to_user(buf, &bptr->type, len)) {
 		/* now what?  We took it off the queue then failed to send it */
 		/* we can't put it back on the queue because it will likely be out-of-order */
 		/* fortunately this should never happen */
 		/* FIXME need to mark this as a transport failure */
+		errk("Supplied buffer too small. count:%d len:%d\n", (int)count, len);
 		return -EFAULT;
 	}
 
@@ -251,9 +412,28 @@ _stp_ctl_read_cmd (struct file *file, char __user *buf, size_t count, loff_t *pp
 	return len;
 }
 
+static int _stp_sym_opens = 0;
+static int _stp_sym_open_cmd (struct inode *inode, struct file *file)
+{
+	/* only allow one reader */
+	if (_stp_sym_opens)
+		return -1;
+
+	_stp_sym_opens++;
+	return 0;
+}
+
+static int _stp_sym_close_cmd (struct inode *inode, struct file *file)
+{
+	if (_stp_sym_opens)
+		_stp_sym_opens--;
+	return 0;
+}
+
 static int _stp_ctl_opens = 0;
 static int _stp_ctl_open_cmd (struct inode *inode, struct file *file)
 {
+	/* only allow one reader */
 	if (_stp_ctl_opens)
 		return -1;
 
@@ -277,6 +457,13 @@ static struct file_operations _stp_proc_fops_cmd = {
 	.open = _stp_ctl_open_cmd,
 	.release = _stp_ctl_close_cmd,
 };
+static struct file_operations _stp_sym_fops_cmd = {
+	.owner = THIS_MODULE,
+	.read = _stp_sym_read_cmd,
+	.write = _stp_sym_write_cmd,
+	.open = _stp_sym_open_cmd,
+	.release = _stp_sym_close_cmd,
+};
 
 /* copy since proc_match is not MODULE_EXPORT'd */
 static int my_proc_match(int len, const char *name, struct proc_dir_entry *de)
@@ -351,7 +538,8 @@ static int _stp_register_ctl_channel (void)
 	struct proc_dir_entry *de, *bs = NULL;
 	struct list_head *p, *tmp;
 
-	INIT_LIST_HEAD(&_stp_ready_q);
+	INIT_LIST_HEAD(&_stp_ctl_ready_q);
+	INIT_LIST_HEAD(&_stp_sym_ready_q);
 	INIT_LIST_HEAD(&_stp_pool_q);
 
 	/* allocate buffers */
@@ -387,15 +575,23 @@ static int _stp_register_ctl_channel (void)
 	bs = create_proc_read_entry("bufsize", 0, _stp_proc_root, _stp_ctl_read_bufsize, NULL);
 #endif /* STP_BULKMODE */
 
-	/* finally create /proc/systemtap/module_name/cmd  */
-	de = create_proc_entry ("cmd", 0600, _stp_proc_root);
+	/* create /proc/systemtap/module_name/.cmd  */
+	de = create_proc_entry (".cmd", 0600, _stp_proc_root);
 	if (de == NULL) 
 		goto err1;
 	de->uid = _stp_uid;
 	de->gid = _stp_gid;
 	de->proc_fops = &_stp_proc_fops_cmd;
-	return 0;
 
+	/* create /proc/systemtap/module_name/.symbols  */
+	de = create_proc_entry (".symbols", 0600, _stp_proc_root);
+	if (de == NULL) 
+		goto err2;
+	de->proc_fops = &_stp_sym_fops_cmd;
+
+	return 0;
+err2:
+	remove_proc_entry (".cmd", _stp_proc_root);	
 err1:
 #ifdef STP_BULKMODE
 	for (de = _stp_proc_root->subdir; de; de = de->next)
@@ -439,7 +635,8 @@ static void _stp_unregister_ctl_channel (void)
 	remove_proc_entry ("bufsize", _stp_proc_root);
 #endif /* STP_BULKMODE */
 
-	remove_proc_entry ("cmd", _stp_proc_root);
+	remove_proc_entry (".symbols", _stp_proc_root);
+	remove_proc_entry (".cmd", _stp_proc_root);
 	_stp_rmdir_proc_module();
 
 	/* free memory pools */
@@ -447,7 +644,11 @@ static void _stp_unregister_ctl_channel (void)
 		list_del(p);
 		kfree(p);
 	}
-	list_for_each_safe(p, tmp, &_stp_ready_q) {
+	list_for_each_safe(p, tmp, &_stp_sym_ready_q) {
+		list_del(p);
+		kfree(p);
+	}
+	list_for_each_safe(p, tmp, &_stp_ctl_ready_q) {
 		list_del(p);
 		kfree(p);
 	}