tty: Drop the lock_kernel in the private ioctl hook

We don't need the BKL here any more so it can go. In a couple of spots the driver requirements are not clear so push the lock down into the driver. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tty: Drop the lock_kernel in the private ioctl hook
We don't need the BKL here any more so it can go. In a couple of spots the driver requirements are not clear so push the lock down into the driver. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Alan Cox · Linus Torvalds
1 parent eeb4613436
Showing 5 changed files with 14 additions and 8 deletions Side-by-side Diff
drivers/usb/serial/ftdi_sio.c
drivers/usb/serial/kl5kusb105.c
drivers/usb/serial/mct_u232.c
drivers/usb/serial/mos7840.c
drivers/usb/serial/usb-serial.c
@@ -1054,6 +1054,8 @@
  
 	if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
 		return -EFAULT;
+
+	lock_kernel();
 	old_priv = *priv;
  
 	/* Do error checking and permission checking */
  
@@ -1069,8 +1071,10 @@
 	}
  
 	if ((new_serial.baud_base != priv->baud_base) &&
-	    (new_serial.baud_base < 9600))
+	    (new_serial.baud_base < 9600)) {
+	    	unlock_kernel();
 		return -EINVAL;
+	}
  
 	/* Make the changes - these are privileged changes! */
  
  
@@ -1098,8 +1102,11 @@
 	     (priv->flags & ASYNC_SPD_MASK)) ||
 	    (((priv->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST) &&
 	     (old_priv.custom_divisor != priv->custom_divisor))) {
+		unlock_kernel();
 		change_speed(tty, port);
 	}
+	else
+		unlock_kernel();
 	return 0;
  
 } /* set_serial_info */
@@ -878,6 +878,7 @@
  
 	dbg("%sstate=%d", __func__, break_state);
  
+	/* LOCKING */
 	if (break_state)
 		lcr |= MCT_U232_SET_BREAK;
  
@@ -721,10 +721,10 @@
  
 	spin_lock_irqsave(&priv->lock, flags);
 	lcr = priv->last_lcr;
-	spin_unlock_irqrestore(&priv->lock, flags);
  
 	if (break_state)
 		lcr |= MCT_U232_SET_BREAK;
+	spin_unlock_irqrestore(&priv->lock, flags);
  
 	mct_u232_set_line_ctrl(serial, lcr);
 } /* mct_u232_break_ctl */
@@ -1343,6 +1343,7 @@
 	else
 		data = mos7840_port->shadowLCR & ~LCR_SET_BREAK;
  
+	/* FIXME: no locking on shadowLCR anywhere in driver */
 	mos7840_port->shadowLCR = data;
 	dbg("mcs7840_break mos7840_port->shadowLCR is %x\n",
 	    mos7840_port->shadowLCR);
  
@@ -2214,10 +2215,12 @@
 		break;
 	}
  
+	lock_kernel();
 	mos7840_port->shadowMCR = mcr;
  
 	Data = mos7840_port->shadowMCR;
 	status = mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
+	unlock_kernel();
 	if (status < 0) {
 		dbg("setting MODEM_CONTROL_REGISTER Failed\n");
 		return -1;
@@ -382,9 +382,7 @@
 	/* pass on to the driver specific version of this function
 	   if it is available */
 	if (port->serial->type->ioctl) {
-		lock_kernel();
 		retval = port->serial->type->ioctl(tty, file, cmd, arg);
-		unlock_kernel();
 	} else
 		retval = -ENOIOCTLCMD;
 	return retval;
  
@@ -413,11 +411,8 @@
 	WARN_ON(!port->port.count);
 	/* pass on to the driver specific version of this function
 	   if it is available */
-	if (port->serial->type->break_ctl) {
-		lock_kernel();
+	if (port->serial->type->break_ctl)
 		port->serial->type->break_ctl(tty, break_state);
-		unlock_kernel();
-	}
 	return 0;
 }
...	...	@@ -1054,6 +1054,8 @@
1054	1054
1055	1055	if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
1056	1056	return -EFAULT;
	1057	+
	1058	+ lock_kernel();
1057	1059	old_priv = *priv;
1058	1060
1059	1061	/* Do error checking and permission checking */
1060	1062
...	...	@@ -1069,8 +1071,10 @@
1069	1071	}
1070	1072
1071	1073	if ((new_serial.baud_base != priv->baud_base) &&
1072		- (new_serial.baud_base < 9600))
	1074	+ (new_serial.baud_base < 9600)) {
	1075	+ unlock_kernel();
1073	1076	return -EINVAL;
	1077	+ }
1074	1078
1075	1079	/* Make the changes - these are privileged changes! */
1076	1080
1077	1081
...	...	@@ -1098,8 +1102,11 @@
1098	1102	(priv->flags & ASYNC_SPD_MASK)) \|\|
1099	1103	(((priv->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST) &&
1100	1104	(old_priv.custom_divisor != priv->custom_divisor))) {
	1105	+ unlock_kernel();
1101	1106	change_speed(tty, port);
1102	1107	}
	1108	+ else
	1109	+ unlock_kernel();
1103	1110	return 0;
1104	1111
1105	1112	} /* set_serial_info */
...	...	@@ -878,6 +878,7 @@
878	878
879	879	dbg("%sstate=%d", __func__, break_state);
880	880
	881	+ /* LOCKING */
881	882	if (break_state)
882	883	lcr \|= MCT_U232_SET_BREAK;
883	884
...	...	@@ -721,10 +721,10 @@
721	721
722	722	spin_lock_irqsave(&priv->lock, flags);
723	723	lcr = priv->last_lcr;
724		- spin_unlock_irqrestore(&priv->lock, flags);
725	724
726	725	if (break_state)
727	726	lcr \|= MCT_U232_SET_BREAK;
	727	+ spin_unlock_irqrestore(&priv->lock, flags);
728	728
729	729	mct_u232_set_line_ctrl(serial, lcr);
730	730	} /* mct_u232_break_ctl */
...	...	@@ -1343,6 +1343,7 @@
1343	1343	else
1344	1344	data = mos7840_port->shadowLCR & ~LCR_SET_BREAK;
1345	1345
	1346	+ /* FIXME: no locking on shadowLCR anywhere in driver */
1346	1347	mos7840_port->shadowLCR = data;
1347	1348	dbg("mcs7840_break mos7840_port->shadowLCR is %x\n",
1348	1349	mos7840_port->shadowLCR);
1349	1350
...	...	@@ -2214,10 +2215,12 @@
2214	2215	break;
2215	2216	}
2216	2217
	2218	+ lock_kernel();
2217	2219	mos7840_port->shadowMCR = mcr;
2218	2220
2219	2221	Data = mos7840_port->shadowMCR;
2220	2222	status = mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
	2223	+ unlock_kernel();
2221	2224	if (status < 0) {
2222	2225	dbg("setting MODEM_CONTROL_REGISTER Failed\n");
2223	2226	return -1;
...	...	@@ -382,9 +382,7 @@
382	382	/* pass on to the driver specific version of this function
383	383	if it is available */
384	384	if (port->serial->type->ioctl) {
385		- lock_kernel();
386	385	retval = port->serial->type->ioctl(tty, file, cmd, arg);
387		- unlock_kernel();
388	386	} else
389	387	retval = -ENOIOCTLCMD;
390	388	return retval;
391	389
...	...	@@ -413,11 +411,8 @@
413	411	WARN_ON(!port->port.count);
414	412	/* pass on to the driver specific version of this function
415	413	if it is available */
416		- if (port->serial->type->break_ctl) {
417		- lock_kernel();
	414	+ if (port->serial->type->break_ctl)
418	415	port->serial->type->break_ctl(tty, break_state);
419		- unlock_kernel();
420		- }
421	416	return 0;
422	417	}
423	418