From: H Hartley Sweeten <hsweeten@visionengravers.com>
Date: Thu, 17 Apr 2014 17:07:46 +0000 (-0700)
Subject: staging: comedi: drivers: core validates chanlist_len max
X-Git-Tag: next-20140428~14^2~222
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=860b7c398a744c1eef42a59b661e870aca12d9be;p=karo-tx-linux.git

staging: comedi: drivers: core validates chanlist_len max

The comedi core checks if the (cmd->chanlist_len > s->len_chanlist) when the
comedi_cmd is copied from user to kernel space by __comedi_get_user_cmd().
If so, the core returns -EINVAL and will not call the subdevice (*do_cmdtest)
and (*do_cmd).

Remove the unnecessary "max" checks in the comedi driver (*do_cmdtest) and
helper functions.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c b/drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c
index 70e8f426285c..66c24e41d0ff 100644
--- a/drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c
+++ b/drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c
@@ -734,7 +734,6 @@ static int apci3120_ai_cmdtest(struct comedi_device *dev,
 			       struct comedi_subdevice *s,
 			       struct comedi_cmd *cmd)
 {
-	const struct addi_board *this_board = comedi_board(dev);
 	int err = 0;
 
 	/* Step 1 : check if triggers are trivially valid */
@@ -779,8 +778,6 @@ static int apci3120_ai_cmdtest(struct comedi_device *dev,
 	}
 
 	err |= cfc_check_trigger_arg_min(&cmd->chanlist_len, 1);
-	err |= cfc_check_trigger_arg_max(&cmd->chanlist_len,
-					 this_board->i_AiChannelList);
 
 	if (cmd->stop_src == TRIG_COUNT)
 		err |= cfc_check_trigger_arg_min(&cmd->stop_arg, 1);
diff --git a/drivers/staging/comedi/drivers/adl_pci9118.c b/drivers/staging/comedi/drivers/adl_pci9118.c
index b6abef6ceab7..53bbc59f6176 100644
--- a/drivers/staging/comedi/drivers/adl_pci9118.c
+++ b/drivers/staging/comedi/drivers/adl_pci9118.c
@@ -1259,8 +1259,6 @@ static int pci9118_ai_cmdtest(struct comedi_device *dev,
 		err |= cfc_check_trigger_arg_is(&cmd->stop_arg, 0);
 
 	err |= cfc_check_trigger_arg_min(&cmd->chanlist_len, 1);
-	err |= cfc_check_trigger_arg_max(&cmd->chanlist_len,
-					 this_board->n_aichanlist);
 
 	err |= cfc_check_trigger_arg_min(&cmd->scan_end_arg,
 					 cmd->chanlist_len);
diff --git a/drivers/staging/comedi/drivers/pcl812.c b/drivers/staging/comedi/drivers/pcl812.c
index 5cc01fe45cf2..0cf115e54308 100644
--- a/drivers/staging/comedi/drivers/pcl812.c
+++ b/drivers/staging/comedi/drivers/pcl812.c
@@ -761,7 +761,6 @@ static int pcl812_ai_cmdtest(struct comedi_device *dev,
 		err |= cfc_check_trigger_arg_is(&cmd->convert_arg, 0);
 
 	err |= cfc_check_trigger_arg_min(&cmd->chanlist_len, 1);
-	err |= cfc_check_trigger_arg_max(&cmd->chanlist_len, MAX_CHANLIST_LEN);
 	err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, cmd->chanlist_len);
 
 	if (cmd->stop_src == TRIG_COUNT)
diff --git a/drivers/staging/comedi/drivers/rtd520.c b/drivers/staging/comedi/drivers/rtd520.c
index cd3fdf973bdd..1b1c166c8e9b 100644
--- a/drivers/staging/comedi/drivers/rtd520.c
+++ b/drivers/staging/comedi/drivers/rtd520.c
@@ -891,10 +891,6 @@ static int rtd_ai_cmdtest(struct comedi_device *dev,
 
 	/* step 4: fix up any arguments */
 
-	if (cmd->chanlist_len > RTD_MAX_CHANLIST) {
-		cmd->chanlist_len = RTD_MAX_CHANLIST;
-		err++;
-	}
 	if (cmd->scan_begin_src == TRIG_TIMER) {
 		tmp = cmd->scan_begin_arg;
 		rtd_ns_to_timer(&cmd->scan_begin_arg,