From: Ian Abbott <abbotti@mev.co.uk>
Date: Thu, 15 Dec 2011 19:55:53 +0000 (+0000)
Subject: ni_labpc: don't access *data when insn->n == 0
X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=29a1568769832fa722fd074be60a9563a8b0b678;p=comedi.git

ni_labpc: don't access *data when insn->n == 0

Due to recent change to do_insnlist_ioctl() and do_insn_ioctl(), the
'data' pointer will be NULL when insn->n == 0.  Do not access *data
in this case.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
---

diff --git a/comedi/drivers/ni_labpc.c b/comedi/drivers/ni_labpc.c
index 93dab429..94764f23 100644
--- a/comedi/drivers/ni_labpc.c
+++ b/comedi/drivers/ni_labpc.c
@@ -1594,6 +1594,9 @@ static int labpc_ao_winsn(comedi_device * dev, comedi_subdevice * s,
 	unsigned long flags;
 	int lsb, msb;
 
+	if (insn->n == 0)
+		return 0;
+
 	channel = CR_CHAN(insn->chanspec);
 
 	// turn off pacing of analog output channel
@@ -1631,6 +1634,9 @@ static int labpc_ao_winsn(comedi_device * dev, comedi_subdevice * s,
 static int labpc_ao_rinsn(comedi_device * dev, comedi_subdevice * s,
 	comedi_insn * insn, lsampl_t * data)
 {
+	if (insn->n == 0)
+		return 0;
+
 	data[0] = devpriv->ao_value[CR_CHAN(insn->chanspec)];
 
 	return 1;
@@ -1639,6 +1645,9 @@ static int labpc_ao_rinsn(comedi_device * dev, comedi_subdevice * s,
 static int labpc_calib_read_insn(comedi_device * dev, comedi_subdevice * s,
 	comedi_insn * insn, lsampl_t * data)
 {
+	if (insn->n == 0)
+		return 0;
+
 	data[0] = devpriv->caldac[CR_CHAN(insn->chanspec)];
 
 	return 1;
@@ -1649,6 +1658,9 @@ static int labpc_calib_write_insn(comedi_device * dev, comedi_subdevice * s,
 {
 	int channel = CR_CHAN(insn->chanspec);
 
+	if (insn->n == 0)
+		return 0;
+
 	write_caldac(dev, channel, data[0]);
 	return 1;
 }
@@ -1656,6 +1668,9 @@ static int labpc_calib_write_insn(comedi_device * dev, comedi_subdevice * s,
 static int labpc_eeprom_read_insn(comedi_device * dev, comedi_subdevice * s,
 	comedi_insn * insn, lsampl_t * data)
 {
+	if (insn->n == 0)
+		return 0;
+
 	data[0] = devpriv->eeprom_data[CR_CHAN(insn->chanspec)];
 
 	return 1;
@@ -1673,6 +1688,9 @@ static int labpc_eeprom_write_insn(comedi_device * dev, comedi_subdevice * s,
 		return -EINVAL;
 	}
 
+	if (insn->n == 0)
+		return 0;
+
 	ret = labpc_eeprom_write(dev, channel, data[0]);
 	if (ret < 0)
 		return ret;