[patch] media/radio: fix copy_to_user to user handling

Dan Carpenter
2010-06-04T10:34:40Z

copy_to/from_user() returns the number of bytes remaining to be copied
but the code here was testing for negative returns. I modified it to
return -EFAULT. These functions are called from si4713_s_ext_ctrls() and
that only tests for negative error codes.

Signed-off-by: Dan Carpenter <error27@gmail.com>

diff --git a/drivers/media/radio/si4713-i2c.c b/drivers/media/radio/si4713-i2c.c
index ab63dd5..fc7f4b7 100644
--- a/drivers/media/radio/si4713-i2c.c
+++ b/drivers/media/radio/si4713-i2c.c
@@ -1009,8 +1009,10 @@ static int si4713_write_econtrol_string(struct si4713_device *sdev,
goto exit;
}
rval = copy_from_user(ps_name, control->string, len);
- if (rval < 0)
+ if (rval) {
+ rval = -EFAULT;
goto exit;
+ }
ps_name[len] = '\0';

if (strlen(ps_name) % vqc.step) {
@@ -1031,8 +1033,10 @@ static int si4713_write_econtrol_string(struct si4713_device *sdev,
goto exit;
}
rval = copy_from_user(radio_text, control->string, len);
- if (rval < 0)
+ if (rval) {
+ rval = -EFAULT;
goto exit;
+ }
radio_text[len] = '\0';

if (strlen(radio_text) % vqc.step) {
@@ -1367,6 +1371,8 @@ static int si4713_read_econtrol_string(struct si4713_device *sdev,
}
rval = copy_to_user(control->string, sdev->rds_info.ps_name,
strlen(sdev->rds_info.ps_name) + 1);
+ if (rval)
+ rval = -EFAULT;
break;

case V4L2_CID_RDS_TX_RADIO_TEXT:
@@ -1377,6 +1383,8 @@ static int si4713_read_econtrol_string(struct si4713_device *sdev,
}
rval = copy_to_user(control->string, sdev->rds_info.radio_text,
strlen(sdev->rds_info.radio_text) + 1);
+ if (rval)
+ rval = -EFAULT;
break;