[PATCH] misc: xilinx-sdfec: remove check for ioctl cmd and argument.

From: Harshal Chaudhari
Date: Sun Nov 01 2020 - 12:10:25 EST


if (_IOC_TYPE(cmd) != PP_IOCTL)
return -ENOTTY;

Invalid ioctl command check normally performs by “default” case.

if (_IOC_DIR(cmd) != _IOC_NONE) {
argp = (void __user *)arg;
if (!argp)
return -EINVAL; }

And for checking ioctl arguments, copy_from_user()/copy_to_user()
checks are enough.

Signed-off-by: Harshal Chaudhari <harshalchau04@xxxxxxxxx>
---
drivers/misc/xilinx_sdfec.c | 16 +++-------------
1 file changed, 3 insertions(+), 13 deletions(-)

diff --git a/drivers/misc/xilinx_sdfec.c b/drivers/misc/xilinx_sdfec.c
index 92291292756a..ff104c894b3b 100644
--- a/drivers/misc/xilinx_sdfec.c
+++ b/drivers/misc/xilinx_sdfec.c
@@ -944,8 +944,8 @@ static long xsdfec_dev_ioctl(struct file *fptr, unsigned int cmd,
unsigned long data)
{
struct xsdfec_dev *xsdfec;
- void __user *arg = NULL;
- int rval = -EINVAL;
+ void __user *arg = (void __user *)data;
+ int rval;

xsdfec = container_of(fptr->private_data, struct xsdfec_dev, miscdev);

@@ -956,16 +956,6 @@ static long xsdfec_dev_ioctl(struct file *fptr, unsigned int cmd,
return -EPERM;
}

- if (_IOC_TYPE(cmd) != XSDFEC_MAGIC)
- return -ENOTTY;
-
- /* check if ioctl argument is present and valid */
- if (_IOC_DIR(cmd) != _IOC_NONE) {
- arg = (void __user *)data;
- if (!arg)
- return rval;
- }
-
switch (cmd) {
case XSDFEC_START_DEV:
rval = xsdfec_start(xsdfec);
@@ -1010,7 +1000,7 @@ static long xsdfec_dev_ioctl(struct file *fptr, unsigned int cmd,
rval = xsdfec_is_active(xsdfec, (bool __user *)arg);
break;
default:
- /* Should not get here */
+ rval = -ENOTTY;
break;
}
return rval;
--
2.17.1