2020-10-25 14:46:05

by Rasmus Villemoes

Subject: [PATCH] watchdog: sbc_fitpc2_wdt: add __user annotations

After a change to the put_user() macro on x86, kernel test robot has
started sending me complaints (from sparse) about passing kernel
pointers to put_user(). So add the __user annotations to the various
casts in fitpc2_wdt_ioctl(), and while in here, also make the write
method actually match the prototype of file_operations::write.

Reported-by: kernel test robot <[email protected]>
Signed-off-by: Rasmus Villemoes <[email protected]>
---
drivers/watchdog/sbc_fitpc2_wdt.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/watchdog/sbc_fitpc2_wdt.c b/drivers/watchdog/sbc_fitpc2_wdt.c
index 04483d6453d6a147703e..13db71e165836eb73249 100644
--- a/drivers/watchdog/sbc_fitpc2_wdt.c
+++ b/drivers/watchdog/sbc_fitpc2_wdt.c
@@ -78,7 +78,7 @@ static int fitpc2_wdt_open(struct inode *inode, struct file *file)
return stream_open(inode, file);
}

-static ssize_t fitpc2_wdt_write(struct file *file, const char *data,
+static ssize_t fitpc2_wdt_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
size_t i;
@@ -125,16 +125,16 @@ static long fitpc2_wdt_ioctl(struct file *file, unsigned int cmd,

switch (cmd) {
case WDIOC_GETSUPPORT:
- ret = copy_to_user((struct watchdog_info *)arg, &ident,
+ ret = copy_to_user((struct watchdog_info __user *)arg, &ident,
sizeof(ident)) ? -EFAULT : 0;
break;

case WDIOC_GETSTATUS:
- ret = put_user(0, (int *)arg);
+ ret = put_user(0, (int __user *)arg);
break;

case WDIOC_GETBOOTSTATUS:
- ret = put_user(0, (int *)arg);
+ ret = put_user(0, (int __user *)arg);
break;

case WDIOC_KEEPALIVE:
@@ -143,7 +143,7 @@ static long fitpc2_wdt_ioctl(struct file *file, unsigned int cmd,
break;

case WDIOC_SETTIMEOUT:
- ret = get_user(time, (int *)arg);
+ ret = get_user(time, (int __user *)arg);
if (ret)
break;

@@ -157,7 +157,7 @@ static long fitpc2_wdt_ioctl(struct file *file, unsigned int cmd,
fallthrough;

case WDIOC_GETTIMEOUT:
- ret = put_user(margin, (int *)arg);
+ ret = put_user(margin, (int __user *)arg);
break;
}

--
2.23.0

2020-10-25 18:36:44

by Guenter Roeck

Subject: Re: [PATCH] watchdog: sbc_fitpc2_wdt: add __user annotations

On 10/25/20 5:45 AM, Rasmus Villemoes wrote:
> After a change to the put_user() macro on x86, kernel test robot has
> started sending me complaints (from sparse) about passing kernel
> pointers to put_user(). So add the __user annotations to the various
> casts in fitpc2_wdt_ioctl(), and while in here, also make the write
> method actually match the prototype of file_operations::write.
>
> Reported-by: kernel test robot <[email protected]>
> Signed-off-by: Rasmus Villemoes <[email protected]>

It would really be great if we can get rid of all those old drivers.
Can we mark them all as deprecated ?

Reviewed-by: Guenter Roeck <[email protected]>

> ---
> drivers/watchdog/sbc_fitpc2_wdt.c | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/watchdog/sbc_fitpc2_wdt.c b/drivers/watchdog/sbc_fitpc2_wdt.c
> index 04483d6453d6a147703e..13db71e165836eb73249 100644
> --- a/drivers/watchdog/sbc_fitpc2_wdt.c
> +++ b/drivers/watchdog/sbc_fitpc2_wdt.c
> @@ -78,7 +78,7 @@ static int fitpc2_wdt_open(struct inode *inode, struct file *file)
> return stream_open(inode, file);
> }
>
> -static ssize_t fitpc2_wdt_write(struct file *file, const char *data,
> +static ssize_t fitpc2_wdt_write(struct file *file, const char __user *data,
> size_t len, loff_t *ppos)
> {
> size_t i;
> @@ -125,16 +125,16 @@ static long fitpc2_wdt_ioctl(struct file *file, unsigned int cmd,
>
> switch (cmd) {
> case WDIOC_GETSUPPORT:
> - ret = copy_to_user((struct watchdog_info *)arg, &ident,
> + ret = copy_to_user((struct watchdog_info __user *)arg, &ident,
> sizeof(ident)) ? -EFAULT : 0;
> break;
>
> case WDIOC_GETSTATUS:
> - ret = put_user(0, (int *)arg);
> + ret = put_user(0, (int __user *)arg);
> break;
>
> case WDIOC_GETBOOTSTATUS:
> - ret = put_user(0, (int *)arg);
> + ret = put_user(0, (int __user *)arg);
> break;
>
> case WDIOC_KEEPALIVE:
> @@ -143,7 +143,7 @@ static long fitpc2_wdt_ioctl(struct file *file, unsigned int cmd,
> break;
>
> case WDIOC_SETTIMEOUT:
> - ret = get_user(time, (int *)arg);
> + ret = get_user(time, (int __user *)arg);
> if (ret)
> break;
>
> @@ -157,7 +157,7 @@ static long fitpc2_wdt_ioctl(struct file *file, unsigned int cmd,
> fallthrough;
>
> case WDIOC_GETTIMEOUT:
> - ret = put_user(margin, (int *)arg);
> + ret = put_user(margin, (int __user *)arg);
> break;
> }
>
>