2018-01-12 07:39:41

by Xiongfeng Wang

Subject: [PATCH] iio: accel: use strlcpy() instead of strncpy()

From: Xiongfeng Wang <[email protected]>

gcc-8 reports

drivers/iio/accel/st_accel_i2c.c: In function 'st_accel_i2c_probe':
./include/linux/string.h:245:9: warning: '__builtin_strncpy' specified
bound 20 equals destination size [-Wstringop-truncation]

The compiler require that the length of the dest string is greater than
the length we want to copy to make sure the dest string is
nul-terminated. We can just use strlcpy() to avoid this warning.

Signed-off-by: Xiongfeng Wang <[email protected]>
---
drivers/iio/accel/st_accel_i2c.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/iio/accel/st_accel_i2c.c b/drivers/iio/accel/st_accel_i2c.c
index 363429b..6bdec8c 100644
--- a/drivers/iio/accel/st_accel_i2c.c
+++ b/drivers/iio/accel/st_accel_i2c.c
@@ -159,9 +159,8 @@ static int st_accel_i2c_probe(struct i2c_client *client,
if ((ret < 0) || (ret >= ST_ACCEL_MAX))
return -ENODEV;

- strncpy(client->name, st_accel_id_table[ret].name,
+ strlcpy(client->name, st_accel_id_table[ret].name,
sizeof(client->name));
- client->name[sizeof(client->name) - 1] = '\0';
} else if (!id)
return -ENODEV;

--
1.8.3.1

2018-01-14 12:02:07

by Jonathan Cameron

Subject: Re: [PATCH] iio: accel: use strlcpy() instead of strncpy()

On Fri, 12 Jan 2018 15:45:38 +0800
Xiongfeng Wang <[email protected]> wrote:

> From: Xiongfeng Wang <[email protected]>
>
> gcc-8 reports
>
> drivers/iio/accel/st_accel_i2c.c: In function 'st_accel_i2c_probe':
> ./include/linux/string.h:245:9: warning: '__builtin_strncpy' specified
> bound 20 equals destination size [-Wstringop-truncation]
>
> The compiler require that the length of the dest string is greater than
> the length we want to copy to make sure the dest string is
> nul-terminated. We can just use strlcpy() to avoid this warning.
>
> Signed-off-by: Xiongfeng Wang <[email protected]>
Hmm. As this is just warning suppression I'm not taking it as a fix
but rather via the slow path.

Applied to the togreg branch of iio.git and pushed out as testing for
the autobuilders to play with it.

Jonathan
> ---
> drivers/iio/accel/st_accel_i2c.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/iio/accel/st_accel_i2c.c b/drivers/iio/accel/st_accel_i2c.c
> index 363429b..6bdec8c 100644
> --- a/drivers/iio/accel/st_accel_i2c.c
> +++ b/drivers/iio/accel/st_accel_i2c.c
> @@ -159,9 +159,8 @@ static int st_accel_i2c_probe(struct i2c_client *client,
> if ((ret < 0) || (ret >= ST_ACCEL_MAX))
> return -ENODEV;
>
> - strncpy(client->name, st_accel_id_table[ret].name,
> + strlcpy(client->name, st_accel_id_table[ret].name,
> sizeof(client->name));
> - client->name[sizeof(client->name) - 1] = '\0';
> } else if (!id)
> return -ENODEV;
>