Re: [PATCH] i2c: strncpy does not null terminate string

[Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>]

On Fri, 17 Jul 2009 15:03:24 +0200, Roel Kluin wrote:
> With `sizeof(string) - 1` strncpy() will null terminate the string.
> 
> Signed-off-by: Roel Kluin <roel.kluin-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> ---
> To test this:
> 
> #include <stdio.h>
> #include <string.h>
> 
> char a[10];
> char b[10];
> 
> int main()
> {
>         const char* str = "0123456789012";
>         strncpy(a, str, sizeof(a));
>         strncpy(b, str, sizeof(b) - 1);
>         printf("String a was %s, b was %s\n", a, b);
> 
>         return 0;
> }
> 
> diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
> index fdd8327..bede75d 100644
> --- a/drivers/i2c/busses/i2c-omap.c
> +++ b/drivers/i2c/busses/i2c-omap.c
> @@ -879,7 +879,7 @@ omap_i2c_probe(struct platform_device *pdev)
>  	i2c_set_adapdata(adap, dev);
>  	adap->owner = THIS_MODULE;
>  	adap->class = I2C_CLASS_HWMON;
> -	strncpy(adap->name, "OMAP I2C adapter", sizeof(adap->name));
> +	strncpy(adap->name, "OMAP I2C adapter", sizeof(adap->name) - 1);
>  	adap->algo = &omap_i2c_algo;
>  	adap->dev.parent = &pdev->dev;

Nack, please just use strlcpy() instead.

IMHO strncpy() should be banned from the kernel.

-- 
Jean Delvare