Re: [PATCH 5/6] staging: rtl8192e: re-use string_escape_mem()

[Joe Perches <joe@perches.com>]

On Wed, 2014-07-02 at 16:20 +0300, Andy Shevchenko wrote:
> Let's use kernel's library function to escape a buffer.
[]
> diff --git a/drivers/staging/rtl8192e/rtllib.h b/drivers/staging/rtl8192e/rtllib.h
[]
> @@ -2956,7 +2957,6 @@ extern inline int rtllib_get_scans(struct rtllib_device *ieee)
>  static inline const char *escape_essid(const char *essid, u8 essid_len)
>  {
>  	static char escaped[IW_ESSID_MAX_SIZE * 2 + 1];
> -	const char *s = essid;
>  	char *d = escaped;
>  
>  	if (rtllib_is_empty_essid(essid, essid_len)) {
> @@ -2965,15 +2965,8 @@ static inline const char *escape_essid(const char *essid, u8 essid_len)
>  	}
>  
>  	essid_len = min(essid_len, (u8)IW_ESSID_MAX_SIZE);
> -	while (essid_len--) {
> -		if (*s == '\0') {
> -			*d++ = '\\';
> -			*d++ = '0';
> -			s++;
> -		} else {
> -			*d++ = *s++;
> -		}
> -	}
> +	d += string_escape_mem(essid, essid_len, escaped, sizeof(escaped) - 1,
> +			       ESCAPE_NULL, NULL);

I'd've probably used

	d += string_escape_mem(essid, essid_len, d, ...
or
	d = escaped + string_escap_mem(essid, essid_len, escaped, ...

so there's some relation between the thing being added to

>  	*d = '\0';

or maybe not used d at all with

	escaped[1 + string_escape_mem(etc...)] = 0;

>  	return escaped;
>  }

Unrelated but this isn't a thread safe or multiple instance
safe function.

It seems it's used only in debugging message output though.