Commit d89a3f73 authored by Kees Cook's avatar Kees Cook Committed by Linus Torvalds
Browse files

lib/string_helpers: clarify esc arg in string_escape_mem 



The esc argument is used to reduce which characters will be escaped.  For
example, using " " with ESCAPE_SPACE will not produce any escaped spaces.

Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Mathias Krause <minipli@googlemail.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent cdf17449

lib/string_helpers.c

+6 −4
Original line number Diff line number Diff line
@@ -410,7 +410,7 @@ static bool escape_hex(unsigned char c, char **dst, char *end) 
 * @dst:	destination buffer (escaped)

 * @osz:	destination buffer size

 * @flags:	combination of the flags (bitwise OR):

 *	%ESCAPE_SPACE:

 *	%ESCAPE_SPACE: (special white space, not space itself)

 *		'\f' - form feed

 *		'\n' - new line

 *		'\r' - carriage return
@@ -432,8 +432,10 @@ static bool escape_hex(unsigned char c, char **dst, char *end) 
 *		all previous together

 *	%ESCAPE_HEX:

 *		'\xHH' - byte with hexadecimal value HH (2 digits)

 * @esc:	NULL-terminated string of characters any of which, if found in

 *		the source, has to be escaped

 * @esc:	NULL-terminated string containing characters used to limit

 *		the selected escape class. If characters are included in @esc

 *		that would not normally be escaped by the classes selected

 *		in @flags, they will be copied to @dst unescaped.

 *

 * Description:

 * The process of escaping byte buffer includes several parts. They are applied
@@ -441,7 +443,7 @@ static bool escape_hex(unsigned char c, char **dst, char *end) 
 *	1. The character is matched to the printable class, if asked, and in

 *	   case of match it passes through to the output.

 *	2. The character is not matched to the one from @esc string and thus

 *	   must go as is to the output.

 *	   must go as-is to the output.

 *	3. The character is checked if it falls into the class given by @flags.

 *	   %ESCAPE_OCTAL and %ESCAPE_HEX are going last since they cover any

 *	   character. Note that they actually can't go together, otherwise

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