From b78049831ffed65f0b4e61f69df14f3ab17922cb Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Tue, 20 Sep 2011 11:23:49 -0400 Subject: [PATCH] lib: add error checking to hex2bin hex2bin converts a hexadecimal string to its binary representation. The original version of hex2bin did not do any error checking. This patch adds error checking and returns the result. Changelog v1: - removed unpack_hex_byte() - changed return code from boolean to int Changelog: - use the new unpack_hex_byte() - add __must_check compiler option (Andy Shevchenko's suggestion) - change function API to return error checking result (based on Tetsuo Handa's initial patch) Signed-off-by: Mimi Zohar Acked-by: Andy Shevchenko --- include/linux/kernel.h | 2 +- lib/hexdump.c | 15 +++++++++++---- 2 files changed, 12 insertions(+), 5 deletions(-) diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 46ac9a50528d..8eefcf7e95eb 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -382,7 +382,7 @@ static inline char *pack_hex_byte(char *buf, u8 byte) } extern int hex_to_bin(char ch); -extern void hex2bin(u8 *dst, const char *src, size_t count); +extern int __must_check hex2bin(u8 *dst, const char *src, size_t count); /* * General tracing related utility functions - trace_printk(), diff --git a/lib/hexdump.c b/lib/hexdump.c index f5fe6ba7a3ab..51d5ae210244 100644 --- a/lib/hexdump.c +++ b/lib/hexdump.c @@ -38,14 +38,21 @@ EXPORT_SYMBOL(hex_to_bin); * @dst: binary result * @src: ascii hexadecimal string * @count: result length + * + * Return 0 on success, -1 in case of bad input. */ -void hex2bin(u8 *dst, const char *src, size_t count) +int hex2bin(u8 *dst, const char *src, size_t count) { while (count--) { - *dst = hex_to_bin(*src++) << 4; - *dst += hex_to_bin(*src++); - dst++; + int hi = hex_to_bin(*src++); + int lo = hex_to_bin(*src++); + + if ((hi < 0) || (lo < 0)) + return -1; + + *dst++ = (hi << 4) | lo; } + return 0; } EXPORT_SYMBOL(hex2bin);