FreeCalypso > hg > freecalypso-tools
view target-utils/libcommon/hexstrings.c @ 965:2969032bdfac
fcup-smsend[mult]: fix buglet in K&R C NULL pointer passing
The only 100% safe way to pass a NULL pointer as a function argument
in K&R C is to cast 0 to a pointer type; failing to do so may cause
mysterious bugs (invalid stack frames or garbage in argument registers)
on 64-bit machines. This issue has already been fixed in most of
FC host tools, but I just found some missed spots: passing of NULL UDH
to PDU encoding functions in fcup-smsend[mult] in the case of single
(not concatenated) SMS.
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Fri, 01 Sep 2023 07:33:51 +0000 |
parents | 0da2cf5a999c |
children |
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/* * The decode_hex_digits() function contained in this module * will be used by the XRAM and flash loading commands * which take SREC-like long hex string arguments. */ #include <ctype.h> #include "types.h" decode_hex_digits(str, ndigits, valp) char *str; int ndigits; u32 *valp; { u32 accum; int i, c; accum = 0; for (i = 0; i < ndigits; i++) { c = *str++; if (!isxdigit(c)) return(-1); accum <<= 4; if (isdigit(c)) accum += c - '0'; else if (islower(c)) accum += c - 'a' + 10; else accum += c - 'A' + 10; } *valp = accum; return(0); }