FreeCalypso > hg > freecalypso-tools
view target-utils/libc/memcmp.S @ 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 | a675cec34076 |
children |
line wrap: on
line source
.text .code 32 .globl bcmp .globl memcmp bcmp: memcmp: cmp r2, #0 beq zero_len_out mov r3, r0 1: ldrb r0, [r3], #1 ldrb r12, [r1], #1 subs r0, r0, r12 bxne lr subs r2, r2, #1 bne 1b bx lr zero_len_out: mov r0, #0 bx lr