FreeCalypso > hg > freecalypso-tools
view target-utils/libcommon/cmd_jump.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 | e7502631a0f9 |
children |
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/* * jump hexaddr -- transfer control with BX */ #include <sys/types.h> #include "types.h" void cmd_jump(argbulk) char *argbulk; { char *argv[2]; u_long addr; if (parse_args(argbulk, 1, 1, argv, 0) < 0) return; if (parse_hexarg(argv[0], 8, &addr) < 0) { printf("ERROR: argument must be a valid 32-bit hex address\n"); return; } serial_flush(); asm volatile ("bx %0" : : "r" (addr)); __builtin_unreachable(); }