FreeCalypso > hg > freecalypso-tools
view loadtools/secondprog.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 | 064d4eedb3a6 |
children |
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/* * This module contains the code for passing the serial channel to a * second program, used by fc-iram and fc-xram. */ #include <stdio.h> #include <stdlib.h> #include <unistd.h> extern char **passon_argv; extern int passon_argc; exec_2nd_prog() { char **execp_argv; char **sp, **dp; extern int target_fd; char desc_arg[16]; sprintf(desc_arg, "-d%d", target_fd); execp_argv = (char **) malloc(sizeof(char *) * (passon_argc + 2)); if (!execp_argv) { perror("malloc argv for execvp"); exit(1); } sp = passon_argv; dp = execp_argv; *dp++ = *sp++; *dp++ = desc_arg; while (*sp) *dp++ = *sp++; *dp = NULL; execvp(execp_argv[0], execp_argv); fprintf(stderr, "Unable to execvp %s\n", passon_argv[0]); exit(1); }