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hush: fix nofork + ctrl-Z clobbering of globals

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This commit is contained in:
Denis Vlasenko
2007-04-28 16:43:18 +00:00
parent a6a1785a30
commit 18e19f2b0d
3 changed files with 58 additions and 37 deletions
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40
shell/hush.c
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@@ -441,30 +441,28 @@ static void signal_SA_RESTART(int sig, void (*handler)(int))
sigaction(sig, &sa, NULL);
}
struct nofork_save_area nofork_save;
static sigjmp_buf nofork_jb;
static smallint nofork_flag;
static struct pipe *nofork_pipe;
static void handler_ctrl_z(int sig)
{
pid_t pid;
fprintf(stderr, "got tty sig %d\n", sig);
if (!nofork_flag)
return;
debug_jobs_printf("got tty sig %d\n", sig);
pid = fork();
if (pid < 0) /* can't fork. Pretend there were no Ctrl-Z */
return;
fprintf(stderr, "bg'ing nofork\n");
nofork_flag = 0;
debug_jobs_printf("bg'ing nofork\n");
nofork_save.saved = 0; /* flag the fact that Ctrl-Z was handled */
nofork_pipe->running_progs = 1;
nofork_pipe->stopped_progs = 0;
if (!pid) { /* child */
fprintf(stderr, "setting pgrp for child\n");
debug_jobs_printf("setting pgrp for child\n");
setpgrp();
signal(sig, SIG_DFL); /* make child do default action (stop) */
raise(sig); /* resend TSTP so that child will be stopped */
fprintf(stderr, "returning to child\n");
signal(SIGTSTP, SIG_DFL); /* make child do default action (stop) */
raise(SIGTSTP); /* resend TSTP so that child will be stopped */
debug_jobs_printf("returning to child\n");
/* return to nofork, it will eventually exit now,
* not return back to shell */
return;
@@ -1588,25 +1586,23 @@ static int run_pipe_real(struct pipe *pi)
const struct bb_applet *a = find_applet_by_name(argv[i]);
if (a && a->nofork) {
setup_redirects(child, squirrel);
/* TSTP handler will store pid etc in pi */
nofork_pipe = pi;
save_nofork_data(&nofork_save);
if (sigsetjmp(nofork_jb, 1) == 0) {
// enable ctrl_z here, not globally?
nofork_flag = 1;
/* TSTP handler will store pid there etc */
nofork_pipe = pi;
rcode = run_nofork_applet(a, argv + i);
if (--nofork_flag != 0)
signal_SA_RESTART(SIGTSTP, handler_ctrl_z);
rcode = run_nofork_applet_prime(&nofork_save, a, argv + i);
if (--nofork_save.saved != 0)
/* Ctrl-Z! forked, we are child */
exit(rcode);
restore_redirects(squirrel);
return rcode;
} else {
fprintf(stderr, "Exiting nofork early\n");
/* Ctrl-Z, forked, we are parent.
* Sighandler has longjmped us here */
//problem: run_nofork_applet did not do the
// "restore" trick and globals are trashed:
// for one, applet_name is not "hush" :)
// need to split run_nofork_applet into setup/run/restore...
signal(SIGTSTP, SIG_IGN);
debug_jobs_printf("Exiting nofork early\n");
restore_nofork_data(&nofork_save);
restore_redirects(squirrel);
insert_bg_job(pi);
return 0;
@@ -3021,8 +3017,6 @@ static void setup_job_control(void)
/* Grab control of the terminal. */
tcsetpgrp(interactive_fd, shell_pgrp);
signal_SA_RESTART(SIGTSTP, handler_ctrl_z);
}
int hush_main(int argc, char **argv);