hush: reset die_sleep to 0 in child after fork

diff --git a/shell/hush.c b/shell/hush.c
index f3ea1a2129516379cec50ca6d05407950bea0cb7..e9d0355f8359e47a2ada10ff6416c208a959bf82 100644 (file)
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -759,6 +759,7 @@ static void handler_ctrl_z(int sig)
                return;
        ctrl_z_flag = 1;
        if (!pid) { /* child */
+               die_sleep = 0; /* let nofork's xfuncs die */
                setpgrp();
                debug_printf_jobs("set pgrp for child %d ok\n", getpid());
                set_every_sighandler(SIG_DFL);
@@ -1899,6 +1900,7 @@ static int run_pipe(struct pipe *pi)
 
                child->pid = BB_MMU ? fork() : vfork();
                if (!child->pid) { /* child */
+                       die_sleep = 0; /* let nofork's xfuncs die */
 #if ENABLE_HUSH_JOB
                        /* Every child adds itself to new process group
                         * with pgid == pid_of_first_child_in_pipe */
@@ -2571,7 +2573,7 @@ static int expand_vars_to_list(char **list, int n, char **posp, char *arg, char
                /* Highest bit in first_ch indicates that var is double-quoted */
                case '$': /* pid */
                        /* FIXME: (echo $$) should still print pid of main shell */
-                       val = utoa(getpid());
+                       val = utoa(getpid()); /* rootpid? */
                        break;
                case '!': /* bg pid */
                        val = last_bg_pid ? utoa(last_bg_pid) : (char*)"";
@@ -3237,6 +3239,7 @@ static FILE *generate_stream_from_list(struct pipe *head)
        if (pid < 0)
                bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
        if (pid == 0) { /* child */
+               die_sleep = 0; /* let nofork's xfuncs die */
                close(channel[0]);
                xmove_fd(channel[1], 1);
                /* Prevent it from trying to handle ctrl-z etc */
@@ -3250,12 +3253,13 @@ static FILE *generate_stream_from_list(struct pipe *head)
                 * everywhere outside actual command execution. */
                /*set_jobctrl_sighandler(SIG_IGN);*/
                set_misc_sighandler(SIG_DFL);
-               _exit(run_list(head));   /* leaks memory */
+               /* Freeing 'head' here would break NOMMU. */
+               _exit(run_list(head));
        }
        close(channel[1]);
        pf = fdopen(channel[0], "r");
        return pf;
-       /* head is freed by the caller */
+       /* 'head' is freed by the caller */
 }
 
 /* Return code is exit status of the process that is run. */
@@ -3878,9 +3882,9 @@ int hush_main(int argc, char **argv)
        if (interactive_fd) {
                /* Looks like they want an interactive shell */
                setup_job_control();
-               /* Make xfuncs do cleanup on exit */
-               die_sleep = -1; /* flag */
-// FIXME: should we reset die_sleep = 0 whereever we fork?
+               /* -1 is special - makes xfuncs longjmp on exit
+                * (we reset die_sleep = 0 whereever we [v]fork) */
+               die_sleep = -1;
                if (setjmp(die_jmp)) {
                        /* xfunc has failed! die die die */
                        hush_exit(xfunc_error_retval);