hush: reset die_sleep to 0 in child after fork

1 files changed, 10 insertions, 6 deletions

diff --git a/shell/hush.c b/shell/hush.c
index f3ea1a212..e9d0355f8 100644
--- 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);