hush: feeble attempt at making it more NOMMU-friendly

diff --git a/shell/hush.c b/shell/hush.c
index 9181641b9fb351f4055fb1a366aee9e9f777d6ef..19d516dffbf09c9c63bfbb9d2984516a2b2e95c0 100644 (file)
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -86,6 +86,15 @@ extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
 #include "busybox.h" /* for struct bb_applet */
 
 
+#if !BB_MMU
+/* A bit drastic. Can allow some simpler commands
+ * by analysing command in generate_stream_from_list()
+ */
+#undef ENABLE_HUSH_TICK
+#define ENABLE_HUSH_TICK 0
+#endif
+
+
 /* If you comment out one of these below, it will be #defined later
  * to perform debug printfs to stderr: */
 #define debug_printf(...)        do {} while (0)
@@ -1268,7 +1277,7 @@ static int setup_redirects(struct child_prog *prog, int squirrel[])
                                squirrel[redir->fd] = dup(redir->fd);
                        }
                        if (openfd == -3) {
-                               close(openfd);
+                               //close(openfd); // close(-3) ??!
                        } else {
                                dup2(openfd, redir->fd);
                                if (redir->dup == -1)
@@ -1291,8 +1300,9 @@ static void restore_redirects(int squirrel[])
        }
 }
 
-/* never returns */
-/* XXX no exit() here.  If you don't exec, use _exit instead.
+/* Called after [v]fork() in run_pipe_real(), or from builtin_exec().
+ * Never returns.
+ * XXX no exit() here.  If you don't exec, use _exit instead.
  * The at_exit handlers apparently confuse the calling process,
  * in particular stdin handling.  Not sure why? -- because of vfork! (vda) */
 static void pseudo_exec_argv(char **argv)
@@ -1359,6 +1369,8 @@ static void pseudo_exec_argv(char **argv)
        _exit(1);
 }
 
+/* Called after [v]fork() in run_pipe_real()
+ */
 static void pseudo_exec(struct child_prog *child)
 {
 // FIXME: buggy wrt NOMMU! Must not modify any global data
@@ -1370,7 +1382,9 @@ static void pseudo_exec(struct child_prog *child)
        }
 
        if (child->group) {
-       // FIXME: do not modify globals! Think vfork!
+#if !BB_MMU
+               bb_error_msg_and_exit("nested lists are not supported on NOMMU");
+#else
 #if ENABLE_HUSH_INTERACTIVE
                debug_printf_exec("pseudo_exec: setting interactive_fd=0\n");
                interactive_fd = 0;    /* crucial!!!! */
@@ -1380,6 +1394,7 @@ static void pseudo_exec(struct child_prog *child)
                /* OK to leak memory by not calling free_pipe_list,
                 * since this process is about to exit */
                _exit(rcode);
+#endif
        }
 
        /* Can happen.  See what bash does with ">foo" by itself. */
@@ -1787,14 +1802,8 @@ static int run_pipe_real(struct pipe *pi)
                        }
 #endif
                        /* in non-interactive case fatal sigs are already SIG_DFL */
-                       if (nextin != 0) {
-                               dup2(nextin, 0);
-                               close(nextin);
-                       }
-                       if (nextout != 1) {
-                               dup2(nextout, 1);
-                               close(nextout);
-                       }
+                       xmove_fd(nextin, 0);
+                       xmove_fd(nextout, 1);
                        if (pipefds[0] != -1) {
                                close(pipefds[0]);  /* opposite end of our output pipe */
                        }
@@ -3084,17 +3093,14 @@ static int redirect_opt_num(o_string *o)
 }
 
 #if ENABLE_HUSH_TICK
+/* NB: currently disabled on NOMMU */
 static FILE *generate_stream_from_list(struct pipe *head)
 {
        FILE *pf;
        int pid, channel[2];
 
        xpipe(channel);
-#if BB_MMU
        pid = fork();
-#else
-       pid = vfork();
-#endif
        if (pid < 0) {
                bb_perror_msg_and_die("fork");
        } else if (pid == 0) {