hush: fix thinko in re_execute_shell; pass even less junk to heredoc helper

function                                             old     new   delta
re_execute_shell                                     284     314     +30
setup_heredoc                                        290     303     +13
execv                                                 23       -     -23

diff --git a/shell/hush.c b/shell/hush.c
index 9920e98c65b99a1c56ab4f81b4078a58ac6e27ba..3959da1ea60d510e532ffbc917b6946aa06e6e0e 100644 (file)
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -2180,10 +2180,21 @@ static void re_execute_shell(const char *s, int is_heredoc) NORETURN;
 static void re_execute_shell(const char *s, int is_heredoc)
 {
        char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
+       char *heredoc_argv[4];
        struct variable *cur;
        char **argv, **pp, **pp2;
        unsigned cnt;
 
+       if (is_heredoc) {
+               argv = heredoc_argv;
+               argv[0] = (char *) G.argv0_for_re_execing;
+               argv[1] = (char *) "-<";
+               argv[2] = (char *) s;
+               argv[3] = NULL;
+               pp = &argv[3]; /* used as pointer to empty environmaent */
+               goto do_exec;
+       }
+
        sprintf(param_buf, "-$%x:%x:%x" USE_HUSH_LOOPS(":%x")
                        , (unsigned) G.root_pid
                        , (unsigned) G.last_bg_pid
@@ -2198,7 +2209,7 @@ static void re_execute_shell(const char *s, int is_heredoc)
                if (!cur->flg_export || cur->flg_read_only)
                        cnt += 2;
        }
-       G.argv_from_re_execing = pp = xzalloc(sizeof(argv[0]) * cnt);
+       G.argv_from_re_execing = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
        *pp++ = (char *) G.argv0_for_re_execing;
        *pp++ = param_buf;
        for (cur = G.top_var; cur; cur = cur->next) {
@@ -2232,22 +2243,21 @@ static void re_execute_shell(const char *s, int is_heredoc)
         * I conclude it means we don't need to pass active traps here.
         * exec syscall below resets them to SIG_DFL for us.
         */
-       *pp++ = (char *) (is_heredoc ? "-<" : "-c");
+       *pp++ = (char *) "-c";
        *pp++ = (char *) s;
        pp2 = G.global_argv;
        while (*pp2)
                *pp++ = *pp2++;
        /* *pp = NULL; - is already there */
+       pp = environ;
 
+ do_exec:
        debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
        sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
-       execve(bb_busybox_exec_path,
-               G.argv_from_re_execing,
-               (is_heredoc ? pp /* points to NULL ptr */ : environ)
-               );
+       execve(bb_busybox_exec_path, argv, pp);
        /* Fallback. Useful for init=/bin/hush usage etc */
-       if (G.argv0_for_re_execing[0] == '/')
-               execv(G.argv0_for_re_execing, G.argv_from_re_execing);
+       if (argv[0][0] == '/')
+               execve(argv[0], argv, pp);
        xfunc_error_retval = 127;
        bb_error_msg_and_die("can't re-execute the shell");
 }
@@ -2281,6 +2291,7 @@ static void setup_heredoc(struct redir_struct *redir)
        }
        len = strlen(heredoc);
 
+       close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
        xpiped_pair(pair);
        xmove_fd(pair.rd, redir->rd_fd);