Changeset 3621 in MondoRescue for branches/3.3/mindi-busybox/libbb/vfork_daemon_rexec.c

Timestamp:

Dec 20, 2016, 4:07:32 PM (7 years ago)

Author:

Bruno Cornec

Message:

New 3?3 banch for incorporation of latest busybox 1.25. Changing minor version to handle potential incompatibilities.

Location:

branches/3.3

Files:

• . (copied) (copied from branches/3.2 )
• mindi-busybox/libbb/vfork_daemon_rexec.c (modified) (5 diffs)

branches/3.3/mindi-busybox/libbb/vfork_daemon_rexec.c

@@ -70 +70 @@
 
 #if ENABLE_FEATURE_PREFER_APPLETS
+static jmp_buf die_jmp;
+static void jump(void)
+{
+    /* Special case. We arrive here if NOFORK applet
+     * calls xfunc, which then decides to die.
+     * We don't die, but jump instead back to caller.
+     * NOFORK applets still cannot carelessly call xfuncs:
+     * p = xmalloc(10);
+     * q = xmalloc(10); // BUG! if this dies, we leak p!
+     */
+    /* | 0x100 allows to pass zero exitcode (longjmp can't pass 0).
+     * This works because exitcodes are bytes,
+     * run_nofork_applet() ensures that by "& 0xff" */
+    longjmp(die_jmp, xfunc_error_retval | 0x100);
+}
+
 struct nofork_save_area {
     jmp_buf die_jmp;
+    void (*die_func)(void);
     const char *applet_name;
     uint32_t option_mask32;
-    int die_sleep;
     uint8_t xfunc_error_retval;
 };
@@ -80 +96 @@
 {
     memcpy(&save->die_jmp, &die_jmp, sizeof(die_jmp));
+    save->die_func = die_func;
     save->applet_name = applet_name;
+    save->option_mask32 = option_mask32;
     save->xfunc_error_retval = xfunc_error_retval;
-    save->option_mask32 = option_mask32;
-    save->die_sleep = die_sleep;
 }
 static void restore_nofork_data(struct nofork_save_area *save)
 {
     memcpy(&die_jmp, &save->die_jmp, sizeof(die_jmp));
+    die_func = save->die_func;
     applet_name = save->applet_name;
+    option_mask32 = save->option_mask32;
     xfunc_error_retval = save->xfunc_error_retval;
-    option_mask32 = save->option_mask32;
-    die_sleep = save->die_sleep;
 }
 
@@ -100 +116 @@
 
     save_nofork_data(&old);
-
-    applet_name = APPLET_NAME(applet_no);
 
     xfunc_error_retval = EXIT_FAILURE;
@@ -134 +148 @@
         argc++;
 
-    /* Special flag for xfunc_die(). If xfunc will "die"
-     * in NOFORK applet, xfunc_die() sees negative
-     * die_sleep and longjmp here instead. */
-    die_sleep = -1;
-
+    /* If xfunc "dies" in NOFORK applet, die_func longjmp's here instead */
+    die_func = jump;
     rc = setjmp(die_jmp);
     if (!rc) {
@@ -145 +156 @@
         char *tmp_argv[argc+1];
         memcpy(tmp_argv, argv, (argc+1) * sizeof(tmp_argv[0]));
+        applet_name = tmp_argv[0];
         /* Finally we can call NOFORK applet's main() */
         rc = applet_main[applet_no](argc, tmp_argv);
-    } else { /* xfunc died in NOFORK applet */
-        /* in case they meant to return 0... */
-        if (rc == -2222)
-            rc = 0;
+    } else {
+        /* xfunc died in NOFORK applet */
     }