make a few struct bb_applet members conditional

rename sllep_and_die -> xfunc_die
make fflush_stdout_and_exit NOFORK-safe
fix some buglets found by randomconfig

8 files changed, 49 insertions, 28 deletions

diff --git a/libbb/copyfd.c b/libbb/copyfd.c
index e0596d5f6..aa8fbb967 100644
--- a/libbb/copyfd.c
+++ b/libbb/copyfd.c
@@ -74,7 +74,7 @@ void complain_copyfd_and_die(off_t sz)
         if (sz != -1)
                 bb_error_msg_and_die("short read");
         /* if sz == -1, bb_copyfd_XX already complained */
-        sleep_and_die();
+        xfunc_die();
 }
 #endif
 
@@ -94,7 +94,7 @@ void bb_copyfd_exact_size(int fd1, int fd2, off_t size)
         if (sz != -1)
                 bb_error_msg_and_die("short read");
         /* if sz == -1, bb_copyfd_XX already complained */
-        sleep_and_die();
+        xfunc_die();
 }
 
 off_t bb_copyfd_eof(int fd1, int fd2)
diff --git a/libbb/error_msg_and_die.c b/libbb/error_msg_and_die.c
index 39178a3ce..4a9049364 100644
--- a/libbb/error_msg_and_die.c
+++ b/libbb/error_msg_and_die.c
@@ -10,14 +10,25 @@
 #include "libbb.h"
 
 int die_sleep;
+#if ENABLE_FEATURE_EXEC_PREFER_APPLETS
 jmp_buf die_jmp;
+#endif
 
-void sleep_and_die(void)
+void xfunc_die(void)
 {
         if (die_sleep) {
-                /* Special case: don't die, but jump */
-                if (die_sleep < 0)
-                        longjmp(die_jmp, xfunc_error_retval);
+                if (ENABLE_FEATURE_EXEC_PREFER_APPLETS && die_sleep < 0) {
+                        /* 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!
+                         */
+                        /* -111 means "zero" (longjmp can't pass 0)
+                         * spawn_and_wait() catches -111. */
+                        longjmp(die_jmp, xfunc_error_retval ? xfunc_error_retval : -111);
+                }
                 sleep(die_sleep);
         }
         exit(xfunc_error_retval);
@@ -30,5 +41,5 @@ void bb_error_msg_and_die(const char *s, ...)
         va_start(p, s);
         bb_verror_msg(s, p, NULL);
         va_end(p);
-        sleep_and_die();
+        xfunc_die();
 }
diff --git a/libbb/fflush_stdout_and_exit.c b/libbb/fflush_stdout_and_exit.c
index ae68222b4..d79827f45 100644
--- a/libbb/fflush_stdout_and_exit.c
+++ b/libbb/fflush_stdout_and_exit.c
@@ -13,13 +13,17 @@
 
 #include "libbb.h"
 
-// TODO: make it safe to call from NOFORK applets
-// Currently, it can exit(0). Even if it is made to do longjmp trick
-// (see sleep_and_die internals), zero cannot be passed thru this way!
-
 void fflush_stdout_and_exit(int retval)
 {
         if (fflush(stdout))
-                sleep_and_die();
+                xfunc_die();
+
+        if (ENABLE_FEATURE_EXEC_PREFER_APPLETS && die_sleep < 0) {
+                /* We are in NOFORK applet. Do not exit() directly,
+                 * but use xfunc_die() */
+                xfunc_error_retval = retval;
+                xfunc_die();
+        }
+
         exit(retval);
 }
diff --git a/libbb/herror_msg_and_die.c b/libbb/herror_msg_and_die.c
index a7a22caf7..8c77378d7 100644
--- a/libbb/herror_msg_and_die.c
+++ b/libbb/herror_msg_and_die.c
@@ -7,9 +7,6 @@
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
 
-#include <stdarg.h>
-#include <stdlib.h>
-
 #include "libbb.h"
 
 void bb_herror_msg_and_die(const char *s, ...)
@@ -19,5 +16,5 @@ void bb_herror_msg_and_die(const char *s, ...)
         va_start(p, s);
         bb_vherror_msg(s, p);
         va_end(p);
-        sleep_and_die();
+        xfunc_die();
 }
diff --git a/libbb/perror_msg_and_die.c b/libbb/perror_msg_and_die.c
index 7521e7157..3a06b654b 100644
--- a/libbb/perror_msg_and_die.c
+++ b/libbb/perror_msg_and_die.c
@@ -7,10 +7,6 @@
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
 
-#include <stdio.h>
-#include <errno.h>
-#include <string.h>
-#include <stdlib.h>
 #include "libbb.h"
 
 void bb_perror_msg_and_die(const char *s, ...)
@@ -20,5 +16,5 @@ void bb_perror_msg_and_die(const char *s, ...)
         va_start(p, s);
         bb_vperror_msg(s, p);
         va_end(p);
-        sleep_and_die();
+        xfunc_die();
 }
diff --git a/libbb/vfork_daemon_rexec.c b/libbb/vfork_daemon_rexec.c
index 286ee2678..dabd1a6d6 100644
--- a/libbb/vfork_daemon_rexec.c
+++ b/libbb/vfork_daemon_rexec.c
@@ -16,7 +16,7 @@
  */
 
 #include <paths.h>
-#include "busybox.h" /* for struct BB_applet */
+#include "busybox.h" /* for struct bb_applet */
 
 /* This does a fork/exec in one call, using vfork().  Returns PID of new child,
  * -1 for failure.  Runs argv[0], searching path if that has no / in it. */
@@ -104,8 +104,9 @@ int spawn_and_wait(char **argv)
 {
         int rc;
 
-        if (ENABLE_FEATURE_EXEC_PREFER_APPLETS) {
-                const struct BB_applet *a = find_applet_by_name(argv[0]);
+#if ENABLE_FEATURE_EXEC_PREFER_APPLETS
+        {
+                const struct bb_applet *a = find_applet_by_name(argv[0]);
                 if (a && (a->nofork
 #ifndef BB_NOMMU
                          || a->noexec /* NOEXEC cannot be used on NOMMU */
@@ -120,19 +121,27 @@ int spawn_and_wait(char **argv)
 #endif
                         {
                                 int old_sleep = die_sleep;
+                                int old_x = xfunc_error_retval;
                                 die_sleep = -1; /* special flag */
-                                /* sleep_and_die() checks for it */
+                                /* xfunc_die() checks for it */
+
                                 rc = setjmp(die_jmp);
                                 if (!rc) {
-                                        const struct BB_applet *old_a = current_applet;
+                                        const struct bb_applet *old_a = current_applet;
                                         current_applet = a;
                                         applet_name = a->name;
 // what else should we save/restore?
                                         rc = a->main(argc, argv);
                                         current_applet = old_a;
                                         applet_name = old_a->name;                                      
+                                } else {
+                                        /* xfunc died in NOFORK applet */
+                                        if (rc == -111)
+                                                rc = 0;
                                 }
+
                                 die_sleep = old_sleep;
+                                xfunc_error_retval = old_x;
                                 return rc;
                         }
 #ifndef BB_NOMMU        /* MMU only */
@@ -145,9 +154,13 @@ int spawn_and_wait(char **argv)
                         run_current_applet_and_exit(argc, argv);
 #endif
                 }
+
         }
         rc = spawn(argv);
  w:
+#else /* !FEATURE_EXEC_PREFER_APPLETS */
+        rc = spawn(argv);
+#endif /* FEATURE_EXEC_PREFER_APPLETS */
         return wait4pid(rc);
 }
 
diff --git a/libbb/xconnect.c b/libbb/xconnect.c
index 8466325c7..e7d510678 100644
--- a/libbb/xconnect.c
+++ b/libbb/xconnect.c
@@ -166,7 +166,7 @@ USE_FEATURE_IPV6(sa_family_t af,)
         if (rc || !result) {
                 bb_error_msg("bad address '%s'", org_host);
                 if (ai_flags & DIE_ON_ERROR)
-                        sleep_and_die();
+                        xfunc_die();
                 goto ret;
         }
         r = xmalloc(offsetof(len_and_sockaddr, sa) + result->ai_addrlen);
diff --git a/libbb/xfuncs.c b/libbb/xfuncs.c
index fa4a15236..b9d013a24 100644
--- a/libbb/xfuncs.c
+++ b/libbb/xfuncs.c
@@ -476,7 +476,7 @@ void xprint_and_close_file(FILE *file)
         fflush(stdout);
         // copyfd outputs error messages for us.
         if (bb_copyfd_eof(fileno(file), 1) == -1)
-                sleep_and_die();
+                xfunc_die();
 
         fclose(file);
 }