make compressed help code NOMMU- and NOFORK-friendly -

no forking anymore, bunzip2 unpack routine now does all it in memory.

3 files changed, 59 insertions, 101 deletions

diff --git a/libbb/crc32.c b/libbb/crc32.c
index 1e4a57e8a..acbc45827 100644
--- a/libbb/crc32.c
+++ b/libbb/crc32.c
@@ -16,14 +16,15 @@
 
 #include "libbb.h"
 
-uint32_t *crc32_filltable(int endian)
+uint32_t *crc32_filltable(uint32_t *crc_table, int endian)
 {
-
-        uint32_t *crc_table = xmalloc(256 * sizeof(uint32_t));
         uint32_t polynomial = endian ? 0x04c11db7 : 0xedb88320;
         uint32_t c;
         int i, j;
 
+        if (!crc_table)
+                crc_table = xmalloc(256 * sizeof(uint32_t));
+
         for (i = 0; i < 256; i++) {
                 c = endian ? (i << 24) : i;
                 for (j = 8; j; j--) {
diff --git a/libbb/vfork_daemon_rexec.c b/libbb/vfork_daemon_rexec.c
index dabd1a6d6..cf88a2b28 100644
--- a/libbb/vfork_daemon_rexec.c
+++ b/libbb/vfork_daemon_rexec.c
@@ -102,120 +102,68 @@ int wait_pid(int *wstat, int pid)
 
 int spawn_and_wait(char **argv)
 {
+#if ENABLE_FEATURE_EXEC_PREFER_APPLETS
         int rc;
+        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
+        if (a && (a->nofork
 #ifndef BB_NOMMU
-                         || a->noexec /* NOEXEC cannot be used on NOMMU */
+                 || a->noexec /* NOEXEC cannot be used on NOMMU */
 #endif
-                )) {
-                        int argc = 1;
-                        char **pp = argv;
-                        while (*++pp)
-                                argc++;
+        )) {
+                int argc = 1;
+                char **pp = argv;
+                while (*++pp)
+                        argc++;
 #ifndef BB_NOMMU
-                        if (a->nofork)
+                if (a->nofork)
 #endif
-                        {
-                                int old_sleep = die_sleep;
-                                int old_x = xfunc_error_retval;
-                                die_sleep = -1; /* special flag */
-                                /* xfunc_die() checks for it */
-
-                                rc = setjmp(die_jmp);
-                                if (!rc) {
-                                        const struct bb_applet *old_a = current_applet;
-                                        current_applet = a;
-                                        applet_name = a->name;
+                {
+                        int old_sleep = die_sleep;
+                        int old_x = xfunc_error_retval;
+                        die_sleep = -1; /* special flag */
+                        /* xfunc_die() checks for it */
+
+                        rc = setjmp(die_jmp);
+                        if (!rc) {
+                                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;
+// TODO: what if applet will mangle argv vector?
+// xargs needs argv untouched because it frees the vector!
+// shouldn't we pass a copy?
+                                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 */
-                        /* a->noexec is true */
-                        rc = fork();
-                        if (rc)
-                                goto w;
-                        /* child */
-                        current_applet = a;
-                        run_current_applet_and_exit(argc, argv);
+                /* a->noexec is true */
+                rc = fork();
+                if (rc)
+                        goto w;
+                /* child */
+                current_applet = a;
+                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);
-}
-
-
-#if 0 //ndef BB_NOMMU
-// Die with an error message if we can't daemonize.
-void xdaemon(int nochdir, int noclose)
-{
-        if (daemon(nochdir, noclose))
-                bb_perror_msg_and_die("daemon");
-}
+#else /* !FEATURE_EXEC_PREFER_APPLETS */
+        return wait4pid(spawn(argv));
 #endif
-
-#if 0 // def BB_NOMMU
-void vfork_daemon_rexec(int nochdir, int noclose, char **argv)
-{
-        int fd;
-
-        /* Maybe we are already re-execed and come here again? */
-        if (re_execed)
-                return;
-
-        setsid();
-
-        if (!nochdir)
-                xchdir("/");
-
-        if (!noclose) {
-                /* if "/dev/null" doesn't exist, bail out! */
-                fd = xopen(bb_dev_null, O_RDWR);
-                dup2(fd, STDIN_FILENO);
-                dup2(fd, STDOUT_FILENO);
-                dup2(fd, STDERR_FILENO);
-                while (fd > 2)
-                        close(fd--);
-        }
-
-        switch (vfork()) {
-        case 0: /* child */
-                /* Make certain we are not a session leader, or else we
-                 * might reacquire a controlling terminal */
-                if (vfork())
-                        _exit(0);
-                /* High-order bit of first char in argv[0] is a hidden
-                 * "we have (alrealy) re-execed, don't do it again" flag */
-                argv[0][0] |= 0x80;
-                execv(CONFIG_BUSYBOX_EXEC_PATH, argv);
-                bb_perror_msg_and_die("exec %s", CONFIG_BUSYBOX_EXEC_PATH);
-        case -1: /* error */
-                bb_perror_msg_and_die("vfork");
-        default: /* parent */
-                exit(0);
-        }
 }
-#endif /* BB_NOMMU */
+
 
 #ifdef BB_NOMMU
 void forkexit_or_rexec(char **argv)
diff --git a/libbb/xfuncs.c b/libbb/xfuncs.c
index b9d013a24..dde91a2ba 100644
--- a/libbb/xfuncs.c
+++ b/libbb/xfuncs.c
@@ -20,6 +20,15 @@
  * Since dmalloc's prototypes overwrite the impls here as they are
  * included after these prototypes in libbb.h, all is well.
  */
+// Warn if we can't allocate size bytes of memory.
+void *malloc_or_warn(size_t size)
+{
+        void *ptr = malloc(size);
+        if (ptr == NULL && size != 0)
+                bb_error_msg(bb_msg_memory_exhausted);
+        return ptr;
+}
+
 // Die if we can't allocate size bytes of memory.
 void *xmalloc(size_t size)
 {