OS-3280 need a way to specify the root of a native system in the lx brand
OS-3279 lx brand should allow delegated datasets
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>

@@ -179,10 +179,37 @@
         -1,                     /* number of iterations; infinitely */
         OPT_PSINFO | OPT_FULLSCREEN | OPT_USEHOME | OPT_TERMCAP,
         -1                      /* sort in decreasing order */
 };
 
+
+static int
+proc_snprintf(char *_RESTRICT_KYWD s, size_t n,
+    const char *_RESTRICT_KYWD fmt, ...)
+{
+        static boolean_t ptools_zroot_valid = B_FALSE;
+        static const char *ptools_zroot = NULL;
+        va_list args;
+        int ret, nret = 0;
+
+        if (ptools_zroot_valid == B_FALSE) {
+                ptools_zroot_valid = B_TRUE;
+                ptools_zroot = zone_get_nroot();
+        }
+
+        if (ptools_zroot != NULL) {
+                nret = snprintf(s, n, "%s", ptools_zroot);
+                if (nret > n)
+                        return (nret);
+        }
+        va_start(args, fmt);
+        ret = vsnprintf(s + nret, n - nret, fmt, args);
+        va_end(args);
+
+        return (ret + nret);
+}
+
 /*
  * Print timestamp as decimal reprentation of time_t value (-d u was specified)
  * or the standard date format (-d d was specified).
  */
 static void

@@ -846,13 +873,13 @@
 }
 
 static int
 read_procfile(fd_t **fd, char *pidstr, char *file, void *buf, size_t bufsize)
 {
-        char procfile[MAX_PROCFS_PATH];
+        char procfile[PATH_MAX];
 
-        (void) snprintf(procfile, MAX_PROCFS_PATH,
+        (void) proc_snprintf(procfile, PATH_MAX,
             "/proc/%s/%s", pidstr, file);
         if ((*fd = fd_open(procfile, O_RDONLY, *fd)) == NULL)
                 return (1);
         if (pread(fd_getfd(*fd), buf, bufsize, 0) != bufsize) {
                 fd_close(*fd);

@@ -1374,10 +1401,11 @@
         char *sortk = "cpu";    /* default sort key */
         int opt;
         int timeout;
         struct pollfd pollset;
         char key;
+        char procpath[PATH_MAX];
 
         (void) setlocale(LC_ALL, "");
         (void) textdomain(TEXT_DOMAIN);
         Progname(argv[0]);
         lwpid_init();

@@ -1573,11 +1601,12 @@
         list_setkeyfunc(NULL, &opts, &projects, LT_PROJECTS);
         list_setkeyfunc(NULL, &opts, &zones, LT_ZONES);
         list_setkeyfunc(NULL, &opts, &lgroups, LT_LGRPS);
         if (opts.o_outpmode & OPT_TERMCAP)
                 curses_on();
-        if ((procdir = opendir("/proc")) == NULL)
+        (void) proc_snprintf(procpath, sizeof (procpath), "/proc");
+        if ((procdir = opendir(procpath)) == NULL)
                 Die(gettext("cannot open /proc directory\n"));
         if (opts.o_outpmode & OPT_TTY) {
                 (void) printf(gettext("Please wait...\r"));
                 if (!(opts.o_outpmode & OPT_TERMCAP))
                         (void) putchar('\n');