setarch: do not try to use non-existent data in argv[]

diff --git a/util-linux/setarch.c b/util-linux/setarch.c
index 250a938..8213382 100644 (file)
--- a/util-linux/setarch.c
+++ b/util-linux/setarch.c
@@ -1,6 +1,6 @@
 /* vi: set sw=4 ts=4: */
 /*
- * Linux32/linux64 allows for changing uname emulation.
+ * linux32/linux64 allows for changing uname emulation.
  *
  * Copyright 2002 Andi Kleen, SuSE Labs.
  *
@@ -14,32 +14,32 @@
 int setarch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int setarch_main(int argc UNUSED_PARAM, char **argv)
 {
-       int pers = -1;
+       int pers;
 
        /* Figure out what personality we are supposed to switch to ...
         * we can be invoked as either:
-        * argv[0],argv[1] -> "setarch","personality"
-        * argv[0]         -> "personality"
+        * argv[0],argv[1] == "setarch","personality"
+        * argv[0]         == "personality"
         */
-retry:
-       if (argv[0][5] == '6') /* linux64 */
+       if (ENABLE_SETARCH && applet_name[0] == 's'
+        && argv[1] && strncpy(argv[1], "linux", 5)
+       ) {
+               applet_name = argv[1];
+               argv++;
+       }
+       if (applet_name[5] == '6') /* linux64 */
                pers = PER_LINUX;
-       else if (argv[0][5] == '3') /* linux32 */
-               pers = PER_LINUX32;
-       else if (pers == -1 && argv[1] != NULL) {
+       else if (applet_name[5] == '3') /* linux32 */
                pers = PER_LINUX32;
-               ++argv;
-               goto retry;
-       }
+       else
+               bb_show_usage();
 
-       /* make user actually gave us something to do */
-       ++argv;
+       argv++;
        if (argv[0] == NULL)
                bb_show_usage();
 
        /* Try to set personality */
        if (personality(pers) >= 0) {
-
                /* Try to execute the program */
                BB_EXECVP(argv[0], argv);
        }