Stub out the syscall, not the whole application. The stubbed
out syscall sets errno properly and whines about missing kernel
support.
-Erik
diff --git a/pivot_root.c b/pivot_root.c
index d34dcd7..4d7f8a3 100644
--- a/pivot_root.c
+++ b/pivot_root.c
@@ -3,24 +3,35 @@
* pivot_root.c - Change root file system. Based on util-linux 2.10s
*
* busyboxed by Evin Robertson
+ * pivot_root syscall stubbed by Erik Andersen, so it will compile
+ * regardless of the kernel being used.
*/
#include <stdlib.h>
#include <stdio.h>
+#include <errno.h>
#include <sys/syscall.h>
#include <linux/unistd.h>
#include "busybox.h"
#ifndef __NR_pivot_root
#warning This kernel does not support the pivot_root syscall
-#warning The pivot_root application is being stubbed out...
-int pivot_root_main(int argc, char **argv)
+#warning The pivot_root system call is being stubbed out...
+int pivot_root(const char * new_root,const char * put_old)
{
- printf("Please recompile with a kernel supporting the pivot_root syscall.\n");
- return 0;
+ /* BusyBox was compiled against a kernel that did not support
+ * the pivot_root system call. To make this application work,
+ * you will need to recompile with a kernel supporting the
+ * pivot_root system call.
+ */
+ fprintf(stderr, "\n\nTo make this application work, you will need to recompile\n");
+ fprintf(stderr, "with a kernel supporting the pivot_root system call. -Erik\n\n");
+ errno=ENOSYS;
+ return -1;
}
#else
-
static _syscall2(int,pivot_root,const char *,new_root,const char *,put_old)
+#endif
+
int pivot_root_main(int argc, char **argv)
@@ -28,13 +39,12 @@
if (argc != 3)
show_usage();
- if (pivot_root(argv[1],argv[2]) < 0)
- perror_msg_and_die("pivot_root");
+ if (pivot_root(argv[1],argv[2]) < 0)
+ perror_msg_and_die("pivot_root");
return EXIT_SUCCESS;
}
-#endif
/*