BusyBox has no business hard coding the number of major and minor bits for a

dev_t.  This is especially important now that the user space concept of a dev_t
and the kernel concept of a dev_t are divergant.  The only bit of user space
allowed to know the number of major and minor bits is include/sys/sysmacros.h
(i.e. part of libc).  When used with a current C library and a 2.6.x kernel,
this fix should allow BusyBox to support wide device major/minor numbers.
 -Erik

2 files changed, 4 insertions, 3 deletions

diff --git a/archival/libunarchive/get_header_cpio.c b/archival/libunarchive/get_header_cpio.c
index f72c37634..11925c4e3 100644
--- a/archival/libunarchive/get_header_cpio.c
+++ b/archival/libunarchive/get_header_cpio.c
@@ -18,6 +18,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <sys/sysmacros.h>     /* major() and minor() */
 #include "unarchive.h"
 #include "libbb.h"
 
@@ -143,7 +144,7 @@ extern char get_header_cpio(archive_handle_t *archive_handle)
                         }
                 }
         }
-        file_header->device = (major << 8) | minor;
+        file_header->device = makedev(major, minor);
 
         if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) {
                 archive_handle->action_data(archive_handle);
diff --git a/archival/libunarchive/get_header_tar.c b/archival/libunarchive/get_header_tar.c
index 33f19c60a..1ad9ac5e5 100644
--- a/archival/libunarchive/get_header_tar.c
+++ b/archival/libunarchive/get_header_tar.c
@@ -121,8 +121,8 @@ extern char get_header_tar(archive_handle_t *archive_handle)
         file_header->mtime = strtol(tar.formated.mtime, NULL, 8);
         file_header->link_name = (tar.formated.linkname[0] != '\0') ?
             bb_xstrdup(tar.formated.linkname) : NULL;
-        file_header->device = (dev_t) ((strtol(tar.formated.devmajor, NULL, 8) << 8) +
-                                 strtol(tar.formated.devminor, NULL, 8));
+        file_header->device = makedev(strtol(tar.formated.devmajor, NULL, 8),
+                strtol(tar.formated.devminor, NULL, 8));
 
         /* Set bits 0-11 of the files mode */
         file_header->mode = 07777 & strtol(tar.formated.mode, NULL, 8);