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

3 files changed, 9 insertions, 12 deletions

diff --git a/archival/libunarchive/get_header_cpio.c b/archival/libunarchive/get_header_cpio.c
index f72c376..11925c4 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 33f19c6..1ad9ac5 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);
diff --git a/archival/tar.c b/archival/tar.c
index 2de6454..689dd14 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -49,6 +49,7 @@
 #include <signal.h>
 #include <sys/wait.h>
 #include <sys/socket.h>
+#include <sys/sysmacros.h>     /* major() and minor() */
 #include "unarchive.h"
 #include "busybox.h"
 
@@ -58,11 +59,6 @@
 # define TAR_MAGIC          "ustar"	/* ustar and a null */
 # define TAR_VERSION        "  "	/* Be compatable with GNU tar format */
 
-# ifndef MAJOR
-#  define MAJOR(dev) (((dev)>>8)&0xff)
-#  define MINOR(dev) ((dev)&0xff)
-# endif
-
 static const int TAR_BLOCK_SIZE = 512;
 static const int TAR_MAGIC_LEN = 6;
 static const int TAR_VERSION_LEN = 2;
@@ -262,15 +258,15 @@ static inline int writeTarHeader(struct TarBallInfo *tbInfo,
 	} else if (S_ISCHR(statbuf->st_mode)) {
 		header.typeflag = CHRTYPE;
 		putOctal(header.devmajor, sizeof(header.devmajor),
-				 MAJOR(statbuf->st_rdev));
+				 major(statbuf->st_rdev));
 		putOctal(header.devminor, sizeof(header.devminor),
-				 MINOR(statbuf->st_rdev));
+				 minor(statbuf->st_rdev));
 	} else if (S_ISBLK(statbuf->st_mode)) {
 		header.typeflag = BLKTYPE;
 		putOctal(header.devmajor, sizeof(header.devmajor),
-				 MAJOR(statbuf->st_rdev));
+				 major(statbuf->st_rdev));
 		putOctal(header.devminor, sizeof(header.devminor),
-				 MINOR(statbuf->st_rdev));
+				 minor(statbuf->st_rdev));
 	} else if (S_ISFIFO(statbuf->st_mode)) {
 		header.typeflag = FIFOTYPE;
 	} else if (S_ISREG(statbuf->st_mode)) {