189 lines
4.9 KiB

# --- SDE-COPYRIGHT-NOTE-BEGIN ---
# This copyright note is auto-generated by ./scripts/Create-CopyPatch.
#
# Filename: package/.../embutils/x-switch_root.patch
# Copyright (C) 2007 The OpenSDE Project
# Copyright (C) 2004 - 2006 The T2 SDE Project
#
# More information can be found in the files COPYING and README.
#
# This patch file is dual-licensed. It is available under the license the
# patched project is licensed under, as long as it is an OpenSource license
# as defined at http://www.opensource.org/ (e.g. BSD, X11) or under the terms
# of the GNU General Public License as published by the Free Software
# Foundation; either version 2 of the License, or (at your option) any later
# version.
# --- SDE-COPYRIGHT-NOTE-END ---
pivot_root'ing rootfs does uncover kernel inf. loops, thus I extraced some
bits form the Fedora Core's nash to trick around with moving the mount point
and chroot to move the real root device to / - yuck.
- Rene Rebe <rene@exactcode.de>
--- embutils-0.17/switch_root.c 1970-01-01 00:00:00.000000000 +0000
+++ embutils-0.17-more/switch_root.c 2005-08-27 09:05:22.000000000 +0000
@@ -0,0 +1,151 @@
+
+/* inspired by Fedora Core's mkinitrd/nash beast
+ - to pivot_root alike functionality with initramfs
+
+ 2005 by Rene Rebe
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <dirent.h>
+#include <stdio.h>
+#include <errno.h>
+
+#ifndef MS_REMOUNT
+#define MS_REMOUNT 32
+#endif
+
+#ifndef MS_BIND
+#define MS_BIND 4096
+#endif
+
+#ifndef MS_MOVE
+#define MS_MOVE 8192
+#endif
+
+/* remove all files/directories below dirName -- don't cross mountpoints */
+int recursiveRemove(char * dirName) {
+ struct stat sb,rb;
+ DIR * dir;
+ struct dirent * d;
+ char * strBuf = alloca(strlen(dirName) + 1024);
+
+ if (!(dir = opendir(dirName))) {
+ fprintf(stderr, "error opening %s: %d\n", dirName, errno);
+ return 0;
+ }
+
+ if (fstat(dirfd(dir),&rb)) {
+ fprintf(stderr, "unable to stat %s: %d\n", dirName, errno);
+ return 0;
+ }
+
+ errno = 0;
+ while ((d = readdir(dir))) {
+ errno = 0;
+
+ if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, "..")) {
+ errno = 0;
+ continue;
+ }
+
+ strcpy(strBuf, dirName);
+ strcat(strBuf, "/");
+ strcat(strBuf, d->d_name);
+
+ if (lstat(strBuf, &sb)) {
+ fprintf(stderr, "failed to stat %s: %d\n", strBuf, errno);
+ errno = 0;
+ continue;
+ }
+
+ /* only descend into subdirectories if device is same as dir */
+ if (S_ISDIR(sb.st_mode)) {
+ if (sb.st_dev == rb.st_dev) {
+ recursiveRemove(strBuf);
+ if (rmdir(strBuf))
+ fprintf(stderr, "failed to rmdir %s: %d\n", strBuf, errno);
+ }
+ errno = 0;
+ continue;
+ }
+
+ if (unlink(strBuf)) {
+ fprintf(stderr, "failed to remove %s: %d\n", strBuf, errno);
+ errno = 0;
+ continue;
+ }
+ }
+
+ if (errno) {
+ closedir(dir);
+ printf("error reading from %s: %d\n", dirName, errno);
+ return 1;
+ }
+
+ closedir(dir);
+
+ return 0;
+}
+
+/* 2.6 magic not-pivot-root but kind of similar stuff.
+ * This is based on code from klibc/utils/run_init.c
+ */
+int main (int argc, char* argv[]) {
+ char * new;
+
+ if (!*++argv) {
+ printf("switch_root: new root mount point expected\n");
+ return 1;
+ }
+ new = *argv;
+
+ if (!*++argv) {
+ printf("switch_root: new init expected\n");
+ return 1;
+ }
+
+ int fd, i = 0;
+
+ if (chdir(new)) {
+ printf("switch_root: chdir(%s) failed: %d\n", new, errno);
+ return 1;
+ }
+
+ if ((fd = open("./dev/console", O_RDWR)) < 0) {
+ printf("ERROR opening /dev/console!!!!: %d\n", errno);
+ fd = 0;
+ }
+
+ if (dup2(fd, 0) != 0) printf("error dup2'ing fd of %d to 0\n", fd);
+ if (dup2(fd, 1) != 1) printf("error dup2'ing fd of %d to 1\n", fd);
+ if (dup2(fd, 2) != 2) printf("error dup2'ing fd of %d to 2\n", fd);
+ if (fd > 2)
+ close(fd);
+
+// recursiveRemove("/");
+
+ fd = open("/", O_RDONLY);
+
+ if (mount(".", "/", NULL, MS_MOVE, NULL)) {
+ printf("switch_root: mount failed: %d\n", errno);
+ close(fd);
+ return 1;
+ }
+
+ if (chroot(".") || chdir("/")) {
+ printf("switch_root: chroot() failed: %d\n", errno);
+ close(fd);
+ return 1;
+ }
+
+ /* release the old "/" */
+ close(fd);
+
+ /* exec the init */
+ fd = execvp (argv[0], argv);
+ printf ("switch_root: execvp failed: %d\n", fd);
+ return fd;
+}
+
--- ./Makefile.orig 2007-03-28 00:46:09.000000000 -0400
+++ ./Makefile 2007-03-28 00:46:49.000000000 -0400
@@ -12,7 +12,7 @@
domainname id ln mv cp yes which cat rm wc ls whoami mkfifo head install \
sosrm soscp sosmv sosln soslns md5sum sleep2 allinone uniq tr mesg du \
uuencode uudecode nohup nice cmp mktemp truncate strings test date \
-printenv chrootuid renice free losetup
+printenv chrootuid renice free losetup switch_root
OS:=$(shell uname)
ifeq ($(OS),Linux)