+2006-12-24 Jim Meyering <jim@meyering.net>
+
+ Work around an fchownat bug in glibc-2.4:
+ http://lists.ubuntu.com/archives/ubuntu-users/2006-September/093218.html
+ This bug would cause "chown -RP ... DIR" to follow symlinks in DIR,
+ in spite of the -P option.
+ * m4/openat.m4 (gl_FUNC_FCHOWNAT, gl_FUNC_FCHOWNAT_DEREF_BUG):
+ New macros.
+ (gl_PREREQ_OPENAT): Require gl_FUNC_FCHOWNAT.
+ * modules/openat (Files): Add lib/fchownat.c.
+ * lib/openat.c (fchownat): Don't define here. Move to...
+ * lib/fchownat.c: ...this new file.
+
2006-12-23 Paul Eggert <eggert@cs.ucla.edu>
Fix bug reported by Bruno Haible in
--- /dev/null
+/* This function serves as replacement for a missing fchownat function,
+ as well as a work around for the fchownat bug in glibc-2.4:
+ <http://lists.ubuntu.com/archives/ubuntu-users/2006-September/093218.html>
+ when the buggy fchownat-with-AT_SYMLINK_NOFOLLOW operates on a symlink, it
+ mistakenly affects the symlink referent, rather than the symlink itself.
+
+ Copyright (C) 2006 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2, or (at your option)
+ any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software Foundation,
+ Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+/* written by Jim Meyering */
+
+#include <config.h>
+
+#include "openat.h"
+
+#include <unistd.h>
+
+#include "dirname.h" /* solely for definition of IS_ABSOLUTE_FILE_NAME */
+#include "save-cwd.h"
+#include "openat-priv.h"
+
+/* Replacement for Solaris' function by the same name.
+ Invoke chown or lchown on file, FILE, using OWNER and GROUP, in the
+ directory open on descriptor FD. If FLAG is AT_SYMLINK_NOFOLLOW, then
+ use lchown, otherwise, use chown. If possible, do it without changing
+ the working directory. Otherwise, resort to using save_cwd/fchdir,
+ then mkdir/restore_cwd. If either the save_cwd or the restore_cwd
+ fails, then give a diagnostic and exit nonzero. */
+
+#define AT_FUNC_NAME fchownat
+#define AT_FUNC_F1 lchown
+#define AT_FUNC_F2 chown
+#define AT_FUNC_USE_F1_COND flag == AT_SYMLINK_NOFOLLOW
+#define AT_FUNC_POST_FILE_PARAM_DECLS , uid_t owner, gid_t group, int flag
+#define AT_FUNC_POST_FILE_ARGS , owner, group
+#include "at-func.c"
#undef AT_FUNC_USE_F1_COND
#undef AT_FUNC_POST_FILE_PARAM_DECLS
#undef AT_FUNC_POST_FILE_ARGS
-
-/* Replacement for Solaris' function by the same name.
- Invoke chown or lchown on file, FILE, using OWNER and GROUP, in the
- directory open on descriptor FD. If FLAG is AT_SYMLINK_NOFOLLOW, then
- use lchown, otherwise, use chown. If possible, do it without changing
- the working directory. Otherwise, resort to using save_cwd/fchdir,
- then mkdir/restore_cwd. If either the save_cwd or the restore_cwd
- fails, then give a diagnostic and exit nonzero. */
-
-#define AT_FUNC_NAME fchownat
-#define AT_FUNC_F1 lchown
-#define AT_FUNC_F2 chown
-#define AT_FUNC_USE_F1_COND flag == AT_SYMLINK_NOFOLLOW
-#define AT_FUNC_POST_FILE_PARAM_DECLS , uid_t owner, gid_t group, int flag
-#define AT_FUNC_POST_FILE_ARGS , owner, group
-#include "at-func.c"
-#serial 12
+#serial 13
# See if we need to use our replacement for Solaris' openat et al functions.
dnl Copyright (C) 2004, 2005, 2006 Free Software Foundation, Inc.
[Define to rpl_ if the openat replacement function should be used.])
gl_PREREQ_OPENAT;;
esac
+ AC_REQUIRE([gl_FUNC_FCHOWNAT])
+])
+
+# gl_FUNC_FCHOWNAT_DEREF_BUG([ACTION-IF-BUGGY[, ACTION-IF-NOT_BUGGY]])
+AC_DEFUN([gl_FUNC_FCHOWNAT_DEREF_BUG],
+[
+ AC_CACHE_CHECK([whether fchownat works with AT_SYMLINK_NOFOLLOW],
+ gl_cv_func_fchownat_nofollow_works,
+ [
+ gl_dangle=conftest.dangle
+ # Remove any remnants of a previous test.
+ rm -f $gl_dangle
+ # Arrange for deletion of the temporary file this test creates.
+ ac_clean_files="$ac_clean_files $gl_dangle"
+ AC_RUN_IFELSE(
+ [AC_LANG_SOURCE(
+ [[
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <sys/types.h>
+int
+main ()
+{
+ return (fchownat (AT_FDCWD, "$gl_dangle", -1, getgid (),
+ AT_SYMLINK_NOFOLLOW) != 0
+ && errno == ENOENT);
+}
+ ]])],
+ [gl_cv_func_fchownat_nofollow_works=yes],
+ [gl_cv_func_fchownat_nofollow_works=no],
+ [gl_cv_func_fchownat_nofollow_works=no],
+ )
+ ])
+ AS_IF([test $gl_cv_func_fchownat_nofollow_works = no], [$1], [$2])
+])
+
+# If we have the fchownat function, and it has the bug (in glibc-2.4)
+# that it dereferences symlinks even with AT_SYMLINK_NOFOLLOW, then
+# use the replacement function.
+# Also use the replacement function if fchownat is simply not available.
+AC_DEFUN([gl_FUNC_FCHOWNAT],
+[
+ # Assume we'll use the replacement function.
+ # The only case in which we won't is when we have fchownat, and it works.
+ use_replacement_fchownat=yes
+
+ AC_CHECK_FUNC([fchownat], [have_fchownat=yes], [have_fchownat=no])
+ if test $have_fchownat = yes; then
+ gl_FUNC_FCHOWNAT_DEREF_BUG([have_fchownat_bug=yes])
+ if test $have_fchownat_bug = no; then
+ use_replacement_fchownat=no
+ fi
+ fi
+
+ if test $use_replacement_fchownat = yes; then
+ AC_LIBOBJ(fchownat)
+ AC_DEFINE(fchownat, rpl_fchownat,
+ [Define to rpl_fchownat if the replacement function should be used.])
+ fi
])
AC_DEFUN([gl_PREREQ_OPENAT],
Files:
lib/at-func.c
lib/fchmodat.c
+lib/fchownat.c
lib/fstatat.c
lib/mkdirat.c
lib/openat.c
projects / pspp / commitdiff