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changeset 5153:df81ae7d9c8b

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librestrict: Add linux-2.6-i686 stat support.
author Jan Nieuwenhuizen <janneke@gnu.org>
date Mon, 16 Feb 2009 14:49:42 +0100
parents 449189cf5824
children e366616c0120 8602011649e7
files librestrict/GNUmakefile librestrict/TODO librestrict/kernel-features.h librestrict/kernel_stat.h librestrict/restrict-stat.c librestrict/xstatconv.c librestrict/xstatconv.h
diffstat 7 files changed, 838 insertions(+), 2 deletions(-) [+]
line wrap: on
line diff
--- a/librestrict/GNUmakefile	Sun Feb 15 21:29:26 2009 +0100
+++ b/librestrict/GNUmakefile	Mon Feb 16 14:49:42 2009 +0100
@@ -2,7 +2,7 @@
 
 CC = gcc
 NM = nm
-CFLAGS = -W -Wall
+CFLAGS = -W -Wall -I .
 
 ALL_CFLAGS = $(CFLAGS)
 INSTALL = install
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/librestrict/TODO	Mon Feb 16 14:49:42 2009 +0100
@@ -0,0 +1,12 @@
+Fix the struct stat64/LARGEFILE/ configure mess, get rid of
+
+   /* FIXME: CONFIG? */
+
+xstat is verified to work on two linux boxes
+
+   Linux heerbeest 2.6.28-7-generic #20-Ubuntu SMP Mon Feb 9 15:42:34 UTC 2009 x86_64 GNU/Linux
+   ii  libc6                       2.9-0ubuntu9                GNU C Library: Shared libraries
+
+   Linux abc 2.6.26.webdev.nl #1 SMP Sat Jan 10 23:39:09 CET 2009 i686 GNU/Linux
+   ii  libc6          2.7-18         GNU C Library: Shared libraries
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/librestrict/kernel-features.h	Mon Feb 16 14:49:42 2009 +0100
@@ -0,0 +1,430 @@
+/* Set flags signalling availability of kernel features based on given
+   kernel version number.
+   Copyright (C) 1999-2003, 2004 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+/* This file must not contain any C code.  At least it must be protected
+   to allow using the file also in assembler files.  */
+
+#if defined __mips__
+# include <sgidefs.h>
+#endif
+
+#ifndef __LINUX_KERNEL_VERSION
+/* We assume the worst; all kernels should be supported.  */
+# define __LINUX_KERNEL_VERSION	0
+#endif
+
+/* We assume for __LINUX_KERNEL_VERSION the same encoding used in
+   linux/version.h.  I.e., the major, minor, and subminor all get a
+   byte with the major number being in the highest byte.  This means
+   we can do numeric comparisons.
+
+   In the following we will define certain symbols depending on
+   whether the describes kernel feature is available in the kernel
+   version given by __LINUX_KERNEL_VERSION.  We are not always exactly
+   recording the correct versions in which the features were
+   introduced.  If somebody cares these values can afterwards be
+   corrected.  Most of the numbers here are set corresponding to
+   2.2.0.  */
+
+/* `getcwd' system call.  */
+#if __LINUX_KERNEL_VERSION >= 131584
+# define __ASSUME_GETCWD_SYSCALL	1
+#endif
+
+/* Real-time signal became usable in 2.1.70.  */
+#if __LINUX_KERNEL_VERSION >= 131398
+# define __ASSUME_REALTIME_SIGNALS	1
+#endif
+
+/* When were the `pread'/`pwrite' syscalls introduced?  */
+#if __LINUX_KERNEL_VERSION >= 131584
+# define __ASSUME_PREAD_SYSCALL		1
+# define __ASSUME_PWRITE_SYSCALL	1
+#endif
+
+/* When was `poll' introduced?  */
+#if __LINUX_KERNEL_VERSION >= 131584
+# define __ASSUME_POLL_SYSCALL		1
+#endif
+
+/* The `lchown' syscall was introduced in 2.1.80.  */
+#if __LINUX_KERNEL_VERSION >= 131408
+# define __ASSUME_LCHOWN_SYSCALL	1
+#endif
+
+/* When did the `setresuid' sysall became available?  */
+#if __LINUX_KERNEL_VERSION >= 131584 && !defined __sparc__
+# define __ASSUME_SETRESUID_SYSCALL	1
+#endif
+
+/* The SIOCGIFNAME ioctl is available starting with 2.1.50.  */
+#if __LINUX_KERNEL_VERSION >= 131408
+# define __ASSUME_SIOCGIFNAME		1
+#endif
+
+/* MSG_NOSIGNAL was at least available with Linux 2.2.0.  */
+#if __LINUX_KERNEL_VERSION >= 131584
+# define __ASSUME_MSG_NOSIGNAL		1
+#endif
+
+/* On x86 another `getrlimit' syscall was added in 2.3.25.  */
+#if __LINUX_KERNEL_VERSION >= 131865 && defined __i386__
+# define __ASSUME_NEW_GETRLIMIT_SYSCALL	1
+#endif
+
+/* On x86 the truncate64/ftruncate64 syscalls were introduced in 2.3.31.  */
+#if __LINUX_KERNEL_VERSION >= 131871 && defined __i386__
+# define __ASSUME_TRUNCATE64_SYSCALL	1
+#endif
+
+/* On x86 the mmap2 syscall was introduced in 2.3.31.  */
+#if __LINUX_KERNEL_VERSION >= 131871 && defined __i386__
+# define __ASSUME_MMAP2_SYSCALL	1
+#endif
+
+/* On x86 the stat64/lstat64/fstat64 syscalls were introduced in 2.3.34.  */
+#if __LINUX_KERNEL_VERSION >= 131874 && defined __i386__
+# define __ASSUME_STAT64_SYSCALL	1
+#endif
+
+/* On sparc and ARM the truncate64/ftruncate64/mmap2/stat64/lstat64/fstat64
+   syscalls were introduced in 2.3.35.  */
+#if __LINUX_KERNEL_VERSION >= 131875 && (defined __sparc__ || defined __arm__)
+# define __ASSUME_TRUNCATE64_SYSCALL	1
+# define __ASSUME_MMAP2_SYSCALL		1
+# define __ASSUME_STAT64_SYSCALL	1
+#endif
+
+/* I know for sure that getrlimit are in 2.3.35 on powerpc.  */
+#if __LINUX_KERNEL_VERSION >= 131875 && defined __powerpc__
+# define __ASSUME_NEW_GETRLIMIT_SYSCALL	1
+#endif
+
+/* I know for sure that these are in 2.3.35 on powerpc. But PowerPC64 does not
+   support separate 64-bit syscalls, already 64-bit */
+#if __LINUX_KERNEL_VERSION >= 131875 && defined __powerpc__ \
+    && !defined __powerpc64__
+# define __ASSUME_TRUNCATE64_SYSCALL	1
+# define __ASSUME_STAT64_SYSCALL	1
+#endif
+
+/* Linux 2.3.39 introduced 32bit UID/GIDs.  Some platforms had 32
+   bit type all along.  */
+#if __LINUX_KERNEL_VERSION >= 131879 || defined __powerpc__ || defined __mips__
+# define __ASSUME_32BITUIDS		1
+#endif
+
+/* Linux 2.3.39 sparc added setresuid.  */
+#if __LINUX_KERNEL_VERSION >= 131879 && defined __sparc__
+# define __ASSUME_SETRESUID_SYSCALL	1
+#endif
+
+#if __LINUX_KERNEL_VERSION >= 131879
+# define __ASSUME_SETRESGID_SYSCALL	1
+#endif
+
+/* Linux 2.3.39 introduced IPC64.  Except for powerpc.  */
+#if __LINUX_KERNEL_VERSION >= 131879 && !defined __powerpc__
+# define __ASSUME_IPC64		1
+#endif
+
+/* MIPS platforms had IPC64 all along.  */
+#if defined __mips__
+# define __ASSUME_IPC64		1
+#endif
+
+/* We can use the LDTs for threading with Linux 2.3.99 and newer.  */
+#if __LINUX_KERNEL_VERSION >= 131939
+# define __ASSUME_LDT_WORKS		1
+#endif
+
+/* Linux 2.4.0 on PPC introduced a correct IPC64. But PowerPC64 does not
+   support a separate 64-bit sys call, already 64-bit */
+#if __LINUX_KERNEL_VERSION >= 132096 && defined __powerpc__ \
+    && !defined __powerpc64__
+# define __ASSUME_IPC64			1
+#endif
+
+/* SH kernels got stat64, mmap2, and truncate64 during 2.4.0-test.  */
+#if __LINUX_KERNEL_VERSION >= 132096 && defined __sh__
+# define __ASSUME_TRUNCATE64_SYSCALL	1
+# define __ASSUME_MMAP2_SYSCALL		1
+# define __ASSUME_STAT64_SYSCALL	1
+#endif
+
+/* The changed st_ino field appeared in 2.4.0-test6.  But we cannot
+   distinguish this version from other 2.4.0 releases.  Therefore play
+   save and assume it available is for 2.4.1 and up.  However, SH is lame,
+   and still does not have a 64-bit inode field.  */
+#if __LINUX_KERNEL_VERSION >= 132097 && !defined __alpha__ && !defined __sh__
+# define __ASSUME_ST_INO_64_BIT		1
+#endif
+
+/* To support locking of large files a new fcntl() syscall was introduced
+   in 2.4.0-test7.  We test for 2.4.1 for the earliest version we know
+   the syscall is available.  */
+#if __LINUX_KERNEL_VERSION >= 132097 && (defined __i386__ || defined __sparc__)
+# define __ASSUME_FCNTL64		1
+#endif
+
+/* The AT_CLKTCK auxiliary vector entry was introduction in the 2.4.0
+   series.  */
+#if __LINUX_KERNEL_VERSION >= 132097
+# define __ASSUME_AT_CLKTCK		1
+#endif
+
+/* Arm got fcntl64 in 2.4.4, PowerPC and SH have it also in 2.4.4 (I
+   don't know when it got introduced).  But PowerPC64 does not support
+   separate FCNTL64 call, FCNTL is already 64-bit */
+#if __LINUX_KERNEL_VERSION >= 132100 \
+    && (defined __arm__ || defined __powerpc__ || defined __sh__) \
+    && !defined __powerpc64__
+# define __ASSUME_FCNTL64		1
+#endif
+
+/* The getdents64 syscall was introduced in 2.4.0-test7.  We test for
+   2.4.1 for the earliest version we know the syscall is available.  */
+#if __LINUX_KERNEL_VERSION >= 132097
+# define __ASSUME_GETDENTS64_SYSCALL	1
+#endif
+
+/* When did O_DIRECTORY became available?  Early in 2.3 but when?
+   Be safe, use 2.3.99.  */
+#if __LINUX_KERNEL_VERSION >= 131939
+# define __ASSUME_O_DIRECTORY		1
+#endif
+
+/* Starting with one of the 2.4.0 pre-releases the Linux kernel passes
+   up the page size information.  */
+#if __LINUX_KERNEL_VERSION >= 132097
+# define __ASSUME_AT_PAGESIZE		1
+#endif
+
+/* Starting with at least 2.4.0 the kernel passes the uid/gid unconditionally
+   up to the child.  */
+#if __LINUX_KERNEL_VERSION >= 132097
+# define __ASSUME_AT_XID		1
+#endif
+
+/* Starting with 2.4.5 kernels PPC passes the AUXV in the standard way
+   and the vfork syscall made it into the official kernel.  */
+#if __LINUX_KERNEL_VERSION >= (132096+5) && defined __powerpc__
+# define __ASSUME_STD_AUXV		1
+# define __ASSUME_VFORK_SYSCALL		1
+#endif
+
+/* Starting with 2.4.5 kernels the mmap2 syscall made it into the official
+   kernel.  But PowerPC64 does not support a separate MMAP2 call.  */
+#if __LINUX_KERNEL_VERSION >= (132096+5) && defined __powerpc__ \
+    && !defined __powerpc64__
+# define __ASSUME_MMAP2_SYSCALL		1
+#endif
+
+/* Starting with 2.4.21 PowerPC implements the new prctl syscall.
+   This allows applications to get/set the Floating Point Exception Mode.  */
+#if __LINUX_KERNEL_VERSION >= (132096+21) && defined __powerpc__
+# define __ASSUME_NEW_PRCTL_SYSCALL		1
+#endif
+
+/* Starting with 2.4.21 the PowerPC32 clone syscall works as expected.  */
+#if __LINUX_KERNEL_VERSION >= (132096+21) && defined __powerpc__ \
+    && !defined __powerpc64__
+# define __ASSUME_FIXED_CLONE_SYSCALL		1
+#endif
+
+/* Starting with 2.4.21 PowerPC64 implements the new rt_sigreturn syscall.
+   The new rt_sigreturn takes an ucontext pointer allowing rt_sigreturn
+   to be used in the set/swapcontext implementation.  */
+#if __LINUX_KERNEL_VERSION >= (132096+21) && defined __powerpc64__
+# define __ASSUME_NEW_RT_SIGRETURN_SYSCALL		1
+#endif
+
+/* On x86, the set_thread_area syscall was introduced in 2.5.29, but its
+   semantics was changed in 2.5.30, and again after 2.5.31.  */
+#if __LINUX_KERNEL_VERSION >= 132384 && defined __i386__
+# define __ASSUME_SET_THREAD_AREA_SYSCALL	1
+#endif
+
+/* The vfork syscall on x86 and arm was definitely available in 2.4.  */
+#if __LINUX_KERNEL_VERSION >= 132097 && (defined __i386__ || defined __arm__)
+# define __ASSUME_VFORK_SYSCALL		1
+#endif
+
+/* There are an infinite number of PA-RISC kernel versions numbered
+   2.4.0.  But they've not really been released as such.  We require
+   and expect the final version here.  */
+#ifdef __hppa__
+# define __ASSUME_32BITUIDS		1
+# define __ASSUME_TRUNCATE64_SYSCALL	1
+# define __ASSUME_MMAP2_SYSCALL		1
+# define __ASSUME_STAT64_SYSCALL	1
+# define __ASSUME_IPC64			1
+# define __ASSUME_ST_INO_64_BIT		1
+# define __ASSUME_FCNTL64		1
+# define __ASSUME_GETDENTS64_SYSCALL	1
+#endif
+
+/* Alpha switched to a 64-bit timeval sometime before 2.2.0.  */
+#if __LINUX_KERNEL_VERSION >= 131584 && defined __alpha__
+# define __ASSUME_TIMEVAL64		1
+#endif
+
+#if defined __mips__ && _MIPS_SIM == _ABIN32
+# define __ASSUME_FCNTL64		1
+#endif
+
+/* The late 2.5 kernels saw a lot of new CLONE_* flags.  Summarize
+   their availability with one define.  The changes were made first
+   for i386 and the have to be done separately for the other archs.
+   For i386 we pick 2.5.50 as the first version with support.  */
+#if __LINUX_KERNEL_VERSION >= 132402 && defined __i386__
+# define __ASSUME_CLONE_THREAD_FLAGS	1
+#endif
+
+/* These features were surely available with 2.4.12.  */
+#if __LINUX_KERNEL_VERSION >= 132108 && defined __mc68000__
+# define __ASSUME_MMAP2_SYSCALL		1
+# define __ASSUME_TRUNCATE64_SYSCALL	1
+# define __ASSUME_STAT64_SYSCALL	1
+# define __ASSUME_FCNTL64		1
+# define __ASSUME_VFORK_SYSCALL		1
+#endif
+
+/* Beginning with 2.5.63 support for realtime and monotonic clocks and
+   timers based on them is available.  */
+#if __LINUX_KERNEL_VERSION >= 132415
+# define __ASSUME_POSIX_TIMERS		1
+#endif
+
+/* The late 2.5 kernels saw a lot of new CLONE_* flags.  Summarize
+   their availability with one define.  The changes were made first
+   for i386 and the have to be done separately for the other archs.
+   For ia64, s390*, PPC, x86-64 we pick 2.5.64 as the first version
+   with support.  */
+#if __LINUX_KERNEL_VERSION >= 132416 \
+    && (defined __ia64__ || defined __s390__ || defined __powerpc__ \
+	|| defined __x86_64__ || defined __sh__)
+# define __ASSUME_CLONE_THREAD_FLAGS	1
+#endif
+
+/* With kernel 2.4.17 we always have netlink support.  */
+#if __LINUX_KERNEL_VERSION >= (132096+17)
+# define __ASSUME_NETLINK_SUPPORT	1
+#endif
+
+/* The requeue futex functionality was introduced in 2.5.70.  */
+#if __LINUX_KERNEL_VERSION >= 132422
+# define __ASSUME_FUTEX_REQUEUE	1
+#endif
+
+/* The statfs64 syscalls are available in 2.5.74.  */
+#if __LINUX_KERNEL_VERSION >= 132426
+# define __ASSUME_STATFS64	1
+#endif
+
+/* Starting with at least 2.5.74 the kernel passes the setuid-like exec
+   flag unconditionally up to the child.  */
+#if __LINUX_KERNEL_VERSION >= 132426
+# define __ASSUME_AT_SECURE	1
+#endif
+
+/* Starting with the 2.5.75 kernel the kernel fills in the correct value
+   in the si_pid field passed as part of the siginfo_t struct to signal
+   handlers.  */
+#if __LINUX_KERNEL_VERSION >= 132427
+# define __ASSUME_CORRECT_SI_PID	1
+#endif
+
+/* The tgkill syscall was instroduced for i386 in 2.5.75.  For Alpha
+   it was introduced in 2.6.0-test1 which unfortunately cannot be
+   distinguished from 2.6.0.  On x86-64 it was introduced in
+   2.6.0-test3. */
+#if (__LINUX_KERNEL_VERSION >= 132427 && defined __i386__) \
+    || (__LINUX_KERNEL_VERSION >= 132609 && defined __alpha__) \
+    || (__LINUX_KERNEL_VERSION >= 132609 && defined __x86_64__) \
+    || (__LINUX_KERNEL_VERSION >= 132609 && defined __sh__)
+# define __ASSUME_TGKILL	1
+#endif
+
+/* The utimes syscall has been available for some architectures
+   forever.  For x86 it was introduced after 2.5.75, for x86-64 in
+   2.6.0-test3.  */
+#if defined __alpha__ || defined __ia64__ || defined __hppa__ \
+    || defined __sparc__ \
+    || (__LINUX_KERNEL_VERSION > 132427 && defined __i386__) \
+    || (__LINUX_KERNEL_VERSION > 132609 && defined __x86_64__) \
+    || (__LINUX_KERNEL_VERSION >= 132609 && defined __sh__)
+# define __ASSUME_UTIMES	1
+#endif
+
+// XXX Disabled for now since the semantics we want is not achieved.
+#if 0
+/* The CLONE_STOPPED flag was introduced in the 2.6.0-test1 series.  */
+#if __LINUX_KERNEL_VERSION >= 132609
+# define __ASSUME_CLONE_STOPPED	1
+#endif
+#endif
+
+/* The fixed version of the posix_fadvise64 syscall appeared in
+   2.6.0-test3.  At least for x86.  */
+#if __LINUX_KERNEL_VERSION >= 132609 && defined __i386__
+# define __ASSUME_FADVISE64_64_SYSCALL	1
+#endif
+
+/* The PROT_GROWSDOWN/PROT_GROWSUP flags were introduced in the 2.6.0-test
+   series.  */
+#if __LINUX_KERNEL_VERSION >= 132609
+# define __ASSUME_PROT_GROWSUPDOWN	1
+#endif
+
+/* Starting with 2.6.0 PowerPC adds signal/swapcontext support for Vector
+   SIMD (AKA Altivec, VMX) instructions and register state.  This changes
+   the overall size of the sigcontext and adds the swapcontext syscall.  */
+#if __LINUX_KERNEL_VERSION >= 132608 && defined __powerpc__
+# define __ASSUME_SWAPCONTEXT_SYSCALL	1
+#endif
+
+/* The CLONE_DETACHED flag is not necessary in 2.6.2 kernels, it is
+   implied.  */
+#if __LINUX_KERNEL_VERSION >= 132610
+# define __ASSUME_NO_CLONE_DETACHED	1
+#endif
+
+/* Starting with version 2.6.4-rc1 the getdents syscall returns d_type
+   information as well.  */
+#if __LINUX_KERNEL_VERSION >= 132612
+# define __ASSUME_GETDENTS32_D_TYPE	1
+#endif
+
+/* Starting with version 2.5.3, the initial location returned by `brk'
+   after exec is always rounded up to the next page.  */
+#if __LINUX_KERNEL_VERSION >= 132355
+# define __ASSUME_BRK_PAGE_ROUNDED	1
+#endif
+
+/* Starting with version 2.6.9, the waitid system call is available.  */
+#if __LINUX_KERNEL_VERSION >=  0x020609
+# define __ASSUME_WAITID_SYSCALL	1
+#endif
+
+/* Starting with version 2.6.9, SSI_IEEE_RAISE_EXCEPTION exists.  */
+#if __LINUX_KERNEL_VERSION >= 0x020609 && defined __alpha__
+#define __ASSUME_IEEE_RAISE_EXCEPTION	1
+#endif
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/librestrict/kernel_stat.h	Mon Feb 16 14:49:42 2009 +0100
@@ -0,0 +1,37 @@
+/* Definition of `struct stat' used in the kernel..  */
+struct kernel_stat
+  {
+    unsigned short int st_dev;
+    unsigned short int __pad1;
+#define _HAVE___PAD1
+    unsigned long int st_ino;
+    unsigned short int st_mode;
+    unsigned short int st_nlink;
+    unsigned short int st_uid;
+    unsigned short int st_gid;
+    unsigned short int st_rdev;
+    unsigned short int __pad2;
+#define _HAVE___PAD2
+    unsigned long int st_size;
+    unsigned long int st_blksize;
+    unsigned long int st_blocks;
+    struct timespec st_atim;
+    struct timespec st_mtim;
+    struct timespec st_ctim;
+    unsigned long int __unused4;
+#define _HAVE___UNUSED4
+    unsigned long int __unused5;
+#define _HAVE___UNUSED5
+  };
+
+#define _HAVE_STAT___UNUSED4
+#define _HAVE_STAT___UNUSED5
+#define _HAVE_STAT___PAD1
+#define _HAVE_STAT___PAD2
+#define _HAVE_STAT_NSEC
+#define _HAVE_STAT64___PAD1
+#define _HAVE_STAT64___PAD2
+# ifdef __USE_FILE_OFFSET64 /* FIXME: CONFIG? */
+# define _HAVE_STAT64___ST_INO
+# endif
+#define _HAVE_STAT64_NSEC
--- a/librestrict/restrict-stat.c	Sun Feb 15 21:29:26 2009 +0100
+++ b/librestrict/restrict-stat.c	Mon Feb 16 14:49:42 2009 +0100
@@ -4,6 +4,7 @@
 
 */
 
+#include <stddef.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>
 
@@ -83,6 +84,49 @@
 int ustat (char const *file_name, struct stat *buf)  __attribute__ ((alias ("__ustat")));
 #endif /* SYS_ustat */
 
+#ifdef __linux__
+
+/*
+  Lifted from glibc-2.3-20070416
+*/
+
+#include <errno.h>
+#ifndef __set_errno
+#define __set_errno(e) (errno = (e))
+#endif
+
+#include <kernel-features.h>
+#ifdef __x86_64__
+#define STAT_IS_KERNEL_STAT 1
+#define XSTAT_IS_XSTAT64 1
+#define kernel_stat stat
+#define __xstat_conv(a, b, c) 0
+#else /* !__x86_64__ */
+#define stat64 kernel_stat /* FIXME: CONFIG? */
+#include <xstatconv.c>
+#endif /* !__x86_64__ */
+
+
+static int sys_xstat (int ver, char const *file_name, struct stat *buf)
+{
+#ifdef STAT_IS_KERNEL_STAT
+  //  if (ver == _STAT_VER_KERNEL)
+  if (ver == _STAT_VER_LINUX)
+    return syscall (SYS_stat, file_name, buf);
+
+  errno = EINVAL;
+  return -1;
+#else /* !STAT_IS_KERNEL_STAT */
+  (void) ver;
+  struct kernel_stat kbuf;
+  int result = syscall (SYS_stat, file_name, &kbuf);
+  if (result == 0)
+    result = __xstat_conv (ver, &kbuf, buf);
+
+  return result;
+#endif /* !STAT_IS_KERNEL_STAT */
+}
+
 int
 __xstat (int ver, char const *file_name, struct stat *buf)
 {
@@ -91,7 +135,9 @@
   if (!is_allowed (file_name, "xstat"))
     abort ();
 
-  return sys_stat (file_name, buf);
+  return sys_xstat (ver, file_name, buf);
 }
 
 int xstat (int ver, char const *file_name, struct stat *buf)  __attribute__ ((alias ("__xstat")));
+
+#endif /* __linux__ */
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/librestrict/xstatconv.c	Mon Feb 16 14:49:42 2009 +0100
@@ -0,0 +1,285 @@
+/* Convert between the kernel's `struct stat' format, and libc's.
+   Copyright (C) 1991,1995-1997,2000,2002,2003 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <errno.h>
+#include <sys/stat.h>
+#include <kernel_stat.h>
+
+#ifdef STAT_IS_KERNEL_STAT
+
+/* Dummy.  */
+struct kernel_stat;
+
+#else
+
+#include <string.h>
+
+
+#if !defined __ASSUME_STAT64_SYSCALL || defined XSTAT_IS_XSTAT64
+int
+__xstat_conv (int vers, struct kernel_stat *kbuf, void *ubuf)
+{
+  switch (vers)
+    {
+    case _STAT_VER_KERNEL:
+      /* Nothing to do.  The struct is in the form the kernel expects.
+         We should have short-circuted before we got here, but for
+         completeness... */
+      *(struct kernel_stat *) ubuf = *kbuf;
+      break;
+
+    case _STAT_VER_LINUX:
+      {
+	struct stat *buf = ubuf;
+
+	/* Convert to current kernel version of `struct stat'.  */
+	buf->st_dev = kbuf->st_dev;
+#ifdef _HAVE_STAT___PAD1
+	buf->__pad1 = 0;
+#endif
+	buf->st_ino = kbuf->st_ino;
+	buf->st_mode = kbuf->st_mode;
+	buf->st_nlink = kbuf->st_nlink;
+	buf->st_uid = kbuf->st_uid;
+	buf->st_gid = kbuf->st_gid;
+	buf->st_rdev = kbuf->st_rdev;
+#ifdef _HAVE_STAT___PAD2
+	buf->__pad2 = 0;
+#endif
+	buf->st_size = kbuf->st_size;
+	buf->st_blksize = kbuf->st_blksize;
+	buf->st_blocks = kbuf->st_blocks;
+#ifdef _HAVE_STAT_NSEC
+	buf->st_atim.tv_sec = kbuf->st_atim.tv_sec;
+	buf->st_atim.tv_nsec = kbuf->st_atim.tv_nsec;
+	buf->st_mtim.tv_sec = kbuf->st_mtim.tv_sec;
+	buf->st_mtim.tv_nsec = kbuf->st_mtim.tv_nsec;
+	buf->st_ctim.tv_sec = kbuf->st_ctim.tv_sec;
+	buf->st_ctim.tv_nsec = kbuf->st_ctim.tv_nsec;
+#else
+	buf->st_atime = kbuf->st_atime;
+	buf->st_mtime = kbuf->st_mtime;
+	buf->st_ctime = kbuf->st_ctime;
+#endif
+#ifdef _HAVE_STAT___UNUSED1
+	buf->__unused1 = 0;
+#endif
+#ifdef _HAVE_STAT___UNUSED2
+	buf->__unused2 = 0;
+#endif
+#ifdef _HAVE_STAT___UNUSED3
+	buf->__unused3 = 0;
+#endif
+#ifdef _HAVE_STAT___UNUSED4
+	buf->__unused4 = 0;
+#endif
+#ifdef _HAVE_STAT___UNUSED5
+	buf->__unused5 = 0;
+#endif
+      }
+      break;
+
+    default:
+      __set_errno (EINVAL);
+      return -1;
+    }
+
+  return 0;
+}
+#endif
+
+int
+__xstat64_conv (int vers, struct kernel_stat *kbuf, void *ubuf)
+{
+#ifdef XSTAT_IS_XSTAT64
+  return __xstat_conv (vers, kbuf, ubuf);
+#else
+  switch (vers)
+    {
+    case _STAT_VER_LINUX:
+      {
+	struct stat64 *buf = ubuf;
+
+	/* Convert to current kernel version of `struct stat64'.  */
+	buf->st_dev = kbuf->st_dev;
+#ifdef _HAVE_STAT64___PAD1
+	buf->__pad1 = 0;
+#endif
+	buf->st_ino = kbuf->st_ino;
+#ifdef _HAVE_STAT64___ST_INO
+	buf->__st_ino = kbuf->st_ino;
+#endif
+	buf->st_mode = kbuf->st_mode;
+	buf->st_nlink = kbuf->st_nlink;
+	buf->st_uid = kbuf->st_uid;
+	buf->st_gid = kbuf->st_gid;
+	buf->st_rdev = kbuf->st_rdev;
+#ifdef _HAVE_STAT64___PAD2
+	buf->__pad2 = 0;
+#endif
+	buf->st_size = kbuf->st_size;
+	buf->st_blksize = kbuf->st_blksize;
+	buf->st_blocks = kbuf->st_blocks;
+#ifdef _HAVE_STAT64_NSEC
+	buf->st_atim.tv_sec = kbuf->st_atim.tv_sec;
+	buf->st_atim.tv_nsec = kbuf->st_atim.tv_nsec;
+	buf->st_mtim.tv_sec = kbuf->st_mtim.tv_sec;
+	buf->st_mtim.tv_nsec = kbuf->st_mtim.tv_nsec;
+	buf->st_ctim.tv_sec = kbuf->st_ctim.tv_sec;
+	buf->st_ctim.tv_nsec = kbuf->st_ctim.tv_nsec;
+#else
+	buf->st_atime = kbuf->st_atime;
+	buf->st_mtime = kbuf->st_mtime;
+	buf->st_ctime = kbuf->st_ctime;
+#endif
+#ifdef _HAVE_STAT64___UNUSED1
+	buf->__unused1 = 0;
+#endif
+#ifdef _HAVE_STAT64___UNUSED2
+	buf->__unused2 = 0;
+#endif
+#ifdef _HAVE_STAT64___UNUSED3
+	buf->__unused3 = 0;
+#endif
+#ifdef _HAVE_STAT64___UNUSED4
+	buf->__unused4 = 0;
+#endif
+#ifdef _HAVE_STAT64___UNUSED5
+	buf->__unused5 = 0;
+#endif
+      }
+      break;
+
+      /* If struct stat64 is different from struct stat then
+	 _STAT_VER_KERNEL does not make sense.  */
+    case _STAT_VER_KERNEL:
+    default:
+      __set_errno (EINVAL);
+      return -1;
+    }
+
+  return 0;
+#endif
+}
+
+int
+__xstat32_conv (int vers, struct stat64 *kbuf, struct stat *buf)
+{
+  switch (vers)
+    {
+    case _STAT_VER_LINUX:
+      {
+	/* Convert current kernel version of `struct stat64' to
+           `struct stat'.  */
+	buf->st_dev = kbuf->st_dev;
+#ifdef _HAVE_STAT___PAD1
+	buf->__pad1 = 0;
+#endif
+#ifdef _HAVE_STAT64___ST_INO
+# if __ASSUME_ST_INO_64_BIT == 0
+	if (kbuf->st_ino == 0)
+	  buf->st_ino = kbuf->__st_ino;
+	else
+# endif
+	  {
+	    buf->st_ino = kbuf->st_ino;
+	    if (sizeof (buf->st_ino) != sizeof (kbuf->st_ino)
+		&& buf->st_ino != kbuf->st_ino)
+	      {
+		__set_errno (EOVERFLOW);
+		return -1;
+	      }
+	  }
+#else
+	buf->st_ino = kbuf->st_ino;
+	if (sizeof (buf->st_ino) != sizeof (kbuf->st_ino)
+	    && buf->st_ino != kbuf->st_ino)
+	  {
+	    __set_errno (EOVERFLOW);
+	    return -1;
+	  }
+#endif
+	buf->st_mode = kbuf->st_mode;
+	buf->st_nlink = kbuf->st_nlink;
+	buf->st_uid = kbuf->st_uid;
+	buf->st_gid = kbuf->st_gid;
+	buf->st_rdev = kbuf->st_rdev;
+#ifdef _HAVE_STAT___PAD2
+	buf->__pad2 = 0;
+#endif
+	buf->st_size = kbuf->st_size;
+	/* Check for overflow.  */
+	if (sizeof (buf->st_size) != sizeof (kbuf->st_size)
+	    && buf->st_size != kbuf->st_size)
+	  {
+	    __set_errno (EOVERFLOW);
+	    return -1;
+	  }
+	buf->st_blksize = kbuf->st_blksize;
+	buf->st_blocks = kbuf->st_blocks;
+	/* Check for overflow.  */
+	if (sizeof (buf->st_blocks) != sizeof (kbuf->st_blocks)
+	    && buf->st_blocks != kbuf->st_blocks)
+	  {
+	    __set_errno (EOVERFLOW);
+	    return -1;
+	  }
+#ifdef _HAVE_STAT_NSEC
+	buf->st_atim.tv_sec = kbuf->st_atim.tv_sec;
+	buf->st_atim.tv_nsec = kbuf->st_atim.tv_nsec;
+	buf->st_mtim.tv_sec = kbuf->st_mtim.tv_sec;
+	buf->st_mtim.tv_nsec = kbuf->st_mtim.tv_nsec;
+	buf->st_ctim.tv_sec = kbuf->st_ctim.tv_sec;
+	buf->st_ctim.tv_nsec = kbuf->st_ctim.tv_nsec;
+#else
+	buf->st_atime = kbuf->st_atime;
+	buf->st_mtime = kbuf->st_mtime;
+	buf->st_ctime = kbuf->st_ctime;
+#endif
+
+#ifdef _HAVE_STAT___UNUSED1
+	buf->__unused1 = 0;
+#endif
+#ifdef _HAVE_STAT___UNUSED2
+	buf->__unused2 = 0;
+#endif
+#ifdef _HAVE_STAT___UNUSED3
+	buf->__unused3 = 0;
+#endif
+#ifdef _HAVE_STAT___UNUSED4
+	buf->__unused4 = 0;
+#endif
+#ifdef _HAVE_STAT___UNUSED5
+	buf->__unused5 = 0;
+#endif
+      }
+      break;
+
+      /* If struct stat64 is different from struct stat then
+	 _STAT_VER_KERNEL does not make sense.  */
+    case _STAT_VER_KERNEL:
+    default:
+      __set_errno (EINVAL);
+      return -1;
+    }
+
+  return 0;
+}
+
+#endif
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/librestrict/xstatconv.h	Mon Feb 16 14:49:42 2009 +0100
@@ -0,0 +1,26 @@
+/* Convert between the kernel's `struct stat' format, and libc's.
+   Copyright (C) 1991,1995-1997,2000,2002,2003 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include "kernel-features.h"
+
+#ifndef STAT_IS_KERNEL_STAT
+extern int __xstat_conv (int vers, struct kernel_stat *kbuf, void *ubuf);
+extern int __xstat64_conv (int vers, struct kernel_stat *kbuf, void *ubuf);
+#endif
+extern int __xstat32_conv (int vers, struct stat64 *kbuf, struct stat *buf);