[PATCHv3,xfstests,2/3] generic: test openat and new O_BENEATH flag

Commit Message

David Drysdale March 9, 2015, 2 p.m. UTC

Test basic openat(2) behaviour.

Test that if O_BENEATH flag is set, openat() will only
open paths that have no .. component and do not start
with /.  Symlinks are also checked for the same restrictions.

Signed-off-by: David Drysdale <[e-mail]>
---
 .gitignore            |   1 +
 common/openat         |  61 ++++++++++++++++++++++++++++++
 src/Makefile          |   3 +-
 src/openat.c          | 100 +++++++++++++++++++++++++++++++++++++++++++++++++
 tests/generic/151     |  89 ++++++++++++++++++++++++++++++++++++++++++++
 tests/generic/151.out |   9 +++++
 tests/generic/152     | 101 ++++++++++++++++++++++++++++++++++++++++++++++++++
 tests/generic/152.out |  23 ++++++++++++
 tests/generic/group   |   2 +
 9 files changed, 388 insertions(+), 1 deletion(-)
 create mode 100644 common/openat
 create mode 100644 src/openat.c
 create mode 100755 tests/generic/151
 create mode 100644 tests/generic/151.out
 create mode 100755 tests/generic/152
 create mode 100644 tests/generic/152.out

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Comments

Dave Chinner March 16, 2015, 11:24 p.m. UTC | #1

On Mon, Mar 09, 2015 at 02:00:11PM +0000, David Drysdale wrote:
> Test basic openat(2) behaviour.
> 
> Test that if O_BENEATH flag is set, openat() will only
> open paths that have no .. component and do not start
> with /.  Symlinks are also checked for the same restrictions.
> 
> Signed-off-by: David Drysdale <[e-mail]>
> ---
>  .gitignore            |   1 +
>  common/openat         |  61 ++++++++++++++++++++++++++++++
>  src/Makefile          |   3 +-
>  src/openat.c          | 100 +++++++++++++++++++++++++++++++++++++++++++++++++

This strikes me as something that shoul dbe added to xfs_io for
testing, as it already supports a heap of other open flags and
xfstests is already dependent on it.

>  tests/generic/151     |  89 ++++++++++++++++++++++++++++++++++++++++++++
>  tests/generic/151.out |   9 +++++
>  tests/generic/152     | 101 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  tests/generic/152.out |  23 ++++++++++++
>  tests/generic/group   |   2 +

I'd also prefer one patch per new test - it's easier to review...

> +_openat_setup()
> +{
> +	local dir=$1
> +
> +	mkdir -p $dir/subdir
> +	echo 0123456789 > $dir/topfile
> +	echo 0123456789 > $dir/subdir/bottomfile
> +
> +	ln -s subdir/bottomfile $dir/symlinkdown
> +	ln -s ../topfile $dir/subdir/symlinkup
> +	ln -s $dir/topfile $dir/subdir/symlinkout
> +	ln -s bottomfile  $dir/subdir/symlinkin
> +}
> +
> +#
> +# Check whether the openat wrapper program is available
> +#
> +_requires_openat()
> +{
> +	OPENAT_PROG=$here/src/openat
> +        _require_command $OPENAT_PROG
> +}

if this is part of xfs_io, then _requires_xfs_io_command "open -b"
could be used to test if the command is supported, and no need for
this function at all.

> +#
> +# This checks whether the O_BENEATH flag is supported by the openat syscall
> +#
> +_requires_o_beneath()
> +{
> +	# Kernels that don't support O_BENEATH will silently accept it, so
> +	# check for O_BENEATH behavior: attempting to open an absolute
> +	# path should fail with EPERM.
> +	$OPENAT_PROG -t -b $TEST_DIR
> +	if [ $? -ne 0 ]; then
> +		_notrun "kernel doesn't support O_BENEATH flag in openat syscall"
> +	fi
> +}

as running the command would tell us if the kernel supports it, too.

> +#endif
> +#endif
> +
> +void usage(const char *progname)
> +{
> +	fprintf(stderr, "Usage: %s [-f dirname] [-b] [-n] [-t] <file>\n",
> +		progname);
> +	fprintf(stderr,"    -f dirname : use this dir for dfd\n");
> +	fprintf(stderr,"    -b         : open with O_BENEATH\n");
> +	fprintf(stderr,"    -n         : open with O_NOFOLLOW\n");
> +	fprintf(stderr,"    -t         : test for expected EPERM failure\n");
> +	fprintf(stderr,"    -h         : show this usage message\n");
> +	exit(1);

Hmm - you're also testing O_NOFOLLOW behaviour too? Perhaps that
should be mentioned/added to xfs_io, too?

The reason I suggest this, even though it's a little more work, is
tht we can then re-use the new flags in other tests easily without
needing to write new helper functions...

Cheers,

Dave.

Kees Cook March 17, 2015, 3:33 p.m. UTC | #2

On Mon, Mar 16, 2015 at 4:24 PM, Dave Chinner <[e-mail]> wrote:
> On Mon, Mar 09, 2015 at 02:00:11PM +0000, David Drysdale wrote:
>> Test basic openat(2) behaviour.
>>
>> Test that if O_BENEATH flag is set, openat() will only
>> open paths that have no .. component and do not start
>> with /.  Symlinks are also checked for the same restrictions.
>>
>> Signed-off-by: David Drysdale <[e-mail]>
>> ---
>>  .gitignore            |   1 +
>>  common/openat         |  61 ++++++++++++++++++++++++++++++
>>  src/Makefile          |   3 +-
>>  src/openat.c          | 100 +++++++++++++++++++++++++++++++++++++++++++++++++
>
> This strikes me as something that shoul dbe added to xfs_io for
> testing, as it already supports a heap of other open flags and
> xfstests is already dependent on it.

While I don't see a problem adding this to xfs_io, I'd still like to
see this test live in the kernel tree too. Having it in the same
source means more testing, IMO.

-Kees

Dave Chinner March 18, 2015, 2:52 a.m. UTC | #3

On Tue, Mar 17, 2015 at 08:33:27AM -0700, Kees Cook wrote:
> On Mon, Mar 16, 2015 at 4:24 PM, Dave Chinner
> <[e-mail]> wrote:
> > On Mon, Mar 09, 2015 at 02:00:11PM +0000, David Drysdale wrote:
> >> Test basic openat(2) behaviour.
> >>
> >> Test that if O_BENEATH flag is set, openat() will only open
> >> paths that have no .. component and do not start with /.
> >> Symlinks are also checked for the same restrictions.
> >>
> >> Signed-off-by: David Drysdale <[e-mail]> ---
> >> .gitignore            |   1 + common/openat         |  61
> >> ++++++++++++++++++++++++++++++ src/Makefile          |   3 +-
> >> src/openat.c          | 100
> >> +++++++++++++++++++++++++++++++++++++++++++++++++
> >
> > This strikes me as something that shoul dbe added to xfs_io for
> > testing, as it already supports a heap of other open flags and
> > xfstests is already dependent on it.
> 
> While I don't see a problem adding this to xfs_io, I'd still like
> to see this test live in the kernel tree too.

You can do whatever you want with the kernel tree - it doesn't
concern me at all.

> Having it in the
> same source means more testing, IMO.

That's complete bunk, though.  This helper binary is a limited use,
one shot test that can't be combined with anything else.  "sharing"
the source code across multiple different test suites doesn't change
that. However, putting support into xfs_io means it will get more
testing because we can *easily* use the functionality in many, many
different ways.

Cheers,

Dave.

David Drysdale March 18, 2015, 10:17 a.m. UTC | #4

[resend, remembering to tick the Plaintext button this time -- sorry]

On Wed, Mar 18, 2015 at 2:52 AM, Dave Chinner <[e-mail]> wrote:
> On Tue, Mar 17, 2015 at 08:33:27AM -0700, Kees Cook wrote:
>> On Mon, Mar 16, 2015 at 4:24 PM, Dave Chinner
>> <[e-mail]> wrote:
>> > On Mon, Mar 09, 2015 at 02:00:11PM +0000, David Drysdale wrote:
>> >> Test basic openat(2) behaviour.
>> >>
>> >> Test that if O_BENEATH flag is set, openat() will only open
>> >> paths that have no .. component and do not start with /.
>> >> Symlinks are also checked for the same restrictions.
>> >>
>> >> Signed-off-by: David Drysdale <[e-mail]> ---
>> >> .gitignore            |   1 + common/openat         |  61
>> >> ++++++++++++++++++++++++++++++ src/Makefile          |   3 +-
>> >> src/openat.c          | 100
>> >> +++++++++++++++++++++++++++++++++++++++++++++++++
>> >
>> > This strikes me as something that shoul dbe added to xfs_io for
>> > testing, as it already supports a heap of other open flags and
>> > xfstests is already dependent on it.
>>
>> While I don't see a problem adding this to xfs_io, I'd still like
>> to see this test live in the kernel tree too.
>
> You can do whatever you want with the kernel tree - it doesn't
> concern me at all.
>
>> Having it in the
>> same source means more testing, IMO.
>
> That's complete bunk, though.  This helper binary is a limited use,
> one shot test that can't be combined with anything else.  "sharing"
> the source code across multiple different test suites doesn't change
> that. However, putting support into xfs_io means it will get more
> testing because we can *easily* use the functionality in many, many
> different ways.

It's useful to have a simple self-test in the kernel tree, so
that kernel developers (and their buildbots) can catch any
obvious regressions that might arise when working in related
areas, without requiring any other dependencies.

(Personally, I also think it's good that new kernel APIs
come with demonstrations of their use in userspace in a
nearby commit.)

OTOH, testing openat() behaviour should clearly be a part of
the xfstests suite (as a general/comprehensive filesystem
test repository), and Dave makes a good point that putting
the openat() functionality into xfs_io allows for more flexible
test combinations.

So I guess ideally we should end up with:
 a) Reinstate the kernel-tree selftests from the earlier iteration.
 b) Add openat test functionality into xfs_io
 c) Migrate the new xfstests cases to use xfs_io rather than
   a local openat utility program

However, given that I've already moved the test code once,
and that a)-c) involve three different source trees, I'd like
to de-couple things:
- Concentrate on kernel changes and a) on the LKML.
 - If & when the kernel changes make progress, return to
   b) and c).

Sound sensible?

Thanks,
David.

> Cheers,
>
> Dave.
> --
> Dave Chinner
> [e-mail]
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Patch

diff --git a/.gitignore b/.gitignore
index 2c9d640..6ea79ee 100644
--- a/.gitignore
+++ b/.gitignore
@@ -109,6 +109,7 @@ 
 /src/cloner
 /src/renameat2
 /src/t_rename_overwrite
+/src/openat

 # dmapi/ binaries
 /dmapi/src/common/cmd/read_invis
diff --git a/common/openat b/common/openat
new file mode 100644
index 0000000..8f04457
--- /dev/null
+++ b/common/openat
@@ -0,0 +1,61 @@ 
+######
+#
+# openat helpers
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2014 Google, Inc.  All Rights Reserved.
+#
+# 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.
+#
+# This program is distributed in the hope that it would 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 the Free Software Foundation,
+# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#-----------------------------------------------------------------------
+#
+
+#
+# Setup a collection of files to be opened.
+#
+_openat_setup()
+{
+	local dir=$1
+
+	mkdir -p $dir/subdir
+	echo 0123456789 > $dir/topfile
+	echo 0123456789 > $dir/subdir/bottomfile
+
+	ln -s subdir/bottomfile $dir/symlinkdown
+	ln -s ../topfile $dir/subdir/symlinkup
+	ln -s $dir/topfile $dir/subdir/symlinkout
+	ln -s bottomfile  $dir/subdir/symlinkin
+}
+
+#
+# Check whether the openat wrapper program is available
+#
+_requires_openat()
+{
+	OPENAT_PROG=$here/src/openat
+        _require_command $OPENAT_PROG
+}
+
+#
+# This checks whether the O_BENEATH flag is supported by the openat syscall
+#
+_requires_o_beneath()
+{
+	# Kernels that don't support O_BENEATH will silently accept it, so
+	# check for O_BENEATH behavior: attempting to open an absolute
+	# path should fail with EPERM.
+	$OPENAT_PROG -t -b $TEST_DIR
+	if [ $? -ne 0 ]; then
+		_notrun "kernel doesn't support O_BENEATH flag in openat syscall"
+	fi
+}
diff --git a/src/Makefile b/src/Makefile
index 4781736..d9f0508 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -11,7 +11,8 @@  TARGETS = dirstress fill fill2 getpagesize holes lstat64 \
 	devzero feature alloc fault fstest t_access_root \
 	godown resvtest writemod makeextents itrash rename \
 	multi_open_unlink dmiperf unwritten_sync genhashnames t_holes \
-	t_mmap_writev t_truncate_cmtime dirhash_collide t_rename_overwrite
+	t_mmap_writev t_truncate_cmtime dirhash_collide t_rename_overwrite \
+	openat

 LINUX_TARGETS = xfsctl bstat t_mtab getdevicesize preallo_rw_pattern_reader \
 	preallo_rw_pattern_writer ftrunc trunc fs_perms testx looptest \
diff --git a/src/openat.c b/src/openat.c
new file mode 100644
index 0000000..06e77c6
--- /dev/null
+++ b/src/openat.c
@@ -0,0 +1,100 @@ 
+/*
+ * Copyright (c) 2014 Google, Inc.
+ * All Rights Reserved.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it would 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 the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * This is a trivial wrapper around the openat syscall.
+ */
+
+#include "global.h"
+
+#if !defined(O_BENEATH)
+#if defined(__x86_64__) || defined(__i386__)
+#define O_BENEATH	040000000
+#endif
+#endif
+
+void usage(const char *progname)
+{
+	fprintf(stderr, "Usage: %s [-f dirname] [-b] [-n] [-t] <file>\n",
+		progname);
+	fprintf(stderr,"    -f dirname : use this dir for dfd\n");
+	fprintf(stderr,"    -b         : open with O_BENEATH\n");
+	fprintf(stderr,"    -n         : open with O_NOFOLLOW\n");
+	fprintf(stderr,"    -t         : test for expected EPERM failure\n");
+	fprintf(stderr,"    -h         : show this usage message\n");
+	exit(1);
+}
+
+int main(int argc, char *argv[])
+{
+	int dfd = AT_FDCWD;
+	const char *path = NULL;
+	int flags = O_RDONLY;
+	int test = 0;
+	const char *progname;
+	int opt;
+	int fd;
+
+	progname = strrchr(argv[0], '/');
+	progname = (progname ? progname + 1 : argv[0]);
+
+	while ((opt = getopt(argc, argv, "f:bnth")) != EOF) {
+		switch (opt) {
+		case 'f':
+			dfd = open(optarg, O_RDONLY);
+			if (dfd < 0) {
+				perror("Failed to open -f argument");
+				exit(1);
+			}
+			break;
+		case 'b':
+#ifdef O_BENEATH
+			flags |= O_BENEATH;
+#else
+			printf("O_BENEATH flag unavailable");
+			exit(1);
+#endif
+			break;
+		case 'n':
+			flags |= O_NOFOLLOW;
+			break;
+		case 't':
+			test = 1;
+			break;
+		case 'h':
+		default:
+			usage(progname);
+		}
+	}
+	if (argc - optind != 1)
+		usage(progname);
+	path = argv[optind];
+
+	/* Perform the openat operation */
+	fd = openat(dfd, path, flags);
+
+	if (fd >= 0) {
+		close(fd);
+		return test;
+	} else {
+		if (test) {
+			return (errno != EPERM);
+		} else {
+			perror("");
+			return 1;
+		}
+	}
+}
diff --git a/tests/generic/151 b/tests/generic/151
new file mode 100755
index 0000000..26584f4
--- /dev/null
+++ b/tests/generic/151
@@ -0,0 +1,89 @@ 
+#! /bin/bash
+# FS QA Test No. generic/039
+#
+# Check openat system call
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2014 Google, Inc.  All Rights Reserved.
+#
+# 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.
+#
+# This program is distributed in the hope that it would 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 the Free Software Foundation,
+# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#-----------------------------------------------------------------------
+#
+
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1	# failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+    cd /
+    rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/openat
+
+_supported_fs generic
+_supported_os Linux
+
+_require_test
+_requires_openat
+_require_test_symlinks
+
+# real QA test starts here
+
+openat_dir=$TEST_DIR/$$
+rm -rf $openat_dir
+mkdir -p $openat_dir
+_openat_setup $openat_dir
+cd $openat_dir
+
+echo "normal behavior, AT_FDCWD"
+$OPENAT_PROG topfile
+$OPENAT_PROG subdir/bottomfile
+$OPENAT_PROG $openat_dir/topfile
+$OPENAT_PROG $openat_dir/subdir/bottomfile
+
+echo "normal behavior, dfd to main dir"
+$OPENAT_PROG -f $openat_dir topfile
+$OPENAT_PROG -f $openat_dir subdir/bottomfile
+$OPENAT_PROG -f $openat_dir subdir/../topfile
+
+echo "normal behavior, dfd to subdir"
+$OPENAT_PROG -f $openat_dir/subdir ../topfile
+$OPENAT_PROG -f $openat_dir/subdir bottomfile
+$OPENAT_PROG -f $openat_dir/subdir ../subdir/bottomfile
+$OPENAT_PROG -f $openat_dir/subdir symlinkup
+$OPENAT_PROG -f $openat_dir/subdir symlinkout
+
+echo "normal behavior, absolute path"
+$OPENAT_PROG $openat_dir/topfile
+$OPENAT_PROG -f $openat_dir $openat_dir/topfile
+$OPENAT_PROG -f $openat_dir/subdir $openat_dir/topfile
+
+echo "normal behavior, non-existent file (ENOENT)"
+$OPENAT_PROG bogus
+$OPENAT_PROG -f $openat_dir bogus
+$OPENAT_PROG -f $openat_dir/subdir bogus
+
+# success, all done
+status=0
+exit
+
diff --git a/tests/generic/151.out b/tests/generic/151.out
new file mode 100644
index 0000000..dc1168c
--- /dev/null
+++ b/tests/generic/151.out
@@ -0,0 +1,9 @@ 
+QA output created by 151
+normal behavior, AT_FDCWD
+normal behavior, dfd to main dir
+normal behavior, dfd to subdir
+normal behavior, absolute path
+normal behavior, non-existent file (ENOENT)
+No such file or directory
+No such file or directory
+No such file or directory
diff --git a/tests/generic/152 b/tests/generic/152
new file mode 100755
index 0000000..f5ccb25
--- /dev/null
+++ b/tests/generic/152
@@ -0,0 +1,101 @@ 
+#! /bin/bash
+# FS QA Test No. generic/040
+#
+# Check O_BENEATH argument to openat system call
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2014 Google, Inc.  All Rights Reserved.
+#
+# 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.
+#
+# This program is distributed in the hope that it would 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 the Free Software Foundation,
+# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#-----------------------------------------------------------------------
+#
+
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1	# failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+    cd /
+    rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/openat
+
+_supported_fs generic
+_supported_os Linux
+
+_require_test
+_requires_openat
+_requires_o_beneath
+_require_test_symlinks
+
+# real QA test starts here
+
+openat_dir=$TEST_DIR/$$
+rm -rf $openat_dir
+mkdir -p $openat_dir
+_openat_setup $openat_dir
+cd $openat_dir
+
+echo "Test O_BENEATH:"
+$OPENAT_PROG -b topfile
+$OPENAT_PROG -b subdir/bottomfile
+
+$OPENAT_PROG -b -f $openat_dir topfile
+$OPENAT_PROG -b -f $openat_dir subdir/bottomfile
+$OPENAT_PROG -b -f $openat_dir/subdir bottomfile
+$OPENAT_PROG -b -f $openat_dir/subdir .
+
+echo "  Symlinks without .. or leading / are OK"
+$OPENAT_PROG -b -f $openat_dir symlinkdown
+$OPENAT_PROG -b -f $openat_dir subdir/symlinkin
+$OPENAT_PROG -b -f $openat_dir/subdir symlinkin
+
+echo "  ...unless of course we specify O_NOFOLLOW (ELOOP)"
+$OPENAT_PROG -b -n -f $openat_dir symlinkdown
+$OPENAT_PROG -b -n -f $openat_dir subdir/symlinkin
+$OPENAT_PROG -b -n -f $openat_dir/subdir symlinkin
+
+echo "  Can't open paths with .. in them (EPERM)"
+$OPENAT_PROG -b -f $openat_dir subdir/../topfile
+$OPENAT_PROG -b -f $openat_dir/subdir ../topfile
+$OPENAT_PROG -b -f $openat_dir/subdir ../subdir/bottomfile
+$OPENAT_PROG -b -f $openat_dir/subdir ..
+
+echo "  Can't open paths starting with / (EPERM)"
+$OPENAT_PROG -b $openat_dir/topfile
+$OPENAT_PROG -b -f $openat_dir $openat_dir/topfile
+$OPENAT_PROG -b -f $openat_dir/subdir $openat_dir/topfile
+
+echo "  Can't sneak around constraints with symlinks (EPERM)"
+$OPENAT_PROG -b -f $openat_dir/subdir symlinkup
+$OPENAT_PROG -b -f $openat_dir/subdir symlinkout
+$OPENAT_PROG -b -f $openat_dir/subdir ../symlinkdown
+$OPENAT_PROG -b -f $openat_dir subdir/symlinkup
+
+echo "  Can't open files below pre-resolved symlinks in /proc"
+$OPENAT_PROG -b -f /proc/self root/etc/passwd
+
+# success, all done
+status=0
+exit
+
diff --git a/tests/generic/152.out b/tests/generic/152.out
new file mode 100644
index 0000000..57d9f50
--- /dev/null
+++ b/tests/generic/152.out
@@ -0,0 +1,23 @@ 
+QA output created by 152
+Test O_BENEATH:
+  Symlinks without .. or leading / are OK
+  ...unless of course we specify O_NOFOLLOW (ELOOP)
+Too many levels of symbolic links
+Too many levels of symbolic links
+Too many levels of symbolic links
+  Can't open paths with .. in them (EPERM)
+Operation not permitted
+Operation not permitted
+Operation not permitted
+Operation not permitted
+  Can't open paths starting with / (EPERM)
+Operation not permitted
+Operation not permitted
+Operation not permitted
+  Can't sneak around constraints with symlinks (EPERM)
+Operation not permitted
+Operation not permitted
+Operation not permitted
+Operation not permitted
+  Can't open files below pre-resolved symlinks in /proc
+Operation not permitted
diff --git a/tests/generic/group b/tests/generic/group
index f2eb87a..030a076 100644
--- a/tests/generic/group
+++ b/tests/generic/group
@@ -96,6 +96,8 @@ 
 133 rw auto
 135 metadata auto quick
 141 rw auto quick
+151 metadata auto quick
+152 metadata auto quick
 169 rw metadata auto quick
 184 metadata auto quick
 192 atime auto