Libguestfs - May 2014 - Re: [PATCH] tests: simple test for execstack supermin

Add a simple test which uses scanelf or readelf to detect whether the
supermin executable is really not executable.

Kind of followup of commit c9f7a7998021e1cbe22a8ec325d43e2bdc3eff5a.
---
 tests/Makefile.am       |  1 +
 tests/test-execstack.sh | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 33 insertions(+)
 create mode 100755 tests/test-execstack.sh

diff --git a/tests/Makefile.am b/tests/Makefile.am
index dc73737..4dc5958 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -23,6 +23,7 @@ EXTRA_DIST = \
 
 TESTS = \
 	test-basic.sh \
+	test-execstack.sh \
 	test-build-bash.sh \
 	test-binaries-exist.sh \
 	test-harder.sh
diff --git a/tests/test-execstack.sh b/tests/test-execstack.sh
new file mode 100755
index 0000000..a9cb5e0
--- /dev/null
+++ b/tests/test-execstack.sh
@@ -0,0 +1,32 @@
+#!/bin/bash -
+# supermin
+# (C) Copyright 2014 Red Hat 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 of the License, 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+set -e
+
+if scanelf --help >/dev/null 2>&1; then
+    echo "using scanelf"
+    scanelf -e ../src/supermin
+    test `scanelf -qe ../src/supermin | wc -l` -eq 0
+elif readelf --help >/dev/null 2>&1; then
+    echo "using readelf"
+    readelf -lW ../src/supermin | grep GNU_STACK
+    ! readelf -lW ../src/supermin | grep GNU_STACK | grep 'E '
>/dev/null 2>&1
+else
+    echo "$0: test skipped because none of the following tools is
installed: scanelf, readelf"
+    exit 77
+fi
-- 
1.9.0

On Fri, May 02, 2014 at 02:47:11PM +0200, Pino Toscano
wrote:
> Add a simple test which uses scanelf or readelf to detect whether the
> supermin executable is really not executable.
> 
> Kind of followup of commit c9f7a7998021e1cbe22a8ec325d43e2bdc3eff5a.
ACK.

(Not that executable stacks matter for OCaml programs.  It's
fixing something which is a problem for C programs :-)

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-builder quickly builds VMs from scratch
http://libguestfs.org/virt-builder.1.html

On Fri, May 02, 2014 at 02:47:11PM +0200, Pino Toscano
wrote:
> Add a simple test which uses scanelf or readelf to detect whether the
> supermin executable is really not executable.
FYI this test failed on ARM.  It's a genuine failure showing that we
are building a supermin binary with an executable stack.

It turns out to be an OCaml bug.  Years ago I filed:

http://caml.inria.fr/mantis/view.php?id=4564

It was only fixed upstream on i686 & x86-64 ... not on ARM.

$ touch empty.ml
$ ocamlopt empty.ml 
$ readelf -lW a.out | grep GNU_STACK
  GNU_STACK      0x000000 0x00000000 0x00000000 0x00000 0x00000 RWE 0x4

So I will have to apply the same fix to the OCaml ARM compiler too.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
Fedora Windows cross-compiler. Compile Windows programs, test, and
build Windows installers. Over 100 libraries supported.
http://fedoraproject.org/wiki/MinGW

---
 tests/test-execstack.sh | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tests/test-execstack.sh b/tests/test-execstack.sh
index a9cb5e0..a02803b 100755
--- a/tests/test-execstack.sh
+++ b/tests/test-execstack.sh
@@ -18,6 +18,11 @@
 
 set -e
 
+if [ -n "$SKIP_TEST_EXECSTACK" ]; then
+    echo "$0: test skipped because SKIP_TEST_EXECSTACK is set."
+    exit 77
+fi
+
 if scanelf --help >/dev/null 2>&1; then
     echo "using scanelf"
     scanelf -e ../src/supermin
-- 
2.0.0.rc2

On Friday 09 May 2014 22:19:02 Richard W.M. Jones wrote:
> On Fri, May 02, 2014 at 02:47:11PM +0200, Pino Toscano wrote:
> > Add a simple test which uses scanelf or readelf to detect whether
> > the
> > supermin executable is really not executable.
> 
> FYI this test failed on ARM.  It's a genuine failure showing that we
> are building a supermin binary with an executable stack.
Ouch, I didn't know about this issue, sorry for the tests breakage on 
!x86 & !x86_64 platforms.
> It turns out to be an OCaml bug.  Years ago I filed:
> 
> http://caml.inria.fr/mantis/view.php?id=4564
> 
> It was only fixed upstream on i686 & x86-64 ... not on ARM.
> 
> $ touch empty.ml
> $ ocamlopt empty.ml
> $ readelf -lW a.out | grep GNU_STACK
>   GNU_STACK      0x000000 0x00000000 0x00000000 0x00000 0x00000 RWE
> 0x4
> 
> So I will have to apply the same fix to the OCaml ARM compiler too.
Judging from the Debian build logs of pristine supermin 5.1.8, 
architecture affected were for sure arm, mips, powerpc.

-- 
Pino Toscano