[LTP] [RFC] [PATCH] lib32: Add support for linking 32bit programs on 64bit

[LTP] [RFC] [PATCH] lib32: Add support for linking 32bit programs on 64bit

[Cyril Hrubis]

This is proof of concept for building 32bit testcases on 64bit platform.

What we do is:

* Configure test if compiler supports -m32
  TODO: Does 32bit compiler accept -m32?
        If so, we should fail the test on 32bit
	platforms by default.

* The directory lib32 contains symlinks of minimal set of sources
  needed to link newlib testcase + Makefile.

* The testcases.mk builds 32bit library as well if
  32bit compiler was installed (-m32 configure test was succesful)

* And finally the env_post.mk switches between lib and lib32 depeding
  on if -m32 was passed in the CFLAGS

TODO: Check if LTP works with -m32 in CFLAGS passed to configure as well

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
---
 configure.ac                               |  1 +
 include/mk/config.mk.in                    |  2 ++
 include/mk/env_post.mk                     |  4 ++++
 include/mk/testcases.mk                    |  9 +++++++
 lib32/Makefile                             | 38 ++++++++++++++++++++++++++++++
 lib32/errnos.h                             |  1 +
 lib32/ltp_priv.h                           |  1 +
 lib32/safe_file_ops.c                      |  1 +
 lib32/safe_macros.c                        |  1 +
 lib32/signame.h                            |  1 +
 lib32/tst_ansi_color.c                     |  1 +
 lib32/tst_checkpoint.c                     |  1 +
 lib32/tst_device.c                         |  1 +
 lib32/tst_fill_file.c                      |  1 +
 lib32/tst_kvercmp.c                        |  1 +
 lib32/tst_mkfs.c                           |  1 +
 lib32/tst_res.c                            |  1 +
 lib32/tst_resource.c                       |  1 +
 lib32/tst_run_cmd.c                        |  1 +
 lib32/tst_safe_macros.c                    |  1 +
 lib32/tst_test.c                           |  1 +
 lib32/tst_tmpdir.c                         |  1 +
 m4/ltp-m32.m4                              | 36 ++++++++++++++++++++++++++++
 testcases/kernel/syscalls/add_key/Makefile |  2 ++
 24 files changed, 109 insertions(+)
 create mode 100644 lib32/Makefile
 create mode 120000 lib32/errnos.h
 create mode 120000 lib32/ltp_priv.h
 create mode 120000 lib32/safe_file_ops.c
 create mode 120000 lib32/safe_macros.c
 create mode 120000 lib32/signame.h
 create mode 120000 lib32/tst_ansi_color.c
 create mode 120000 lib32/tst_checkpoint.c
 create mode 120000 lib32/tst_device.c
 create mode 120000 lib32/tst_fill_file.c
 create mode 120000 lib32/tst_kvercmp.c
 create mode 120000 lib32/tst_mkfs.c
 create mode 120000 lib32/tst_res.c
 create mode 120000 lib32/tst_resource.c
 create mode 120000 lib32/tst_run_cmd.c
 create mode 120000 lib32/tst_safe_macros.c
 create mode 120000 lib32/tst_test.c
 create mode 120000 lib32/tst_tmpdir.c
 create mode 100644 m4/ltp-m32.m4

diff --git a/configure.ac b/configure.ac
index 6b765f0..3c519d3 100644
--- a/configure.ac
+++ b/configure.ac
@@ -190,5 +190,6 @@ LTP_CHECK_EPOLL_PWAIT
 LTP_CHECK_KEYUTILS_SUPPORT
 LTP_CHECK_SYNC_ADD_AND_FETCH
 LTP_CHECK_BUILTIN_CLEAR_CACHE
+LTP_CHECK_CC_M32
 
 AC_OUTPUT
diff --git a/include/mk/config.mk.in b/include/mk/config.mk.in
index dde2a9e..c160211 100644
--- a/include/mk/config.mk.in
+++ b/include/mk/config.mk.in
@@ -76,6 +76,8 @@ LDFLAGS			+= $(WLDFLAGS)
 CFLAGS			+= $(DEBUG_CFLAGS) $(OPT_CFLAGS) $(WCFLAGS)
 CXXFLAGS		+= $(DEBUG_CXXFLAGS) $(OPT_CXXFLAGS) $(WCXXFLAGS)
 
+CC_M32			:= @CC_M32@
+
 LINUX_VERSION		:= @LINUX_VERSION@
 LINUX_DIR		:= @LINUX_DIR@
 LINUX_VERSION_MAJOR	:= @LINUX_VERSION_MAJOR@
diff --git a/include/mk/env_post.mk b/include/mk/env_post.mk
index 4c57fff..fdf13e2 100644
--- a/include/mk/env_post.mk
+++ b/include/mk/env_post.mk
@@ -35,7 +35,11 @@ vpath %.c $(abs_srcdir)
 # For config.h, et all.
 CPPFLAGS			+= -I$(top_srcdir)/include -I$(top_builddir)/include -I$(top_srcdir)/include/old/
 
+ifeq ($(filter -m32,$(CFLAGS)),)
 LDFLAGS				+= -L$(top_builddir)/lib
+else
+LDFLAGS				+= -L$(top_builddir)/lib32
+endif
 
 ifeq ($(UCLINUX),1)
 CPPFLAGS			+= -D__UCLIBC__ -DUCLINUX
diff --git a/include/mk/testcases.mk b/include/mk/testcases.mk
index f453f4e..03446f2 100644
--- a/include/mk/testcases.mk
+++ b/include/mk/testcases.mk
@@ -30,8 +30,10 @@ TKI_DIR		:= testcases/kernel/include
 LSN_H		:= $(abs_top_builddir)/$(TKI_DIR)/linux_syscall_numbers.h
 
 LIBLTP_DIR	:= $(abs_top_builddir)/lib
+LIBLTP_DIR32	:= $(abs_top_builddir)/lib32
 
 LIBLTP		:= $(LIBLTP_DIR)/libltp.a
+LIBLTP32	:= $(LIBLTP_DIR32)/libltp.a
 
 $(APICMDS_DIR)/tst_kvercmp: $(APICMDS_DIR)
 	$(MAKE) -C "$^" -f "$(abs_top_srcdir)/tools/apicmds/Makefile" all
@@ -39,11 +41,18 @@ $(APICMDS_DIR)/tst_kvercmp: $(APICMDS_DIR)
 $(LIBLTP): $(LIBLTP_DIR)
 	$(MAKE) -C "$^" -f "$(abs_top_srcdir)/lib/Makefile" all
 
+$(LIBLTP32): $(LIBLTP_DIR32)
+	$(MAKE) -C "$^" -f "$(abs_top_srcdir)/lib32/Makefile" all
+
 $(LSN_H): $(abs_top_builddir)/$(TKI_DIR)
 	$(MAKE) -C "$^" -f "$(abs_top_srcdir)/$(TKI_DIR)/Makefile" all
 
 MAKE_DEPS	:= $(LIBLTP) $(LSN_H)
 
+ifneq ($(CC_M32),)
+MAKE_DEPS	+= $(LIBLTP32)
+endif
+
 # For linux_syscall_numbers.h
 CPPFLAGS	+= -I$(abs_top_builddir)/$(TKI_DIR)
 
diff --git a/lib32/Makefile b/lib32/Makefile
new file mode 100644
index 0000000..221b71e
--- /dev/null
+++ b/lib32/Makefile
@@ -0,0 +1,38 @@
+#
+#    lib Makefile.
+#
+#    Copyright (C) 2009, Cisco Systems 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.,
+#    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+#
+# Ngie Cooper, July 2009
+#
+
+top_srcdir		?= ..
+
+include $(top_srcdir)/include/mk/env_pre.mk
+
+CFLAGS			+= -I -DLTPLIB -m32
+
+ifneq ($(ANDROID),1)
+FILTER_OUT_DIRS		+= android_libpthread android_librt
+else
+FILTER_OUT_LIBSRCS	+= tlibio.c tst_path_has_mnt_flags.c
+endif
+
+LIB			:= libltp.a
+
+include $(top_srcdir)/include/mk/lib.mk
+include $(top_srcdir)/include/mk/generic_trunk_target.mk
diff --git a/lib32/errnos.h b/lib32/errnos.h
new file mode 120000
index 0000000..caff095
--- /dev/null
+++ b/lib32/errnos.h
@@ -0,0 +1 @@
+../lib/errnos.h
\ No newline at end of file
diff --git a/lib32/ltp_priv.h b/lib32/ltp_priv.h
new file mode 120000
index 0000000..783e267
--- /dev/null
+++ b/lib32/ltp_priv.h
@@ -0,0 +1 @@
+../lib/ltp_priv.h
\ No newline at end of file
diff --git a/lib32/safe_file_ops.c b/lib32/safe_file_ops.c
new file mode 120000
index 0000000..eeb29a7
--- /dev/null
+++ b/lib32/safe_file_ops.c
@@ -0,0 +1 @@
+../lib/safe_file_ops.c
\ No newline at end of file
diff --git a/lib32/safe_macros.c b/lib32/safe_macros.c
new file mode 120000
index 0000000..832d7ae
--- /dev/null
+++ b/lib32/safe_macros.c
@@ -0,0 +1 @@
+../lib/safe_macros.c
\ No newline at end of file
diff --git a/lib32/signame.h b/lib32/signame.h
new file mode 120000
index 0000000..f59345b
--- /dev/null
+++ b/lib32/signame.h
@@ -0,0 +1 @@
+../lib/signame.h
\ No newline at end of file
diff --git a/lib32/tst_ansi_color.c b/lib32/tst_ansi_color.c
new file mode 120000
index 0000000..14d8c5d
--- /dev/null
+++ b/lib32/tst_ansi_color.c
@@ -0,0 +1 @@
+../lib/tst_ansi_color.c
\ No newline at end of file
diff --git a/lib32/tst_checkpoint.c b/lib32/tst_checkpoint.c
new file mode 120000
index 0000000..28e332f
--- /dev/null
+++ b/lib32/tst_checkpoint.c
@@ -0,0 +1 @@
+../lib/tst_checkpoint.c
\ No newline at end of file
diff --git a/lib32/tst_device.c b/lib32/tst_device.c
new file mode 120000
index 0000000..f8c7982
--- /dev/null
+++ b/lib32/tst_device.c
@@ -0,0 +1 @@
+../lib/tst_device.c
\ No newline at end of file
diff --git a/lib32/tst_fill_file.c b/lib32/tst_fill_file.c
new file mode 120000
index 0000000..7439f3e
--- /dev/null
+++ b/lib32/tst_fill_file.c
@@ -0,0 +1 @@
+../lib/tst_fill_file.c
\ No newline at end of file
diff --git a/lib32/tst_kvercmp.c b/lib32/tst_kvercmp.c
new file mode 120000
index 0000000..ac15523
--- /dev/null
+++ b/lib32/tst_kvercmp.c
@@ -0,0 +1 @@
+../lib/tst_kvercmp.c
\ No newline at end of file
diff --git a/lib32/tst_mkfs.c b/lib32/tst_mkfs.c
new file mode 120000
index 0000000..a0e0421
--- /dev/null
+++ b/lib32/tst_mkfs.c
@@ -0,0 +1 @@
+../lib/tst_mkfs.c
\ No newline at end of file
diff --git a/lib32/tst_res.c b/lib32/tst_res.c
new file mode 120000
index 0000000..f2083bc
--- /dev/null
+++ b/lib32/tst_res.c
@@ -0,0 +1 @@
+../lib/tst_res.c
\ No newline at end of file
diff --git a/lib32/tst_resource.c b/lib32/tst_resource.c
new file mode 120000
index 0000000..a3c021e
--- /dev/null
+++ b/lib32/tst_resource.c
@@ -0,0 +1 @@
+../lib/tst_resource.c
\ No newline at end of file
diff --git a/lib32/tst_run_cmd.c b/lib32/tst_run_cmd.c
new file mode 120000
index 0000000..d57dbb6
--- /dev/null
+++ b/lib32/tst_run_cmd.c
@@ -0,0 +1 @@
+../lib/tst_run_cmd.c
\ No newline at end of file
diff --git a/lib32/tst_safe_macros.c b/lib32/tst_safe_macros.c
new file mode 120000
index 0000000..a1bf8c5
--- /dev/null
+++ b/lib32/tst_safe_macros.c
@@ -0,0 +1 @@
+../lib/tst_safe_macros.c
\ No newline at end of file
diff --git a/lib32/tst_test.c b/lib32/tst_test.c
new file mode 120000
index 0000000..a82ad7a
--- /dev/null
+++ b/lib32/tst_test.c
@@ -0,0 +1 @@
+../lib/tst_test.c
\ No newline at end of file
diff --git a/lib32/tst_tmpdir.c b/lib32/tst_tmpdir.c
new file mode 120000
index 0000000..a34cf42
--- /dev/null
+++ b/lib32/tst_tmpdir.c
@@ -0,0 +1 @@
+../lib/tst_tmpdir.c
\ No newline at end of file
diff --git a/m4/ltp-m32.m4 b/m4/ltp-m32.m4
new file mode 100644
index 0000000..e5b3ff6
--- /dev/null
+++ b/m4/ltp-m32.m4
@@ -0,0 +1,36 @@
+dnl Copyright (c) 2017 Cyril Hrubis <chrubis@suse.cz>
+dnl
+dnl This program is free software; you can redistribute it and/or
+dnl modify it under the terms of the GNU General Public License as
+dnl published by the Free Software Foundation; either version 2 of
+dnl the License, or (at your option) any later version.
+dnl
+dnl This program is distributed in the hope that it would be useful,
+dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
+dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+dnl GNU General Public License for more details.
+dnl
+dnl You should have received a copy of the GNU General Public License
+dnl along with this program; if not, write the Free Software Foundation,
+dnl Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+dnl
+
+AC_DEFUN([LTP_CHECK_CC_M32],[dnl
+
+flag="-m32"
+AC_MSG_CHECKING([if $CC supports $flag])
+
+backup_cflags="$CFLAGS"
+CFLAGS="$CFLAGS $flag"
+
+AC_LINK_IFELSE(
+	[AC_LANG_PROGRAM([])],
+	[CC_M32="$flag"]
+	[AC_MSG_RESULT([yes])],
+	[AC_MSG_RESULT([no])]
+)
+
+AC_SUBST(CC_M32)
+CFLAGS="$backup_cflags"
+
+])
diff --git a/testcases/kernel/syscalls/add_key/Makefile b/testcases/kernel/syscalls/add_key/Makefile
index 2ef86f0..0db5233 100644
--- a/testcases/kernel/syscalls/add_key/Makefile
+++ b/testcases/kernel/syscalls/add_key/Makefile
@@ -20,4 +20,6 @@ top_srcdir		?= ../../../..
 
 include $(top_srcdir)/include/mk/testcases.mk
 
+CFLAGS += $(CC_M32)
+
 include $(top_srcdir)/include/mk/generic_leaf_target.mk
-- 
2.10.2

[LTP] [RFC] [PATCH] lib32: Add support for linking 32bit programs on 64bit

[Richard Palethorpe]

Hi Metan!

On Tue, 28 Mar 2017 12:01:14 +0200
"Cyril Hrubis" <chrubis@suse.cz> wrote:

> This is proof of concept for building 32bit testcases on 64bit platform.

Great thanks! I have tried running it and have a couple of minor issues.

> 
> What we do is:
> 
> * Configure test if compiler supports -m32
>   TODO: Does 32bit compiler accept -m32?
>         If so, we should fail the test on 32bit
> 	platforms by default.
> 
> * The directory lib32 contains symlinks of minimal set of sources
>   needed to link newlib testcase + Makefile.

Apparently missing safe_socket which is required for cve-2016-4997.c, but that
is easy to fix I suppose.

> 
> * The testcases.mk builds 32bit library as well if
>   32bit compiler was installed (-m32 configure test was succesful)
> 
> * And finally the env_post.mk switches between lib and lib32 depeding
>   on if -m32 was passed in the CFLAGS

I added "cve-2016-4997: CFLAGS += -m32" and it still tried to look in
"../../lib"

> +ifeq ($(filter -m32,$(CFLAGS)),)
>  LDFLAGS				+= -L$(top_builddir)/lib
> +else
> +LDFLAGS				+= -L$(top_builddir)/lib32
> +endif

I was able to remove the if statement (i.e. put both dirs on the search path)
and the 64-bit tests still compiled fine and so did the 32-bit test, although
maybe not all linkers can be trusted to ignore libs with the wrong number of
bits.

Thank you,
Richard.

[LTP] [RFC] [PATCH] lib32: Add support for linking 32bit programs on 64bit

[Cyril Hrubis]

Hi!
> > * The directory lib32 contains symlinks of minimal set of sources
> >   needed to link newlib testcase + Makefile.
> 
> Apparently missing safe_socket which is required for cve-2016-4997.c, but that
> is easy to fix I suppose.

That is just one symlink away...

> > * The testcases.mk builds 32bit library as well if
> >   32bit compiler was installed (-m32 configure test was succesful)
> > 
> > * And finally the env_post.mk switches between lib and lib32 depeding
> >   on if -m32 was passed in the CFLAGS
> 
> I added "cve-2016-4997: CFLAGS += -m32" and it still tried to look in
> "../../lib"

Hmm, that is not easy to fix, since this is target specific variable and
we simply do not see the -m32 in the CFLAGS in the condition below.

We would have to set the LDFLAGS per target and I'm not sure if we can
easily do that.

> > +ifeq ($(filter -m32,$(CFLAGS)),)
> >  LDFLAGS				+= -L$(top_builddir)/lib
> > +else
> > +LDFLAGS				+= -L$(top_builddir)/lib32
> > +endif
> 
> I was able to remove the if statement (i.e. put both dirs on the search path)
> and the 64-bit tests still compiled fine and so did the 32-bit test, although
> maybe not all linkers can be trusted to ignore libs with the wrong number of
> bits.

While this works mostly fine it produces warnings I would like to avoid.

-- 
Cyril Hrubis
chrubis@suse.cz

[LTP] [RFC] [PATCH] lib32: Add support for linking 32bit programs on 64bit

[Cyril Hrubis]

Hi!
> > I added "cve-2016-4997: CFLAGS += -m32" and it still tried to look in
> > "../../lib"
> 
> Hmm, that is not easy to fix, since this is target specific variable and
> we simply do not see the -m32 in the CFLAGS in the condition below.
> 
> We would have to set the LDFLAGS per target and I'm not sure if we can
> easily do that.
> 
> > > +ifeq ($(filter -m32,$(CFLAGS)),)
> > >  LDFLAGS				+= -L$(top_builddir)/lib
> > > +else
> > > +LDFLAGS				+= -L$(top_builddir)/lib32
> > > +endif

Try with this condition instead of the above ifeqs:

$(MAKE_TARGETS): LDFLAGS += -L$(top_builddir)/lib$(subst -m,,$(filter -m32,$(CFLAGS)))

It's a bit hairy but seems to work.

-- 
Cyril Hrubis
chrubis@suse.cz

[LTP] [RFC] [PATCH] lib32: Add support for linking 32bit programs on 64bit

[Jan Stancek]

----- Original Message -----
> From: "Cyril Hrubis" <chrubis@suse.cz>
> To: ltp@lists.linux.it
> Sent: Tuesday, 28 March, 2017 12:01:14 PM
> Subject: [LTP] [RFC] [PATCH] lib32: Add support for linking 32bit programs	on 64bit
> 
> This is proof of concept for building 32bit testcases on 64bit platform.
> 
> What we do is:
> 
> * Configure test if compiler supports -m32
>   TODO: Does 32bit compiler accept -m32?
>         If so, we should fail the test on 32bit
> 	platforms by default.
> 
> * The directory lib32 contains symlinks of minimal set of sources
>   needed to link newlib testcase + Makefile.
> 
> * The testcases.mk builds 32bit library as well if
>   32bit compiler was installed (-m32 configure test was succesful)
> 
> * And finally the env_post.mk switches between lib and lib32 depeding
>   on if -m32 was passed in the CFLAGS
> 

One issue I ran into is that configure checks can vary
between default and -m32. Here's one exception from RHEL5.6:

# cat 1.c 
int main(void) {
        int i = 0;
        return __sync_add_and_fetch(&i, 1);
}

# gcc 1.c 
# gcc -m32 1.c 
/tmp/ccwrlcJi.o: In function `main':
1.c:(.text+0x27): undefined reference to `__sync_add_and_fetch_4'
collect2: ld returned 1 exit status

> TODO: Check if LTP works with -m32 in CFLAGS passed to configure as well

This fails for me on RHEL7:

# make
make[1]: Entering directory `/root/ltp/lib/newlib_tests'
gcc -m32 -g -O2 -fno-strict-aliasing -pipe -Wall -W -Wold-style-definition -W -Wall  -I../../include -I../../include -I../../include/old/   -L../../lib32  test14.c   -lltp -o test14
/tmp/ccPZUDSr.o: In function `cleanup':
/root/ltp/lib/newlib_tests/test14.c:31: undefined reference to `safe_fopen'
/root/ltp/lib/newlib_tests/test14.c:32: undefined reference to `safe_socket'
collect2: error: ld returned 1 exit status
make[1]: *** [test14] Error 1
make[1]: Leaving directory `/root/ltp/lib/newlib_tests'
make: *** [all] Error 2

I ran into one other problem, but I don't think that's relevant
for this patch. I'll follow up in separate email thread.

Regards,
Jan

[LTP] [RFC] [PATCH] lib32: Add support for linking 32bit programs on 64bit

[Cyril Hrubis]

Hi!
> > * Configure test if compiler supports -m32
> >   TODO: Does 32bit compiler accept -m32?
> >         If so, we should fail the test on 32bit
> > 	platforms by default.
> > 
> > * The directory lib32 contains symlinks of minimal set of sources
> >   needed to link newlib testcase + Makefile.
> > 
> > * The testcases.mk builds 32bit library as well if
> >   32bit compiler was installed (-m32 configure test was succesful)
> > 
> > * And finally the env_post.mk switches between lib and lib32 depeding
> >   on if -m32 was passed in the CFLAGS
> > 
> 
> One issue I ran into is that configure checks can vary
> between default and -m32. Here's one exception from RHEL5.6:
> 
> # cat 1.c 
> int main(void) {
>         int i = 0;
>         return __sync_add_and_fetch(&i, 1);
> }
> 
> # gcc 1.c 
> # gcc -m32 1.c 
> /tmp/ccwrlcJi.o: In function `main':
> 1.c:(.text+0x27): undefined reference to `__sync_add_and_fetch_4'
> collect2: ld returned 1 exit status

Right, we would have to check for atomic operations with -m32 as well.

I guess that we can add -DUSE_M32 into the lib32/Makefile and add a few
ifdefs into the tst_atomic.h something as:

#if (defined(USE_M32) && HAVE_SYNC_AND_FETCH32 == 1) || \
    (!defined(USE_M32) && HAVE_SYNC_AND_FETCH == 1)
...
#elif ...
...

> > TODO: Check if LTP works with -m32 in CFLAGS passed to configure as well
> 
> This fails for me on RHEL7:
> 
> # make
> make[1]: Entering directory `/root/ltp/lib/newlib_tests'
> gcc -m32 -g -O2 -fno-strict-aliasing -pipe -Wall -W -Wold-style-definition -W -Wall  -I../../include -I../../include -I../../include/old/   -L../../lib32  test14.c   -lltp -o test14
> /tmp/ccPZUDSr.o: In function `cleanup':
> /root/ltp/lib/newlib_tests/test14.c:31: undefined reference to `safe_fopen'
> /root/ltp/lib/newlib_tests/test14.c:32: undefined reference to `safe_socket'
> collect2: error: ld returned 1 exit status
> make[1]: *** [test14] Error 1
> make[1]: Leaving directory `/root/ltp/lib/newlib_tests'
> make: *** [all] Error 2

This is likely because we try to link against lib32 since -m32 is passed
in CFLAGS but lib32/ directory links only subset of the C sources. I
would like to disable all the lib32 machinery either when we run on
32bit machine or if -m32 was passed to the configure and use lib32 only
in a case that we run on 64 bit machine and want to link 32 bit binary.

-- 
Cyril Hrubis
chrubis@suse.cz

[LTP] [RFC] [PATCH] lib32: Add support for linking 32bit programs on 64bit

[Richard Palethorpe]

Hello Metan,

On Tue, 28 Mar 2017 17:46:47 +0200
"Cyril Hrubis" <chrubis@suse.cz> wrote:
> 
> Try with this condition instead of the above ifeqs:
> 
> $(MAKE_TARGETS): LDFLAGS += -L$(top_builddir)/lib$(subst -m,,$(filter -m32,$(CFLAGS)))
> 
> It's a bit hairy but seems to work.
> 

It works (if added after MAKE_TARGETS is defined ofcourse) and also I
symlinked in the safe socket lib, so the test now compiles and runs fine, at
least on x86_64 SUSE.

I will try it on SLE-11 SP4 i586.

Thank you,
Richard.

[LTP] [RFC] [PATCH] lib32: Add support for linking 32bit programs on 64bit

[Richard Palethorpe]

Hi Metan,

On Tue, 28 Mar 2017 12:01:14 +0200
"Cyril Hrubis" <chrubis@suse.cz> wrote:

> This is proof of concept for building 32bit testcases on 64bit platform.
> 
> What we do is:
> 
> * Configure test if compiler supports -m32
>   TODO: Does 32bit compiler accept -m32?
>         If so, we should fail the test on 32bit
> 	platforms by default.
> 

Yes it does accept -m32. I think the best thing to do is call
tst_kernelbits(), as you suggested, at runtime anyway, as someone might be
running a 32bit compiler on a 64bit kernel and/or cross compiling.

Also it turns out that I am using some C syntax which is not accepted by GCC
4.3.4. This is annoying considering the tests compile fine with -std=C99 on
GCC 6.

Thank you,
Richard.

[LTP] [RFC] [PATCH] lib32: Add support for linking 32bit programs on 64bit

[Richard Palethorpe]

On Wed, 29 Mar 2017 14:48:00 +0200
"Richard Palethorpe" <Richard.Palethorpe@suse.com> wrote:
> 
> Also it turns out that I am using some C syntax which is not accepted by GCC
> 4.3.4. This is annoying considering the tests compile fine with -std=C99 on
> GCC 6.
> 

Spoke too soon, it is just missing struct definitions.