[libvirt] [PATCH 2/2] makefile: fix build on systems where gnutls is not in /usr/include

[Michal Privoznik]

On 23.05.2016 17:06, Pavel Hrdina wrote:
> On Mon, May 23, 2016 at 04:42:43PM +0200, Michal Privoznik wrote:
>> On 23.05.2016 10:18, Pavel Hrdina wrote:
>>> We need to append GNUTLS_CFLAGS while building utils because virtcrypto
>>> is using it.  This fixes build on freebsd where gnutuls is in
>>> /usr/local/include.
>>>
>>> Signed-off-by: Pavel Hrdina <phrdina at redhat.com>
>>> ---
>>>  src/Makefile.am | 2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/src/Makefile.am b/src/Makefile.am
>>> index 314f6df..12b66c2 100644
>>> --- a/src/Makefile.am
>>> +++ b/src/Makefile.am
>>> @@ -1106,7 +1106,7 @@ libvirt_util_la_SOURCES =					\
>>>  libvirt_util_la_CFLAGS = $(CAPNG_CFLAGS) $(YAJL_CFLAGS) $(LIBNL_CFLAGS) \
>>>  		$(AM_CFLAGS) $(AUDIT_CFLAGS) $(DEVMAPPER_CFLAGS) \
>>>  		$(DBUS_CFLAGS) $(LDEXP_LIBM) $(NUMACTL_CFLAGS)	\
>>> -		$(SYSTEMD_DAEMON_CFLAGS) $(POLKIT_CFLAGS) \
>>> +		$(SYSTEMD_DAEMON_CFLAGS) $(POLKIT_CFLAGS) $(GNUTLS_CFLAGS) \
>>>  		-I$(srcdir)/conf
>>>  libvirt_util_la_LIBADD = $(CAPNG_LIBS) $(YAJL_LIBS) $(LIBNL_LIBS) \
>>>  		$(THREAD_LIBS) $(AUDIT_LIBS) $(DEVMAPPER_LIBS) \
>>>
>>
>> I think we need to update _LIBADD too so that it contains GNUTLS_LIBS
>> because now libvirt_uitls lib is depending on gnutls lib. This, however,
> 
> Yes, I've realized that too few minutes ago.
> 
>> make commandtest fail as gnutls upon its init opens /dev/urandom and
>> keeps it opened for the rest of binary runtime which makes commandhelper
>> report the FD and in turn commandtest sad.
>> I'm not sure I have proper solution for that - other than what you did
>> in 1/2.
> 
> We could wrap all gnutls functions and for tests mock those wrapper functions.
> 

That won't fly. Problem is, this is in gnutls_init which is ran when the library is linked. It's not that we are calling something that leaves FD open.

#0  open64 () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007ffff5808a7a in open (__oflag=0, __path=0x7ffff581c4c2 "/dev/urandom") at /usr/include/bits/fcntl2.h:53
#2  _rnd_system_entropy_init () at /var/tmp/portage/net-libs/gnutls-3.3.17.1/work/gnutls-3.3.17.1/lib/nettle/rnd-common.c:216
#3  0x00007ffff580903c in wrap_nettle_rnd_init (ctx=<optimized out>) at /var/tmp/portage/net-libs/gnutls-3.3.17.1/work/gnutls-3.3.17.1/lib/nettle/rnd.c:230
#4  0x00007ffff577fff9 in _gnutls_rnd_init () at /var/tmp/portage/net-libs/gnutls-3.3.17.1/work/gnutls-3.3.17.1/lib/random.c:49
#5  0x00007ffff5774a26 in gnutls_global_init () at /var/tmp/portage/net-libs/gnutls-3.3.17.1/work/gnutls-3.3.17.1/lib/gnutls_global.c:272
#6  0x00007ffff57569c9 in lib_init () at /var/tmp/portage/net-libs/gnutls-3.3.17.1/work/gnutls-3.3.17.1/lib/gnutls_global.c:434
#7  0x00007ffff7dea26a in call_init (l=<optimized out>, argc=argc at entry=1, argv=argv at entry=0x7fffffffdee8, env=env at entry=0x7fffffffdef8) at dl-init.c:72
#8  0x00007ffff7dea37b in call_init (env=0x7fffffffdef8, argv=0x7fffffffdee8, argc=1, l=<optimized out>) at dl-init.c:30
#9  _dl_init (main_map=0x7ffff7ffe148, argc=1, argv=0x7fffffffdee8, env=0x7fffffffdef8) at dl-init.c:120
#10 0x00007ffff7ddbc7a in _dl_start_user () from /lib64/ld-linux-x86-64.so.2
#11 0x0000000000000001 in ?? ()
#12 0x00007fffffffe2f4 in ?? ()
#13 0x0000000000000000 in ?? ()

But making commandtest dependent on WITH_GNULTS just doesn't sound right.

Michal