[Spice-devel] [PATCH spice-server v2] gstreamer: Check if ORC library can work

[Frediano Ziglio]

> 
> On Fri, Aug 18, 2017 at 12:32:12PM +0100, Frediano Ziglio wrote:
> > ORC lirabry is used internally by GStreamer to generate code
> > dynamically.
> 
> "The ORC library"
> 
> > If ORC cannot allocate executable memory the failure cause
> > an abort(3) to be called.
> 
> "memory, the failure causes"
> 
> > This happens on some SELinux configuration that disable executable
> > memory allocation (execmem boolean).
> 
> Either "SELinux configurations" or "that disables"
> 
> > Check that ORC could work before attempting to use GStreamer to
> > avoid crashes. The log will report an error.
> 
> > 
> > Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
> > ---
> >  configure.ac               |  6 ++++++
> >  server/Makefile.am         |  2 ++
> >  server/gstreamer-encoder.c | 30 ++++++++++++++++++++++++++++++
> >  3 files changed, 38 insertions(+)
> > 
> > Changes since v1:
> > - rename orc_cached to orc_dynamic_code_ok.
> > 
> > diff --git a/configure.ac b/configure.ac
> > index e1e74862..4bdf8588 100644
> > --- a/configure.ac
> > +++ b/configure.ac
> > @@ -116,6 +116,12 @@ AS_IF([test x"$missing_gstreamer_elements" = xyes],
> >      [SPICE_WARNING([The GStreamer video encoder can be built but may not
> >      work.])
> >  ])
> >  
> > +if test "x$have_gstreamer_0_10" = "xyes" -o "x$have_gstreamer_1_0" =
> > "xyes"; then
> > +    PKG_CHECK_MODULES(ORC, orc-0.4)
> > +    AC_SUBST(ORC_CFLAGS)
> > +    AC_SUBST(ORC_LIBS)
> > +fi
> > +
> >  AC_ARG_ENABLE([automated_tests],
> >                AS_HELP_STRING([--enable-automated-tests], [Enable automated
> >                tests using spicy-screenshot (part of spice-gtk)]),,
> >                [enable_automated_tests="no"])
> > diff --git a/server/Makefile.am b/server/Makefile.am
> > index ef8d31fc..5d5590af 100644
> > --- a/server/Makefile.am
> > +++ b/server/Makefile.am
> > @@ -20,6 +20,7 @@ AM_CPPFLAGS =					\
> >  	$(SSL_CFLAGS)				\
> >  	$(VISIBILITY_HIDDEN_CFLAGS)		\
> >  	$(WARN_CFLAGS)				\
> > +	$(ORC_CFLAGS)				\
> >  	$(NULL)
> >  
> >  noinst_LTLIBRARIES = libserver.la
> > @@ -54,6 +55,7 @@ libserver_la_LIBADD =							\
> >  	$(SSL_LIBS)							\
> >  	$(Z_LIBS)							\
> >  	$(SPICE_NONPKGCONFIG_LIBS)					\
> > +	$(ORC_LIBS)							\
> >  	$(NULL)
> >  
> >  libspice_serverincludedir = $(includedir)/spice-server
> > diff --git a/server/gstreamer-encoder.c b/server/gstreamer-encoder.c
> > index bb4f27ba..2a39154f 100644
> > --- a/server/gstreamer-encoder.c
> > +++ b/server/gstreamer-encoder.c
> > @@ -27,6 +27,7 @@
> >  #include <gst/app/gstappsrc.h>
> >  #include <gst/app/gstappsink.h>
> >  #include <gst/video/video.h>
> > +#include <orc/orcprogram.h>
> >  
> >  #include "red-common.h"
> >  #include "video-encoder.h"
> > @@ -1702,6 +1703,30 @@ static void spice_gst_encoder_get_stats(VideoEncoder
> > *video_encoder,
> >      }
> >  }
> >  
> > +/* Check if ORC library can work.
> > + * ORC library is used quite extensively by GStreamer
> > + * to generate code dynamically. If ORC cannot work GStreamer
> 
> "cannot work, GStreamer"
> 
> > + * will abort(3) the entire process.
> > + */
> > +static bool orc_check(void)
> > +{
> > +    static bool orc_checked = false;
> > +    static bool orc_dynamic_code_ok = false;
> > +
> > +    if (SPICE_UNLIKELY(!orc_checked)) {
> > +        OrcCode *code = orc_code_new();
> > +        if (code) {
> > +            /* allocating 0 byte for code make the function not crash
> 
> "makes"
> 
> > +             * but doing all initializations and checks */
> 
> I would use "but it does all the initializations and checks"
> 
> Acked-by: Christophe Fergeau <cfergeau at redhat.com>
> 

I'll do the changes.

I just noted that if the check fails is quite silence.
Maybe the first time we discover the issue we should log
something? 

Frediano