isa/mutter
1
0
Fork 0
mirror of https://github.com/brl/mutter.git synced 2025-06-13 16:59:30 +00:00
Code Issues Packages Projects Releases Wiki Activity

Don't use the 'NULL' GModule to resolve GL symbols

Browse Source 
Previously, _cogl_get_proc_address had a fallback to resolve the
symbol using g_module_open(NULL) to get the symbol from anywhere in
the address space. The EGL backend ends up using this on some drivers
because eglGetProcAddress isn't meant to return a pointer for core
functions. This causes problems if something in the process is linking
against a different GL library, for example Cairo may be linking
against libGL itself. In this case it may end up resolving symbols
from the GL library even if GLES is being used.

This patch removes the fallback. The EGL version now has its own
fallback instead which passes the existing libgl_module from the
renderer to g_module_symbol so that it should only get symbols from
that library or its dependency chain. The GLX and WGL winsys only call
glXGetProcAddress and wglGetProcAddress. The stub winsys does however
continue using the global symbol lookup.

The internal _cogl_get_proc_address function has been renamed to
_cogl_renderer_get_proc_address because it needs a connected renderer
to work so it could be considered to be a renderer method. The pointer
to the renderer is passed down to the winsys backends so that it can
use the data attached to the renderer to get the module pointers.

https://bugzilla.gnome.org/show_bug.cgi?id=655412

Reviewed-by: Robert Bragg <robert@linux.intel.com>
This commit is contained in:
Neil Roberts
2011-07-27 12:30:02 +01:00
parent 76c88958b7
commit d259a87602
15 changed files with 80 additions and 99 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
cogl/driver/gl/cogl-gl.c
View File

@ -33,6 +33,7 @@
#include "cogl-internal.h"
#include "cogl-context-private.h"
#include "cogl-feature-private.h"
#include "cogl-renderer-private.h"
static gboolean
_cogl_get_gl_version (int *major_out, int *minor_out)
@ -137,8 +138,8 @@ _cogl_gl_update_features (CoglContext *context,
function because we need to use it to determine what functions we
can expect */
context->glGetString =
(void *) _cogl_get_proc_address (_cogl_context_get_winsys (context),
"glGetString");
(void *) _cogl_renderer_get_proc_address (context->display->renderer,
"glGetString");
if (!check_gl_version (context, error))
return FALSE;

5
cogl/driver/gles/cogl-gles.c
View File

@ -31,6 +31,7 @@
#include "cogl-internal.h"
#include "cogl-context-private.h"
#include "cogl-feature-private.h"
#include "cogl-renderer-private.h"
gboolean
_cogl_gles_update_features (CoglContext *context,
@ -45,8 +46,8 @@ _cogl_gles_update_features (CoglContext *context,
function because we need to use it to determine what functions we
can expect */
context->glGetString =
(void *) _cogl_get_proc_address (_cogl_context_get_winsys (context),
"glGetString");
(void *) _cogl_renderer_get_proc_address (context->display->renderer,
"glGetString");
COGL_NOTE (WINSYS,
"Checking features\n"