[Mesa-dev] [PATCH] egl/dri2: dri2_make_current: Make sure display is initialized before using it

[Nicolas Boichat]

android.opengl.cts.WrapperTest#testGetIntegerv1 CTS test calls
eglTerminate, followed by eglReleaseThread. In that case, the
display will not be initialized when eglReleaseThread calls
MakeCurrent with NULL parameters, to unbind the context, which
causes a a segfault in drv->API.MakeCurrent (dri2_make_current),
either in glFlush or in a latter call.

A similar case is observed in this bug:
https://bugs.freedesktop.org/show_bug.cgi?id=69622, where the test
call eglTerminate, then eglMakeCurrent(dpy, NULL, NULL, NULL).

This patch:
 1. Validates that the display is initialized, if ctx/dsurf/rsurf
    are not all NULL.
 2. Does not call glFlush/unBindContext is there is no display.
 3. However, it still goes through the normal path as
    drv->API.DestroyContext decrements the reference count on the
    context, and frees the structure.

Cc: "11.2 12.0" <mesa-stable at lists.freedesktop.org>
Signed-off-by: Nicolas Boichat <drinkcat at chromium.org>
---

I did not actually test the case reported on the bug, only the CTS
test, would be nice if someone can try it out (Rhys? Chad?).

Applies after "egl/dri2: dri2_make_current: Set EGL error if bindContext
fails", but wanted to keep the 2 patches separate as they are different
problems and discussions.

 src/egl/drivers/dri2/egl_dri2.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/egl/drivers/dri2/egl_dri2.c b/src/egl/drivers/dri2/egl_dri2.c
index 2e97d85..3269e52 100644
--- a/src/egl/drivers/dri2/egl_dri2.c
+++ b/src/egl/drivers/dri2/egl_dri2.c
@@ -1166,7 +1166,8 @@ dri2_destroy_context(_EGLDriver *drv, _EGLDisplay *disp, _EGLContext *ctx)
    struct dri2_egl_display *dri2_dpy = dri2_egl_display(disp);
 
    if (_eglPutContext(ctx)) {
-      dri2_dpy->core->destroyContext(dri2_ctx->dri_context);
+      if (dri2_dpy)
+         dri2_dpy->core->destroyContext(dri2_ctx->dri_context);
       free(dri2_ctx);
    }
 
@@ -1189,6 +1190,10 @@ dri2_make_current(_EGLDriver *drv, _EGLDisplay *disp, _EGLSurface *dsurf,
    __DRIdrawable *ddraw, *rdraw;
    __DRIcontext *cctx;
 
+   /* Check that the display is initialized */
+   if ((ctx != NULL || dsurf != NULL || rsurf != NULL) && !dri2_dpy)
+      return _eglError(EGL_NOT_INITIALIZED, "eglMakeCurrent error");
+
    /* make new bindings */
    if (!_eglBindContext(ctx, dsurf, rsurf, &old_ctx, &old_dsurf, &old_rsurf)) {
       /* _eglBindContext already sets the EGL error (in _eglCheckMakeCurrent) */
@@ -1196,14 +1201,14 @@ dri2_make_current(_EGLDriver *drv, _EGLDisplay *disp, _EGLSurface *dsurf,
    }
 
    /* flush before context switch */
-   if (old_ctx && dri2_drv->glFlush)
+   if (old_ctx && dri2_dpy && dri2_drv->glFlush)
       dri2_drv->glFlush();
 
    ddraw = (dsurf) ? dri2_dpy->vtbl->get_dri_drawable(dsurf) : NULL;
    rdraw = (rsurf) ? dri2_dpy->vtbl->get_dri_drawable(rsurf) : NULL;
    cctx = (dri2_ctx) ? dri2_ctx->dri_context : NULL;
 
-   if (old_ctx) {
+   if (old_ctx && dri2_dpy) {
       __DRIcontext *old_cctx = dri2_egl_context(old_ctx)->dri_context;
       dri2_dpy->core->unbindContext(old_cctx);
    }
@@ -1292,6 +1297,8 @@ static EGLBoolean
 dri2_destroy_surface(_EGLDriver *drv, _EGLDisplay *dpy, _EGLSurface *surf)
 {
    struct dri2_egl_display *dri2_dpy = dri2_egl_display(dpy);
+   if (!dri2_dpy)
+      return EGL_TRUE;
    return dri2_dpy->vtbl->destroy_surface(drv, dpy, surf);
 }
 
-- 
2.8.0.rc3.226.g39d4020