[Mesa-dev] [PATCH] st/mesa: destroy pipe_context before destroying st_context (v2)

[Marek Olšák]

From: Marek Olšák <marek.olsak at amd.com>

If radeonsi starts compiling an optimized shader variant asynchronously
with a GL debug callback set and the application destroys the GL context,
radeonsi crashes when trying to write shader stats into the debug output
of a non-existent context after compilation, because st/mesa was destroyed
before pipe_context.

Firefox with WebGL2 enabled hits this bug.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99456

v2: protect against a double destroy in st_create_context_priv and callers.

Cc: 17.0 <mesa-stable at lists.freedesktop.org>
---
 src/mesa/state_tracker/st_context.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/src/mesa/state_tracker/st_context.c b/src/mesa/state_tracker/st_context.c
index 0eae971..5523734 100644
--- a/src/mesa/state_tracker/st_context.c
+++ b/src/mesa/state_tracker/st_context.c
@@ -271,21 +271,21 @@ void st_invalidate_state(struct gl_context * ctx, GLbitfield new_state)
       st->dirty |= st->active_states & ST_NEW_CONSTANTS;
 
    /* This is the only core Mesa module we depend upon.
     * No longer use swrast, swsetup, tnl.
     */
    _vbo_InvalidateState(ctx, new_state);
 }
 
 
 static void
-st_destroy_context_priv(struct st_context *st)
+st_destroy_context_priv(struct st_context *st, bool destroy_pipe)
 {
    uint shader, i;
 
    st_destroy_atoms( st );
    st_destroy_draw( st );
    st_destroy_clear(st);
    st_destroy_bitmap(st);
    st_destroy_drawpix(st);
    st_destroy_drawtex(st);
    st_destroy_perfmon(st);
@@ -307,20 +307,24 @@ st_destroy_context_priv(struct st_context *st)
    }
 
    /* free glDrawPixels cache data */
    free(st->drawpix_cache.image);
    pipe_resource_reference(&st->drawpix_cache.texture, NULL);
 
    /* free glReadPixels cache data */
    st_invalidate_readpix_cache(st);
 
    cso_destroy_context(st->cso_context);
+
+   if (st->pipe && destroy_pipe)
+      st->pipe->destroy(st->pipe);
+
    free( st );
 }
 
 
 static struct st_context *
 st_create_context_priv( struct gl_context *ctx, struct pipe_context *pipe,
 		const struct st_config_options *options)
 {
    struct pipe_screen *screen = pipe->screen;
    uint i;
@@ -496,21 +500,21 @@ st_create_context_priv( struct gl_context *ctx, struct pipe_context *pipe,
    st->shader_has_one_variant[MESA_SHADER_TESS_EVAL] = st->has_shareable_shaders;
    st->shader_has_one_variant[MESA_SHADER_GEOMETRY] = st->has_shareable_shaders;
    st->shader_has_one_variant[MESA_SHADER_COMPUTE] = st->has_shareable_shaders;
 
    _mesa_compute_version(ctx);
 
    if (ctx->Version == 0) {
       /* This can happen when a core profile was requested, but the driver
        * does not support some features of GL 3.1 or later.
        */
-      st_destroy_context_priv(st);
+      st_destroy_context_priv(st, false);
       return NULL;
    }
 
    _mesa_initialize_dispatch_tables(ctx);
    _mesa_initialize_vbo_vtxfmt(ctx);
 
    return st;
 }
 
 static void st_init_driver_flags(struct gl_driver_flags *f)
@@ -572,21 +576,20 @@ static void
 destroy_tex_sampler_cb(GLuint id, void *data, void *userData)
 {
    struct gl_texture_object *texObj = (struct gl_texture_object *) data;
    struct st_context *st = (struct st_context *) userData;
 
    st_texture_release_sampler_view(st, st_texture_object(texObj));
 }
  
 void st_destroy_context( struct st_context *st )
 {
-   struct pipe_context *pipe = st->pipe;
    struct gl_context *ctx = st->ctx;
    GLuint i;
 
    _mesa_HashWalk(ctx->Shared->TexObjects, destroy_tex_sampler_cb, st);
 
    st_reference_fragprog(st, &st->fp, NULL);
    st_reference_geomprog(st, &st->gp, NULL);
    st_reference_vertprog(st, &st->vp, NULL);
    st_reference_tesscprog(st, &st->tcp, NULL);
    st_reference_tesseprog(st, &st->tep, NULL);
@@ -601,25 +604,23 @@ void st_destroy_context( struct st_context *st )
    pipe_resource_reference(&st->pixel_xfer.pixelmap_texture, NULL);
 
    _vbo_DestroyContext(ctx);
 
    st_destroy_program_variants(st);
 
    _mesa_free_context_data(ctx);
 
    /* This will free the st_context too, so 'st' must not be accessed
     * afterwards. */
-   st_destroy_context_priv(st);
+   st_destroy_context_priv(st, true);
    st = NULL;
 
-   pipe->destroy( pipe );
-
    free(ctx);
 }
 
 static void
 st_emit_string_marker(struct gl_context *ctx, const GLchar *string, GLsizei len)
 {
    struct st_context *st = ctx->st;
    st->pipe->emit_string_marker(st->pipe, string, len);
 }
 
-- 
2.7.4