[Mesa-dev] [PATCH] st/mesa: add destroy_drawable interface

Brian Paul brianp at vmware.com
Thu Jul 20 22:35:32 UTC 2017


Looks good to me, but you might want to wait a day to see if there's any 
additional review feedback.

Reviewed-by: Brian Paul <brianp at vmware.com>


On 07/20/2017 12:26 PM, Charmaine Lee wrote:
> With this patch, the st manager will maintain a hash table for
> the active framebuffer interface objects. A destroy_drawable interface
> is added to allow the state tracker to notify the st manager to remove
> the associated framebuffer interface object from the hash table,
> so the associated framebuffer and its resources can be deleted
> at framebuffers purge time.
>
> Fixes bug 101829 "read-after-free in st_framebuffer_validate"
>
> Tested-by: Brad King <brad.king at kitware.com>
> Tested-by: Gert Wollny <gw.fossdev at gmail.com>
> ---
>   src/gallium/include/state_tracker/st_api.h    |  7 ++
>   src/gallium/state_trackers/dri/dri_drawable.c |  6 +-
>   src/gallium/state_trackers/glx/xlib/xm_api.c  |  5 ++
>   src/gallium/state_trackers/glx/xlib/xm_st.c   |  2 +
>   src/gallium/state_trackers/wgl/stw_st.c       |  6 +-
>   src/mesa/state_tracker/st_manager.c           | 95 ++++++++++++++++++++++++++-
>   src/mesa/state_tracker/st_manager.h           |  5 ++
>   7 files changed, 123 insertions(+), 3 deletions(-)
>
> diff --git a/src/gallium/include/state_tracker/st_api.h b/src/gallium/include/state_tracker/st_api.h
> index 30a4866..9b660f7 100644
> --- a/src/gallium/include/state_tracker/st_api.h
> +++ b/src/gallium/include/state_tracker/st_api.h
> @@ -552,6 +552,13 @@ struct st_api
>       * Get the currently bound context in the calling thread.
>       */
>      struct st_context_iface *(*get_current)(struct st_api *stapi);
> +
> +   /**
> +    * Notify the st manager the framebuffer interface object
> +    * is no longer valid.
> +    */
> +   void (*destroy_drawable)(struct st_api *stapi,
> +                            struct st_framebuffer_iface *stfbi);
>   };
>
>   /**
> diff --git a/src/gallium/state_trackers/dri/dri_drawable.c b/src/gallium/state_trackers/dri/dri_drawable.c
> index 0cfdc30..c7df0f6 100644
> --- a/src/gallium/state_trackers/dri/dri_drawable.c
> +++ b/src/gallium/state_trackers/dri/dri_drawable.c
> @@ -169,6 +169,8 @@ void
>   dri_destroy_buffer(__DRIdrawable * dPriv)
>   {
>      struct dri_drawable *drawable = dri_drawable(dPriv);
> +   struct dri_screen *screen = drawable->screen;
> +   struct st_api *stapi = screen->st_api;
>      int i;
>
>      pipe_surface_reference(&drawable->drisw_surface, NULL);
> @@ -180,7 +182,9 @@ dri_destroy_buffer(__DRIdrawable * dPriv)
>
>      swap_fences_unref(drawable);
>
> -   drawable->base.ID = 0;
> +   /* Notify the st manager that this drawable is no longer valid */
> +   stapi->destroy_drawable(stapi, &drawable->base);
> +
>      FREE(drawable);
>   }
>
> diff --git a/src/gallium/state_trackers/glx/xlib/xm_api.c b/src/gallium/state_trackers/glx/xlib/xm_api.c
> index 881dd44..e4b1e9d 100644
> --- a/src/gallium/state_trackers/glx/xlib/xm_api.c
> +++ b/src/gallium/state_trackers/glx/xlib/xm_api.c
> @@ -595,6 +595,11 @@ xmesa_free_buffer(XMesaBuffer buffer)
>             */
>            b->ws.drawable = 0;
>
> +         /* Notify the st manager that the associated framebuffer interface
> +          * object is no longer valid.
> +          */
> +         stapi->destroy_drawable(stapi, buffer->stfb);
> +
>            /* XXX we should move the buffer to a delete-pending list and destroy
>             * the buffer until it is no longer current.
>             */
> diff --git a/src/gallium/state_trackers/glx/xlib/xm_st.c b/src/gallium/state_trackers/glx/xlib/xm_st.c
> index 9e30efa..6a0f4aa 100644
> --- a/src/gallium/state_trackers/glx/xlib/xm_st.c
> +++ b/src/gallium/state_trackers/glx/xlib/xm_st.c
> @@ -273,6 +273,7 @@ xmesa_st_framebuffer_flush_front(struct st_context_iface *stctx,
>      return ret;
>   }
>
> +static uint32_t xmesa_stfbi_ID = 0;
>
>   struct st_framebuffer_iface *
>   xmesa_create_st_framebuffer(XMesaDisplay xmdpy, XMesaBuffer b)
> @@ -302,6 +303,7 @@ xmesa_create_st_framebuffer(XMesaDisplay xmdpy, XMesaBuffer b)
>      stfbi->visual = &xstfb->stvis;
>      stfbi->flush_front = xmesa_st_framebuffer_flush_front;
>      stfbi->validate = xmesa_st_framebuffer_validate;
> +   stfbi->ID = p_atomic_inc_return(&xmesa_stfbi_ID);
>      p_atomic_set(&stfbi->stamp, 1);
>      stfbi->st_manager_private = (void *) xstfb;
>
> diff --git a/src/gallium/state_trackers/wgl/stw_st.c b/src/gallium/state_trackers/wgl/stw_st.c
> index c2844b0..85a8b17 100644
> --- a/src/gallium/state_trackers/wgl/stw_st.c
> +++ b/src/gallium/state_trackers/wgl/stw_st.c
> @@ -256,7 +256,11 @@ stw_st_destroy_framebuffer_locked(struct st_framebuffer_iface *stfb)
>      for (i = 0; i < ST_ATTACHMENT_COUNT; i++)
>         pipe_resource_reference(&stwfb->textures[i], NULL);
>
> -   stwfb->base.ID = 0;
> +   /* Notify the st manager that the framebuffer interface is no
> +    * longer valid.
> +    */
> +   stw_dev->stapi->destroy_drawable(stw_dev->stapi, &stwfb->base);
> +
>      FREE(stwfb);
>   }
>
> diff --git a/src/mesa/state_tracker/st_manager.c b/src/mesa/state_tracker/st_manager.c
> index cb816de..ebc7ca8 100644
> --- a/src/mesa/state_tracker/st_manager.c
> +++ b/src/mesa/state_tracker/st_manager.c
> @@ -38,6 +38,7 @@
>   #include "main/fbobject.h"
>   #include "main/renderbuffer.h"
>   #include "main/version.h"
> +#include "util/hash_table.h"
>   #include "st_texture.h"
>
>   #include "st_context.h"
> @@ -59,6 +60,10 @@
>   #include "util/u_surface.h"
>   #include "util/list.h"
>
> +struct hash_table;
> +static struct hash_table *st_fbi_ht; /* framebuffer iface objects hash table */
> +
> +static mtx_t st_mutex = _MTX_INITIALIZER_NP;
>
>   /**
>    * Map an attachment to a buffer index.
> @@ -490,6 +495,76 @@ st_framebuffer_reference(struct st_framebuffer **ptr,
>      _mesa_reference_framebuffer((struct gl_framebuffer **) ptr, fb);
>   }
>
> +
> +static uint32_t
> +st_framebuffer_iface_hash(const void *key)
> +{
> +   return (uintptr_t)key;
> +}
> +
> +
> +static bool
> +st_framebuffer_iface_equal(const void *a, const void *b)
> +{
> +   return (struct st_framebuffer_iface *)a == (struct st_framebuffer_iface *)b;
> +}
> +
> +
> +static boolean
> +st_framebuffer_iface_lookup(const struct st_framebuffer_iface *stfbi)
> +{
> +   struct hash_entry *entry;
> +
> +   mtx_lock(&st_mutex);
> +   entry = _mesa_hash_table_search(st_fbi_ht, stfbi);
> +   mtx_unlock(&st_mutex);
> +
> +   return entry != NULL;
> +}
> +
> +
> +static boolean
> +st_framebuffer_iface_insert(struct st_framebuffer_iface *stfbi)
> +{
> +   struct hash_entry *entry;
> +
> +   mtx_lock(&st_mutex);
> +   entry = _mesa_hash_table_insert(st_fbi_ht, stfbi, stfbi);
> +   mtx_unlock(&st_mutex);
> +
> +   return entry != NULL;
> +}
> +
> +
> +static void
> +st_framebuffer_iface_remove(struct st_framebuffer_iface *stfbi)
> +{
> +   struct hash_entry *entry;
> +
> +   mtx_lock(&st_mutex);
> +   entry = _mesa_hash_table_search(st_fbi_ht, stfbi);
> +   if (!entry)
> +      goto unlock;
> +
> +   _mesa_hash_table_remove(st_fbi_ht, entry);
> +
> +unlock:
> +   mtx_unlock(&st_mutex);
> +}
> +
> +
> +/**
> + * The framebuffer interface object is no longer valid.
> + * Remove the object from the framebuffer interface hash table.
> + */
> +static void
> +st_api_destroy_drawable(struct st_api *stapi,
> +                        struct st_framebuffer_iface *stfbi)
> +{
> +   st_framebuffer_iface_remove(stfbi);
> +}
> +
> +
>   /**
>    * Purge the winsys buffers list to remove any references to
>    * non-existing framebuffer interface objects.
> @@ -506,7 +581,7 @@ st_framebuffers_purge(struct st_context *st)
>          * and unreference the framebuffer object, so its resources can be
>          * deleted.
>          */
> -      if (stfb->iface->ID != stfb->iface_ID) {
> +      if (!st_framebuffer_iface_lookup(stfb->iface)) {
>            LIST_DEL(&stfb->head);
>            st_framebuffer_reference(&stfb, NULL);
>         }
> @@ -810,6 +885,14 @@ st_framebuffer_reuse_or_create(struct st_context *st,
>         cur = st_framebuffer_create(st, stfbi);
>
>         if (cur) {
> +         /* add the referenced framebuffer interface object to
> +          * the framebuffer interface object hash table.
> +          */
> +         if (!st_framebuffer_iface_insert(stfbi)) {
> +            st_framebuffer_reference(&cur, NULL);
> +            return NULL;
> +         }
> +
>            /* add to the context's winsys buffers list */
>            LIST_ADD(&cur->head, &st->winsys_buffers);
>
> @@ -881,6 +964,8 @@ st_api_make_current(struct st_api *stapi, struct st_context_iface *stctxi,
>   static void
>   st_api_destroy(struct st_api *stapi)
>   {
> +   _mesa_hash_table_destroy(st_fbi_ht, NULL);
> +   mtx_destroy(&st_mutex);
>   }
>
>   /**
> @@ -1015,10 +1100,18 @@ static const struct st_api st_gl_api = {
>      .create_context = st_api_create_context,
>      .make_current = st_api_make_current,
>      .get_current = st_api_get_current,
> +   .destroy_drawable = st_api_destroy_drawable,
>   };
>
>   struct st_api *
>   st_gl_api_create(void)
>   {
> +   /* Create a hash table for all the framebuffer interface objects */
> +
> +   mtx_init(&st_mutex, mtx_plain);
> +   st_fbi_ht = _mesa_hash_table_create(NULL,
> +                                       st_framebuffer_iface_hash,
> +                                       st_framebuffer_iface_equal);
> +
>      return (struct st_api *) &st_gl_api;
>   }
> diff --git a/src/mesa/state_tracker/st_manager.h b/src/mesa/state_tracker/st_manager.h
> index 68adf2f..c54f29e 100644
> --- a/src/mesa/state_tracker/st_manager.h
> +++ b/src/mesa/state_tracker/st_manager.h
> @@ -34,6 +34,7 @@
>
>   struct st_context;
>   struct st_framebuffer;
> +struct st_framebuffer_interface;
>
>   void
>   st_manager_flush_frontbuffer(struct st_context *st);
> @@ -48,4 +49,8 @@ st_manager_add_color_renderbuffer(struct st_context *st, struct gl_framebuffer *
>   void
>   st_framebuffer_reference(struct st_framebuffer **ptr,
>                            struct st_framebuffer *stfb);
> +
> +void
> +st_framebuffer_interface_destroy(struct st_framebuffer_interface *stfbi);
> +
>   #endif /* ST_MANAGER_H */
>



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