drm: mark context support as a legacy subsystem
So after a lot of digging around in git histories it looks like this
has only ever be used by dri1 render clients. Hence we can fully
disable the entire thing for modesetting drivers and so greatly reduce
the attack surface for potential exploits (or at least tools like
trinity ...).
Also add the drm_legacy prefix for functions which are called from
common code. To further reduce the impact on common code also extract
all the ctx release handling into a function (instead of only
releasing individual handles) and make ctxbitmap_cleanup return void -
it can never fail.
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_context.c b/drivers/gpu/drm/drm_context.c
index 224ff96..b4fb86d 100644
--- a/drivers/gpu/drm/drm_context.c
+++ b/drivers/gpu/drm/drm_context.c
@@ -42,10 +42,6 @@
#include <drm/drmP.h>
-/******************************************************************/
-/** \name Context bitmap support */
-/*@{*/
-
/**
* Free a handle from the context bitmap.
*
@@ -56,13 +52,48 @@
* in drm_device::ctx_idr, while holding the drm_device::struct_mutex
* lock.
*/
-void drm_ctxbitmap_free(struct drm_device * dev, int ctx_handle)
+static void drm_ctxbitmap_free(struct drm_device * dev, int ctx_handle)
{
+ if (drm_core_check_feature(dev, DRIVER_MODESET))
+ return;
+
mutex_lock(&dev->struct_mutex);
idr_remove(&dev->ctx_idr, ctx_handle);
mutex_unlock(&dev->struct_mutex);
}
+/******************************************************************/
+/** \name Context bitmap support */
+/*@{*/
+
+void drm_legacy_ctxbitmap_release(struct drm_device *dev,
+ struct drm_file *file_priv)
+{
+ if (drm_core_check_feature(dev, DRIVER_MODESET))
+ return;
+
+ mutex_lock(&dev->ctxlist_mutex);
+ if (!list_empty(&dev->ctxlist)) {
+ struct drm_ctx_list *pos, *n;
+
+ list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
+ if (pos->tag == file_priv &&
+ pos->handle != DRM_KERNEL_CONTEXT) {
+ if (dev->driver->context_dtor)
+ dev->driver->context_dtor(dev,
+ pos->handle);
+
+ drm_ctxbitmap_free(dev, pos->handle);
+
+ list_del(&pos->head);
+ kfree(pos);
+ --dev->ctx_count;
+ }
+ }
+ }
+ mutex_unlock(&dev->ctxlist_mutex);
+}
+
/**
* Context bitmap allocation.
*
@@ -90,10 +121,12 @@
*
* Initialise the drm_device::ctx_idr
*/
-int drm_ctxbitmap_init(struct drm_device * dev)
+void drm_legacy_ctxbitmap_init(struct drm_device * dev)
{
+ if (drm_core_check_feature(dev, DRIVER_MODESET))
+ return;
+
idr_init(&dev->ctx_idr);
- return 0;
}
/**
@@ -104,7 +137,7 @@
* Free all idr members using drm_ctx_sarea_free helper function
* while holding the drm_device::struct_mutex lock.
*/
-void drm_ctxbitmap_cleanup(struct drm_device * dev)
+void drm_legacy_ctxbitmap_cleanup(struct drm_device * dev)
{
mutex_lock(&dev->struct_mutex);
idr_destroy(&dev->ctx_idr);
@@ -136,6 +169,9 @@
struct drm_local_map *map;
struct drm_map_list *_entry;
+ if (drm_core_check_feature(dev, DRIVER_MODESET))
+ return -EINVAL;
+
mutex_lock(&dev->struct_mutex);
map = idr_find(&dev->ctx_idr, request->ctx_id);
@@ -180,6 +216,9 @@
struct drm_local_map *map = NULL;
struct drm_map_list *r_list = NULL;
+ if (drm_core_check_feature(dev, DRIVER_MODESET))
+ return -EINVAL;
+
mutex_lock(&dev->struct_mutex);
list_for_each_entry(r_list, &dev->maplist, head) {
if (r_list->map
@@ -280,6 +319,9 @@
struct drm_ctx ctx;
int i;
+ if (drm_core_check_feature(dev, DRIVER_MODESET))
+ return -EINVAL;
+
if (res->count >= DRM_RESERVED_CONTEXTS) {
memset(&ctx, 0, sizeof(ctx));
for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
@@ -310,6 +352,9 @@
struct drm_ctx_list *ctx_entry;
struct drm_ctx *ctx = data;
+ if (drm_core_check_feature(dev, DRIVER_MODESET))
+ return -EINVAL;
+
ctx->handle = drm_ctxbitmap_next(dev);
if (ctx->handle == DRM_KERNEL_CONTEXT) {
/* Skip kernel's context and get a new one. */
@@ -353,6 +398,9 @@
{
struct drm_ctx *ctx = data;
+ if (drm_core_check_feature(dev, DRIVER_MODESET))
+ return -EINVAL;
+
/* This is 0, because we don't handle any context flags */
ctx->flags = 0;
@@ -375,6 +423,9 @@
{
struct drm_ctx *ctx = data;
+ if (drm_core_check_feature(dev, DRIVER_MODESET))
+ return -EINVAL;
+
DRM_DEBUG("%d\n", ctx->handle);
return drm_context_switch(dev, dev->last_context, ctx->handle);
}
@@ -395,6 +446,9 @@
{
struct drm_ctx *ctx = data;
+ if (drm_core_check_feature(dev, DRIVER_MODESET))
+ return -EINVAL;
+
DRM_DEBUG("%d\n", ctx->handle);
drm_context_switch_complete(dev, file_priv, ctx->handle);
@@ -417,6 +471,9 @@
{
struct drm_ctx *ctx = data;
+ if (drm_core_check_feature(dev, DRIVER_MODESET))
+ return -EINVAL;
+
DRM_DEBUG("%d\n", ctx->handle);
if (ctx->handle != DRM_KERNEL_CONTEXT) {
if (dev->driver->context_dtor)