Hi Daniel.
On Mon, Mar 23, 2020 at 03:49:20PM +0100, Daniel Vetter wrote:
Well for the simple stuff at least, vblank, gem and minor cleanup I want to further split up as a demonstration.
v2: We need to clear drm_device->dev otherwise the debug drm printing after our cleanup hook (e.g. in drm_manged_release) will chase released memory and result in a use-after-free. Not really pretty, but oh well.
Signed-off-by: Daniel Vetter daniel.vetter@intel.com
drivers/gpu/drm/drm_drv.c | 48 ++++++++++++++++++++------------------- 1 file changed, 25 insertions(+), 23 deletions(-)
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index c80ebc6811b1..a710c53d13a8 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -580,6 +580,23 @@ static void drm_fs_inode_free(struct inode *inode)
- used.
*/
+static void drm_dev_init_release(struct drm_device *dev, void *res) +{
- drm_legacy_ctxbitmap_cleanup(dev);
- drm_legacy_remove_map_hash(dev);
- drm_fs_inode_free(dev->anon_inode);
- put_device(dev->dev);
- /* Prevent use-after-free in drm_managed_release when debugging is
* enabled. Slightly awkward, but can't really be helped. */- dev->dev = NULL;
- mutex_destroy(&dev->master_mutex);
- mutex_destroy(&dev->clientlist_mutex);
- mutex_destroy(&dev->filelist_mutex);
- mutex_destroy(&dev->struct_mutex);
- drm_legacy_destroy_members(dev);
+}
/**
- drm_dev_init - Initialise new DRM device
- @dev: DRM device
@@ -647,11 +664,15 @@ int drm_dev_init(struct drm_device *dev, mutex_init(&dev->clientlist_mutex); mutex_init(&dev->master_mutex);
- ret = drmm_add_action(dev, drm_dev_init_release, NULL);
- if (ret)
return ret;- dev->anon_inode = drm_fs_inode_new(); if (IS_ERR(dev->anon_inode)) { ret = PTR_ERR(dev->anon_inode); DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
goto err_free;
goto err;}
if (drm_core_check_feature(dev, DRIVER_RENDER)) {
@@ -688,19 +709,12 @@ int drm_dev_init(struct drm_device *dev, if (drm_core_check_feature(dev, DRIVER_GEM)) drm_gem_destroy(dev); err_ctxbitmap:
- drm_legacy_ctxbitmap_cleanup(dev);
- drm_legacy_remove_map_hash(dev);
err_minors: drm_minor_free(dev, DRM_MINOR_PRIMARY); drm_minor_free(dev, DRM_MINOR_RENDER);
- drm_fs_inode_free(dev->anon_inode);
-err_free:
- put_device(dev->dev);
- mutex_destroy(&dev->master_mutex);
- mutex_destroy(&dev->clientlist_mutex);
- mutex_destroy(&dev->filelist_mutex);
- mutex_destroy(&dev->struct_mutex);
- drm_legacy_destroy_members(dev);
+err:
- drm_managed_release(dev);
If for example drmm_add_action() fails this will call the following functions without their init parts called:
drm_legacy_ctxbitmap_cleanup(dev);
This function do: mutex_lock(&dev->struct_mutex); idr_destroy(&dev->ctx_idr); mutex_unlock(&dev->struct_mutex); Use of struct_mutex - OK Call to idr_destroy() - I could not convince myself this was OK. But I did not look too deep into idr_destroy() - thsi is unknown land for me.
drm_legacy_remove_map_hash(dev);
This function do: drm_ht_remove(&dev->map_hash); => if ((&dev->map_hash)->table) {
->table is NULL is init fucntion is not called - OK
drm_fs_inode_free(dev->anon_inode);
NOP if anon_inode is NULL - OK
So if idr_destroy() call is OK then error handling looks OK and the patch is: Reviewed-by: Sam Ravnborg sam@ravnborg.org
The error handling is even nicer later in this series. But I looked only at this patch for now.
Sam
- return ret;
} EXPORT_SYMBOL(drm_dev_init); @@ -763,20 +777,8 @@ void drm_dev_fini(struct drm_device *dev) if (drm_core_check_feature(dev, DRIVER_GEM)) drm_gem_destroy(dev);
- drm_legacy_ctxbitmap_cleanup(dev);
- drm_legacy_remove_map_hash(dev);
- drm_fs_inode_free(dev->anon_inode);
- drm_minor_free(dev, DRM_MINOR_PRIMARY); drm_minor_free(dev, DRM_MINOR_RENDER);
- put_device(dev->dev);
- mutex_destroy(&dev->master_mutex);
- mutex_destroy(&dev->clientlist_mutex);
- mutex_destroy(&dev->filelist_mutex);
- mutex_destroy(&dev->struct_mutex);
- drm_legacy_destroy_members(dev);
} EXPORT_SYMBOL(drm_dev_fini);
-- 2.25.1
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