There can only be one current master, and it's for the overall device. Render/control minors don't support master-based auth at all.
This simplifies the master logic a lot, at least in my eyes: All these additional pointer chases are just confusing.
While doing the conversion I spotted some locking fail: - drm_lock/drm_auth check dev->master without holding the master_mutex. This is fallout from
commit c996fd0b956450563454e7ccc97a82ca31f9d043 Author: Thomas Hellstrom thellstrom@vmware.com Date: Tue Feb 25 19:57:44 2014 +0100
drm: Protect the master management with a drm_device::master_mutex v3
but I honestly don't care one bit about those old legacy drivers using this.
- debugfs name info should just grab master_mutex.
- And the fbdev helper looked at it to figure out whether someone is using KMS. We just need a consistent value, so READ_ONCE. Aside: We should probably check if anyone has opened a control node too, but I guess current userspace doesn't really do that yet.
v2: Balance locking, reported by Julia.
Cc: Julia Lawall julia.lawall@lip6.fr Cc: Chris Wilson chris@chris-wilson.co.uk Signed-off-by: Daniel Vetter daniel.vetter@intel.com --- drivers/gpu/drm/drm_auth.c | 26 +++++++++++++------------- drivers/gpu/drm/drm_bufs.c | 8 ++++---- drivers/gpu/drm/drm_fb_helper.c | 2 +- drivers/gpu/drm/drm_info.c | 10 ++++++++-- drivers/gpu/drm/drm_lock.c | 2 +- drivers/gpu/drm/sis/sis_mm.c | 2 +- drivers/gpu/drm/via/via_mm.c | 2 +- include/drm/drmP.h | 9 +++++---- 8 files changed, 34 insertions(+), 27 deletions(-)
diff --git a/drivers/gpu/drm/drm_auth.c b/drivers/gpu/drm/drm_auth.c index d858e69d337b..6bba6b9e9dcc 100644 --- a/drivers/gpu/drm/drm_auth.c +++ b/drivers/gpu/drm/drm_auth.c @@ -128,13 +128,13 @@ static int drm_new_set_master(struct drm_device *dev, struct drm_file *fpriv) lockdep_assert_held_once(&dev->master_mutex);
/* create a new master */ - fpriv->minor->master = drm_master_create(fpriv->minor->dev); - if (!fpriv->minor->master) + dev->master = drm_master_create(dev); + if (!dev->master) return -ENOMEM;
/* take another reference for the copy in the local file priv */ old_master = fpriv->master; - fpriv->master = drm_master_get(fpriv->minor->master); + fpriv->master = drm_master_get(dev->master);
if (dev->driver->master_create) { ret = dev->driver->master_create(dev, fpriv->master); @@ -157,7 +157,7 @@ static int drm_new_set_master(struct drm_device *dev, struct drm_file *fpriv)
out_err: /* drop both references and restore old master on failure */ - drm_master_put(&fpriv->minor->master); + drm_master_put(&dev->master); drm_master_put(&fpriv->master); fpriv->master = old_master;
@@ -173,7 +173,7 @@ int drm_setmaster_ioctl(struct drm_device *dev, void *data, if (file_priv->is_master) goto out_unlock;
- if (file_priv->minor->master) { + if (dev->master) { ret = -EINVAL; goto out_unlock; } @@ -188,13 +188,13 @@ int drm_setmaster_ioctl(struct drm_device *dev, void *data, goto out_unlock; }
- file_priv->minor->master = drm_master_get(file_priv->master); + dev->master = drm_master_get(file_priv->master); file_priv->is_master = 1; if (dev->driver->master_set) { ret = dev->driver->master_set(dev, file_priv, false); if (unlikely(ret != 0)) { file_priv->is_master = 0; - drm_master_put(&file_priv->minor->master); + drm_master_put(&dev->master); } }
@@ -212,13 +212,13 @@ int drm_dropmaster_ioctl(struct drm_device *dev, void *data, if (!file_priv->is_master) goto out_unlock;
- if (!file_priv->minor->master) + if (!dev->master) goto out_unlock;
ret = 0; if (dev->driver->master_drop) dev->driver->master_drop(dev, file_priv, false); - drm_master_put(&file_priv->minor->master); + drm_master_put(&dev->master); file_priv->is_master = 0;
out_unlock: @@ -234,10 +234,10 @@ int drm_master_open(struct drm_file *file_priv) /* if there is no current master make this fd it, but do not create * any master object for render clients */ mutex_lock(&dev->master_mutex); - if (!file_priv->minor->master) + if (!dev->master) ret = drm_new_set_master(dev, file_priv); else - file_priv->master = drm_master_get(file_priv->minor->master); + file_priv->master = drm_master_get(dev->master); mutex_unlock(&dev->master_mutex);
return ret; @@ -271,11 +271,11 @@ void drm_master_release(struct drm_file *file_priv) mutex_unlock(&dev->struct_mutex); }
- if (file_priv->minor->master == file_priv->master) { + if (dev->master == file_priv->master) { /* drop the reference held my the minor */ if (dev->driver->master_drop) dev->driver->master_drop(dev, file_priv, true); - drm_master_put(&file_priv->minor->master); + drm_master_put(&dev->master); } out: /* drop the master reference held by the file priv */ diff --git a/drivers/gpu/drm/drm_bufs.c b/drivers/gpu/drm/drm_bufs.c index 9b34158c0f77..c3a12cd8bd0d 100644 --- a/drivers/gpu/drm/drm_bufs.c +++ b/drivers/gpu/drm/drm_bufs.c @@ -51,7 +51,7 @@ static struct drm_map_list *drm_find_matching_map(struct drm_device *dev, */ if (!entry->map || map->type != entry->map->type || - entry->master != dev->primary->master) + entry->master != dev->master) continue; switch (map->type) { case _DRM_SHM: @@ -245,12 +245,12 @@ static int drm_addmap_core(struct drm_device * dev, resource_size_t offset, map->offset = (unsigned long)map->handle; if (map->flags & _DRM_CONTAINS_LOCK) { /* Prevent a 2nd X Server from creating a 2nd lock */ - if (dev->primary->master->lock.hw_lock != NULL) { + if (dev->master->lock.hw_lock != NULL) { vfree(map->handle); kfree(map); return -EBUSY; } - dev->sigdata.lock = dev->primary->master->lock.hw_lock = map->handle; /* Pointer to lock */ + dev->sigdata.lock = dev->master->lock.hw_lock = map->handle; /* Pointer to lock */ } break; case _DRM_AGP: { @@ -356,7 +356,7 @@ static int drm_addmap_core(struct drm_device * dev, resource_size_t offset, mutex_unlock(&dev->struct_mutex);
if (!(map->flags & _DRM_DRIVER)) - list->master = dev->primary->master; + list->master = dev->master; *maplist = list; return 0; } diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 0bac5246e5a7..0a06f9120b5a 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -464,7 +464,7 @@ static bool drm_fb_helper_is_bound(struct drm_fb_helper *fb_helper)
/* Sometimes user space wants everything disabled, so don't steal the * display if there's a master. */ - if (dev->primary->master) + if (READ_ONCE(dev->master)) return false;
drm_for_each_crtc(crtc, dev) { diff --git a/drivers/gpu/drm/drm_info.c b/drivers/gpu/drm/drm_info.c index 0090d5987801..24c80dd13837 100644 --- a/drivers/gpu/drm/drm_info.c +++ b/drivers/gpu/drm/drm_info.c @@ -50,9 +50,12 @@ int drm_name_info(struct seq_file *m, void *data) struct drm_info_node *node = (struct drm_info_node *) m->private; struct drm_minor *minor = node->minor; struct drm_device *dev = minor->dev; - struct drm_master *master = minor->master; + struct drm_master *master; + + mutex_lock(&dev->master_mutex); + master = dev->master; if (!master) - return 0; + goto out_unlock;
if (master->unique) { seq_printf(m, "%s %s %s\n", @@ -62,6 +65,9 @@ int drm_name_info(struct seq_file *m, void *data) seq_printf(m, "%s %s\n", dev->driver->name, dev_name(dev->dev)); } +out_unlock: + mutex_unlock(&dev->master_mutex); + return 0; }
diff --git a/drivers/gpu/drm/drm_lock.c b/drivers/gpu/drm/drm_lock.c index 0fb8f9e73486..ae0a4d39deec 100644 --- a/drivers/gpu/drm/drm_lock.c +++ b/drivers/gpu/drm/drm_lock.c @@ -334,7 +334,7 @@ void drm_legacy_lock_release(struct drm_device *dev, struct file *filp) struct drm_file *file_priv = filp->private_data;
/* if the master has gone away we can't do anything with the lock */ - if (!file_priv->minor->master) + if (!dev->master) return;
if (drm_legacy_i_have_hw_lock(dev, file_priv)) { diff --git a/drivers/gpu/drm/sis/sis_mm.c b/drivers/gpu/drm/sis/sis_mm.c index 93ad8a5704d1..03defda77766 100644 --- a/drivers/gpu/drm/sis/sis_mm.c +++ b/drivers/gpu/drm/sis/sis_mm.c @@ -316,7 +316,7 @@ void sis_reclaim_buffers_locked(struct drm_device *dev, struct sis_file_private *file_priv = file->driver_priv; struct sis_memblock *entry, *next;
- if (!(file->minor->master && file->master->lock.hw_lock)) + if (!(dev->master && file->master->lock.hw_lock)) return;
drm_legacy_idlelock_take(&file->master->lock); diff --git a/drivers/gpu/drm/via/via_mm.c b/drivers/gpu/drm/via/via_mm.c index 4f20742e7788..a04ef1c992d9 100644 --- a/drivers/gpu/drm/via/via_mm.c +++ b/drivers/gpu/drm/via/via_mm.c @@ -208,7 +208,7 @@ void via_reclaim_buffers_locked(struct drm_device *dev, struct via_file_private *file_priv = file->driver_priv; struct via_memblock *entry, *next;
- if (!(file->minor->master && file->master->lock.hw_lock)) + if (!(dev->master && file->master->lock.hw_lock)) return;
drm_legacy_idlelock_take(&file->master->lock); diff --git a/include/drm/drmP.h b/include/drm/drmP.h index e8788d7b29dc..62e0e70cb5a2 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -336,7 +336,7 @@ struct drm_file { void *driver_priv;
struct drm_master *master; /* master this node is currently associated with - N.B. not always minor->master */ + N.B. not always dev->master */ /** * fbs - List of framebuffers associated with this file. * @@ -708,9 +708,6 @@ struct drm_minor {
struct list_head debugfs_list; struct mutex debugfs_lock; /* Protects debugfs_list. */ - - /* currently active master for this node. Protected by master_mutex */ - struct drm_master *master; };
@@ -759,6 +756,10 @@ struct drm_device { struct drm_minor *control; /**< Control node */ struct drm_minor *primary; /**< Primary node */ struct drm_minor *render; /**< Render node */ + + /* currently active master for this device. Protected by master_mutex */ + struct drm_master *master; + atomic_t unplugged; /**< Flag whether dev is dead */ struct inode *anon_inode; /**< inode for private address-space */ char *unique; /**< unique name of the device */