drm: Cleanup after failing to create master->unique and dev->name

v2: Userspace (notably xf86-video-{intel,ati}) became confused when
drmSetInterfaceVersion() started returning -EBUSY as they used a second
call (the first done in drmOpen()) to check their master credentials.
Since userspace wants to be able to repeatedly call
drmSetInterfaceVersion() allow them to do so.

v3: Rebase to drm-core-next.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
index 76d3d18056dd881a7c7f16b40050e4b4f56de359..7b03b197fc0066f5521e20b90c06e372e41e4c3f 100644 (file)
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -64,6 +64,19 @@ int drm_getunique(struct drm_device *dev, void *data,
        return 0;
 }
 
+static void
+drm_unset_busid(struct drm_device *dev,
+               struct drm_master *master)
+{
+       kfree(dev->devname);
+       dev->devname = NULL;
+
+       kfree(master->unique);
+       master->unique = NULL;
+       master->unique_len = 0;
+       master->unique_size = 0;
+}
+
 /**
  * Set the bus id.
  *
@@ -94,17 +107,24 @@ int drm_setunique(struct drm_device *dev, void *data,
        master->unique_len = u->unique_len;
        master->unique_size = u->unique_len + 1;
        master->unique = kmalloc(master->unique_size, GFP_KERNEL);
-       if (!master->unique)
-               return -ENOMEM;
-       if (copy_from_user(master->unique, u->unique, master->unique_len))
-               return -EFAULT;
+       if (!master->unique) {
+               ret = -ENOMEM;
+               goto err;
+       }
+
+       if (copy_from_user(master->unique, u->unique, master->unique_len)) {
+               ret = -EFAULT;
+               goto err;
+       }
 
        master->unique[master->unique_len] = '\0';
 
        dev->devname = kmalloc(strlen(dev->driver->pci_driver.name) +
                               strlen(master->unique) + 2, GFP_KERNEL);
-       if (!dev->devname)
-               return -ENOMEM;
+       if (!dev->devname) {
+               ret = -ENOMEM;
+               goto err;
+       }
 
        sprintf(dev->devname, "%s@%s", dev->driver->pci_driver.name,
                master->unique);
@@ -113,24 +133,36 @@ int drm_setunique(struct drm_device *dev, void *data,
         * busid.
         */
        ret = sscanf(master->unique, "PCI:%d:%d:%d", &bus, &slot, &func);
-       if (ret != 3)
-               return -EINVAL;
+       if (ret != 3) {
+               ret = -EINVAL;
+               goto err;
+       }
+
        domain = bus >> 8;
        bus &= 0xff;
 
        if ((domain != drm_get_pci_domain(dev)) ||
            (bus != dev->pdev->bus->number) ||
            (slot != PCI_SLOT(dev->pdev->devfn)) ||
-           (func != PCI_FUNC(dev->pdev->devfn)))
-               return -EINVAL;
+           (func != PCI_FUNC(dev->pdev->devfn))) {
+               ret = -EINVAL;
+               goto err;
+       }
 
        return 0;
+
+err:
+       drm_unset_busid(dev, master);
+       return ret;
 }
 
 static int drm_set_busid(struct drm_device *dev, struct drm_file *file_priv)
 {
        struct drm_master *master = file_priv->master;
-       int len;
+       int len, ret;
+
+       if (master->unique != NULL)
+               drm_unset_busid(dev, master);
 
        if (drm_core_check_feature(dev, DRIVER_USE_PLATFORM_DEVICE)) {
                master->unique_len = 10 + strlen(dev->platformdev->name);
@@ -142,15 +174,20 @@ static int drm_set_busid(struct drm_device *dev, struct drm_file *file_priv)
                len = snprintf(master->unique, master->unique_len,
                        "platform:%s", dev->platformdev->name);
 
-               if (len > master->unique_len)
+               if (len > master->unique_len) {
                        DRM_ERROR("Unique buffer overflowed\n");
+                       ret = -EINVAL;
+                       goto err;
+               }
 
                dev->devname =
                        kmalloc(strlen(dev->platformdev->name) +
                                master->unique_len + 2, GFP_KERNEL);
 
-               if (dev->devname == NULL)
-                       return -ENOMEM;
+               if (dev->devname == NULL) {
+                       ret = -ENOMEM;
+                       goto err;
+               }
 
                sprintf(dev->devname, "%s@%s", dev->platformdev->name,
                        master->unique);
@@ -168,23 +205,31 @@ static int drm_set_busid(struct drm_device *dev, struct drm_file *file_priv)
                        dev->pdev->bus->number,
                        PCI_SLOT(dev->pdev->devfn),
                        PCI_FUNC(dev->pdev->devfn));
-               if (len >= master->unique_len)
+               if (len >= master->unique_len) {
                        DRM_ERROR("buffer overflow");
-               else
+                       ret = -EINVAL;
+                       goto err;
+               } else
                        master->unique_len = len;
 
                dev->devname =
                        kmalloc(strlen(dev->driver->pci_driver.name) +
                                master->unique_len + 2, GFP_KERNEL);
 
-               if (dev->devname == NULL)
-                       return -ENOMEM;
+               if (dev->devname == NULL) {
+                       ret = -ENOMEM;
+                       goto err;
+               }
 
                sprintf(dev->devname, "%s@%s", dev->driver->pci_driver.name,
                        master->unique);
        }
 
        return 0;
+
+err:
+       drm_unset_busid(dev, master);
+       return ret;
 }
 
 /**
@@ -348,7 +393,9 @@ int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_pri
                        /*
                         * Version 1.1 includes tying of DRM to specific device
                         */
-                       drm_set_busid(dev, file_priv);
+                       retcode = drm_set_busid(dev, file_priv);
+                       if (retcode)
+                               goto done;
                }
        }