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Patch "drm: Fix GETCONNECTOR regression" has been added to the 4.11-stable tree

PATCH [email protected] 1 participant 1 message Jun 26, 2017

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This is a note to let you know that I've just added the patch titled

drm: Fix GETCONNECTOR regression

to the 4.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
drm-fix-getconnector-regression.patch
and it can be found in the queue-4.11 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From e94ac3510b6a0f696f2c442c4fc4051c8101ef12 Mon Sep 17 00:00:00 2001

From: Daniel Vetter <[email protected]>
Date: Tue, 20 Jun 2017 22:28:37 +0200
Subject: drm: Fix GETCONNECTOR regression

From: Daniel Vetter <[email protected]>

commit e94ac3510b6a0f696f2c442c4fc4051c8101ef12 upstream.

In

commit 91eefc05f0ac71902906b2058360e61bd25137fe

Author: Daniel Vetter <[email protected]>
Date:   Wed Dec 14 00:08:10 2016 +0100

drm: Tighten locking in drm_mode_getconnector

I reordered the logic a bit in that IOCTL, but that broke userspace since it'll get the new mode list, but not the new property values. Fix that again.

v2: Fix up the error path handling when copy_to_user for the modes failes (Dhinakaran).

Fixes 91eefc05f0ac ("drm: Tighten locking in drm_mode_getconnector")
Cc Sean Paul <[email protected]>
Cc Daniel Vetter <[email protected]>
Cc Jani Nikula <[email protected]>
Cc David Airlie <[email protected]>
Cc [email protected]
Reported-by "H.J. Lu" <[email protected]>
Tested-by "H.J. Lu" <[email protected]>

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=100576

Cc "H.J. Lu" <[email protected]>
Cc "Pandiyan, Dhinakaran" <[email protected]>
Reviewed-by Sean Paul <[email protected]>
Reviewed-by Dhinakaran Pandiyan <[email protected]>
Signed-off-by Daniel Vetter <[email protected]>
Link http://patchwork.freedesktop.org/patch/msgid/[email protected]
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 drivers/gpu/drm/drm_connector.c |   38 ++++++++++++++++++++------------------
 1 file changed, 20 insertions(+), 18 deletions(-)
drivers/gpu/drm/drm_connector.c +20 -18
@@ -1169,21 +1169,6 @@ int drm_mode_getconnector(struct drm_dev
 	if (!connector)
 		return -ENOENT;
 
-	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
-	encoder = drm_connector_get_encoder(connector);
-	if (encoder)
-		out_resp->encoder_id = encoder->base.id;
-	else
-		out_resp->encoder_id = 0;
-
-	ret = drm_mode_object_get_properties(&connector->base, file_priv->atomic,
-			(uint32_t __user *)(unsigned long)(out_resp->props_ptr),
-			(uint64_t __user *)(unsigned long)(out_resp->prop_values_ptr),
-			&out_resp->count_props);
-	drm_modeset_unlock(&dev->mode_config.connection_mutex);
-	if (ret)
-		goto out_unref;
-
 	for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++)
 		if (connector->encoder_ids[i] != 0)
 			encoders_count++;

@@ -1196,7 +1181,7 @@ int drm_mode_getconnector(struct drm_dev
 				if (put_user(connector->encoder_ids[i],
 					     encoder_ptr + copied)) {
 					ret = -EFAULT;
-					goto out_unref;
+					goto out;
 				}
 				copied++;
 			}

@@ -1240,15 +1225,32 @@ int drm_mode_getconnector(struct drm_dev
 			if (copy_to_user(mode_ptr + copied,
 					 &u_mode, sizeof(u_mode))) {
 				ret = -EFAULT;
+				mutex_unlock(&dev->mode_config.mutex);
+
 				goto out;
 			}
 			copied++;
 		}
 	}
 	out_resp->count_modes = mode_count;
-out:
 	mutex_unlock(&dev->mode_config.mutex);
-out_unref:
+
+	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
+	encoder = drm_connector_get_encoder(connector);
+	if (encoder)
+		out_resp->encoder_id = encoder->base.id;
+	else
+		out_resp->encoder_id = 0;
+
+	/* Only grab properties after probing, to make sure EDID and other
+	 * properties reflect the latest status. */
+	ret = drm_mode_object_get_properties(&connector->base, file_priv->atomic,
+			(uint32_t __user *)(unsigned long)(out_resp->props_ptr),
+			(uint64_t __user *)(unsigned long)(out_resp->prop_values_ptr),
+			&out_resp->count_props);
+	drm_modeset_unlock(&dev->mode_config.connection_mutex);
+
+out:
 	drm_connector_unreference(connector);
 
 	return ret;

Patches currently in stable-queue which might be from [email protected] are

queue-4.11/drm-fix-getconnector-regression.patch