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drm: Tighten locking in drm_mode_getconnector

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- Modeset state needs mode_config->connection mutex, that covers
  figuring out the encoder, and reading properties (since in the
  atomic case those need to look at connector->state).

- Don't hold any locks for stuff that's invariant (i.e. possible
  connectors).

- Same for connector lookup and unref, those don't need any locks.

- And finally the probe stuff is only protected by mode_config->mutex.

While at it updated the kerneldoc for these fields in drm_connector
and add docs explaining what's protected by which locks.

Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161213230814.19598-10-daniel.vetter@ffwll.ch
This commit is contained in:
Daniel Vetter 2016-12-14 00:08:10 +01:00
parent e73ab00e9a
commit 91eefc05f0
2 changed files with 72 additions and 61 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

110
drivers/gpu/drm/drm_connector.c
View file

@ -1163,36 +1163,9 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,
memset(&u_mode, 0, sizeof(struct drm_mode_modeinfo));
mutex_lock(&dev->mode_config.mutex);
connector = drm_connector_lookup(dev, out_resp->connector_id);
if (!connector) {
ret = -ENOENT;
goto out_unlock;
}
for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++)
if (connector->encoder_ids[i] != 0)
encoders_count++;
if (out_resp->count_modes == 0) {
connector->funcs->fill_modes(connector,
dev->mode_config.max_width,
dev->mode_config.max_height);
}
/* delayed so we get modes regardless of pre-fill_modes state */
list_for_each_entry(mode, &connector->modes, head)
if (drm_mode_expose_to_userspace(mode, file_priv))
mode_count++;
out_resp->connector_id = connector->base.id;
out_resp->connector_type = connector->connector_type;
out_resp->connector_type_id = connector->connector_type_id;
out_resp->mm_width = connector->display_info.width_mm;
out_resp->mm_height = connector->display_info.height_mm;
out_resp->subpixel = connector->display_info.subpixel_order;
out_resp->connection = connector->status;
if (!connector)
return -ENOENT;
drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
encoder = drm_connector_get_encoder(connector);
@ -1201,6 +1174,55 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,
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++;
if ((out_resp->count_encoders >= encoders_count) && encoders_count) {
copied = 0;
encoder_ptr = (uint32_t __user *)(unsigned long)(out_resp->encoders_ptr);
for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++) {
if (connector->encoder_ids[i] != 0) {
if (put_user(connector->encoder_ids[i],
encoder_ptr + copied)) {
ret = -EFAULT;
goto out_unref;
}
copied++;
}
}
}
out_resp->count_encoders = encoders_count;
out_resp->connector_id = connector->base.id;
out_resp->connector_type = connector->connector_type;
out_resp->connector_type_id = connector->connector_type_id;
mutex_lock(&dev->mode_config.mutex);
if (out_resp->count_modes == 0) {
connector->funcs->fill_modes(connector,
dev->mode_config.max_width,
dev->mode_config.max_height);
}
out_resp->mm_width = connector->display_info.width_mm;
out_resp->mm_height = connector->display_info.height_mm;
out_resp->subpixel = connector->display_info.subpixel_order;
out_resp->connection = connector->status;
/* delayed so we get modes regardless of pre-fill_modes state */
list_for_each_entry(mode, &connector->modes, head)
if (drm_mode_expose_to_userspace(mode, file_priv))
mode_count++;
/*
* This ioctl is called twice, once to determine how much space is
* needed, and the 2nd time to fill it.
@ -1222,36 +1244,10 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,
}
}
out_resp->count_modes = mode_count;
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);
if (ret)
goto out;
if ((out_resp->count_encoders >= encoders_count) && encoders_count) {
copied = 0;
encoder_ptr = (uint32_t __user *)(unsigned long)(out_resp->encoders_ptr);
for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++) {
if (connector->encoder_ids[i] != 0) {
if (put_user(connector->encoder_ids[i],
encoder_ptr + copied)) {
ret = -EFAULT;
goto out;
}
copied++;
}
}
}
out_resp->count_encoders = encoders_count;
out:
drm_modeset_unlock(&dev->mode_config.connection_mutex);
drm_connector_unreference(connector);
out_unlock:
mutex_unlock(&dev->mode_config.mutex);
out_unref:
drm_connector_unreference(connector);
return ret;
}

23
include/drm/drm_connector.h
View file

@ -563,9 +563,6 @@ struct drm_cmdline_mode {
* @interlace_allowed: can this connector handle interlaced modes?
* @doublescan_allowed: can this connector handle doublescan?
* @stereo_allowed: can this connector handle stereo modes?
* @modes: modes available on this connector (from fill_modes() + user)
* @status: one of the drm_connector_status enums (connected, not, or unknown)
* @probed_modes: list of modes derived directly from the display
* @funcs: connector control functions
* @edid_blob_ptr: DRM property containing EDID if present
* @properties: property tracking for this connector
@ -635,11 +632,27 @@ struct drm_connector {
* Protected by @mutex.
*/
bool registered;
/**
* @modes:
* Modes available on this connector (from fill_modes() + user).
* Protected by dev->mode_config.mutex.
*/
struct list_head modes; /* list of modes on this connector */
/**
* @status:
* One of the drm_connector_status enums (connected, not, or unknown).
* Protected by dev->mode_config.mutex.
*/
enum drm_connector_status status;
/* these are modes added by probing with DDC or the BIOS */
/**
* @probed_modes:
* These are modes added by probing with DDC or the BIOS, before
* filtering is applied. Used by the probe helpers.Protected by
* dev->mode_config.mutex.
*/
struct list_head probed_modes;
/**
@ -648,6 +661,8 @@ struct drm_connector {
* flat panels in embedded systems, the driver should initialize the
* display_info.width_mm and display_info.height_mm fields with the
* physical size of the display.
*
* Protected by dev->mode_config.mutex.
*/
struct drm_display_info display_info;
const struct drm_connector_funcs *funcs;