We chase pointers/lists without taking the locks protecting them, which isn't that good.
Fix it.
v2: Actually unlock properly, spotted by Julia.
Cc: Julia Lawall julia.lawall@lip6.fr Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch --- drivers/gpu/drm/drm_sysfs.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c index 7506de0a75b4..9bffa63fe849 100644 --- a/drivers/gpu/drm/drm_sysfs.c +++ b/drivers/gpu/drm/drm_sysfs.c @@ -261,23 +261,29 @@ static ssize_t edid_show(struct file *filp, struct kobject *kobj, struct drm_connector *connector = to_drm_connector(connector_dev); unsigned char *edid; size_t size; + ssize_t ret = 0;
+ mutex_lock(&connector->dev->mode_config.mutex); if (!connector->edid_blob_ptr) - return 0; + goto unlock;
edid = connector->edid_blob_ptr->data; size = connector->edid_blob_ptr->length; if (!edid) - return 0; + goto unlock;
if (off >= size) - return 0; + goto unlock;
if (off + count > size) count = size - off; memcpy(buf, edid + off, count);
- return count; + ret = count; + mutex_unlock(&connector->dev->mode_config.mutex); +unlock: + + return ret; }
static ssize_t modes_show(struct device *device, @@ -288,10 +294,12 @@ static ssize_t modes_show(struct device *device, struct drm_display_mode *mode; int written = 0;
+ mutex_lock(&connector->dev->mode_config.mutex); list_for_each_entry(mode, &connector->modes, head) { written += snprintf(buf + written, PAGE_SIZE - written, "%s\n", mode->name); } + mutex_unlock(&connector->dev->mode_config.mutex);
return written; }