From 2a8d3eac3d6e11638893ec3c4ba8bc5884db2ef9 Mon Sep 17 00:00:00 2001 From: Ville Syrjälä Date: Thu, 25 Jan 2018 15:30:20 +0200 Subject: drm: Warn if plane/crtc/encoder/connector index exceeds our 32bit bitmasks MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We use 32bit bitmasks to track planes/crtcs/encoders/connectors. Naturally we can only do that if the index of those objects stays below 32. Issue a warning whenever we exceed that limit, hopefully prompting someone to fix the problem. For connectors the issue is a bit more complicated as they can be created/destroyed at runtime due to MST. So the problem is no longer a purely theoretical programmer error. As the connector indexes are allocated via ida, we can simply limit the maximum value the ida is allowed to hand out. The error handling is already in place. v2: Return an error to the caller (Harry) v3: Print a debug message so that we know what happened (Maarten) Cc: Harry Wentland Cc: Maarten Lankhorst Cc: Daniel Vetter Reviewed-by: Maarten Lankhorst Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20180125133020.23845-1-ville.syrjala@linux.intel.com Reviewed-by: Harry Wentland --- drivers/gpu/drm/drm_crtc.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/gpu/drm/drm_crtc.c') diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index f0556e654116..5b4be382a1d7 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -282,6 +282,10 @@ int drm_crtc_init_with_planes(struct drm_device *dev, struct drm_crtc *crtc, WARN_ON(primary && primary->type != DRM_PLANE_TYPE_PRIMARY); WARN_ON(cursor && cursor->type != DRM_PLANE_TYPE_CURSOR); + /* crtc index is used with 32bit bitmasks */ + if (WARN_ON(config->num_crtc >= 32)) + return -EINVAL; + crtc->dev = dev; crtc->funcs = funcs; -- cgit v1.2.3