From: Julia Lawall Julia.Lawall@lip6.fr
If list_for_each_entry, etc complete a traversal of the list, the iterator variable ends up pointing to an address at an offset from the list head, and not a meaningful structure. Thus this value should not be used after the end of the iterator.
A break is added after the switch; the break in the switch would jump out of the switch, but not out of the complete iteration. The null test on connector is also removed, because the iterator variable of list_for_each_entry is never null.
A simplified version of the semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/)
// <smpl> @@ identifier c; expression E; iterator name list_for_each_entry; statement S; @@
list_for_each_entry(c,...) { ... when != break; when forall when strict } ... ( c = E | *c ) // </smpl>
Signed-off-by: Julia Lawall Julia.Lawall@lip6.fr Acked-by: Paul Menzel paulepanter@users.sourceforge.net
--- drivers/gpu/drm/gma500/mdfld_intel_display.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/gma500/mdfld_intel_display.c b/drivers/gpu/drm/gma500/mdfld_intel_display.c index 3f3cd61..fc1ced0 100644 --- a/drivers/gpu/drm/gma500/mdfld_intel_display.c +++ b/drivers/gpu/drm/gma500/mdfld_intel_display.c @@ -755,9 +755,6 @@ static int mdfld_crtc_mode_set(struct drm_crtc *crtc, sizeof(struct drm_display_mode));
list_for_each_entry(connector, &mode_config->connector_list, head) { - if (!connector) - continue; - encoder = connector->encoder;
if (!encoder) @@ -779,6 +776,7 @@ static int mdfld_crtc_mode_set(struct drm_crtc *crtc, is_hdmi = true; break; } + break; }
/* Disable the VGA plane that we never use */