[PATCH] drm/crtc: fix uninitialized variable use even harder

From: Rob Clark
Date: Mon Feb 12 2024 - 16:55:53 EST


From: Rob Clark <robdclark@xxxxxxxxxxxx>

DRM_MODESET_LOCK_ALL_BEGIN() has a hidden trap-door (aka retry loop),
which means we can't rely too much on variable initializers.

Fixes: 6e455f5dcdd1 ("drm/crtc: fix uninitialized variable use")
Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
---
I have mixed feelings about DRM_MODESET_LOCK_ALL_BEGIN() (and friends)
magic. On one hand it simplifies the deadlock/back dance. OTOH it
conceals a nasty sharp edge. Maybe it is better to have the complicated
restart path a bit more explicit, like it was originally.

drivers/gpu/drm/drm_crtc.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index cb90e70d85e8..65f9f66933bb 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -904,6 +904,7 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
connector_set = NULL;
fb = NULL;
mode = NULL;
+ num_connectors = 0;

DRM_MODESET_LOCK_ALL_END(dev, ctx, ret);

--
2.43.0