From 25b357f1f82a5d2c061f5fb3e6110572f2285036 Mon Sep 17 00:00:00 2001 From: Ben Skeggs Date: Tue, 28 Jan 2020 14:39:26 +1000 Subject: [PATCH] drm/nouveau/disp/nv50-: prevent oops when no channel method map provided [ Upstream commit 0e6176c6d286316e9431b4f695940cfac4ffe6c2 ] The implementations for most channel types contains a map of methods to priv registers in order to provide debugging info when a disp exception has been raised. This info is missing from the implementation of PIO channels as they're rather simplistic already, however, if an exception is raised by one of them, we'd end up triggering a NULL-pointer deref. Not ideal... Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=206299 Signed-off-by: Ben Skeggs Signed-off-by: Sasha Levin --- drivers/gpu/drm/nouveau/nvkm/engine/disp/channv50.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/channv50.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/channv50.c index 9d90d8b..f5a8db1 100644 --- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/channv50.c +++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/channv50.c @@ -72,6 +72,8 @@ nv50_disp_chan_mthd(struct nv50_disp_chan *chan, int debug) if (debug > subdev->debug) return; + if (!mthd) + return; for (i = 0; (list = mthd->data[i].mthd) != NULL; i++) { u32 base = chan->head * mthd->addr; -- 2.7.4