nouveau_bo_wr32 expects offset to be in words, but we pass value in bytes, so after commit 73412c3854c877e5f37ad944ee8977addde4d35a ("drm/nouveau: allocate kernel's notifier object at end of block") we started to overwrite some memory after notifier buffer object (previously m2mf_ntfy was always 0, so it didn't matter it was a value in bytes).
Reported-by: Dominik Brodowski linux@dominikbrodowski.net Reported-by: Nigel Cunningham lkml@nigelcunningham.com.au Signed-off-by: Marcin Slusarz marcin.slusarz@gmail.com Cc: Ben Skeggs bskeggs@redhat.com Cc: Pekka Paalanen pq@iki.fi Cc: stable@kernel.org [2.6.38] --- drivers/gpu/drm/nouveau/nouveau_fbcon.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/nouveau_fbcon.c b/drivers/gpu/drm/nouveau/nouveau_fbcon.c index 889c445..39aee6d 100644 --- a/drivers/gpu/drm/nouveau/nouveau_fbcon.c +++ b/drivers/gpu/drm/nouveau/nouveau_fbcon.c @@ -181,13 +181,13 @@ nouveau_fbcon_sync(struct fb_info *info) OUT_RING (chan, 0); }
- nouveau_bo_wr32(chan->notifier_bo, chan->m2mf_ntfy + 3, 0xffffffff); + nouveau_bo_wr32(chan->notifier_bo, chan->m2mf_ntfy/4 + 3, 0xffffffff); FIRE_RING(chan); mutex_unlock(&chan->mutex);
ret = -EBUSY; for (i = 0; i < 100000; i++) { - if (!nouveau_bo_rd32(chan->notifier_bo, chan->m2mf_ntfy + 3)) { + if (!nouveau_bo_rd32(chan->notifier_bo, chan->m2mf_ntfy/4 + 3)) { ret = 0; break; }