gpu: nova-core: zero-pad radix3 page table levels to page boundary

On Turing through Ada, the booter, a firmware stage that runs on the
GPU's SEC2 falcon, copies the GSP firmware image from system memory into
the framebuffer. It walks the radix3 table to find each page of the
image, and it reads each level of the table by DMA, a whole 4 KiB page
at a time. The last page of a level is only partly filled with entries,
so the bytes past the last entry reach the booter too.

Nova-core allocated each level at the size of its entries and wrote only
the entries, so the rest of the level's last page held whatever the
allocator left there, and the booter read that stale kernel memory.

Allocate each level zeroed and sized to a whole number of 4 KiB pages,
as Open RM does, and write the entries into it.

Assisted-by: LLM
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Timur Tabi <ttabi@nvidia.com>
Link: https://patch.msgid.link/20260913195413.742143-3-jhubbard@nvidia.com
[acourbot: move chunks from previous commit into this one for
 consistency]
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>

0 files changed, 0 insertions, 0 deletions