16 Dec
2021
16 Dec
'21
5:12 p.m.
On Thu, Dec 16, 2021 at 10:16 AM Steven Price steven.price@arm.com wrote:
panfrost_copy_in_sync() takes the number of fences from user space (in_sync_count) and used to kvmalloc() an array to hold that number of fences before processing them. This provides an easy method for user space to trigger the OOM killer (by temporarily allocating large amounts of kernel memory) or hit the WARN_ONCE() added by 7661809d493b ("mm: don't allow oversized kvmalloc() calls").
Since we don't expect there to be a large number of fences we can instead iterate over the fences one-by-one and avoid the temporary allocation altogether. This also makes the code simpler.
Doesn't the BO lookup suffer from the same issue?
Rob