Message ID | 20200630122710.1119158-10-ppandit@redhat.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | memory: assert and define MemoryRegionOps callbacks | expand |
On Tue, 30 Jun 2020 at 13:31, P J P <ppandit@redhat.com> wrote: > > From: Prasad J Pandit <pjp@fedoraproject.org> > > When registering a MemoryRegionOps object, assert that its > read/write callback methods are defined. This avoids potential > guest crash via a NULL pointer dereference. > > Suggested-by: Peter Maydell <peter.maydell@linaro.org> > Reviewed-by: Li Qiang <liq3ea@gmail.com> > Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org> > --- Reviewed-by: Peter Maydell <peter.maydell@linaro.org> thanks -- PMM
diff --git a/memory.c b/memory.c index 9200b20130..5e22bce326 100644 --- a/memory.c +++ b/memory.c @@ -1485,7 +1485,13 @@ void memory_region_init_io(MemoryRegion *mr, uint64_t size) { memory_region_init(mr, owner, name, size); - mr->ops = ops ? ops : &unassigned_mem_ops; + if (ops) { + assert(ops->read || ops->read_with_attrs); + assert(ops->write || ops->write_with_attrs); + mr->ops = ops; + } else { + mr->ops = &unassigned_mem_ops; + } mr->opaque = opaque; mr->terminates = true; } @@ -1663,6 +1669,8 @@ void memory_region_init_rom_device_nomigrate(MemoryRegion *mr, { Error *err = NULL; assert(ops); + assert(ops->read || ops->read_with_attrs); + assert(ops->write || ops->write_with_attrs); memory_region_init(mr, owner, name, size); mr->ops = ops; mr->opaque = opaque;