Mathias Krause 81f859c572 drivers/linux: reinstantiate DMA32 allocations ...

Commit 81fa32bd7e ("drivers/linux: enforce address requirement for
IOCTL_ALLOC_PHYSMEM") tried to enforce the physical address constraints
provided by the user. However, it's broken for the memory range 16M-4G
as there's no DMA32 kmalloc cache, making the request allocate from the
normal zone which is free to return an address above 4GB for systems
with enough RAM.

Commit d010b82b0d ("Fix malloc issue in Linux driver") worked around
that issue by simple dropping the DMA32 allocation and only using DMA
allocations for which kmalloc slabs do exist.

As the DMA zone is a scarce resource and might be exhausted already, use
a different allocation scheme for chipsec that directly allocates memory
from the page allocator which honours both, DMA and DMA32 requests.

Also fix the allocation list handling while at it. The stored physical
address might be truncated on 32-bit PAE systems because of the use of
'physaddr_t' instead of 'phys_addr_t'.

Signed-off-by: Mathias Krause <minipli@grsecurity.net>

2022-08-26 11:52:02 -07:00

..

chipsec.h

drivers/linux: reinstantiate DMA32 allocations

2022-08-26 11:52:02 -07:00