This commit introduces integer underflow mitigation in max_addr calculation
in grub_relocator_alloc_chunk_align() invocation.
It consists of 2 fixes:
1. Introduced grub_relocator_alloc_chunk_align_safe() wrapper function to perform
sanity check for min/max and size values, and to make safe invocation of
grub_relocator_alloc_chunk_align() with validated max_addr value. Replace all
invocations such as grub_relocator_alloc_chunk_align(..., min_addr, max_addr - size, size, ...)
by grub_relocator_alloc_chunk_align_safe(..., min_addr, max_addr, size, ...).
2. Introduced UP_TO_TOP32(s) macro for the cases where max_addr is 32-bit top
address (0xffffffff - size + 1) or similar.
Signed-off-by: Alexey Makhalov <amakhalov@vmware.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Add grub_relocator64_efi relocator. It will be used on EFI 64-bit platforms
when multiboot2 compatible image requests MULTIBOOT_TAG_TYPE_EFI_BS. Relocator
will set lower parts of %rax and %rbx accordingly to multiboot2 specification.
On the other hand processor mode, just before jumping into loaded image, will
be set accordingly to Unified Extensible Firmware Interface Specification,
Version 2.4 Errata B, section 2.3.4, x64 Platforms, boot services. This way
loaded image will be able to use EFI boot services without any issues.
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Vladimir Serbinenko <phcoder@gmail.com>
Alexey Makhalov