efi_loader: Track size of pool allocations to allow freeing
We need a functional free_pool implementation, as otherwise each allocate_pool causes growth of the memory descriptor table. Different to free_pages, free_pool does not provide the size for the to be freed allocation, thus we have to track the size ourselves. As the only EFI requirement for pool allocation is an alignment of 8 bytes, we can keep allocating a range using the page allocator, reserve the first 8 bytes for our bookkeeping and hand out the remainder to the caller. This saves us from having to use any independent data structures for tracking. To simplify the conversion between pool allocations and the corresponding page allocation, we create an auxiliary struct efi_pool_allocation. Given the allocation size free_pool size can handoff freeing the page range, which was indirectly allocated by a call to allocate_pool, to free_pages. Signed-off-by: NStefan Brüns <stefan.bruens@rwth-aachen.de> Reviewed-by: NAlexander Graf <agraf@suse.de> Signed-off-by: NAlexander Graf <agraf@suse.de>
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