From b7b898ae0c0a82489511a1ce1b35f26215e6beb5 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Sat, 18 Jan 2014 12:48:17 +0100 Subject: [PATCH] x86/efi: Make efi virtual runtime map passing more robust Currently, running SetVirtualAddressMap() and passing the physical address of the virtual map array was working only by a lucky coincidence because the memory was present in the EFI page table too. Until Toshi went and booted this on a big HP box - the krealloc() manner of resizing the memmap we're doing did allocate from such physical addresses which were not mapped anymore and boom: http://lkml.kernel.org/r/1386806463.1791.295.camel@misato.fc.hp.com One way to take care of that issue is to reimplement the krealloc thing but with pages. We start with contiguous pages of order 1, i.e. 2 pages, and when we deplete that memory (shouldn't happen all that often but you know firmware) we realloc the next power-of-two pages. Having the pages, it is much more handy and easy to map them into the EFI page table with the already existing mapping code which we're using for building the virtual mappings. Thanks to Toshi Kani and Matt for the great debugging help. Reported-by: Toshi Kani Signed-off-by: Borislav Petkov Tested-by: Toshi Kani Signed-off-by: Matt Fleming --- Reading git-format-patch failed