Jiri Kosina bf29bddf04 x86/efi: Always map the first physical page into the EFI pagetables ... Commit: 129766708 ("x86/efi: Only map RAM into EFI page tables if in mixed-mode") stopped creating 1:1 mappings for all RAM, when running in native 64-bit mode. It turns out though that there are 64-bit EFI implementations in the wild (this particular problem has been reported on a Lenovo Yoga 710-11IKB), which still make use of the first physical page for their own private use, even though they explicitly mark it EFI_CONVENTIONAL_MEMORY in the memory map. In case there is no mapping for this particular frame in the EFI pagetables, as soon as firmware tries to make use of it, a triple fault occurs and the system reboots (in case of the Yoga 710-11IKB this is very early during bootup). Fix that by always mapping the first page of physical memory into the EFI pagetables. We're free to hand this page to the BIOS, as trim_bios_range() will reserve the first page and isolate it away from memory allocators anyway. Note that just reverting 129766708 alone is not enough on v4.9-rc1+ to fix the regression on affected hardware, as this commit: ab72a27da ("x86/efi: Consolidate region mapping logic") later made the first physical frame not to be mapped anyway. Reported-by: Hanka Pavlikova <hanka@ucw.cz> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Laura Abbott <labbott@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vojtech Pavlik <vojtech@ucw.cz> Cc: Waiman Long <waiman.long@hpe.com> Cc: linux-efi@vger.kernel.org Cc: stable@kernel.org # v4.8+ Fixes: 129766708 ("x86/efi: Only map RAM into EFI page tables if in mixed-mode") Link: http://lkml.kernel.org/r/20170127222552.22336-1-matt@codeblueprint.co.uk [ Tidied up the changelog and the comment. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>		2017-01-28 09:18:56 +01:00
..
early_printk.c	treewide: replace obsolete _refok by __ref	2016-08-02 17:31:41 -04:00
efi-bgrt.c	x86/efi-bgrt: Use efi_mem_reserve() to avoid copying image data	2016-09-09 16:08:38 +01:00
efi.c	efi/x86: Prune invalid memory map entries and fix boot regression	2017-01-14 16:48:53 +01:00
efi_32.c	x86/mm: Remove kernel_unmap_pages_in_pgd() and efi_cleanup_page_tables()	2016-07-15 10:26:26 +02:00
efi_64.c	x86/efi: Always map the first physical page into the EFI pagetables	2017-01-28 09:18:56 +01:00
efi_stub_32.S	x86/efi: Mark initialization code as such	2014-10-03 18:41:03 +01:00
efi_stub_64.S	x86/efi: Fix 7-parameter efi_call()s	2016-05-17 08:25:06 +02:00
efi_thunk_64.S	x86/efi: Avoid triple faults during EFI mixed mode calls	2015-02-13 15:42:56 +00:00
Makefile	objtool: Mark non-standard object files and directories	2016-02-29 08:35:02 +01:00
quirks.c	x86/efi: Don't allocate memmap through memblock after mm_init()	2017-01-07 08:58:07 +01:00