[tip:x86/mm] x86/efi/32: Fix EFI on systems where the per-cpu GDT is virtually mapped

[tip-bot for Andy Lutomirski]

Commit-ID:  3fa1cabbc3b61224ef33d3ca4a1a96998529bc68
Gitweb:     http://git.kernel.org/tip/3fa1cabbc3b61224ef33d3ca4a1a96998529bc68
Author:     Andy Lutomirski <luto@xxxxxxxxxx>
AuthorDate: Wed, 22 Mar 2017 14:32:31 -0700
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Thu, 23 Mar 2017 08:25:07 +0100

x86/efi/32: Fix EFI on systems where the per-cpu GDT is virtually mapped

__pa() on a per-cpu pointer is invalid.  This bug appears to go *waaay*
back, and I guess it's just never been triggered.

Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Garnier <thgarnie@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-efi@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/5ba1d3ffca85e1a5b3ac99265ebe55df4cf0dbe4.1490218061.git.luto@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 arch/x86/platform/efi/efi_32.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/platform/efi/efi_32.c b/arch/x86/platform/efi/efi_32.c
index 9500711..3481268 100644
--- a/arch/x86/platform/efi/efi_32.c
+++ b/arch/x86/platform/efi/efi_32.c
@@ -68,7 +68,7 @@ pgd_t * __init efi_call_phys_prolog(void)
 	load_cr3(initial_page_table);
 	__flush_tlb_all();
 
-	gdt_descr.address = __pa(get_cpu_gdt_rw(0));
+	gdt_descr.address = get_cpu_gdt_paddr(0);
 	gdt_descr.size = GDT_SIZE - 1;
 	load_gdt(&gdt_descr);