[tip:efi/core] efi: Process the MEMATTR table only if EFI_MEMMAP is enabled

[tip-bot for Daniel Kiper]

Commit-ID:  457ea3f7e97881f937136ce0ba1f29f82b9abdb0
Gitweb:     http://git.kernel.org/tip/457ea3f7e97881f937136ce0ba1f29f82b9abdb0
Author:     Daniel Kiper <daniel.kiper@xxxxxxxxxx>
AuthorDate: Thu, 22 Jun 2017 12:51:36 +0200
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Fri, 23 Jun 2017 11:11:02 +0200

efi: Process the MEMATTR table only if EFI_MEMMAP is enabled

Otherwise e.g. Xen dom0 on x86_64 EFI platforms crashes.

In theory we can check EFI_PARAVIRT too, however,
EFI_MEMMAP looks more targeted and covers more cases.

Signed-off-by: Daniel Kiper <daniel.kiper@xxxxxxxxxx>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: andrew.cooper3@xxxxxxxxxx
Cc: boris.ostrovsky@xxxxxxxxxx
Cc: jgross@xxxxxxxx
Cc: linux-efi@xxxxxxxxxxxxxxx
Cc: matt@xxxxxxxxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/1498128697-12943-2-git-send-email-daniel.kiper@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 drivers/firmware/efi/efi.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index b372aad..045d6d3 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -528,7 +528,8 @@ int __init efi_config_parse_tables(void *config_tables, int count, int sz,
 		}
 	}
 
-	efi_memattr_init();
+	if (efi_enabled(EFI_MEMMAP))
+		efi_memattr_init();
 
 	/* Parse the EFI Properties table if it exists */
 	if (efi.properties_table != EFI_INVALID_TABLE_ADDR) {