From: Matt Fleming <matt.fleming@intel.com>
Date: Thu, 11 Jul 2013 06:30:33 +0000 (+0100)
Subject: efivars: check for EFI_RUNTIME_SERVICES
X-Git-Tag: firefly_0821_release~3680^2~36^2~41^2~48
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=b082f48205a0c8f3294f7de0852ac379a76fdc08;p=firefly-linux-kernel-4.4.55.git

efivars: check for EFI_RUNTIME_SERVICES

The efivars code requires EFI runtime services to function, so check
that they are enabled.

This fixes a crash when booting with the "noefi" kernel parameter, and
also when mixing kernel and firmware "bitness", e.g. 32-bit kernel with
64-bit firmware.

Tested-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
(cherry picked from commit d320c079efd46db1be0640d00bd6723d9e738f9f)
Signed-off-by: Mark Brown <broonie@linaro.org>
---

diff --git a/drivers/firmware/efi/efivars.c b/drivers/firmware/efi/efivars.c
index 8bd1bb6dbe47..8a7432a4b413 100644
--- a/drivers/firmware/efi/efivars.c
+++ b/drivers/firmware/efi/efivars.c
@@ -583,6 +583,9 @@ int efivars_sysfs_init(void)
 	struct kobject *parent_kobj = efivars_kobject();
 	int error = 0;
 
+	if (!efi_enabled(EFI_RUNTIME_SERVICES))
+		return -ENODEV;
+
 	/* No efivars has been registered yet */
 	if (!parent_kobj)
 		return 0;