[ 3.5.y.z extended stable ] Patch "x86, efi: Check max_size only if it is non-zero." has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    x86,efi: Check max_size only if it is non-zero.

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 4a720d95adb772fc1d8e5f4fb5378634f8d5b0a2 Mon Sep 17 00:00:00 2001
From: Richard Weinberger <richard at nod.at>
Date: Wed, 10 Apr 2013 10:59:34 +0200
Subject: [PATCH] x86,efi: Check max_size only if it is non-zero.

commit 7791c8423f1f7f4dad94e753bae67461d5b80be8 upstream.

Some EFI implementations return always a MaximumVariableSize of 0,
check against max_size only if it is non-zero.
My Intel DQ67SW desktop board has such an implementation.

Signed-off-by: Richard Weinberger <richard at nod.at>
Signed-off-by: Matt Fleming <matt.fleming at intel.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 arch/x86/platform/efi/efi.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index b8699b3..0eb3066 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -983,7 +983,12 @@ efi_status_t efi_query_variable_store(u32 attributes, unsigned long size)
 	if (status != EFI_SUCCESS)
 		return status;

-	if (!storage_size || size > remaining_size || size > max_size ||
+	if (!max_size && remaining_size > size)
+		printk_once(KERN_ERR FW_BUG "Broken EFI implementation"
+			    " is returning MaxVariableSize=0\n");
+
+	if (!storage_size || size > remaining_size ||
+	    (max_size && size > max_size) ||
 	    (remaining_size - size) < (storage_size / 2))
 		return EFI_OUT_OF_RESOURCES;

--
1.8.1.2