From: Richard Weinberger <richard@nod.at>
Date: Wed, 10 Apr 2013 08:59:34 +0000 (+0200)
Subject: x86,efi: Check max_size only if it is non-zero.
X-Git-Tag: firefly_0821_release~3680^2~694^2~8
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=7791c8423f1f7f4dad94e753bae67461d5b80be8;p=firefly-linux-kernel-4.4.55.git

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

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@nod.at>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
---

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index c89c245eff40..3f96a487aa2a 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -1018,7 +1018,12 @@ 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;