From: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Date: Thu, 5 Mar 2009 01:36:57 +0000 (-0800)
Subject: xen/mmu: weaken flush_tlb_other test
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=e3f8a74e3a884b91a4390c66ed8175ef74db7067;p=linux-beck.git

xen/mmu: weaken flush_tlb_other test

Impact: fixes crashing bug

There's no particular problem with getting an empty cpu mask,
so just shortcut-return if we get one.

Avoids crash reported by Christophe Saout <christophe@saout.de>

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
---

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 4db24e1393a2..7ef880c51dca 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1302,8 +1302,8 @@ static void xen_flush_tlb_others(const struct cpumask *cpus,
 	} *args;
 	struct multicall_space mcs;
 
-	BUG_ON(cpumask_empty(cpus));
-	BUG_ON(!mm);
+	if (cpumask_empty(cpus))
+		return;		/* nothing to do */
 
 	mcs = xen_mc_entry(sizeof(*args));
 	args = mcs.args;