linux-kernel - [PATCH] kvm mmu: fix another largepage memory leak

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Date:	Thu, 19 Feb 2009 12:18:56 +0100
From:	Joerg Roedel <joerg.roedel@....com>
To:	Avi Kivity <avi@...hat.com>, Marcelo Tosatti <mtosatti@...hat.com>
CC:	kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
	Joerg Roedel <joerg.roedel@....com>
Subject: [PATCH] kvm mmu: fix another largepage memory leak

In the paging_fetch function rmap_remove is called after setting a large
pte to non-present. This causes rmap_remove to not drop the reference to
the large page. The result is a memory leak of that page.

Signed-off-by: Joerg Roedel <joerg.roedel@....com>
---
 arch/x86/kvm/paging_tmpl.h |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 7314c09..0f11792 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -306,9 +306,9 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
 			continue;
 
 		if (is_large_pte(*sptep)) {
+			rmap_remove(vcpu->kvm, sptep);
 			set_shadow_pte(sptep, shadow_trap_nonpresent_pte);
 			kvm_flush_remote_tlbs(vcpu->kvm);
-			rmap_remove(vcpu->kvm, sptep);
 		}
 
 		if (level == PT_DIRECTORY_LEVEL
-- 
1.5.6.4


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