linux-kernel - [PATCH 1/5] KVM: x86/mmu: Return a u64 (the old SPTE) from mmu_spte_clear_track

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20220712015558.1247978-2-seanjc@google.com>
Date:   Tue, 12 Jul 2022 01:55:54 +0000
From:   Sean Christopherson <seanjc@...gle.com>
To:     Sean Christopherson <seanjc@...gle.com>,
        Paolo Bonzini <pbonzini@...hat.com>
Cc:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH 1/5] KVM: x86/mmu: Return a u64 (the old SPTE) from mmu_spte_clear_track_bits()

Return a u64, not an int, from mmu_spte_clear_track_bits().  The return
value is the old SPTE value, which is very much a 64-bit value.  The sole
caller that consumes the return value, drop_spte(), already uses a u64.
The only reason that truncating the SPTE value is not problematic is
because drop_spte() only queries the shadow-present bit, which is in the
lower 32 bits.

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/mmu/mmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index f7fa4c31b7c5..2605d6ebc193 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -529,7 +529,7 @@ static bool mmu_spte_update(u64 *sptep, u64 new_spte)
  * state bits, it is used to clear the last level sptep.
  * Returns the old PTE.
  */
-static int mmu_spte_clear_track_bits(struct kvm *kvm, u64 *sptep)
+static u64 mmu_spte_clear_track_bits(struct kvm *kvm, u64 *sptep)
 {
 	kvm_pfn_t pfn;
 	u64 old_spte = *sptep;
-- 
2.37.0.144.g8ac04bfd2-goog