linux-kernel - [PATCH v12 72/84] KVM: PPC: Remove extra get

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Message-ID: <20240726235234.228822-73-seanjc@google.com>
Date: Fri, 26 Jul 2024 16:52:21 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Paolo Bonzini <pbonzini@...hat.com>, Marc Zyngier <maz@...nel.org>, 
	Oliver Upton <oliver.upton@...ux.dev>, Tianrui Zhao <zhaotianrui@...ngson.cn>, 
	Bibo Mao <maobibo@...ngson.cn>, Huacai Chen <chenhuacai@...nel.org>, 
	Michael Ellerman <mpe@...erman.id.au>, Anup Patel <anup@...infault.org>, 
	Paul Walmsley <paul.walmsley@...ive.com>, Palmer Dabbelt <palmer@...belt.com>, 
	Albert Ou <aou@...s.berkeley.edu>, Christian Borntraeger <borntraeger@...ux.ibm.com>, 
	Janosch Frank <frankja@...ux.ibm.com>, Claudio Imbrenda <imbrenda@...ux.ibm.com>, 
	Sean Christopherson <seanjc@...gle.com>
Cc: kvm@...r.kernel.org, linux-arm-kernel@...ts.infradead.org, 
	kvmarm@...ts.linux.dev, loongarch@...ts.linux.dev, linux-mips@...r.kernel.org, 
	linuxppc-dev@...ts.ozlabs.org, kvm-riscv@...ts.infradead.org, 
	linux-riscv@...ts.infradead.org, linux-kernel@...r.kernel.org, 
	David Matlack <dmatlack@...gle.com>, David Stevens <stevensd@...omium.org>
Subject: [PATCH v12 72/84] KVM: PPC: Remove extra get_page() to fix page
 refcount leak

Don't manually do get_page() when patching dcbz, as gfn_to_page() gifts
the caller a reference.  I.e. doing get_page() will leak the page due to
not putting all references.

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/powerpc/kvm/book3s_pr.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index 1bdcd4ee4813..ae4757ac0848 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -652,7 +652,6 @@ static void kvmppc_patch_dcbz(struct kvm_vcpu *vcpu, struct kvmppc_pte *pte)
 	hpage_offset &= ~0xFFFULL;
 	hpage_offset /= 4;
 
-	get_page(hpage);
 	page = kmap_atomic(hpage);
 
 	/* patch dcbz into reserved instruction, so we trap */
-- 
2.46.0.rc1.232.g9752f9e123-goog