linux-kernel - [PATCH v12 18/84] KVM: Remove pointless sanity check on @map param to kvm_vcpu

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Message-ID: <20240726235234.228822-19-seanjc@google.com>
Date: Fri, 26 Jul 2024 16:51:27 -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 18/84] KVM: Remove pointless sanity check on @map param to kvm_vcpu_(un)map()

Drop kvm_vcpu_{,un}map()'s useless checks on @map being non-NULL.  The map
is 100% kernel controlled, any caller that passes a NULL pointer is broken
and needs to be fixed, i.e. a crash due to a NULL pointer dereference is
desirable (though obviously not as desirable as not having a bug in the
first place).

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 virt/kvm/kvm_main.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 56c2d11761e0..21ff0f4fa02c 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -3092,9 +3092,6 @@ int kvm_vcpu_map(struct kvm_vcpu *vcpu, gfn_t gfn, struct kvm_host_map *map)
 	void *hva = NULL;
 	struct page *page = KVM_UNMAPPED_PAGE;
 
-	if (!map)
-		return -EINVAL;
-
 	pfn = gfn_to_pfn(vcpu->kvm, gfn);
 	if (is_error_noslot_pfn(pfn))
 		return -EINVAL;
@@ -3122,9 +3119,6 @@ EXPORT_SYMBOL_GPL(kvm_vcpu_map);
 
 void kvm_vcpu_unmap(struct kvm_vcpu *vcpu, struct kvm_host_map *map, bool dirty)
 {
-	if (!map)
-		return;
-
 	if (!map->hva)
 		return;
 
-- 
2.46.0.rc1.232.g9752f9e123-goog