Thread (133 messages) 133 messages, 11 authors, 2024-08-22

[PATCH v12 18/84] KVM: Remove pointless sanity check on @map param to kvm_vcpu_(un)map()

From: Sean Christopherson <seanjc@google.com>
Date: 2024-07-26 23:53:14
Also in: kvm, kvm-riscv, kvmarm, linux-arm-kernel, linux-mips, linux-riscv, lkml, loongarch
Subsystem: kernel virtual machine (kvm), the rest · Maintainers: Paolo Bonzini, Linus Torvalds

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@google.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
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