From: Paolo Bonzini <pbonzini@redhat.com>
Date: Thu, 9 Dec 2021 13:12:48 +0000 (-0500)
Subject: KVM: x86: warn on incorrectly NULL members of kvm_x86_ops
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=dd2319c61888018a5295264c9b631e151dad364d;p=linux.git

KVM: x86: warn on incorrectly NULL members of kvm_x86_ops

Use the newly corrected KVM_X86_OP annotations to warn about possible
NULL pointer dereferences as soon as the vendor module is loaded.

Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 7d733f601106f..a7e82fc1f1f3a 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1545,10 +1545,13 @@ extern struct kvm_x86_ops kvm_x86_ops;
 
 static inline void kvm_ops_static_call_update(void)
 {
-#define KVM_X86_OP(func) \
+#define __KVM_X86_OP(func) \
 	static_call_update(kvm_x86_##func, kvm_x86_ops.func);
-#define KVM_X86_OP_OPTIONAL KVM_X86_OP
+#define KVM_X86_OP(func) \
+	WARN_ON(!kvm_x86_ops.func); __KVM_X86_OP(func)
+#define KVM_X86_OP_OPTIONAL __KVM_X86_OP
 #include <asm/kvm-x86-ops.h>
+#undef __KVM_X86_OP
 }
 
 #define __KVM_HAVE_ARCH_VM_ALLOC