KVM: x86: Use ERR_PTR_USR() to return -EFAULT as a __user pointer

mainline inclusion
from mainline-v5.17-rc3
commit 6e37ec88
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I5RQLJ
CVE: NA

Intel-SIG: commit 6e37ec88 KVM: x86: Use ERR_PTR_USR() to return -EFAULT as a __user pointer.

--------------------------------

Use ERR_PTR_USR() when returning -EFAULT from kvm_get_attr_addr(), sparse
complains about implicitly casting the kernel pointer from ERR_PTR() into
a __user pointer.

>> arch/x86/kvm/x86.c:4342:31: sparse: sparse: incorrect type in return expression
   (different address spaces) @@     expected void [noderef] __user * @@     got void * @@
   arch/x86/kvm/x86.c:4342:31: sparse:     expected void [noderef] __user *
   arch/x86/kvm/x86.c:4342:31: sparse:     got void *
>> arch/x86/kvm/x86.c:4342:31: sparse: sparse: incorrect type in return expression
   (different address spaces) @@     expected void [noderef] __user * @@     got void * @@
   arch/x86/kvm/x86.c:4342:31: sparse:     expected void [noderef] __user *
   arch/x86/kvm/x86.c:4342:31: sparse:     got void *

No functional change intended.

Fixes: 56f289a8 ("KVM: x86: Add a helper to retrieve userspace address from kvm_device_attr")
Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NSean Christopherson <seanjc@google.com>
Message-Id: <20220202005157.2545816-1-seanjc@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NLin Wang <lin.x.wang@intel.com>

arch/x86/kvm/x86.c

@@ -88,6 +88,8 @@
 u64 __read_mostly kvm_mce_cap_supported = MCG_CTL_P | MCG_SER_P;
 EXPORT_SYMBOL_GPL(kvm_mce_cap_supported);
 
+#define  ERR_PTR_USR(e)  ((void __user *)ERR_PTR(e))
+
 #define emul_to_vcpu(ctxt) \
 	((struct kvm_vcpu *)(ctxt)->vcpu)
 
@@ -4014,7 +4016,7 @@ static inline void __user *kvm_get_attr_addr(struct kvm_device_attr *attr)
 	void __user *uaddr = (void __user*)(unsigned long)attr->addr;
 
 	if ((u64)(unsigned long)uaddr != attr->addr)
-		return ERR_PTR(-EFAULT);
+		return ERR_PTR_USR(-EFAULT);
 	return uaddr;
 }