[PATCH 2/4] KVM-S390: Use memdup_user() rather than duplicating its implementation

[SF Markus Elfring <elfring@users.sourceforge.net>]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Wed, 17 Aug 2016 18:41:43 +0200

* Reuse existing functionality from memdup_user() instead of keeping
  duplicate source code.

  This issue was detected by using the Coccinelle software.

* Return directly if this copy operation failed.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 arch/s390/kvm/guestdbg.c | 13 +++----------
 1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/arch/s390/kvm/guestdbg.c b/arch/s390/kvm/guestdbg.c
index b68db4b..8f886ee 100644
--- a/arch/s390/kvm/guestdbg.c
+++ b/arch/s390/kvm/guestdbg.c
@@ -217,16 +217,9 @@ int kvm_s390_import_bp_data(struct kvm_vcpu *vcpu,
 		return -EINVAL;
 
 	size = dbg->arch.nr_hw_bp * sizeof(*bp_data);
-	bp_data = kmalloc(size, GFP_KERNEL);
-	if (!bp_data) {
-		ret = -ENOMEM;
-		goto error;
-	}
-
-	if (copy_from_user(bp_data, dbg->arch.hw_bp, size)) {
-		ret = -EFAULT;
-		goto error;
-	}
+	bp_data = memdup_user(dbg->arch.hw_bp, size);
+	if (IS_ERR(bp_data))
+		return PTR_ERR(bp_data);
 
 	for (i = 0; i < dbg->arch.nr_hw_bp; i++) {
 		switch (bp_data[i].type) {
-- 
2.9.3