[PATCH] KVM: Use vmemdup_user()

[Denis Efremov]

Replace opencoded alloc and copy with vmemdup_user().

Signed-off-by: Denis Efremov <efre...@linux.com>
---
Looks like these are the only places in KVM that are suitable for
vmemdup_user().

 arch/x86/kvm/cpuid.c | 17 +++++++----------
 virt/kvm/kvm_main.c  | 19 ++++++++-----------
 2 files changed, 15 insertions(+), 21 deletions(-)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 901cd1fdecd9..27438a2bdb62 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -182,17 +182,14 @@ int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
        r = -E2BIG;
        if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
                goto out;
-       r = -ENOMEM;
        if (cpuid->nent) {
-               cpuid_entries =
-                       vmalloc(array_size(sizeof(struct kvm_cpuid_entry),
-                                          cpuid->nent));
-               if (!cpuid_entries)
-                       goto out;
-               r = -EFAULT;
-               if (copy_from_user(cpuid_entries, entries,
-                                  cpuid->nent * sizeof(struct 
kvm_cpuid_entry)))
+               cpuid_entries = vmemdup_user(entries,
+                                            array_size(sizeof(struct 
kvm_cpuid_entry),
+                                                       cpuid->nent));
+               if (IS_ERR(cpuid_entries)) {
+                       r = PTR_ERR(cpuid_entries);
                        goto out;
+               }
        }
        for (i = 0; i < cpuid->nent; i++) {
                vcpu->arch.cpuid_entries[i].function = 
cpuid_entries[i].function;
@@ -212,8 +209,8 @@ int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
        kvm_x86_ops.cpuid_update(vcpu);
        r = kvm_update_cpuid(vcpu);
 
+       kvfree(cpuid_entries);
 out:
-       vfree(cpuid_entries);
        return r;
 }
 
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 731c1e517716..46a3743e95ff 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -3722,21 +3722,18 @@ static long kvm_vm_ioctl(struct file *filp,
                if (routing.flags)
                        goto out;
                if (routing.nr) {
-                       r = -ENOMEM;
-                       entries = vmalloc(array_size(sizeof(*entries),
-                                                    routing.nr));
-                       if (!entries)
-                               goto out;
-                       r = -EFAULT;
                        urouting = argp;
-                       if (copy_from_user(entries, urouting->entries,
-                                          routing.nr * sizeof(*entries)))
-                               goto out_free_irq_routing;
+                       entries = vmemdup_user(urouting->entries,
+                                              array_size(sizeof(*entries),
+                                                         routing.nr));
+                       if (IS_ERR(entries)) {
+                               r = PTR_ERR(entries);
+                               goto out;
+                       }
                }
                r = kvm_set_irq_routing(kvm, entries, routing.nr,
                                        routing.flags);
-out_free_irq_routing:
-               vfree(entries);
+               kvfree(entries);
                break;
        }
 #endif /* CONFIG_HAVE_KVM_IRQ_ROUTING */
-- 
2.26.2