[PATCH 01/11] KVM: PPC: Book3S HV: Move assignments for the variable "err" in kvm_htab_write()

[SF Markus Elfring]

From: Markus Elfring <elfr...@users.sourceforge.net>
Date: Thu, 19 Jan 2017 22:45:56 +0100

* A local variable was set to an error code in five cases
  before a concrete error situation was detected.
  Thus move the corresponding assignments into
  if branches to indicate a software failure there.

  This issue was detected by using the Coccinelle software.

* Delete two zero assignments which became unnecessary with
  this refactoring.

Signed-off-by: Markus Elfring <elfr...@users.sourceforge.net>
---
 arch/powerpc/kvm/book3s_64_mmu_hv.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c 
b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index b795dd1ac2ef..dc34729e4ad0 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -1399,22 +1399,23 @@ static ssize_t kvm_htab_write(struct file *file, const 
char __user *buf,
 
        err = 0;
        for (nb = 0; nb + sizeof(hdr) <= count; ) {
-               err = -EFAULT;
-               if (__copy_from_user(&hdr, buf, sizeof(hdr)))
+               if (__copy_from_user(&hdr, buf, sizeof(hdr))) {
+                       err = -EFAULT;
                        break;
+               }
 
-               err = 0;
                if (nb + hdr.n_valid * HPTE_SIZE > count)
                        break;
 
                nb += sizeof(hdr);
                buf += sizeof(hdr);
 
-               err = -EINVAL;
                i = hdr.index;
                if (i >= kvm->arch.hpt_npte ||
-                   i + hdr.n_valid + hdr.n_invalid > kvm->arch.hpt_npte)
+                   i + hdr.n_valid + hdr.n_invalid > kvm->arch.hpt_npte) {
+                       err = -EINVAL;
                        break;
+               }
 
                hptp = (__be64 *)(kvm->arch.hpt_virt + (i * HPTE_SIZE));
                lbuf = (unsigned long __user *)buf;
@@ -1422,26 +1423,28 @@ static ssize_t kvm_htab_write(struct file *file, const 
char __user *buf,
                        __be64 hpte_v;
                        __be64 hpte_r;
 
-                       err = -EFAULT;
                        if (__get_user(hpte_v, lbuf) ||
-                           __get_user(hpte_r, lbuf + 1))
+                           __get_user(hpte_r, lbuf + 1)) {
+                               err = -EFAULT;
                                goto out;
+                       }
                        v = be64_to_cpu(hpte_v);
                        r = be64_to_cpu(hpte_r);
-                       err = -EINVAL;
-                       if (!(v & HPTE_V_VALID))
+                       if (!(v & HPTE_V_VALID)) {
+                               err = -EINVAL;
                                goto out;
+                       }
                        lbuf += 2;
                        nb += HPTE_SIZE;
 
                        if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | 
HPTE_V_ABSENT))
                                kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
-                       err = -EIO;
                        ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, i, v, r,
                                                         tmp);
                        if (ret != H_SUCCESS) {
                                pr_err("kvm_htab_write ret %ld i=%ld v=%lx "
                                       "r=%lx\n", ret, i, v, r);
+                               err = -EIO;
                                goto out;
                        }
                        if (!hpte_setup && is_vrma_hpte(v)) {
@@ -1465,7 +1468,6 @@ static ssize_t kvm_htab_write(struct file *file, const 
char __user *buf,
                        ++i;
                        hptp += 2;
                }
-               err = 0;
        }
 
  out:
-- 
2.11.0