From: Jan Beulich <jbeulich@suse.com>
Date: Thu, 19 Jul 2018 09:54:45 +0000 (+0200)
Subject: VMX: fix vmx_{find,del}_msr() build
X-Git-Tag: 4.12.0-rc1~938
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=97cb0516a322ecdf0032fa9d8aa1525c03d7772f;p=xen.git

VMX: fix vmx_{find,del}_msr() build

Older gcc at -O2 (and perhaps higher) does not recognize that apparently
uninitialized variables aren't really uninitialized. Pull out the
assignments used by two of the three case blocks and make them
initializers of the variables, as I think I had suggested during review.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Kevin Tian <kevin.tian@intel.com>
---

diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c
index 6059d614ff..096a26a36f 100644
--- a/xen/arch/x86/hvm/vmx/vmcs.c
+++ b/xen/arch/x86/hvm/vmx/vmcs.c
@@ -1305,7 +1305,8 @@ struct vmx_msr_entry *vmx_find_msr(const struct vcpu *v, uint32_t msr,
 {
     const struct arch_vmx_struct *vmx = &v->arch.hvm_vmx;
     struct vmx_msr_entry *start = NULL, *ent, *end;
-    unsigned int substart, subend, total;
+    unsigned int substart = 0, subend = vmx->msr_save_count;
+    unsigned int total = vmx->msr_load_count;
 
     ASSERT(v == current || !vcpu_runnable(v));
 
@@ -1313,23 +1314,18 @@ struct vmx_msr_entry *vmx_find_msr(const struct vcpu *v, uint32_t msr,
     {
     case VMX_MSR_HOST:
         start    = vmx->host_msr_area;
-        substart = 0;
         subend   = vmx->host_msr_count;
         total    = subend;
         break;
 
     case VMX_MSR_GUEST:
         start    = vmx->msr_area;
-        substart = 0;
-        subend   = vmx->msr_save_count;
-        total    = vmx->msr_load_count;
         break;
 
     case VMX_MSR_GUEST_LOADONLY:
         start    = vmx->msr_area;
-        substart = vmx->msr_save_count;
-        subend   = vmx->msr_load_count;
-        total    = subend;
+        substart = subend;
+        subend   = total;
         break;
 
     default:
@@ -1461,7 +1457,8 @@ int vmx_del_msr(struct vcpu *v, uint32_t msr, enum vmx_msr_list_type type)
 {
     struct arch_vmx_struct *vmx = &v->arch.hvm_vmx;
     struct vmx_msr_entry *start = NULL, *ent, *end;
-    unsigned int substart, subend, total;
+    unsigned int substart = 0, subend = vmx->msr_save_count;
+    unsigned int total = vmx->msr_load_count;
 
     ASSERT(v == current || !vcpu_runnable(v));
 
@@ -1469,23 +1466,18 @@ int vmx_del_msr(struct vcpu *v, uint32_t msr, enum vmx_msr_list_type type)
     {
     case VMX_MSR_HOST:
         start    = vmx->host_msr_area;
-        substart = 0;
         subend   = vmx->host_msr_count;
         total    = subend;
         break;
 
     case VMX_MSR_GUEST:
         start    = vmx->msr_area;
-        substart = 0;
-        subend   = vmx->msr_save_count;
-        total    = vmx->msr_load_count;
         break;
 
     case VMX_MSR_GUEST_LOADONLY:
         start    = vmx->msr_area;
-        substart = vmx->msr_save_count;
-        subend   = vmx->msr_load_count;
-        total    = subend;
+        substart = subend;
+        subend   = total;
         break;
 
     default: