[Xen-devel] [PATCH] VMX: fix vmx_{find,del}_msr() build

["Jan Beulich" <JBeulich@xxxxxxxx>]

For a reason that I can't explain, it is only the shim build that fails
for me with an older gcc due to the compiler not recognizing 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@xxxxxxxx>

--- 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
 {
     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
     {
     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
 {
     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
     {
     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:





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