Cleanup and sanity-checking of assorted additional issues from second pass (Coverity...

[palacios.git] / palacios / src / palacios / svm_msr.c

diff --git a/palacios/src/palacios/svm_msr.c b/palacios/src/palacios/svm_msr.c
index 2ffcfac..bca1dd2 100644 (file)
--- a/palacios/src/palacios/svm_msr.c
+++ b/palacios/src/palacios/svm_msr.c
@@ -37,6 +37,7 @@
 
 
 static int get_bitmap_index(uint_t msr) {
+    // unsigend cmoparison with zero intentional for clarity
     if ((msr >= PENTIUM_MSRS_START) && 
        (msr <= PENTIUM_MSRS_END)) {
        return (PENTIUM_MSRS_INDEX + (msr - PENTIUM_MSRS_START));
@@ -47,7 +48,7 @@ static int get_bitmap_index(uint_t msr) {
               (msr <= AMD_7_8_GEN_MSRS_END)) {
        return (AMD_7_8_GEN_MSRS_INDEX + (msr - AMD_7_8_GEN_MSRS_START));
     } else {
-       PrintError("MSR out of range (MSR=0x%x)\n", msr);
+       PrintError(VM_NONE, VCORE_NONE,  "MSR out of range (MSR=0x%x)\n", msr);
        return -1;
     }
 }
@@ -57,15 +58,20 @@ static int update_map(struct v3_vm_info * vm, uint_t msr, int hook_reads, int ho
     int index = get_bitmap_index(msr);
     uint_t major = index / 4;
     uint_t minor = (index % 4) * 2;
-    uchar_t val = 0;
-    uchar_t mask = 0x3;
+    uint8_t val = 0;
+    uint8_t mask = 0x3;
     uint8_t * bitmap = (uint8_t *)(vm->msr_map.arch_data);
 
-    if (hook_reads) {
+    if (index == -1) {
+       PrintError(vm, VCORE_NONE,  "MSR (0x%x) out of bitmap range\n", msr);
+       return 0;
+    }
+
+    if (hook_reads != 0) {
        val |= 0x1;
     } 
     
-    if (hook_writes) {
+    if (hook_writes != 0) {
        val |= 0x2;
     }
 
@@ -77,11 +83,20 @@ static int update_map(struct v3_vm_info * vm, uint_t msr, int hook_reads, int ho
 
 
 int v3_init_svm_msr_map(struct v3_vm_info * vm) {
+    void *temp;
     struct v3_msr_map * msr_map = &(vm->msr_map);
   
     msr_map->update_map = update_map;
 
-    msr_map->arch_data = V3_VAddr(V3_AllocPages(2));  
+    temp = V3_AllocPages(2); // need not be shadow-safe, not exposed to guest
+    
+    if (!temp) { 
+       PrintError(vm, VCORE_NONE,  "Cannot allocate msr bitmap\n");
+       return -1;
+    }
+
+    msr_map->arch_data = V3_VAddr(temp);
+
     memset(msr_map->arch_data, 0xff, PAGE_SIZE_4KB * 2);
 
     v3_refresh_msr_map(vm);
@@ -90,6 +105,8 @@ int v3_init_svm_msr_map(struct v3_vm_info * vm) {
 }
 
 int v3_deinit_svm_msr_map(struct v3_vm_info * vm) {
-    V3_FreePages(V3_PAddr(vm->msr_map.arch_data), 2);
+    if (vm->msr_map.arch_data) { 
+       V3_FreePages(V3_PAddr(vm->msr_map.arch_data), 2);
+    }
     return 0;
 }