virXMLPropInt: Always initialize '@result'

Compilers aren't able to see whether @result is set or not and thus
don't warn of a potential use of uninitialized value. Always set @result
to prevent uninitialized use.

This is done by adding a @defaultResult argument to virXMLPropInt since
many places have a non-0 default.

In certain cases such as in virDomainControllerDefParseXML we pass the
value from the original value, which will still trigger compiler checks
if unused while preserving the existing functionality of keeping the
previous value.

This commit fixes 3 uses of uninitialized value parsed by this function:
 in virDomainDiskSourceNetworkParse introduced by 38dc25989c5
 in virDomainChrSourceDefParseTCP introduced by fa48004af5b
 in virDomainGraphicsListenDefParseXML introduced by 0b20fd3754c

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 78775bb2b34119fdfa4cbde5d0b102f2e48bd05d..2bc2e55ee488fd97eaf65a88677ed5288651e06f 100644 (file)
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -8221,7 +8221,7 @@ virDomainDiskSourceNetworkParse(xmlNodePtr node,
     if (flags & VIR_DOMAIN_DEF_PARSE_STATUS) {
         int value;
         if (virXMLPropInt(node, "tlsFromConfig", 10, VIR_XML_PROP_NONE,
-                          &value) < 0)
+                          &value, 0) < 0)
             return -1;
         src->tlsFromConfig = !!value;
     }
@@ -9414,7 +9414,7 @@ virDomainControllerDefParseXML(virDomainXMLOption *xmlopt,
     g_autofree xmlNodePtr *modelNodes = NULL;
     int nmodelNodes = 0;
     int numaNode = -1;
-    int ports = -1;
+    int ports;
     VIR_XPATH_NODE_AUTORESTORE(ctxt)
     int rc;
     g_autofree char *idx = NULL;
@@ -9494,19 +9494,23 @@ virDomainControllerDefParseXML(virDomainXMLOption *xmlopt,
     if (ntargetNodes == 1) {
         if (def->type == VIR_DOMAIN_CONTROLLER_TYPE_PCI) {
         if (virXMLPropInt(targetNodes[0], "chassisNr", 0, VIR_XML_PROP_NONE,
-                      &def->opts.pciopts.chassisNr) < 0)
+                      &def->opts.pciopts.chassisNr,
+                      def->opts.pciopts.chassisNr) < 0)
             return NULL;
 
         if (virXMLPropInt(targetNodes[0], "chassis", 0, VIR_XML_PROP_NONE,
-                          &def->opts.pciopts.chassis) < 0)
+                          &def->opts.pciopts.chassis,
+                          def->opts.pciopts.chassis) < 0)
             return NULL;
 
         if (virXMLPropInt(targetNodes[0], "port", 0, VIR_XML_PROP_NONE,
-                          &def->opts.pciopts.port) < 0)
+                          &def->opts.pciopts.port,
+                          def->opts.pciopts.port) < 0)
             return NULL;
 
         if (virXMLPropInt(targetNodes[0], "busNr", 0, VIR_XML_PROP_NONE,
-                          &def->opts.pciopts.busNr) < 0)
+                          &def->opts.pciopts.busNr,
+                          def->opts.pciopts.busNr) < 0)
             return NULL;
 
         if (virXMLPropTristateSwitch(targetNodes[0], "hotplug",
@@ -9515,7 +9519,8 @@ virDomainControllerDefParseXML(virDomainXMLOption *xmlopt,
             return NULL;
 
         if ((rc = virXMLPropInt(targetNodes[0], "index", 0, VIR_XML_PROP_NONE,
-                          &def->opts.pciopts.targetIndex)) < 0)
+                          &def->opts.pciopts.targetIndex,
+                          def->opts.pciopts.targetIndex)) < 0)
             return NULL;
 
         if ((rc == 1) && def->opts.pciopts.targetIndex == -1)
@@ -9548,7 +9553,7 @@ virDomainControllerDefParseXML(virDomainXMLOption *xmlopt,
         return NULL;
     }
 
-    if ((rc = virXMLPropInt(node, "ports", 10, VIR_XML_PROP_NONE, &ports)) < 0)
+    if ((rc = virXMLPropInt(node, "ports", 10, VIR_XML_PROP_NONE, &ports, -1)) < 0)
         return NULL;
     if ((rc == 1) && ports < 0) {
         virReportError(VIR_ERR_INTERNAL_ERROR,
@@ -9559,7 +9564,8 @@ virDomainControllerDefParseXML(virDomainXMLOption *xmlopt,
     switch (def->type) {
     case VIR_DOMAIN_CONTROLLER_TYPE_VIRTIO_SERIAL: {
         if ((rc = virXMLPropInt(node, "vectors", 10, VIR_XML_PROP_NONE,
-                                &def->opts.vioserial.vectors)) < 0)
+                                &def->opts.vioserial.vectors,
+                                def->opts.vioserial.vectors)) < 0)
             return NULL;
 
         if ((rc == 1) && def->opts.vioserial.vectors < 0) {
@@ -9630,7 +9636,8 @@ virDomainControllerDefParseXML(virDomainXMLOption *xmlopt,
         break;
     case VIR_DOMAIN_CONTROLLER_TYPE_XENBUS: {
         if ((rc = virXMLPropInt(node, "maxGrantFrames", 10, VIR_XML_PROP_NONE,
-                                &def->opts.xenbusopts.maxGrantFrames)) < 0)
+                                &def->opts.xenbusopts.maxGrantFrames,
+                                def->opts.xenbusopts.maxGrantFrames)) < 0)
             return NULL;
 
         if ((rc == 1) && def->opts.xenbusopts.maxGrantFrames < 0) {
@@ -9641,7 +9648,8 @@ virDomainControllerDefParseXML(virDomainXMLOption *xmlopt,
         }
 
         if ((rc = virXMLPropInt(node, "maxEventChannels", 10, VIR_XML_PROP_NONE,
-                                &def->opts.xenbusopts.maxEventChannels)) < 0)
+                                &def->opts.xenbusopts.maxEventChannels,
+                                def->opts.xenbusopts.maxEventChannels)) < 0)
             return NULL;
 
         if ((rc == 1) && def->opts.xenbusopts.maxEventChannels < 0) {
@@ -11181,7 +11189,7 @@ virDomainChrSourceDefParseTCP(virDomainChrSourceDef *def,
         int tmpVal;
 
         if (virXMLPropInt(source, "tlsFromConfig", 10, VIR_XML_PROP_NONE,
-                          &tmpVal) < 0)
+                          &tmpVal, 0) < 0)
             return -1;
         def->data.tcp.tlsFromConfig = !!tmpVal;
     }
@@ -12376,7 +12384,7 @@ virDomainGraphicsListenDefParseXML(virDomainGraphicsListenDef *def,
 
     if (flags & VIR_DOMAIN_DEF_PARSE_STATUS) {
         int tmp;
-        if (virXMLPropInt(node, "fromConfig", 10, VIR_XML_PROP_NONE, &tmp) < 0)
+        if (virXMLPropInt(node, "fromConfig", 10, VIR_XML_PROP_NONE, &tmp, 0) < 0)
             return -1;
         def->fromConfig = tmp != 0;
     }
@@ -12519,7 +12527,7 @@ virDomainGraphicsDefParseXMLVNC(virDomainGraphicsDef *def,
     }
 
     if (virXMLPropInt(node, "websocket", 10, VIR_XML_PROP_NONE,
-                      &def->data.vnc.websocket) < 0)
+                      &def->data.vnc.websocket, 0) < 0)
         return -1;
 
     if (websocketGenerated)
@@ -12663,14 +12671,12 @@ virDomainGraphicsDefParseXMLSpice(virDomainGraphicsDef *def,
     if (virDomainGraphicsListensParseXML(def, node, ctxt, flags) < 0)
         return -1;
 
-    def->data.spice.port = 0;
     if (virXMLPropInt(node, "port", 10, VIR_XML_PROP_NONE,
-                      &def->data.spice.port) < 0)
+                      &def->data.spice.port, 0) < 0)
         return -1;
 
-    def->data.spice.tlsPort = 0;
     if (virXMLPropInt(node, "tlsPort", 10, VIR_XML_PROP_NONE,
-                      &def->data.spice.tlsPort) < 0)
+                      &def->data.spice.tlsPort, 0) < 0)
         return -1;
 
     if (virXMLPropTristateBool(node, "autoport", VIR_XML_PROP_NONE,
@@ -13527,7 +13533,6 @@ virDomainMemballoonDefParseXML(virDomainXMLOption *xmlopt,
     virDomainMemballoonDef *def;
     VIR_XPATH_NODE_AUTORESTORE(ctxt)
     xmlNodePtr stats;
-    unsigned int period = 0;
 
     ctxt->node = node;
 
@@ -13546,10 +13551,9 @@ virDomainMemballoonDefParseXML(virDomainXMLOption *xmlopt,
                                  &def->free_page_reporting) < 0)
         goto error;
 
-    def->period = period;
     if ((stats = virXPathNode("./stats", ctxt))) {
         if (virXMLPropInt(stats, "period", 0, VIR_XML_PROP_NONE,
-                          &def->period) < 0)
+                          &def->period, 0) < 0)
             goto error;
 
         if (def->period < 0)
@@ -14509,8 +14513,7 @@ virDomainRedirFilterUSBDevDefParseXML(xmlNodePtr node)
 
     def = g_new0(virDomainRedirFilterUSBDevDef, 1);
 
-    def->usbClass = -1;
-    if (virXMLPropInt(node, "class", 0, VIR_XML_PROP_NONE, &def->usbClass) < 0)
+    if (virXMLPropInt(node, "class", 0, VIR_XML_PROP_NONE, &def->usbClass, -1) < 0)
         return NULL;
 
     if (def->usbClass != -1 && def->usbClass &~ 0xFF) {
@@ -14519,12 +14522,10 @@ virDomainRedirFilterUSBDevDefParseXML(xmlNodePtr node)
         return NULL;
     }
 
-    def->vendor = -1;
-    if (virXMLPropInt(node, "vendor", 0, VIR_XML_PROP_NONE, &def->vendor) < 0)
+    if (virXMLPropInt(node, "vendor", 0, VIR_XML_PROP_NONE, &def->vendor, -1) < 0)
         return NULL;
 
-    def->product = -1;
-    if (virXMLPropInt(node, "product", 0, VIR_XML_PROP_NONE, &def->product) < 0)
+    if (virXMLPropInt(node, "product", 0, VIR_XML_PROP_NONE, &def->product, -1) < 0)
         return NULL;
 
     version = virXMLPropString(node, "version");
@@ -17868,7 +17869,7 @@ virDomainSchedulerParseCommonAttrs(xmlNodePtr node,
 
     if (*policy == VIR_PROC_POLICY_FIFO || *policy == VIR_PROC_POLICY_RR) {
         if (virXMLPropInt(node, "priority", 10, VIR_XML_PROP_REQUIRED,
-                          priority) < 0)
+                          priority, 0) < 0)
             return -1;
     }
 

diff --git a/src/util/virxml.c b/src/util/virxml.c
index a03cbf726563e0a989a547dd3e143861fc309dd6..449453121f01be1449f5c0b6887a1248da0ec4ca 100644 (file)
--- a/src/util/virxml.c
+++ b/src/util/virxml.c
@@ -651,6 +651,7 @@ virXMLPropTristateSwitch(xmlNodePtr node,
  * @base: Number base, see strtol
  * @flags: Bitwise or of virXMLPropFlags
  * @result: The returned value
+ * @defaultResult: default value of @result in case the property is not found
  *
  * Convenience function to return value of an integer attribute.
  *
@@ -663,11 +664,14 @@ virXMLPropInt(xmlNodePtr node,
               const char *name,
               int base,
               virXMLPropFlags flags,
-              int *result)
+              int *result,
+              int defaultResult)
 {
     g_autofree char *tmp = NULL;
     int val;
 
+    *result = defaultResult;
+
     if (!(tmp = virXMLPropString(node, name))) {
         if (!(flags & VIR_XML_PROP_REQUIRED))
             return 0;

diff --git a/src/util/virxml.h b/src/util/virxml.h
index eb92fbf94e28af2a350962976d8c0145e1f853e3..939d2482cbbf4e3f4d616944222d2630fedf3784 100644 (file)
--- a/src/util/virxml.h
+++ b/src/util/virxml.h
@@ -123,7 +123,8 @@ virXMLPropInt(xmlNodePtr node,
               const char *name,
               int base,
               virXMLPropFlags flags,
-              int *result)
+              int *result,
+              int defaultResult)
     ATTRIBUTE_NONNULL(0) ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(4);
 
 int