randr: use calloc() instead of malloc()

Using calloc() instead of malloc() as preventive measure, so there
never can be any hidden bugs or leaks due uninitialized memory.

The extra cost of using this compiler intrinsic should be practically
impossible to measure - in many cases a good compiler can even deduce
if certain areas really don't need to be zero'd (because they're written
to right after allocation) and create more efficient machine code.

The code pathes in question are pretty cold anyways, so it's probably
not worth even thinking about potential extra runtime costs.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>

randr/rrcrtc.c

@@ -1204,7 +1204,7 @@ ProcRRGetCrtcInfo(ClientPtr client)
         rep.length = bytes_to_int32(extraLen);
 
         if (extraLen) {
-            extra = malloc(extraLen);
+            extra = calloc(1, extraLen);
             if (!extra)
                 return BadAlloc;
         }
@@ -1658,7 +1658,7 @@ ProcRRGetCrtcGamma(ClientPtr client)
     len = crtc->gammaSize * 3 * 2;
 
     if (crtc->gammaSize) {
-        extra = malloc(len);
+        extra = calloc(1, len);
         if (!extra)
             return BadAlloc;
     }
@@ -1954,7 +1954,7 @@ RRReplaceScanoutPixmap(DrawablePtr pDrawable, PixmapPtr pPixmap, Bool enable)
     PixmapPtr *saved_scanout_pixmap;
     int i;
 
-    saved_scanout_pixmap = malloc(sizeof(PixmapPtr)*pScrPriv->numCrtcs);
+    saved_scanout_pixmap = calloc(pScrPriv->numCrtcs, sizeof(PixmapPtr));
     if (saved_scanout_pixmap == NULL)
         return FALSE;
 

randr/rrdispatch.c

@@ -113,7 +113,7 @@ ProcRRSelectInput(ClientPtr client)
 
         if (!pRREvent) {
             /* build the entry */
-            pRREvent = (RREventPtr) malloc(sizeof(RREventRec));
+            pRREvent = calloc(1, sizeof(RREventRec));
             if (!pRREvent)
                 return BadAlloc;
             pRREvent->next = 0;
@@ -135,7 +135,7 @@ ProcRRSelectInput(ClientPtr client)
              * done through the resource database.
              */
             if (!pHead) {
-                pHead = (RREventPtr *) malloc(sizeof(RREventPtr));
+                pHead = calloc(1, sizeof(RREventPtr));
                 if (!pHead ||
                     !AddResource(pWin->drawable.id, RREventType,
                                  (void *) pHead)) {

randr/rrinfo.c

@@ -59,7 +59,7 @@ RROldModeAdd(RROutputPtr output, RRScreenSizePtr size, int refresh)
         modes = reallocarray(output->modes,
                              output->numModes + 1, sizeof(RRModePtr));
     else
-        modes = malloc(sizeof(RRModePtr));
+        modes = calloc(1, sizeof(RRModePtr));
     if (!modes) {
         RRModeDestroy(mode);
         FreeResource(mode->mode.id, 0);

randr/rrmode.c

@@ -71,7 +71,7 @@ RRModeCreate(xRRModeInfo * modeInfo, const char *name, ScreenPtr userScreen)
     if (!RRInit())
         return NULL;
 
-    mode = malloc(sizeof(RRModeRec) + modeInfo->nameLength + 1);
+    mode = calloc(1, sizeof(RRModeRec) + modeInfo->nameLength + 1);
     if (!mode)
         return NULL;
     mode->refcnt = 1;
@@ -84,7 +84,7 @@ RRModeCreate(xRRModeInfo * modeInfo, const char *name, ScreenPtr userScreen)
     if (num_modes)
         newModes = reallocarray(modes, num_modes + 1, sizeof(RRModePtr));
     else
-        newModes = malloc(sizeof(RRModePtr));
+        newModes = calloc(1, sizeof(RRModePtr));
 
     if (!newModes) {
         free(mode);

randr/rrmonitor.c

@@ -502,7 +502,7 @@ RRMonitorAdd(ClientPtr client, ScreenPtr screen, RRMonitorPtr monitor)
                                 pScrPriv->numMonitors + 1,
                                 sizeof (RRMonitorPtr));
     else
-        monitors = malloc(sizeof (RRMonitorPtr));
+        monitors = calloc(1, sizeof(RRMonitorPtr));
 
     if (!monitors)
         return BadAlloc;

randr/rroutput.c

@@ -209,7 +209,7 @@ RROutputAddUserMode(RROutputPtr output, RRModePtr mode)
         newModes = reallocarray(output->userModes,
                                 output->numUserModes + 1, sizeof(RRModePtr));
     else
-        newModes = malloc(sizeof(RRModePtr));
+        newModes = calloc(1, sizeof(RRModePtr));
     if (!newModes)
         return BadAlloc;
 

randr/rrproperty.c

@@ -108,9 +108,7 @@ RRInitOutputPropertyValue(RRPropertyValuePtr property_value)
 static RRPropertyPtr
 RRCreateOutputProperty(Atom property)
 {
-    RRPropertyPtr prop;
+    RRPropertyPtr prop = calloc(1, sizeof(RRPropertyRec));
-
-    prop = (RRPropertyPtr) malloc(sizeof(RRPropertyRec));
     if (!prop)
         return NULL;
     prop->next = NULL;
@@ -705,7 +703,7 @@ ProcRRGetOutputProperty(ClientPtr client)
     len = min(n - ind, 4 * stuff->longLength);
 
     if (len) {
-        extra = malloc(len);
+        extra = calloc(1, len);
         if (!extra)
             return BadAlloc;
     }

randr/rrprovider.c

@@ -107,7 +107,7 @@ ProcRRGetProviders (ClientPtr client)
     };
 
     if (extraLen) {
-        extra = malloc(extraLen);
+        extra = calloc(1, extraLen);
         if (!extra)
             return BadAlloc;
     } else
@@ -184,7 +184,7 @@ ProcRRGetProviderInfo (ClientPtr client)
 
     extraLen = rep.length << 2;
     if (extraLen) {
-        extra = malloc(extraLen);
+        extra = calloc(1, extraLen);
         if (!extra)
             return BadAlloc;
     }

randr/rrproviderproperty.c

@@ -168,7 +168,7 @@ RRChangeProviderProperty(RRProviderPtr provider, Atom property, Atom type,
         void *new_data = NULL, *old_data = NULL;
 
         total_size = total_len * size_in_bytes;
-        new_value.data = (void *) malloc(total_size);
+        new_value.data = calloc(1, total_size);
         if (!new_value.data && total_size) {
             if (add)
                 RRDestroyProviderProperty(prop);
@@ -604,7 +604,7 @@ ProcRRGetProviderProperty(ClientPtr client)
     len = min(n - ind, 4 * stuff->longLength);
 
     if (len) {
-        extra = malloc(len);
+        extra = calloc(1, len);
         if (!extra)
             return BadAlloc;
     }

randr/rrscreen.c

@@ -422,7 +422,7 @@ rrGetMultiScreenResources(ClientPtr client, Bool query, ScreenPtr pScreen)
 
     extraLen = rep.length << 2;
     if (extraLen) {
-        extra = malloc(extraLen);
+        extra = calloc(1, extraLen);
         if (!extra) {
             return BadAlloc;
         }
@@ -649,7 +649,6 @@ typedef struct _RR10Data {
 static RR10DataPtr
 RR10GetData(ScreenPtr pScreen, RROutputPtr output)
 {
-    RR10DataPtr data;
     RRScreenSizePtr size;
     int nmode = output->numModes + output->numUserModes;
     int o, os, l, r;
@@ -659,7 +658,7 @@ RR10GetData(ScreenPtr pScreen, RROutputPtr output)
     Bool *used;
 
     /* Make sure there is plenty of space for any combination */
-    data = malloc(sizeof(RR10DataRec) +
+    RR10DataPtr data = calloc(1, sizeof(RR10DataRec) +
                   sizeof(RRScreenSize) * nmode +
                   sizeof(RRScreenRate) * nmode + sizeof(Bool) * nmode);
     if (!data)