diff --git a/hw/xwin/InitOutput.c b/hw/xwin/InitOutput.c
index a8a8cac24..65fa17150 100644
--- a/hw/xwin/InitOutput.c
+++ b/hw/xwin/InitOutput.c
@@ -463,7 +463,7 @@ winFixupPaths(void)
 
                     /* allocate memory */
                     if (fontpath == NULL)
-                        fontpath = malloc(newsize + 1);
+                        fontpath = calloc(1, newsize + 1);
                     else
                         fontpath = realloc(fontpath, newsize + 1);
 
@@ -509,7 +509,7 @@ winFixupPaths(void)
         while (ptr != NULL) {
             size_t oldfp_len = (ptr - oldptr);
             size_t newsize = oldfp_len;
-            char *newpath = malloc(newsize + 1);
+            char *newpath = calloc(1, newsize + 1);
 
             strncpy(newpath, oldptr, newsize);
             newpath[newsize] = 0;
@@ -518,7 +518,7 @@ winFixupPaths(void)
                 char *compose;
 
                 newsize = newsize - libx11dir_len + basedirlen;
-                compose = malloc(newsize + 1);
+                compose = calloc(1, newsize + 1);
                 strcpy(compose, basedir);
                 strncat(compose, newpath + libx11dir_len, newsize - basedirlen);
                 compose[newsize] = 0;
@@ -532,7 +532,7 @@ winFixupPaths(void)
             newfp_len += newsize;
 
             if (newfp == NULL)
-                newfp = malloc(newfp_len + 1);
+                newfp = calloc(1, newfp_len + 1);
             else
                 newfp = realloc(newfp, newfp_len + 1);
 
diff --git a/hw/xwin/glx/indirect.c b/hw/xwin/glx/indirect.c
index f8664a8b3..eb30ae99f 100644
--- a/hw/xwin/glx/indirect.c
+++ b/hw/xwin/glx/indirect.c
@@ -843,9 +843,7 @@ glxWinCreateDrawable(ClientPtr client,
                      DrawablePtr pDraw,
                      XID drawId, int type, XID glxDrawId, __GLXconfig * conf)
 {
-    __GLXWinDrawable *glxPriv;
-
-    glxPriv = malloc(sizeof *glxPriv);
+    __GLXWinDrawable *glxPriv = calloc(1, sizeof *glxPriv);
 
     if (glxPriv == NULL)
         return NULL;
@@ -1969,7 +1967,7 @@ glxWinCreateConfigs(HDC hdc, glxWinScreen * screen)
         n++;
 
         // allocate and save
-        work = malloc(sizeof(GLXWinConfig));
+        work = calloc(1, sizeof(GLXWinConfig));
         if (NULL == work) {
             ErrorF("Failed to allocate GLXWinConfig\n");
             break;
@@ -2383,7 +2381,7 @@ glxWinCreateConfigsExt(HDC hdc, glxWinScreen * screen, PixelFormatRejectStats *
         n++;
 
         // allocate and save
-        work = malloc(sizeof(GLXWinConfig));
+        work = calloc(1, sizeof(GLXWinConfig));
         if (NULL == work) {
             ErrorF("Failed to allocate GLXWinConfig\n");
             break;
diff --git a/hw/xwin/winauth.c b/hw/xwin/winauth.c
index 5bc5a7316..09469e0a9 100644
--- a/hw/xwin/winauth.c
+++ b/hw/xwin/winauth.c
@@ -81,10 +81,6 @@ GenerateAuthorization(unsigned name_length,
 BOOL
 winGenerateAuthorization(void)
 {
-#ifdef XCSECURITY
-    SecurityAuthorizationPtr pAuth = NULL;
-#endif
-
     /* Call OS layer to generate authorization key */
     g_authId = GenerateAuthorization(strlen(AUTH_NAME),
                                      AUTH_NAME,
@@ -107,8 +103,7 @@ winGenerateAuthorization(void)
 
 #ifdef XCSECURITY
     /* Allocate structure for additional auth information */
-    pAuth = (SecurityAuthorizationPtr)
-        malloc(sizeof(SecurityAuthorizationRec));
+    SecurityAuthorizationPtr pAuth = calloc(1, sizeof(SecurityAuthorizationRec));
     if (!(pAuth)) {
         ErrorF("winGenerateAuthorization - Failed allocating "
                "SecurityAuthorizationPtr.\n");
diff --git a/hw/xwin/winclipboard/textconv.c b/hw/xwin/winclipboard/textconv.c
index 651ccc666..b2bf0f71d 100644
--- a/hw/xwin/winclipboard/textconv.c
+++ b/hw/xwin/winclipboard/textconv.c
@@ -100,7 +100,7 @@ winClipboardUNIXtoDOS(char **ppszData, int iLength)
         return;
 
     /* Allocate a new string */
-    pszDestBegin = pszDest = malloc(iLength + iNewlineCount + 1);
+    pszDestBegin = pszDest = calloc(1, iLength + iNewlineCount + 1);
 
     /* Set source pointer to beginning of data string */
     pszSrc = *ppszData;
diff --git a/hw/xwin/winclipboard/xevents.c b/hw/xwin/winclipboard/xevents.c
index 6a846902e..41b6d9cbc 100644
--- a/hw/xwin/winclipboard/xevents.c
+++ b/hw/xwin/winclipboard/xevents.c
@@ -138,7 +138,7 @@ static char *get_atom_name(xcb_connection_t *conn, xcb_atom_t atom)
     xcb_get_atom_name_reply_t *reply = xcb_get_atom_name_reply(conn, cookie, NULL);
     if (!reply)
         return NULL;
-    ret = malloc(xcb_get_atom_name_name_length(reply) + 1);
+    ret = calloc(1, xcb_get_atom_name_name_length(reply) + 1);
     if (ret) {
         memcpy(ret, xcb_get_atom_name_name(reply), xcb_get_atom_name_name_length(reply));
         ret[xcb_get_atom_name_name_length(reply)] = '\0';
@@ -166,7 +166,7 @@ winClipboardSelectionNotifyTargets(HWND hwnd, xcb_window_t iWindow, xcb_connecti
       xcb_atom_t *prop = xcb_get_property_value(reply);
       int nitems = xcb_get_property_value_length(reply)/sizeof(xcb_atom_t);
       int i;
-      data->targetList = malloc((nitems+1)*sizeof(xcb_atom_t));
+      data->targetList = calloc(nitems+1, sizeof(xcb_atom_t));
 
       for (i = 0; i < nitems; i++)
           {
@@ -242,8 +242,8 @@ winClipboardSelectionNotifyData(HWND hwnd, xcb_window_t iWindow, xcb_connection_
     if (encoding == atoms->atomIncr) {
         winDebug("winClipboardSelectionNotifyData: starting INCR, anticipated size %d\n", *(int *)value);
         data->incrsize = 0;
-        data->incr = malloc(*(int *)value);
-        // XXX: if malloc failed, we have an error
+        data->incr = calloc(1, *(int *)value);
+        // XXX: if calloc failed, we have an error
         return WIN_XEVENTS_SUCCESS;
     }
     else if (data->incr) {
@@ -276,23 +276,23 @@ winClipboardSelectionNotifyData(HWND hwnd, xcb_window_t iWindow, xcb_connection_
     }
 
     if (xtpText_encoding == atoms->atomUTF8String) {
-        pszReturnData = malloc(xtpText_nitems + 1);
+        pszReturnData = calloc(1, xtpText_nitems + 1);
         memcpy(pszReturnData, xtpText_value, xtpText_nitems);
         pszReturnData[xtpText_nitems] = 0;
         codepage = CP_UTF8; // code page identifier for utf8
     } else if (xtpText_encoding == XCB_ATOM_STRING) {
         // STRING encoding is Latin1 (ISO8859-1) plus tab and newline
-        pszReturnData = malloc(xtpText_nitems + 1);
+        pszReturnData = calloc(1, xtpText_nitems + 1);
         memcpy(pszReturnData, xtpText_value, xtpText_nitems);
         pszReturnData[xtpText_nitems] = 0;
         codepage = CP_ISO_8559_1; // code page identifier for iso-8559-1
     } else if (xtpText_encoding == atoms->atomCompoundText) {
         // COMPOUND_TEXT is complex, based on ISO 2022
         ErrorF("SelectionNotify: data in COMPOUND_TEXT encoding which is not implemented, discarding\n");
-        pszReturnData = malloc(1);
+        pszReturnData = calloc(1, 1);
         pszReturnData[0] = '\0';
     } else { // shouldn't happen as we accept no other encodings
-        pszReturnData = malloc(1);
+        pszReturnData = calloc(1, 1);
         pszReturnData[0] = '\0';
     }
 
@@ -314,10 +314,10 @@ winClipboardSelectionNotifyData(HWND hwnd, xcb_window_t iWindow, xcb_connection_
                                           pszReturnData, -1, NULL, 0);
 
     /* NOTE: iUnicodeLen includes space for null terminator */
-    pwszUnicodeStr = malloc(sizeof(wchar_t) * iUnicodeLen);
+    pwszUnicodeStr = calloc(iUnicodeLen, sizeof(wchar_t));
     if (!pwszUnicodeStr) {
         ErrorF("winClipboardFlushXEvents - SelectionNotify "
-               "malloc failed for pwszUnicodeStr, aborting.\n");
+               "calloc failed for pwszUnicodeStr, aborting.\n");
 
         /* Abort */
         goto winClipboardFlushXEvents_SelectionNotify_Done;
@@ -551,7 +551,7 @@ winClipboardFlushXEvents(HWND hwnd,
                                                       (LPCWSTR) pszGlobalData, -1,
                                                       NULL, 0, NULL, NULL);
             /* NOTE: iConvertDataLen includes space for null terminator */
-            pszConvertData = malloc(iConvertDataLen);
+            pszConvertData = calloc(1, iConvertDataLen);
             WideCharToMultiByte(codepage, 0,
                                 (LPCWSTR) pszGlobalData, -1,
                                 pszConvertData, iConvertDataLen, NULL, NULL);
diff --git a/hw/xwin/wincmap.c b/hw/xwin/wincmap.c
index 3567afad5..7b279f490 100644
--- a/hw/xwin/wincmap.c
+++ b/hw/xwin/wincmap.c
@@ -405,7 +405,6 @@ winGetPaletteDD(ScreenPtr pScreen, ColormapPtr pcmap)
     Pixel pixel;                /* Pixel == CARD32 */
     CARD16 nRed, nGreen, nBlue; /* CARD16 == unsigned short */
     UINT uiSystemPaletteEntries;
-    LPPALETTEENTRY ppeColors = NULL;
     HDC hdc = NULL;
 
     /* Get a DC to obtain the default palette */
@@ -429,9 +428,9 @@ winGetPaletteDD(ScreenPtr pScreen, ColormapPtr pcmap)
 #endif
 
     /* Allocate palette entries structure */
-    ppeColors = malloc(uiSystemPaletteEntries * sizeof(PALETTEENTRY));
+    LPPALETTEENTRY ppeColors = calloc(uiSystemPaletteEntries, sizeof(PALETTEENTRY));
     if (ppeColors == NULL) {
-        ErrorF("winGetPaletteDD - malloc () for colormap failed\n");
+        ErrorF("winGetPaletteDD - calloc () for colormap failed\n");
         return FALSE;
     }
 
diff --git a/hw/xwin/winconfig.c b/hw/xwin/winconfig.c
index 4f16b21e0..bac21d799 100644
--- a/hw/xwin/winconfig.c
+++ b/hw/xwin/winconfig.c
@@ -294,10 +294,9 @@ winConfigKeyboard(DeviceIntPtr pDevice)
             HKEY regkey = NULL;
             const char regtempl[] =
                 "SYSTEM\\CurrentControlSet\\Control\\Keyboard Layouts\\";
-            char *regpath;
             DWORD namesize = sizeof(layoutFriendlyName);
 
-            regpath = malloc(sizeof(regtempl) + KL_NAMELENGTH + 1);
+            char *regpath = calloc(1, sizeof(regtempl) + KL_NAMELENGTH + 1);
             strcpy(regpath, regtempl);
             strcat(regpath, layoutName);
 
@@ -907,7 +906,7 @@ ParseOptionValue(int scrnIndex, void *options, OptionInfoPtr p)
         }
         else {
             free(n);
-            n = malloc(strlen(p->name) + 2 + 1);
+            n = calloc(1, strlen(p->name) + 2 + 1);
             if (!n) {
                 p->found = FALSE;
                 return FALSE;
@@ -995,13 +994,13 @@ GetBoolValue(OptionInfoPtr p, const char *s)
 char *
 winNormalizeName(const char *s)
 {
-    char *ret, *q;
+    char *q;
     const char *p;
 
     if (s == NULL)
         return NULL;
 
-    ret = malloc(strlen(s) + 1);
+    char *ret = calloc(1, strlen(s) + 1);
     for (p = s, q = ret; *p != 0; p++) {
         switch (*p) {
         case '_':
diff --git a/hw/xwin/wincursor.c b/hw/xwin/wincursor.c
index 6b42c990e..f4f88abe0 100644
--- a/hw/xwin/wincursor.c
+++ b/hw/xwin/wincursor.c
@@ -150,7 +150,6 @@ winLoadCursor(ScreenPtr pScreen, CursorPtr pCursor, int screen)
 {
     winScreenPriv(pScreen);
     HCURSOR hCursor = NULL;
-    unsigned char *pAnd;
     unsigned char *pXor;
     int nCX, nCY;
     int nBytes;
@@ -196,7 +195,7 @@ winLoadCursor(ScreenPtr pScreen, CursorPtr pCursor, int screen)
     nCY = min(pScreenPriv->cursor.sm_cy, pCursor->bits->height);
 
     /* Allocate memory for the bitmaps */
-    pAnd = malloc(nBytes);
+    unsigned char *pAnd = calloc(1, nBytes);
     memset(pAnd, 0xFF, nBytes);
     pXor = calloc(1, nBytes);
 
diff --git a/hw/xwin/winmouse.c b/hw/xwin/winmouse.c
index 52166a850..2e8f56d34 100644
--- a/hw/xwin/winmouse.c
+++ b/hw/xwin/winmouse.c
@@ -66,7 +66,6 @@ winMouseProc(DeviceIntPtr pDeviceInt, int iState)
 {
     int lngMouseButtons, i;
     int lngWheelEvents = 4;
-    CARD8 *map;
     DevicePtr pDevice = (DevicePtr) pDeviceInt;
     Atom btn_labels[9];
     Atom axes_labels[2];
@@ -98,7 +97,7 @@ winMouseProc(DeviceIntPtr pDeviceInt, int iState)
         /* allocate memory:
          * number of buttons + 4 x mouse wheel event + 1 extra (offset for map)
          */
-        map = malloc(sizeof(CARD8) * (lngMouseButtons + lngWheelEvents + 1));
+        CARD8 *map = calloc(lngMouseButtons + lngWheelEvents + 1, sizeof(CARD8));
 
         /* initialize button map */
         map[0] = 0;
diff --git a/hw/xwin/winmultiwindowclass.c b/hw/xwin/winmultiwindowclass.c
index 0d5ce3b1c..667858a14 100644
--- a/hw/xwin/winmultiwindowclass.c
+++ b/hw/xwin/winmultiwindowclass.c
@@ -68,7 +68,7 @@ winMultiWindowGetClassHint(WindowPtr pWin, char **res_name, char **res_class)
             len_name = strlen((char *) prop->data);
             if (len_name > prop->size) len_name = prop->size;
 
-            (*res_name) = malloc(len_name + 1);
+            (*res_name) = calloc(1, len_name + 1);
 
             if (!*res_name) {
                 ErrorF("winMultiWindowGetClassHint - *res_name was NULL\n");
@@ -83,7 +83,7 @@ winMultiWindowGetClassHint(WindowPtr pWin, char **res_name, char **res_class)
             len_class = (len_name >= prop->size) ? 0 : (strlen(((char *) prop->data) + 1 + len_name));
             if (len_class > prop->size - 1 - len_name) len_class = prop->size - 1 - len_name;
 
-            (*res_class) = malloc(len_class + 1);
+            (*res_class) = calloc(1, len_class + 1);
 
             if (!*res_class) {
                 ErrorF("winMultiWindowGetClassHint - *res_class was NULL\n");
@@ -146,7 +146,7 @@ winMultiWindowGetWindowRole(WindowPtr pWin, char **res_role)
             && prop->type == XA_STRING && prop->format == 8 && prop->data) {
             len_role = prop->size;
 
-            (*res_role) = malloc(len_role + 1);
+            (*res_role) = calloc(1, len_role + 1);
 
             if (!*res_role) {
                 ErrorF("winMultiWindowGetWindowRole - *res_role was NULL\n");
@@ -235,7 +235,7 @@ winMultiWindowGetWMName(WindowPtr pWin, char **wmName)
             && prop->type == XA_STRING && prop->data) {
             len_name = prop->size;
 
-            (*wmName) = malloc(len_name + 1);
+            (*wmName) = calloc(1, len_name + 1);
 
             if (!*wmName) {
                 ErrorF("winMultiWindowGetWMName - *wmName was NULL\n");
diff --git a/hw/xwin/winmultiwindowicons.c b/hw/xwin/winmultiwindowicons.c
index e5b09e48d..834a6fea9 100644
--- a/hw/xwin/winmultiwindowicons.c
+++ b/hw/xwin/winmultiwindowicons.c
@@ -513,9 +513,9 @@ winXIconToHICON(xcb_connection_t *conn, xcb_window_t id, int iconSize)
                     /* Mask is 1-bit deep */
                     maskStride = ((iconSize * 1 + 15) & (~15)) / 8;
 
-                    image = malloc(stride * iconSize);
-                    imageMask = malloc(stride * iconSize);
-                    mask = malloc(maskStride * iconSize);
+                    image = calloc(stride, iconSize);
+                    imageMask = calloc(stride, iconSize);
+                    mask = calloc(maskStride, iconSize);
 
                     /* Default to a completely black mask */
                     memset(imageMask, 0, stride * iconSize);
diff --git a/hw/xwin/winmultiwindowwindow.c b/hw/xwin/winmultiwindowwindow.c
index 7c7a5d2d6..e50a93a9b 100644
--- a/hw/xwin/winmultiwindowwindow.c
+++ b/hw/xwin/winmultiwindowwindow.c
@@ -872,13 +872,12 @@ winAdjustXWindow(WindowPtr pWin, HWND hwnd)
 static HBITMAP winCreateDIB(ScreenPtr pScreen, int width, int height, int bpp, void **ppvBits, BITMAPINFOHEADER **ppbmih)
 {
     winScreenPriv(pScreen);
-    BITMAPV4HEADER *pbmih = NULL;
     HBITMAP hBitmap = NULL;
 
     /* Allocate bitmap info header */
-    pbmih = malloc(sizeof(BITMAPV4HEADER) + 256 * sizeof(RGBQUAD));
+    BITMAPV4HEADER *pbmih = calloc(1, sizeof(BITMAPV4HEADER) + 256 * sizeof(RGBQUAD));
     if (pbmih == NULL) {
-        ErrorF("winCreateDIB: malloc() failed\n");
+        ErrorF("winCreateDIB: calloc() failed\n");
         return NULL;
     }
     memset(pbmih, 0, sizeof(BITMAPV4HEADER) + 256 * sizeof(RGBQUAD));
diff --git a/hw/xwin/winmultiwindowwm.c b/hw/xwin/winmultiwindowwm.c
index 2d5ebc2f5..ca0cbddf2 100644
--- a/hw/xwin/winmultiwindowwm.c
+++ b/hw/xwin/winmultiwindowwm.c
@@ -458,7 +458,7 @@ GetWindowName(WMInfoPtr pWMInfo, xcb_window_t iWin, char **ppWindowName)
                 (strstr(pszWindowName, pszClientHostname) == 0)) {
                 /* ... add '@<clientmachine>' to end of window name */
                 *ppWindowName =
-                    malloc(strlen(pszWindowName) +
+                    calloc(1, strlen(pszWindowName) +
                            strlen(pszClientMachine) + 2);
                 strcpy(*ppWindowName, pszWindowName);
                 strcat(*ppWindowName, "@");
@@ -634,8 +634,7 @@ UpdateName(WMInfoPtr pWMInfo, xcb_window_t iWindow)
             /* Convert from UTF-8 to wide char */
             int iLen =
                 MultiByteToWideChar(CP_UTF8, 0, pszWindowName, -1, NULL, 0);
-            wchar_t *pwszWideWindowName =
-                malloc(sizeof(wchar_t)*(iLen + 1));
+            wchar_t *pwszWideWindowName = calloc(iLen + 1, sizeof(wchar_t));
             MultiByteToWideChar(CP_UTF8, 0, pszWindowName, -1,
                                 pwszWideWindowName, iLen);
 
@@ -1401,7 +1400,7 @@ winInitWM(void **ppWMInfo,
 
     /* Bail if the input parameters are bad */
     if (pArg == NULL || pWMInfo == NULL || pXMsgArg == NULL) {
-        ErrorF("winInitWM - malloc failed.\n");
+        ErrorF("winInitWM - calloc failed.\n");
         free(pArg);
         free(pWMInfo);
         free(pXMsgArg);
@@ -1629,13 +1628,12 @@ winInitMultiWindowWM(WMInfoPtr pWMInfo, WMProcArgPtr pProcArg)
 void
 winSendMessageToWM(void *pWMInfo, winWMMessagePtr pMsg)
 {
-    WMMsgNodePtr pNode;
 
 #if ENABLE_DEBUG
     ErrorF("winSendMessageToWM %s\n", MessageName(pMsg));
 #endif
 
-    pNode = malloc(sizeof(WMMsgNodeRec));
+    WMMsgNodePtr pNode = calloc(1, sizeof(WMMsgNodeRec));
     if (pNode != NULL) {
         memcpy(&pNode->msg, pMsg, sizeof(winWMMessageRec));
         PushMessage(&((WMInfoPtr) pWMInfo)->wmMsgQueue, pNode);
diff --git a/hw/xwin/winprefs.c b/hw/xwin/winprefs.c
index 8cf45fd51..75ecab9dc 100644
--- a/hw/xwin/winprefs.c
+++ b/hw/xwin/winprefs.c
@@ -541,7 +541,7 @@ LoadImageComma(char *fname, char *iconDirectory, int sx, int sy, int flags)
                           MAKEINTRESOURCE(i), IMAGE_ICON, sx, sy, flags);
     }
     else {
-        char *file = malloc(PATH_MAX + NAME_MAX + 2);
+        char *file = calloc(1, PATH_MAX + NAME_MAX + 2);
 #ifdef  __CYGWIN__
         Bool convert = FALSE;
 #endif
@@ -752,7 +752,7 @@ LoadPreferences(void)
     /* Setup a DISPLAY environment variable, need to allocate on heap */
     /* because putenv doesn't copy the argument... */
     winGetDisplayName(szDisplay, 0);
-    szEnvDisplay = (char *) (malloc(strlen(szDisplay) + strlen("DISPLAY=") + 1));
+    szEnvDisplay = calloc(1, strlen(szDisplay) + strlen("DISPLAY=") + 1);
     if (szEnvDisplay) {
         snprintf(szEnvDisplay, 512, "DISPLAY=%s", szDisplay);
         putenv(szEnvDisplay);
diff --git a/hw/xwin/winprefslex.l b/hw/xwin/winprefslex.l
index 9e6f0d6d4..035204f29 100644
--- a/hw/xwin/winprefslex.l
+++ b/hw/xwin/winprefslex.l
@@ -42,8 +42,7 @@ extern void ErrorF (const char* /*f*/, ...);
 /* Copy the parsed string, must be free()d in yacc parser */
 static char *makestr(char *str)
 {
-  char *ptr;
-  ptr = malloc(strlen(str)+1);
+  char *ptr = calloc(1, strlen(str)+1);
   if (!ptr)
     {
       ErrorF ("winMultiWindowLex:makestr() out of memory\n");
diff --git a/hw/xwin/winprefsyacc.y b/hw/xwin/winprefsyacc.y
index 9bb28ae92..4f2391149 100644
--- a/hw/xwin/winprefsyacc.y
+++ b/hw/xwin/winprefsyacc.y
@@ -310,7 +310,7 @@ static void
 AddMenuLine (const char *text, MENUCOMMANDTYPE cmd, const char *param)
 {
   if (menu.menuItem==NULL)
-    menu.menuItem = malloc(sizeof(MENUITEM));
+    menu.menuItem = calloc(1, sizeof(MENUITEM));
   else
     menu.menuItem = realloc(menu.menuItem, sizeof(MENUITEM)*(menu.menuItems+1));
 
@@ -339,7 +339,7 @@ CloseMenu (void)
   if (pref.menuItems)
     pref.menu = realloc (pref.menu, (pref.menuItems+1)*sizeof(MENUPARSED));
   else
-    pref.menu = malloc (sizeof(MENUPARSED));
+    pref.menu = calloc(1, sizeof(MENUPARSED));
   
   memcpy (pref.menu+pref.menuItems, &menu, sizeof(MENUPARSED));
   pref.menuItems++;
@@ -362,7 +362,7 @@ static void
 AddIconLine (char *matchstr, char *iconfile)
 {
   if (pref.icon==NULL)
-    pref.icon = malloc(sizeof(ICONITEM));
+    pref.icon = calloc(1, sizeof(ICONITEM));
   else
     pref.icon = realloc(pref.icon, sizeof(ICONITEM)*(pref.iconItems+1));
 
@@ -397,7 +397,7 @@ static void
 AddStyleLine (char *matchstr, unsigned long style)
 {
   if (pref.style==NULL)
-    pref.style = malloc(sizeof(STYLEITEM));
+    pref.style = calloc(1, sizeof(STYLEITEM));
   else
     pref.style = realloc(pref.style, sizeof(STYLEITEM)*(pref.styleItems+1));
 
@@ -429,7 +429,7 @@ static void
 AddSysMenuLine (char *matchstr, char *menuname, int pos)
 {
   if (pref.sysMenu==NULL)
-    pref.sysMenu = malloc(sizeof(SYSMENUITEM));
+    pref.sysMenu = calloc(1, sizeof(SYSMENUITEM));
   else
     pref.sysMenu = realloc(pref.sysMenu, sizeof(SYSMENUITEM)*(pref.sysMenuItems+1));
 
diff --git a/hw/xwin/winprocarg.c b/hw/xwin/winprocarg.c
index d87c40936..56280c232 100644
--- a/hw/xwin/winprocarg.c
+++ b/hw/xwin/winprocarg.c
@@ -1123,7 +1123,7 @@ winLogCommandLine(int argc, char *argv[])
         }
 
     /* Allocate memory for concatenated command line */
-    g_pszCommandLine = malloc(iSize + 1);
+    g_pszCommandLine = calloc(1, iSize + 1);
     if (!g_pszCommandLine)
         FatalError("winLogCommandLine - Could not allocate memory for "
                    "command line string.  Exiting.\n");
diff --git a/hw/xwin/winrandr.c b/hw/xwin/winrandr.c
index 0ea235136..262da9fce 100644
--- a/hw/xwin/winrandr.c
+++ b/hw/xwin/winrandr.c
@@ -266,14 +266,14 @@ winRandRInit(ScreenPtr pScreen)
         output->crtc = crtc;
 
         /* Set crtc outputs (should use RRCrtcNotify?) */
-        crtc->outputs = malloc(sizeof(RROutputPtr));
+        crtc->outputs = calloc(1, sizeof(RROutputPtr));
         crtc->outputs[0] = output;
         crtc->numOutputs = 1;
 
         pRRScrPriv->primaryOutput = output;
 
         /* Ensure we have space for exactly one mode */
-        output->modes = malloc(sizeof(RRModePtr));
+        output->modes = calloc(1, sizeof(RRModePtr));
         output->modes[0] = NULL;
 
         /* Set mode to current display size */
diff --git a/hw/xwin/winshadgdi.c b/hw/xwin/winshadgdi.c
index 970ce9550..cf8391413 100644
--- a/hw/xwin/winshadgdi.c
+++ b/hw/xwin/winshadgdi.c
@@ -151,7 +151,6 @@ static
 winQueryRGBBitsAndMasks(ScreenPtr pScreen)
 {
     winScreenPriv(pScreen);
-    BITMAPINFOHEADER *pbmih = NULL;
     Bool fReturn = TRUE;
     LPDWORD pdw = NULL;
     DWORD dwRedBits, dwGreenBits, dwBlueBits;
@@ -187,9 +186,9 @@ winQueryRGBBitsAndMasks(ScreenPtr pScreen)
     }
 
     /* Allocate a bitmap header and color table */
-    pbmih = malloc(sizeof(BITMAPINFOHEADER) + 256 * sizeof(RGBQUAD));
+    BITMAPINFOHEADER *pbmih = calloc(1, sizeof(BITMAPINFOHEADER) + 256 * sizeof(RGBQUAD));
     if (pbmih == NULL) {
-        ErrorF("winQueryRGBBitsAndMasks - malloc failed\n");
+        ErrorF("winQueryRGBBitsAndMasks - calloc failed\n");
         return FALSE;
     }
 
@@ -541,9 +540,9 @@ winInitScreenShadowGDI(ScreenPtr pScreen)
     pScreenPriv->hdcShadow = CreateCompatibleDC(pScreenPriv->hdcScreen);
 
     /* Allocate bitmap info header */
-    pScreenPriv->pbmih = malloc(sizeof(BITMAPINFOHEADER) + 256 * sizeof(RGBQUAD));
+    pScreenPriv->pbmih = calloc(1, sizeof(BITMAPINFOHEADER) + 256 * sizeof(RGBQUAD));
     if (pScreenPriv->pbmih == NULL) {
-        ErrorF("winInitScreenShadowGDI - malloc () failed\n");
+        ErrorF("winInitScreenShadowGDI - calloc () failed\n");
         return FALSE;
     }