Correctly free config file names

We call xf86penConfigDirFiles twice, so we overwrite the configDirPath
variable, losing the pointer. If we move the pointer management to the
upper layer (the function callers), they will be able to call these
functions as many times as they want, but they'll have to free those
returned values.

v2: don't leak inside XWin

4,097 bytes in 1 blocks are definitely lost in loss record 625 of 632
   at 0x4C2779D: malloc (in vgpreload_memcheck-amd64-linux.so)
   by 0x4D7899: DoSubstitution (scan.c:615)
   by 0x4D87B0: OpenConfigDir (scan.c:845)
   by 0x4D8A2D: xf86openConfigDirFiles (scan.c:955)
   by 0x49031F: xf86HandleConfigFile (xf86Config.c:2327)
   by 0x49A9BF: InitOutput (xf86Init.c:365)
   by 0x425A7A: main (main.c:204)

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Dan Nicholson <dbn.lists@gmail.com>

hw/xfree86/common/xf86Config.c

@@ -2300,7 +2300,7 @@ checkInput(serverLayoutPtr layout, Bool implicit_layout) {
 ConfigStatus
 xf86HandleConfigFile(Bool autoconfig)
 {
-    const char *filename, *dirname, *sysdirname;
+    char *filename, *dirname, *sysdirname;
     const char *filesearch, *dirsearch;
     MessageType filefrom = X_DEFAULT;
     MessageType dirfrom = X_DEFAULT;
@@ -2352,6 +2352,10 @@ xf86HandleConfigFile(Bool autoconfig)
 	    return CONFIG_NOFILE;
     }
 
+    free(filename);
+    free(dirname);
+    free(sysdirname);
+
     if ((xf86configptr = xf86readConfigFile ()) == NULL) {
 	xf86Msg(X_ERROR, "Problem parsing the config file\n");
 	return CONFIG_PARSE_ERROR;

hw/xfree86/parser/scan.c

@@ -101,8 +101,6 @@ static int builtinIndex = 0;
 static int configPos = 0;		/* current readers position */
 static int configLineNo = 0;	/* linenumber */
 static char *configBuf, *configRBuf;	/* buffer for lines */
-static char *configPath;		/* path to config file */
-static char *configDirPath;		/* path to config dir */
 static char *configSection = NULL;	/* name of current section being parsed */
 static int numFiles = 0;		/* number of config files */
 static int curFileIndex = 0;		/* index of current config file */
@@ -894,7 +892,8 @@ xf86initConfigFiles(void)
  * of the located files.
  *
  * The return value is a pointer to the actual name of the file that was
- * opened.  When no file is found, the return value is NULL.
+ * opened.  When no file is found, the return value is NULL. The caller should
+ * free() the returned value.
  *
  * The escape sequences allowed in the search path are defined above.
  *
@@ -916,7 +915,7 @@ xf86initConfigFiles(void)
 							"%P/lib/X11/%X"
 #endif
 
-const char *
+char *
 xf86openConfigFile(const char *path, const char *cmdline, const char *projroot)
 {
 	if (!path || !path[0])
@@ -925,8 +924,7 @@ xf86openConfigFile(const char *path, const char *cmdline, const char *projroot)
 		projroot = PROJECTROOT;
 
 	/* Search for a config file */
-	configPath = OpenConfigFile(path, cmdline, projroot, XCONFIGFILE);
+	return OpenConfigFile(path, cmdline, projroot, XCONFIGFILE);
-	return configPath;
 }
 
 /*
@@ -939,12 +937,13 @@ xf86openConfigFile(const char *path, const char *cmdline, const char *projroot)
  * fails if it is not found.
  *
  * The return value is a pointer to the actual name of the direcoty that was
- * opened.  When no directory is found, the return value is NULL.
+ * opened.  When no directory is found, the return value is NULL. The caller
+ * should free() the returned value.
  *
  * The escape sequences allowed in the search path are defined above.
  *
  */
-const char *
+char *
 xf86openConfigDirFiles(const char *path, const char *cmdline,
 		       const char *projroot)
 {
@@ -954,8 +953,7 @@ xf86openConfigDirFiles(const char *path, const char *cmdline,
 		projroot = PROJECTROOT;
 
 	/* Search for the multiconf directory */
-	configDirPath = OpenConfigDir(path, cmdline, projroot, XCONFIGDIR);
+	return OpenConfigDir(path, cmdline, projroot, XCONFIGDIR);
-	return configDirPath;
 }
 
 void
@@ -963,10 +961,6 @@ xf86closeConfigFile (void)
 {
 	int i;
 
-	free (configPath);
-	configPath = NULL;
-	free (configDirPath);
-	configDirPath = NULL;
 	free (configRBuf);
 	configRBuf = NULL;
 	free (configBuf);

hw/xfree86/parser/xf86Parser.h

@@ -487,10 +487,10 @@ xf86ConfigSymTabRec, *xf86ConfigSymTabPtr;
  * prototypes for public functions
  */
 extern void xf86initConfigFiles(void);
-extern const char *xf86openConfigFile(const char *path, const char *cmdline,
+extern char *xf86openConfigFile(const char *path, const char *cmdline,
-				      const char *projroot);
+				const char *projroot);
-extern const char *xf86openConfigDirFiles(const char *path, const char *cmdline,
+extern char *xf86openConfigDirFiles(const char *path, const char *cmdline,
-					  const char *projroot);
+				    const char *projroot);
 extern void xf86setBuiltinConfig(const char *config[]);
 extern XF86ConfigPtr xf86readConfigFile(void);
 extern void xf86closeConfigFile(void);

hw/xwin/winconfig.c

@@ -117,7 +117,7 @@ Bool
 winReadConfigfile ()
 {
   Bool		retval = TRUE;
-  const char	*filename, *dirname;
+  char		*filename, *dirname;
   MessageType	filefrom = X_DEFAULT;
   MessageType	dirfrom = X_DEFAULT;
   char		*xf86ConfigFile = NULL;
@@ -169,6 +169,8 @@ winReadConfigfile ()
     {
       return FALSE;
     }
+  free(filename);
+  free(dirname);
   if ((g_xf86configptr = xf86readConfigFile ()) == NULL)
     {
       winMsg (X_ERROR, "Problem parsing the config file\n");