--- a/hotspot/src/share/vm/runtime/arguments.cpp	Tue Oct 15 11:18:42 2013 +0200
+++ b/hotspot/src/share/vm/runtime/arguments.cpp	Tue Oct 15 04:29:21 2013 -0700
@@ -2694,8 +2694,9 @@
       FLAG_SET_CMDLINE(uintx, MaxHeapSize, (uintx)long_max_heap_size);
     // Xmaxf
     } else if (match_option(option, "-Xmaxf", &tail)) {
-      int maxf = (int)(atof(tail) * 100);
-      if (maxf < 0 || maxf > 100) {
+      char* err;
+      int maxf = (int)(strtod(tail, &err) * 100);
+      if (*err != '\0' || maxf < 0 || maxf > 100) {
         jio_fprintf(defaultStream::error_stream(),
                     "Bad max heap free percentage size: %s\n",
                     option->optionString);
@@ -2705,8 +2706,9 @@
       }
     // Xminf
     } else if (match_option(option, "-Xminf", &tail)) {
-      int minf = (int)(atof(tail) * 100);
-      if (minf < 0 || minf > 100) {
+      char* err;
+      int minf = (int)(strtod(tail, &err) * 100);
+      if (*err != '\0' || minf < 0 || minf > 100) {
         jio_fprintf(defaultStream::error_stream(),
                     "Bad min heap free percentage size: %s\n",
                     option->optionString);

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/gc/arguments/TestHeapFreeRatio.java	Tue Oct 15 04:29:21 2013 -0700
@@ -0,0 +1,105 @@
+/*
+ * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test TestHeapFreeRatio
+ * @key gc
+ * @bug 8025661
+ * @summary Test parsing of -Xminf and -Xmaxf
+ * @library /testlibrary
+ * @run main/othervm TestHeapFreeRatio
+ */
+
+import com.oracle.java.testlibrary.*;
+
+public class TestHeapFreeRatio {
+
+  enum Validation {
+    VALID,
+    MIN_INVALID,
+    MAX_INVALID,
+    COMBINATION_INVALID
+  }
+
+  private static void testMinMaxFreeRatio(String min, String max, Validation type) throws Exception {
+    ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
+        "-Xminf" + min,
+        "-Xmaxf" + max,
+        "-version");
+    OutputAnalyzer output = new OutputAnalyzer(pb.start());
+
+    switch (type) {
+    case VALID:
+      output.shouldNotContain("Error");
+      output.shouldHaveExitValue(0);
+      break;
+    case MIN_INVALID:
+      output.shouldContain("Bad min heap free percentage size: -Xminf" + min);
+      output.shouldContain("Error");
+      output.shouldHaveExitValue(1);
+      break;
+    case MAX_INVALID:
+      output.shouldContain("Bad max heap free percentage size: -Xmaxf" + max);
+      output.shouldContain("Error");
+      output.shouldHaveExitValue(1);
+      break;
+    case COMBINATION_INVALID:
+      output.shouldContain("must be less than or equal to MaxHeapFreeRatio");
+      output.shouldContain("Error");
+      output.shouldHaveExitValue(1);
+      break;
+    default:
+      throw new IllegalStateException("Must specify expected validation type");
+    }
+
+    System.out.println(output.getOutput());
+  }
+
+  public static void main(String args[]) throws Exception {
+    testMinMaxFreeRatio( "0.1", "0.5", Validation.VALID);
+    testMinMaxFreeRatio(  ".1",  ".5", Validation.VALID);
+    testMinMaxFreeRatio( "0.5", "0.5", Validation.VALID);
+
+    testMinMaxFreeRatio("-0.1", "0.5", Validation.MIN_INVALID);
+    testMinMaxFreeRatio( "1.1", "0.5", Validation.MIN_INVALID);
+    testMinMaxFreeRatio("=0.1", "0.5", Validation.MIN_INVALID);
+    testMinMaxFreeRatio("0.1f", "0.5", Validation.MIN_INVALID);
+    testMinMaxFreeRatio(
+                     "INVALID", "0.5", Validation.MIN_INVALID);
+    testMinMaxFreeRatio(
+                  "2147483647", "0.5", Validation.MIN_INVALID);
+
+    testMinMaxFreeRatio( "0.1", "-0.5", Validation.MAX_INVALID);
+    testMinMaxFreeRatio( "0.1",  "1.5", Validation.MAX_INVALID);
+    testMinMaxFreeRatio( "0.1", "0.5f", Validation.MAX_INVALID);
+    testMinMaxFreeRatio( "0.1", "=0.5", Validation.MAX_INVALID);
+    testMinMaxFreeRatio(
+                     "0.1",  "INVALID", Validation.MAX_INVALID);
+    testMinMaxFreeRatio(
+                   "0.1", "2147483647", Validation.MAX_INVALID);
+
+    testMinMaxFreeRatio( "0.5",  "0.1", Validation.COMBINATION_INVALID);
+    testMinMaxFreeRatio(  ".5",  ".10", Validation.COMBINATION_INVALID);
+    testMinMaxFreeRatio("0.12","0.100", Validation.COMBINATION_INVALID);
+  }
+}