1 /*

     2  * Copyright (c) 2014, 2016, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  *

    23  */

    24 #include "precompiled.hpp"

    25 #include "memory/allocation.hpp"

    26 #include "memory/allocation.inline.hpp"

    27 #include "memory/guardedMemory.hpp"

    28 #include "runtime/os.hpp"

    29 

    30 void* GuardedMemory::wrap_copy(const void* ptr, const size_t len, const void* tag) {

    31   size_t total_sz = GuardedMemory::get_total_size(len);

    32   void* outerp = os::malloc(total_sz, mtInternal);

    33   if (outerp != NULL) {

    34     GuardedMemory guarded(outerp, len, tag);

    35     void* innerp = guarded.get_user_ptr();

    36     memcpy(innerp, ptr, len);

    37     return innerp;

    38   }

    39   return NULL; // OOM

    40 }

    41 

    42 bool GuardedMemory::free_copy(void* p) {

    43   if (p == NULL) {

    44     return true;

    45   }

    46   GuardedMemory guarded((u_char*)p);

    47   bool verify_ok = guarded.verify_guards();

    48 

    49   /* always attempt to free, pass problem on to any nested memchecker */

    50   os::free(guarded.release_for_freeing());

    51 

    52   return verify_ok;

    53 }

    54 

    55 void GuardedMemory::print_on(outputStream* st) const {

    56   if (_base_addr == NULL) {

    57     st->print_cr("GuardedMemory(" PTR_FORMAT ") not associated to any memory", p2i(this));

    58     return;

    59   }

    60   st->print_cr("GuardedMemory(" PTR_FORMAT ") base_addr=" PTR_FORMAT

    61       " tag=" PTR_FORMAT " user_size=" SIZE_FORMAT " user_data=" PTR_FORMAT,

    62       p2i(this), p2i(_base_addr), p2i(get_tag()), get_user_size(), p2i(get_user_ptr()));

    63 

    64   Guard* guard = get_head_guard();

    65   st->print_cr("  Header guard @" PTR_FORMAT " is %s", p2i(guard), (guard->verify() ? "OK" : "BROKEN"));

    66   guard = get_tail_guard();

    67   st->print_cr("  Trailer guard @" PTR_FORMAT " is %s", p2i(guard), (guard->verify() ? "OK" : "BROKEN"));

    68 

    69   u_char udata = *get_user_ptr();

    70   switch (udata) {

    71   case uninitBlockPad:

    72     st->print_cr("  User data appears unused");

    73     break;

    74   case freeBlockPad:

    75     st->print_cr("  User data appears to have been freed");

    76     break;

    77   default:

    78     st->print_cr("  User data appears to be in use");

    79     break;

    80   }

    81 }