1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/memory/guardedMemory.cpp Thu Aug 14 15:16:07 2014 +0200
1.3 @@ -0,0 +1,161 @@
1.4 +/*
1.5 + * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +#include "precompiled.hpp"
1.28 +#include "memory/allocation.hpp"
1.29 +#include "memory/allocation.inline.hpp"
1.30 +#include "memory/guardedMemory.hpp"
1.31 +#include "runtime/os.hpp"
1.32 +
1.33 +void* GuardedMemory::wrap_copy(const void* ptr, const size_t len, const void* tag) {
1.34 + size_t total_sz = GuardedMemory::get_total_size(len);
1.35 + void* outerp = os::malloc(total_sz, mtInternal);
1.36 + if (outerp != NULL) {
1.37 + GuardedMemory guarded(outerp, len, tag);
1.38 + void* innerp = guarded.get_user_ptr();
1.39 + memcpy(innerp, ptr, len);
1.40 + return innerp;
1.41 + }
1.42 + return NULL; // OOM
1.43 +}
1.44 +
1.45 +bool GuardedMemory::free_copy(void* p) {
1.46 + if (p == NULL) {
1.47 + return true;
1.48 + }
1.49 + GuardedMemory guarded((u_char*)p);
1.50 + bool verify_ok = guarded.verify_guards();
1.51 +
1.52 + /* always attempt to free, pass problem on to any nested memchecker */
1.53 + os::free(guarded.release_for_freeing());
1.54 +
1.55 + return verify_ok;
1.56 +}
1.57 +
1.58 +void GuardedMemory::print_on(outputStream* st) const {
1.59 + if (_base_addr == NULL) {
1.60 + st->print_cr("GuardedMemory(" PTR_FORMAT ") not associated to any memory", p2i(this));
1.61 + return;
1.62 + }
1.63 + st->print_cr("GuardedMemory(" PTR_FORMAT ") base_addr=" PTR_FORMAT
1.64 + " tag=" PTR_FORMAT " user_size=" SIZE_FORMAT " user_data=" PTR_FORMAT,
1.65 + p2i(this), p2i(_base_addr), p2i(get_tag()), get_user_size(), p2i(get_user_ptr()));
1.66 +
1.67 + Guard* guard = get_head_guard();
1.68 + st->print_cr(" Header guard @" PTR_FORMAT " is %s", p2i(guard), (guard->verify() ? "OK" : "BROKEN"));
1.69 + guard = get_tail_guard();
1.70 + st->print_cr(" Trailer guard @" PTR_FORMAT " is %s", p2i(guard), (guard->verify() ? "OK" : "BROKEN"));
1.71 +
1.72 + u_char udata = *get_user_ptr();
1.73 + switch (udata) {
1.74 + case uninitBlockPad:
1.75 + st->print_cr(" User data appears unused");
1.76 + break;
1.77 + case freeBlockPad:
1.78 + st->print_cr(" User data appears to have been freed");
1.79 + break;
1.80 + default:
1.81 + st->print_cr(" User data appears to be in use");
1.82 + break;
1.83 + }
1.84 +}
1.85 +
1.86 +// test code...
1.87 +
1.88 +#ifndef PRODUCT
1.89 +
1.90 +static void guarded_memory_test_check(void* p, size_t sz, void* tag) {
1.91 + assert(p != NULL, "NULL pointer given to check");
1.92 + u_char* c = (u_char*) p;
1.93 + GuardedMemory guarded(c);
1.94 + assert(guarded.get_tag() == tag, "Tag is not the same as supplied");
1.95 + assert(guarded.get_user_ptr() == c, "User pointer is not the same as supplied");
1.96 + assert(guarded.get_user_size() == sz, "User size is not the same as supplied");
1.97 + assert(guarded.verify_guards(), "Guard broken");
1.98 +}
1.99 +
1.100 +void GuardedMemory::test_guarded_memory() {
1.101 + // Test the basic characteristics...
1.102 + size_t total_sz = GuardedMemory::get_total_size(1);
1.103 + assert(total_sz > 1 && total_sz >= (sizeof(GuardHeader) + 1 + sizeof(Guard)), "Unexpected size");
1.104 + u_char* basep = (u_char*) os::malloc(total_sz, mtInternal);
1.105 +
1.106 + GuardedMemory guarded(basep, 1, (void*)0xf000f000);
1.107 +
1.108 + assert(*basep == badResourceValue, "Expected guard in the form of badResourceValue");
1.109 + u_char* userp = guarded.get_user_ptr();
1.110 + assert(*userp == uninitBlockPad, "Expected uninitialized data in the form of uninitBlockPad");
1.111 + guarded_memory_test_check(userp, 1, (void*)0xf000f000);
1.112 +
1.113 + void* freep = guarded.release_for_freeing();
1.114 + assert((u_char*)freep == basep, "Expected the same pointer guard was ");
1.115 + assert(*userp == freeBlockPad, "Expected user data to be free block padded");
1.116 + assert(!guarded.verify_guards(), "Expected failed");
1.117 + os::free(freep);
1.118 +
1.119 + // Test a number of odd sizes...
1.120 + size_t sz = 0;
1.121 + do {
1.122 + void* p = os::malloc(GuardedMemory::get_total_size(sz), mtInternal);
1.123 + void* up = guarded.wrap_with_guards(p, sz, (void*)1);
1.124 + memset(up, 0, sz);
1.125 + guarded_memory_test_check(up, sz, (void*)1);
1.126 + os::free(guarded.release_for_freeing());
1.127 + sz = (sz << 4) + 1;
1.128 + } while (sz < (256 * 1024));
1.129 +
1.130 + // Test buffer overrun into head...
1.131 + basep = (u_char*) os::malloc(GuardedMemory::get_total_size(1), mtInternal);
1.132 + guarded.wrap_with_guards(basep, 1);
1.133 + *basep = 0;
1.134 + assert(!guarded.verify_guards(), "Expected failure");
1.135 + os::free(basep);
1.136 +
1.137 + // Test buffer overrun into tail with a number of odd sizes...
1.138 + sz = 1;
1.139 + do {
1.140 + void* p = os::malloc(GuardedMemory::get_total_size(sz), mtInternal);
1.141 + void* up = guarded.wrap_with_guards(p, sz, (void*)1);
1.142 + memset(up, 0, sz + 1); // Buffer-overwrite (within guard)
1.143 + assert(!guarded.verify_guards(), "Guard was not broken as expected");
1.144 + os::free(guarded.release_for_freeing());
1.145 + sz = (sz << 4) + 1;
1.146 + } while (sz < (256 * 1024));
1.147 +
1.148 + // Test wrap_copy/wrap_free...
1.149 + assert(GuardedMemory::free_copy(NULL), "Expected free NULL to be OK");
1.150 +
1.151 + const char* str = "Check my bounds out";
1.152 + size_t str_sz = strlen(str) + 1;
1.153 + char* str_copy = (char*) GuardedMemory::wrap_copy(str, str_sz);
1.154 + guarded_memory_test_check(str_copy, str_sz, NULL);
1.155 + assert(strcmp(str, str_copy) == 0, "Not identical copy");
1.156 + assert(GuardedMemory::free_copy(str_copy), "Free copy failed to verify");
1.157 +
1.158 + void* no_data = NULL;
1.159 + void* no_data_copy = GuardedMemory::wrap_copy(no_data, 0);
1.160 + assert(GuardedMemory::free_copy(no_data_copy), "Expected valid guards even for no data copy");
1.161 +}
1.162 +
1.163 +#endif // !PRODUCT
1.164 +
