dsimms@7032: /*
dsimms@7032:  * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
dsimms@7032:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
dsimms@7032:  *
dsimms@7032:  * This code is free software; you can redistribute it and/or modify it
dsimms@7032:  * under the terms of the GNU General Public License version 2 only, as
dsimms@7032:  * published by the Free Software Foundation.
dsimms@7032:  *
dsimms@7032:  * This code is distributed in the hope that it will be useful, but WITHOUT
dsimms@7032:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
dsimms@7032:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
dsimms@7032:  * version 2 for more details (a copy is included in the LICENSE file that
dsimms@7032:  * accompanied this code).
dsimms@7032:  *
dsimms@7032:  * You should have received a copy of the GNU General Public License version
dsimms@7032:  * 2 along with this work; if not, write to the Free Software Foundation,
dsimms@7032:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
dsimms@7032:  *
dsimms@7032:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
dsimms@7032:  * or visit www.oracle.com if you need additional information or have any
dsimms@7032:  * questions.
dsimms@7032:  *
dsimms@7032:  */
dsimms@7032: #include "precompiled.hpp"
dsimms@7032: #include "memory/allocation.hpp"
dsimms@7032: #include "memory/allocation.inline.hpp"
dsimms@7032: #include "memory/guardedMemory.hpp"
dsimms@7032: #include "runtime/os.hpp"
dsimms@7032: 
dsimms@7032: void* GuardedMemory::wrap_copy(const void* ptr, const size_t len, const void* tag) {
dsimms@7032:   size_t total_sz = GuardedMemory::get_total_size(len);
dsimms@7032:   void* outerp = os::malloc(total_sz, mtInternal);
dsimms@7032:   if (outerp != NULL) {
dsimms@7032:     GuardedMemory guarded(outerp, len, tag);
dsimms@7032:     void* innerp = guarded.get_user_ptr();
dsimms@7032:     memcpy(innerp, ptr, len);
dsimms@7032:     return innerp;
dsimms@7032:   }
dsimms@7032:   return NULL; // OOM
dsimms@7032: }
dsimms@7032: 
dsimms@7032: bool GuardedMemory::free_copy(void* p) {
dsimms@7032:   if (p == NULL) {
dsimms@7032:     return true;
dsimms@7032:   }
dsimms@7032:   GuardedMemory guarded((u_char*)p);
dsimms@7032:   bool verify_ok = guarded.verify_guards();
dsimms@7032: 
dsimms@7032:   /* always attempt to free, pass problem on to any nested memchecker */
dsimms@7032:   os::free(guarded.release_for_freeing());
dsimms@7032: 
dsimms@7032:   return verify_ok;
dsimms@7032: }
dsimms@7032: 
dsimms@7032: void GuardedMemory::print_on(outputStream* st) const {
dsimms@7032:   if (_base_addr == NULL) {
dsimms@7032:     st->print_cr("GuardedMemory(" PTR_FORMAT ") not associated to any memory", p2i(this));
dsimms@7032:     return;
dsimms@7032:   }
dsimms@7032:   st->print_cr("GuardedMemory(" PTR_FORMAT ") base_addr=" PTR_FORMAT
dsimms@7032:       " tag=" PTR_FORMAT " user_size=" SIZE_FORMAT " user_data=" PTR_FORMAT,
dsimms@7032:       p2i(this), p2i(_base_addr), p2i(get_tag()), get_user_size(), p2i(get_user_ptr()));
dsimms@7032: 
dsimms@7032:   Guard* guard = get_head_guard();
dsimms@7032:   st->print_cr("  Header guard @" PTR_FORMAT " is %s", p2i(guard), (guard->verify() ? "OK" : "BROKEN"));
dsimms@7032:   guard = get_tail_guard();
dsimms@7032:   st->print_cr("  Trailer guard @" PTR_FORMAT " is %s", p2i(guard), (guard->verify() ? "OK" : "BROKEN"));
dsimms@7032: 
dsimms@7032:   u_char udata = *get_user_ptr();
dsimms@7032:   switch (udata) {
dsimms@7032:   case uninitBlockPad:
dsimms@7032:     st->print_cr("  User data appears unused");
dsimms@7032:     break;
dsimms@7032:   case freeBlockPad:
dsimms@7032:     st->print_cr("  User data appears to have been freed");
dsimms@7032:     break;
dsimms@7032:   default:
dsimms@7032:     st->print_cr("  User data appears to be in use");
dsimms@7032:     break;
dsimms@7032:   }
dsimms@7032: }
dsimms@7032: 
dsimms@7032: // test code...
dsimms@7032: 
dsimms@7032: #ifndef PRODUCT
dsimms@7032: 
dsimms@7032: static void guarded_memory_test_check(void* p, size_t sz, void* tag) {
dsimms@7032:   assert(p != NULL, "NULL pointer given to check");
dsimms@7032:   u_char* c = (u_char*) p;
dsimms@7032:   GuardedMemory guarded(c);
dsimms@7032:   assert(guarded.get_tag() == tag, "Tag is not the same as supplied");
dsimms@7032:   assert(guarded.get_user_ptr() == c, "User pointer is not the same as supplied");
dsimms@7032:   assert(guarded.get_user_size() == sz, "User size is not the same as supplied");
dsimms@7032:   assert(guarded.verify_guards(), "Guard broken");
dsimms@7032: }
dsimms@7032: 
dsimms@7032: void GuardedMemory::test_guarded_memory() {
dsimms@7032:   // Test the basic characteristics...
dsimms@7032:   size_t total_sz = GuardedMemory::get_total_size(1);
dsimms@7032:   assert(total_sz > 1 && total_sz >= (sizeof(GuardHeader) + 1 + sizeof(Guard)), "Unexpected size");
dsimms@7032:   u_char* basep = (u_char*) os::malloc(total_sz, mtInternal);
dsimms@7032: 
dsimms@7032:   GuardedMemory guarded(basep, 1, (void*)0xf000f000);
dsimms@7032: 
dsimms@7032:   assert(*basep == badResourceValue, "Expected guard in the form of badResourceValue");
dsimms@7032:   u_char* userp = guarded.get_user_ptr();
dsimms@7032:   assert(*userp == uninitBlockPad, "Expected uninitialized data in the form of uninitBlockPad");
dsimms@7032:   guarded_memory_test_check(userp, 1, (void*)0xf000f000);
dsimms@7032: 
dsimms@7032:   void* freep = guarded.release_for_freeing();
dsimms@7032:   assert((u_char*)freep == basep, "Expected the same pointer guard was ");
dsimms@7032:   assert(*userp == freeBlockPad, "Expected user data to be free block padded");
dsimms@7032:   assert(!guarded.verify_guards(), "Expected failed");
dsimms@7032:   os::free(freep);
dsimms@7032: 
dsimms@7032:   // Test a number of odd sizes...
dsimms@7032:   size_t sz = 0;
dsimms@7032:   do {
dsimms@7032:     void* p = os::malloc(GuardedMemory::get_total_size(sz), mtInternal);
dsimms@7032:     void* up = guarded.wrap_with_guards(p, sz, (void*)1);
dsimms@7032:     memset(up, 0, sz);
dsimms@7032:     guarded_memory_test_check(up, sz, (void*)1);
dsimms@7032:     os::free(guarded.release_for_freeing());
dsimms@7032:     sz = (sz << 4) + 1;
dsimms@7032:   } while (sz < (256 * 1024));
dsimms@7032: 
dsimms@7032:   // Test buffer overrun into head...
dsimms@7032:   basep = (u_char*) os::malloc(GuardedMemory::get_total_size(1), mtInternal);
dsimms@7032:   guarded.wrap_with_guards(basep, 1);
dsimms@7032:   *basep = 0;
dsimms@7032:   assert(!guarded.verify_guards(), "Expected failure");
dsimms@7032:   os::free(basep);
dsimms@7032: 
dsimms@7032:   // Test buffer overrun into tail with a number of odd sizes...
dsimms@7032:   sz = 1;
dsimms@7032:   do {
dsimms@7032:     void* p = os::malloc(GuardedMemory::get_total_size(sz), mtInternal);
dsimms@7032:     void* up = guarded.wrap_with_guards(p, sz, (void*)1);
dsimms@7032:     memset(up, 0, sz + 1); // Buffer-overwrite (within guard)
dsimms@7032:     assert(!guarded.verify_guards(), "Guard was not broken as expected");
dsimms@7032:     os::free(guarded.release_for_freeing());
dsimms@7032:     sz = (sz << 4) + 1;
dsimms@7032:   } while (sz < (256 * 1024));
dsimms@7032: 
dsimms@7032:   // Test wrap_copy/wrap_free...
dsimms@7032:   assert(GuardedMemory::free_copy(NULL), "Expected free NULL to be OK");
dsimms@7032: 
dsimms@7032:   const char* str = "Check my bounds out";
dsimms@7032:   size_t str_sz = strlen(str) + 1;
dsimms@7032:   char* str_copy = (char*) GuardedMemory::wrap_copy(str, str_sz);
dsimms@7032:   guarded_memory_test_check(str_copy, str_sz, NULL);
dsimms@7032:   assert(strcmp(str, str_copy) == 0, "Not identical copy");
dsimms@7032:   assert(GuardedMemory::free_copy(str_copy), "Free copy failed to verify");
dsimms@7032: 
dsimms@7032:   void* no_data = NULL;
dsimms@7032:   void* no_data_copy = GuardedMemory::wrap_copy(no_data, 0);
dsimms@7032:   assert(GuardedMemory::free_copy(no_data_copy), "Expected valid guards even for no data copy");
dsimms@7032: }
dsimms@7032: 
dsimms@7032: #endif // !PRODUCT
dsimms@7032: