Wed, 03 Apr 2013 16:43:09 -0700
8006103: [parfait] Possible null pointer dereference at hotspot/src/os/linux/vm/os_linux.cpp; os_windows.cpp; os_solaris.cpp; os_bsd.cpp
Reviewed-by: zgu, iklam
zgu@3430 | 1 | /* |
mikael@4153 | 2 | * Copyright (c) 2011, 2012, Oracle and/or its affiliates. All rights reserved. |
zgu@3430 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
zgu@3430 | 4 | * |
zgu@3430 | 5 | * This code is free software; you can redistribute it and/or modify it |
zgu@3430 | 6 | * under the terms of the GNU General Public License version 2 only, as |
zgu@3430 | 7 | * published by the Free Software Foundation. |
zgu@3430 | 8 | * |
zgu@3430 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
zgu@3430 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
zgu@3430 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
zgu@3430 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
zgu@3430 | 13 | * accompanied this code). |
zgu@3430 | 14 | * |
zgu@3430 | 15 | * You should have received a copy of the GNU General Public License version |
zgu@3430 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
zgu@3430 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
zgu@3430 | 18 | * |
zgu@3430 | 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
zgu@3430 | 20 | * or visit www.oracle.com if you need additional information or have any |
zgu@3430 | 21 | * questions. |
zgu@3430 | 22 | * |
zgu@3430 | 23 | */ |
zgu@3430 | 24 | |
zgu@3430 | 25 | #include "precompiled.hpp" |
zgu@3430 | 26 | |
zgu@3430 | 27 | #ifdef __APPLE__ |
zgu@3430 | 28 | #include "decoder_machO.hpp" |
zgu@3961 | 29 | |
zgu@3961 | 30 | #include <cxxabi.h> |
zgu@3961 | 31 | #include <mach-o/loader.h> |
zgu@3961 | 32 | #include <mach-o/nlist.h> |
zgu@3961 | 33 | |
zgu@3961 | 34 | |
zgu@3961 | 35 | bool MachODecoder::demangle(const char* symbol, char *buf, int buflen) { |
zgu@3961 | 36 | int status; |
zgu@3961 | 37 | char* result; |
zgu@3961 | 38 | size_t size = (size_t)buflen; |
zgu@3961 | 39 | // Don't pass buf to __cxa_demangle. In case of the 'buf' is too small, |
zgu@3961 | 40 | // __cxa_demangle will call system "realloc" for additional memory, which |
zgu@3961 | 41 | // may use different malloc/realloc mechanism that allocates 'buf'. |
zgu@3961 | 42 | if ((result = abi::__cxa_demangle(symbol, NULL, NULL, &status)) != NULL) { |
zgu@3961 | 43 | jio_snprintf(buf, buflen, "%s", result); |
zgu@3961 | 44 | // call c library's free |
zgu@3961 | 45 | ::free(result); |
zgu@3961 | 46 | return true; |
zgu@3961 | 47 | } |
zgu@3961 | 48 | return false; |
zgu@3961 | 49 | } |
zgu@3961 | 50 | |
zgu@3961 | 51 | bool MachODecoder::decode(address addr, char *buf, |
zgu@3961 | 52 | int buflen, int *offset, const void *mach_base) { |
zgu@3961 | 53 | struct symtab_command * symt = (struct symtab_command *) |
zgu@3961 | 54 | mach_find_command((struct mach_header_64 *)mach_base, LC_SYMTAB); |
zgu@3961 | 55 | if (symt == NULL) { |
zgu@3961 | 56 | DEBUG_ONLY(tty->print_cr("no symtab in mach file at 0x%lx", mach_base)); |
zgu@3961 | 57 | return false; |
zgu@3961 | 58 | } |
zgu@3961 | 59 | uint32_t off = symt->symoff; /* symbol table offset (within this mach file) */ |
zgu@3961 | 60 | uint32_t nsyms = symt->nsyms; /* number of symbol table entries */ |
zgu@3961 | 61 | uint32_t stroff = symt->stroff; /* string table offset */ |
zgu@3961 | 62 | uint32_t strsize = symt->strsize; /* string table size in bytes */ |
zgu@3961 | 63 | |
zgu@3961 | 64 | // iterate through symbol table trying to match our offset |
zgu@3961 | 65 | |
zgu@3961 | 66 | uint32_t addr_relative = (uintptr_t) mach_base - (uintptr_t) addr; // offset we seek in the symtab |
zgu@3961 | 67 | void * symtab_addr = (void*) ((uintptr_t) mach_base + off); |
zgu@3961 | 68 | struct nlist_64 *cur_nlist = (struct nlist_64 *) symtab_addr; |
zgu@3961 | 69 | struct nlist_64 *last_nlist = cur_nlist; // no size stored in an entry, so keep previously seen nlist |
zgu@3961 | 70 | |
zgu@3961 | 71 | int32_t found_strx = 0; |
zgu@3961 | 72 | int32_t found_symval = 0; |
zgu@3961 | 73 | |
zgu@3961 | 74 | for (uint32_t i=0; i < nsyms; i++) { |
zgu@3961 | 75 | uint32_t this_value = cur_nlist->n_value; |
zgu@3961 | 76 | |
zgu@3961 | 77 | if (addr_relative == this_value) { |
zgu@3961 | 78 | found_strx = cur_nlist->n_un.n_strx; |
zgu@3961 | 79 | found_symval = this_value; |
zgu@3961 | 80 | break; |
zgu@3961 | 81 | } else if (addr_relative > this_value) { |
zgu@3961 | 82 | // gone past it, use previously seen nlist: |
zgu@3961 | 83 | found_strx = last_nlist->n_un.n_strx; |
zgu@3961 | 84 | found_symval = last_nlist->n_value; |
zgu@3961 | 85 | break; |
zgu@3961 | 86 | } |
zgu@3961 | 87 | last_nlist = cur_nlist; |
zgu@3961 | 88 | cur_nlist = cur_nlist + sizeof(struct nlist_64); |
zgu@3961 | 89 | } |
zgu@3961 | 90 | if (found_strx == 0) { |
zgu@3961 | 91 | return false; |
zgu@3961 | 92 | } |
zgu@3961 | 93 | // write the offset: |
zgu@3961 | 94 | *offset = addr_relative - found_symval; |
zgu@3961 | 95 | |
zgu@3961 | 96 | // lookup found_strx in the string table |
zgu@3961 | 97 | char * symname = mach_find_in_stringtable((char*) ((uintptr_t)mach_base + stroff), strsize, found_strx); |
zgu@3961 | 98 | if (symname) { |
zgu@3961 | 99 | strncpy(buf, symname, buflen); |
zgu@3961 | 100 | return true; |
zgu@3961 | 101 | } |
zgu@3961 | 102 | DEBUG_ONLY(tty->print_cr("no string or null string found.")); |
zgu@3961 | 103 | return false; |
zgu@3961 | 104 | } |
zgu@3961 | 105 | |
zgu@3961 | 106 | void* MachODecoder::mach_find_command(struct mach_header_64 * mach_base, uint32_t command_wanted) { |
zgu@3961 | 107 | // possibly verify it is a mach_header, use magic number. |
zgu@3961 | 108 | // commands begin immediately after the header. |
zgu@3961 | 109 | struct load_command *pos = (struct load_command *) mach_base + sizeof(struct mach_header_64); |
zgu@3961 | 110 | for (uint32_t i = 0; i < mach_base->ncmds; i++) { |
zgu@3961 | 111 | struct load_command *this_cmd = (struct load_command *) pos; |
zgu@3961 | 112 | if (this_cmd->cmd == command_wanted) { |
zgu@3961 | 113 | return pos; |
zgu@3961 | 114 | } |
zgu@3961 | 115 | int cmdsize = this_cmd->cmdsize; |
zgu@3961 | 116 | pos += cmdsize; |
zgu@3961 | 117 | } |
zgu@3961 | 118 | return NULL; |
zgu@3961 | 119 | } |
zgu@3961 | 120 | |
zgu@3961 | 121 | char* MachODecoder::mach_find_in_stringtable(char *strtab, uint32_t tablesize, int strx_wanted) { |
zgu@3961 | 122 | |
zgu@3961 | 123 | if (strx_wanted == 0) { |
zgu@3961 | 124 | return NULL; |
zgu@3961 | 125 | } |
zgu@3961 | 126 | char *strtab_end = strtab + tablesize; |
zgu@3961 | 127 | |
zgu@3961 | 128 | // find the first string, skip over the space char |
zgu@3961 | 129 | // (or the four zero bytes we see e.g. in libclient) |
zgu@3961 | 130 | if (*strtab == ' ') { |
zgu@3961 | 131 | strtab++; |
zgu@3961 | 132 | if (*strtab != 0) { |
zgu@3961 | 133 | DEBUG_ONLY(tty->print_cr("string table has leading space but no following zero.")); |
zgu@3961 | 134 | return NULL; |
zgu@3961 | 135 | } |
zgu@3961 | 136 | strtab++; |
zgu@3961 | 137 | } else { |
zgu@3961 | 138 | if ((uint32_t) *strtab != 0) { |
zgu@3961 | 139 | DEBUG_ONLY(tty->print_cr("string table without leading space or leading int of zero.")); |
zgu@3961 | 140 | return NULL; |
zgu@3961 | 141 | } |
zgu@3961 | 142 | strtab+=4; |
zgu@3961 | 143 | } |
zgu@3961 | 144 | // read the real strings starting at index 1 |
zgu@3961 | 145 | int cur_strx = 1; |
zgu@3961 | 146 | while (strtab < strtab_end) { |
zgu@3961 | 147 | if (cur_strx == strx_wanted) { |
zgu@3961 | 148 | return strtab; |
zgu@3961 | 149 | } |
zgu@3961 | 150 | // find start of next string |
zgu@3961 | 151 | while (*strtab != 0) { |
zgu@3961 | 152 | strtab++; |
zgu@3961 | 153 | } |
zgu@3961 | 154 | strtab++; // skip the terminating zero |
zgu@3961 | 155 | cur_strx++; |
zgu@3961 | 156 | } |
zgu@3961 | 157 | DEBUG_ONLY(tty->print_cr("string number %d not found.", strx_wanted)); |
zgu@3961 | 158 | return NULL; |
zgu@3961 | 159 | } |
zgu@3961 | 160 | |
zgu@3961 | 161 | |
zgu@3430 | 162 | #endif |
zgu@3430 | 163 | |
zgu@3430 | 164 |