1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/os/bsd/vm/decoder_machO.cpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,164 @@
1.4 +/*
1.5 + * Copyright (c) 2011, 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 +
1.28 +#include "precompiled.hpp"
1.29 +
1.30 +#ifdef __APPLE__
1.31 +#include "decoder_machO.hpp"
1.32 +
1.33 +#include <cxxabi.h>
1.34 +#include <mach-o/loader.h>
1.35 +#include <mach-o/nlist.h>
1.36 +
1.37 +
1.38 +bool MachODecoder::demangle(const char* symbol, char *buf, int buflen) {
1.39 + int status;
1.40 + char* result;
1.41 + size_t size = (size_t)buflen;
1.42 + // Don't pass buf to __cxa_demangle. In case of the 'buf' is too small,
1.43 + // __cxa_demangle will call system "realloc" for additional memory, which
1.44 + // may use different malloc/realloc mechanism that allocates 'buf'.
1.45 + if ((result = abi::__cxa_demangle(symbol, NULL, NULL, &status)) != NULL) {
1.46 + jio_snprintf(buf, buflen, "%s", result);
1.47 + // call c library's free
1.48 + ::free(result);
1.49 + return true;
1.50 + }
1.51 + return false;
1.52 +}
1.53 +
1.54 +bool MachODecoder::decode(address addr, char *buf,
1.55 + int buflen, int *offset, const void *mach_base) {
1.56 + struct symtab_command * symt = (struct symtab_command *)
1.57 + mach_find_command((struct mach_header_64 *)mach_base, LC_SYMTAB);
1.58 + if (symt == NULL) {
1.59 + DEBUG_ONLY(tty->print_cr("no symtab in mach file at 0x%lx", p2i(mach_base)));
1.60 + return false;
1.61 + }
1.62 + uint32_t off = symt->symoff; /* symbol table offset (within this mach file) */
1.63 + uint32_t nsyms = symt->nsyms; /* number of symbol table entries */
1.64 + uint32_t stroff = symt->stroff; /* string table offset */
1.65 + uint32_t strsize = symt->strsize; /* string table size in bytes */
1.66 +
1.67 + // iterate through symbol table trying to match our offset
1.68 +
1.69 + uint32_t addr_relative = (uintptr_t) mach_base - (uintptr_t) addr; // offset we seek in the symtab
1.70 + void * symtab_addr = (void*) ((uintptr_t) mach_base + off);
1.71 + struct nlist_64 *cur_nlist = (struct nlist_64 *) symtab_addr;
1.72 + struct nlist_64 *last_nlist = cur_nlist; // no size stored in an entry, so keep previously seen nlist
1.73 +
1.74 + int32_t found_strx = 0;
1.75 + int32_t found_symval = 0;
1.76 +
1.77 + for (uint32_t i=0; i < nsyms; i++) {
1.78 + uint32_t this_value = cur_nlist->n_value;
1.79 +
1.80 + if (addr_relative == this_value) {
1.81 + found_strx = cur_nlist->n_un.n_strx;
1.82 + found_symval = this_value;
1.83 + break;
1.84 + } else if (addr_relative > this_value) {
1.85 + // gone past it, use previously seen nlist:
1.86 + found_strx = last_nlist->n_un.n_strx;
1.87 + found_symval = last_nlist->n_value;
1.88 + break;
1.89 + }
1.90 + last_nlist = cur_nlist;
1.91 + cur_nlist = cur_nlist + sizeof(struct nlist_64);
1.92 + }
1.93 + if (found_strx == 0) {
1.94 + return false;
1.95 + }
1.96 + // write the offset:
1.97 + *offset = addr_relative - found_symval;
1.98 +
1.99 + // lookup found_strx in the string table
1.100 + char * symname = mach_find_in_stringtable((char*) ((uintptr_t)mach_base + stroff), strsize, found_strx);
1.101 + if (symname) {
1.102 + strncpy(buf, symname, buflen);
1.103 + return true;
1.104 + }
1.105 + DEBUG_ONLY(tty->print_cr("no string or null string found."));
1.106 + return false;
1.107 +}
1.108 +
1.109 +void* MachODecoder::mach_find_command(struct mach_header_64 * mach_base, uint32_t command_wanted) {
1.110 + // possibly verify it is a mach_header, use magic number.
1.111 + // commands begin immediately after the header.
1.112 + struct load_command *pos = (struct load_command *) mach_base + sizeof(struct mach_header_64);
1.113 + for (uint32_t i = 0; i < mach_base->ncmds; i++) {
1.114 + struct load_command *this_cmd = (struct load_command *) pos;
1.115 + if (this_cmd->cmd == command_wanted) {
1.116 + return pos;
1.117 + }
1.118 + int cmdsize = this_cmd->cmdsize;
1.119 + pos += cmdsize;
1.120 + }
1.121 + return NULL;
1.122 +}
1.123 +
1.124 +char* MachODecoder::mach_find_in_stringtable(char *strtab, uint32_t tablesize, int strx_wanted) {
1.125 +
1.126 + if (strx_wanted == 0) {
1.127 + return NULL;
1.128 + }
1.129 + char *strtab_end = strtab + tablesize;
1.130 +
1.131 + // find the first string, skip over the space char
1.132 + // (or the four zero bytes we see e.g. in libclient)
1.133 + if (*strtab == ' ') {
1.134 + strtab++;
1.135 + if (*strtab != 0) {
1.136 + DEBUG_ONLY(tty->print_cr("string table has leading space but no following zero."));
1.137 + return NULL;
1.138 + }
1.139 + strtab++;
1.140 + } else {
1.141 + if ((uint32_t) *strtab != 0) {
1.142 + DEBUG_ONLY(tty->print_cr("string table without leading space or leading int of zero."));
1.143 + return NULL;
1.144 + }
1.145 + strtab+=4;
1.146 + }
1.147 + // read the real strings starting at index 1
1.148 + int cur_strx = 1;
1.149 + while (strtab < strtab_end) {
1.150 + if (cur_strx == strx_wanted) {
1.151 + return strtab;
1.152 + }
1.153 + // find start of next string
1.154 + while (*strtab != 0) {
1.155 + strtab++;
1.156 + }
1.157 + strtab++; // skip the terminating zero
1.158 + cur_strx++;
1.159 + }
1.160 + DEBUG_ONLY(tty->print_cr("string number %d not found.", strx_wanted));
1.161 + return NULL;
1.162 +}
1.163 +
1.164 +
1.165 +#endif
1.166 +
1.167 +
