| /* |
| * Copyright (c) 2011, 2017, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| |
| #ifdef __APPLE__ |
| #include "prims/jvm.h" |
| #include "decoder_machO.hpp" |
| |
| #include <cxxabi.h> |
| #include <mach-o/loader.h> |
| #include <mach-o/nlist.h> |
| |
| |
| bool MachODecoder::demangle(const char* symbol, char *buf, int buflen) { |
| int status; |
| char* result; |
| size_t size = (size_t)buflen; |
| // Don't pass buf to __cxa_demangle. In case of the 'buf' is too small, |
| // __cxa_demangle will call system "realloc" for additional memory, which |
| // may use different malloc/realloc mechanism that allocates 'buf'. |
| if ((result = abi::__cxa_demangle(symbol, NULL, NULL, &status)) != NULL) { |
| jio_snprintf(buf, buflen, "%s", result); |
| // call c library's free |
| ::free(result); |
| return true; |
| } |
| return false; |
| } |
| |
| bool MachODecoder::decode(address addr, char *buf, |
| int buflen, int *offset, const void *mach_base) { |
| struct symtab_command * symt = (struct symtab_command *) |
| mach_find_command((struct mach_header_64 *)mach_base, LC_SYMTAB); |
| if (symt == NULL) { |
| DEBUG_ONLY(tty->print_cr("no symtab in mach file at 0x%lx", p2i(mach_base))); |
| return false; |
| } |
| uint32_t off = symt->symoff; /* symbol table offset (within this mach file) */ |
| uint32_t nsyms = symt->nsyms; /* number of symbol table entries */ |
| uint32_t stroff = symt->stroff; /* string table offset */ |
| uint32_t strsize = symt->strsize; /* string table size in bytes */ |
| |
| // iterate through symbol table trying to match our offset |
| |
| uint32_t addr_relative = (uintptr_t) mach_base - (uintptr_t) addr; // offset we seek in the symtab |
| void * symtab_addr = (void*) ((uintptr_t) mach_base + off); |
| struct nlist_64 *cur_nlist = (struct nlist_64 *) symtab_addr; |
| struct nlist_64 *last_nlist = cur_nlist; // no size stored in an entry, so keep previously seen nlist |
| |
| int32_t found_strx = 0; |
| int32_t found_symval = 0; |
| |
| for (uint32_t i=0; i < nsyms; i++) { |
| uint32_t this_value = cur_nlist->n_value; |
| |
| if (addr_relative == this_value) { |
| found_strx = cur_nlist->n_un.n_strx; |
| found_symval = this_value; |
| break; |
| } else if (addr_relative > this_value) { |
| // gone past it, use previously seen nlist: |
| found_strx = last_nlist->n_un.n_strx; |
| found_symval = last_nlist->n_value; |
| break; |
| } |
| last_nlist = cur_nlist; |
| cur_nlist = cur_nlist + sizeof(struct nlist_64); |
| } |
| if (found_strx == 0) { |
| return false; |
| } |
| // write the offset: |
| *offset = addr_relative - found_symval; |
| |
| // lookup found_strx in the string table |
| char * symname = mach_find_in_stringtable((char*) ((uintptr_t)mach_base + stroff), strsize, found_strx); |
| if (symname) { |
| strncpy(buf, symname, buflen); |
| buf[buflen - 1] = '\0'; |
| return true; |
| } |
| DEBUG_ONLY(tty->print_cr("no string or null string found.")); |
| return false; |
| } |
| |
| void* MachODecoder::mach_find_command(struct mach_header_64 * mach_base, uint32_t command_wanted) { |
| // possibly verify it is a mach_header, use magic number. |
| // commands begin immediately after the header. |
| struct load_command *pos = (struct load_command *) mach_base + sizeof(struct mach_header_64); |
| for (uint32_t i = 0; i < mach_base->ncmds; i++) { |
| struct load_command *this_cmd = (struct load_command *) pos; |
| if (this_cmd->cmd == command_wanted) { |
| return pos; |
| } |
| int cmdsize = this_cmd->cmdsize; |
| pos += cmdsize; |
| } |
| return NULL; |
| } |
| |
| char* MachODecoder::mach_find_in_stringtable(char *strtab, uint32_t tablesize, int strx_wanted) { |
| |
| if (strx_wanted == 0) { |
| return NULL; |
| } |
| char *strtab_end = strtab + tablesize; |
| |
| // find the first string, skip over the space char |
| // (or the four zero bytes we see e.g. in libclient) |
| if (*strtab == ' ') { |
| strtab++; |
| if (*strtab != 0) { |
| DEBUG_ONLY(tty->print_cr("string table has leading space but no following zero.")); |
| return NULL; |
| } |
| strtab++; |
| } else { |
| if ((uint32_t) *strtab != 0) { |
| DEBUG_ONLY(tty->print_cr("string table without leading space or leading int of zero.")); |
| return NULL; |
| } |
| strtab+=4; |
| } |
| // read the real strings starting at index 1 |
| int cur_strx = 1; |
| while (strtab < strtab_end) { |
| if (cur_strx == strx_wanted) { |
| return strtab; |
| } |
| // find start of next string |
| while (*strtab != 0) { |
| strtab++; |
| } |
| strtab++; // skip the terminating zero |
| cur_strx++; |
| } |
| DEBUG_ONLY(tty->print_cr("string number %d not found.", strx_wanted)); |
| return NULL; |
| } |
| |
| |
| #endif |
| |
| |