aoqi@0: /*
aoqi@0:  * Copyright (c) 2011, 2014, Oracle and/or its affiliates. All rights reserved.
aoqi@0:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0:  *
aoqi@0:  * This code is free software; you can redistribute it and/or modify it
aoqi@0:  * under the terms of the GNU General Public License version 2 only, as
aoqi@0:  * published by the Free Software Foundation.
aoqi@0:  *
aoqi@0:  * This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
aoqi@0:  * version 2 for more details (a copy is included in the LICENSE file that
aoqi@0:  * accompanied this code).
aoqi@0:  *
aoqi@0:  * You should have received a copy of the GNU General Public License version
aoqi@0:  * 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0:  *
aoqi@0:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0:  * or visit www.oracle.com if you need additional information or have any
aoqi@0:  * questions.
aoqi@0:  *
aoqi@0:  */
aoqi@0: 
aoqi@0: #include "precompiled.hpp"
aoqi@0: 
aoqi@0: #ifdef __APPLE__
aoqi@0: #include "decoder_machO.hpp"
aoqi@0: 
aoqi@0: #include <cxxabi.h>
aoqi@0: #include <mach-o/loader.h>
aoqi@0: #include <mach-o/nlist.h>
aoqi@0: 
aoqi@0: 
aoqi@0: bool MachODecoder::demangle(const char* symbol, char *buf, int buflen) {
aoqi@0:   int   status;
aoqi@0:   char* result;
aoqi@0:   size_t size = (size_t)buflen;
aoqi@0:   // Don't pass buf to __cxa_demangle. In case of the 'buf' is too small,
aoqi@0:   // __cxa_demangle will call system "realloc" for additional memory, which
aoqi@0:   // may use different malloc/realloc mechanism that allocates 'buf'.
aoqi@0:   if ((result = abi::__cxa_demangle(symbol, NULL, NULL, &status)) != NULL) {
aoqi@0:     jio_snprintf(buf, buflen, "%s", result);
aoqi@0:       // call c library's free
aoqi@0:       ::free(result);
aoqi@0:       return true;
aoqi@0:   }
aoqi@0:   return false;
aoqi@0: }
aoqi@0: 
aoqi@0: bool MachODecoder::decode(address addr, char *buf,
aoqi@0:       int buflen, int *offset, const void *mach_base) {
aoqi@0:   struct symtab_command * symt = (struct symtab_command *)
aoqi@0:     mach_find_command((struct mach_header_64 *)mach_base, LC_SYMTAB);
aoqi@0:   if (symt == NULL) {
aoqi@0:     DEBUG_ONLY(tty->print_cr("no symtab in mach file at 0x%lx", p2i(mach_base)));
aoqi@0:     return false;
aoqi@0:   }
aoqi@0:   uint32_t off = symt->symoff;          /* symbol table offset (within this mach file) */
aoqi@0:   uint32_t nsyms = symt->nsyms;         /* number of symbol table entries */
aoqi@0:   uint32_t stroff = symt->stroff;       /* string table offset */
aoqi@0:   uint32_t strsize = symt->strsize;     /* string table size in bytes */
aoqi@0: 
aoqi@0:   // iterate through symbol table trying to match our offset
aoqi@0: 
aoqi@0:   uint32_t addr_relative = (uintptr_t) mach_base - (uintptr_t) addr; // offset we seek in the symtab
aoqi@0:   void * symtab_addr = (void*) ((uintptr_t) mach_base + off);
aoqi@0:   struct nlist_64 *cur_nlist = (struct nlist_64 *) symtab_addr;
aoqi@0:   struct nlist_64 *last_nlist = cur_nlist;  // no size stored in an entry, so keep previously seen nlist
aoqi@0: 
aoqi@0:   int32_t found_strx = 0;
aoqi@0:   int32_t found_symval = 0;
aoqi@0: 
aoqi@0:   for (uint32_t i=0; i < nsyms; i++) {
aoqi@0:     uint32_t this_value = cur_nlist->n_value;
aoqi@0: 
aoqi@0:     if (addr_relative == this_value) {
aoqi@0:       found_strx =  cur_nlist->n_un.n_strx;
aoqi@0:       found_symval = this_value;
aoqi@0:       break;
aoqi@0:     } else if (addr_relative > this_value) {
aoqi@0:       // gone past it, use previously seen nlist:
aoqi@0:       found_strx = last_nlist->n_un.n_strx;
aoqi@0:       found_symval = last_nlist->n_value;
aoqi@0:       break;
aoqi@0:     }
aoqi@0:     last_nlist = cur_nlist;
aoqi@0:     cur_nlist = cur_nlist + sizeof(struct nlist_64);
aoqi@0:   }
aoqi@0:   if (found_strx == 0) {
aoqi@0:     return false;
aoqi@0:   }
aoqi@0:   // write the offset:
aoqi@0:   *offset = addr_relative - found_symval;
aoqi@0: 
aoqi@0:   // lookup found_strx in the string table
aoqi@0:   char * symname = mach_find_in_stringtable((char*) ((uintptr_t)mach_base + stroff), strsize, found_strx);
aoqi@0:   if (symname) {
aoqi@0:       strncpy(buf, symname, buflen);
aoqi@0:       return true;
aoqi@0:   }
aoqi@0:   DEBUG_ONLY(tty->print_cr("no string or null string found."));
aoqi@0:   return false;
aoqi@0: }
aoqi@0: 
aoqi@0: void* MachODecoder::mach_find_command(struct mach_header_64 * mach_base, uint32_t command_wanted) {
aoqi@0:   // possibly verify it is a mach_header, use magic number.
aoqi@0:   // commands begin immediately after the header.
aoqi@0:   struct load_command *pos = (struct load_command *) mach_base + sizeof(struct mach_header_64);
aoqi@0:   for (uint32_t i = 0; i < mach_base->ncmds; i++) {
aoqi@0:     struct load_command *this_cmd = (struct load_command *) pos;
aoqi@0:     if (this_cmd->cmd == command_wanted) {
aoqi@0:        return pos;
aoqi@0:     }
aoqi@0:     int cmdsize = this_cmd->cmdsize;
aoqi@0:     pos += cmdsize;
aoqi@0:   }
aoqi@0:   return NULL;
aoqi@0: }
aoqi@0: 
aoqi@0: char* MachODecoder::mach_find_in_stringtable(char *strtab, uint32_t tablesize, int strx_wanted) {
aoqi@0: 
aoqi@0:   if (strx_wanted == 0) {
aoqi@0:     return NULL;
aoqi@0:   }
aoqi@0:   char *strtab_end = strtab + tablesize;
aoqi@0: 
aoqi@0:   // find the first string, skip over the space char
aoqi@0:   // (or the four zero bytes we see e.g. in libclient)
aoqi@0:   if (*strtab == ' ') {
aoqi@0:       strtab++;
aoqi@0:       if (*strtab != 0) {
aoqi@0:           DEBUG_ONLY(tty->print_cr("string table has leading space but no following zero."));
aoqi@0:           return NULL;
aoqi@0:       }
aoqi@0:       strtab++;
aoqi@0:   } else {
aoqi@0:       if ((uint32_t) *strtab != 0) {
aoqi@0:           DEBUG_ONLY(tty->print_cr("string table without leading space or leading int of zero."));
aoqi@0:           return NULL;
aoqi@0:       }
aoqi@0:       strtab+=4;
aoqi@0:   }
aoqi@0:   // read the real strings starting at index 1
aoqi@0:   int cur_strx = 1;
aoqi@0:   while (strtab < strtab_end) {
aoqi@0:     if (cur_strx == strx_wanted) {
aoqi@0:         return strtab;
aoqi@0:     }
aoqi@0:     // find start of next string
aoqi@0:     while (*strtab != 0) {
aoqi@0:         strtab++;
aoqi@0:     }
aoqi@0:     strtab++; // skip the terminating zero
aoqi@0:     cur_strx++;
aoqi@0:   }
aoqi@0:   DEBUG_ONLY(tty->print_cr("string number %d not found.", strx_wanted));
aoqi@0:   return NULL;
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: #endif
aoqi@0: 
aoqi@0: