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src/os/bsd/vm/decoder_machO.cpp@710a3c8b516e (annotated)

src/os/bsd/vm/decoder_machO.cpp

Tue, 08 Aug 2017 15:57:29 +0800

author

aoqi

date

Tue, 08 Aug 2017 15:57:29 +0800

changeset 6876

710a3c8b516e

parent 6680

78bbf4d43a14

parent 0

f90c822e73f8

child 9931

fd44df5e3bc3

permissions

-rw-r--r--

merge

aoqi@0	1	/*
aoqi@0	2	* Copyright (c) 2011, 2014, Oracle and/or its affiliates. All rights reserved.
aoqi@0	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0	4	*
aoqi@0	5	* This code is free software; you can redistribute it and/or modify it
aoqi@0	6	* under the terms of the GNU General Public License version 2 only, as
aoqi@0	7	* published by the Free Software Foundation.
aoqi@0	8	*
aoqi@0	9	* This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
aoqi@0	12	* version 2 for more details (a copy is included in the LICENSE file that
aoqi@0	13	* accompanied this code).
aoqi@0	14	*
aoqi@0	15	* You should have received a copy of the GNU General Public License version
aoqi@0	16	* 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0	18	*
aoqi@0	19	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0	20	* or visit www.oracle.com if you need additional information or have any
aoqi@0	21	* questions.
aoqi@0	22	*
aoqi@0	23	*/
aoqi@0	24
aoqi@0	25	#include "precompiled.hpp"
aoqi@0	26
aoqi@0	27	#ifdef __APPLE__
aoqi@0	28	#include "decoder_machO.hpp"
aoqi@0	29
aoqi@0	30	#include <cxxabi.h>
aoqi@0	31	#include <mach-o/loader.h>
aoqi@0	32	#include <mach-o/nlist.h>
aoqi@0	33
aoqi@0	34
aoqi@0	35	bool MachODecoder::demangle(const char* symbol, char *buf, int buflen) {
aoqi@0	36	int status;
aoqi@0	37	char* result;
aoqi@0	38	size_t size = (size_t)buflen;
aoqi@0	39	// Don't pass buf to __cxa_demangle. In case of the 'buf' is too small,
aoqi@0	40	// __cxa_demangle will call system "realloc" for additional memory, which
aoqi@0	41	// may use different malloc/realloc mechanism that allocates 'buf'.
aoqi@0	42	if ((result = abi::__cxa_demangle(symbol, NULL, NULL, &status)) != NULL) {
aoqi@0	43	jio_snprintf(buf, buflen, "%s", result);
aoqi@0	44	// call c library's free
aoqi@0	45	::free(result);
aoqi@0	46	return true;
aoqi@0	47	}
aoqi@0	48	return false;
aoqi@0	49	}
aoqi@0	50
aoqi@0	51	bool MachODecoder::decode(address addr, char *buf,
aoqi@0	52	int buflen, int *offset, const void *mach_base) {
aoqi@0	53	struct symtab_command * symt = (struct symtab_command *)
aoqi@0	54	mach_find_command((struct mach_header_64 *)mach_base, LC_SYMTAB);
aoqi@0	55	if (symt == NULL) {
aoqi@0	56	DEBUG_ONLY(tty->print_cr("no symtab in mach file at 0x%lx", p2i(mach_base)));
aoqi@0	57	return false;
aoqi@0	58	}
aoqi@0	59	uint32_t off = symt->symoff; /* symbol table offset (within this mach file) */
aoqi@0	60	uint32_t nsyms = symt->nsyms; /* number of symbol table entries */
aoqi@0	61	uint32_t stroff = symt->stroff; /* string table offset */
aoqi@0	62	uint32_t strsize = symt->strsize; /* string table size in bytes */
aoqi@0	63
aoqi@0	64	// iterate through symbol table trying to match our offset
aoqi@0	65
aoqi@0	66	uint32_t addr_relative = (uintptr_t) mach_base - (uintptr_t) addr; // offset we seek in the symtab
aoqi@0	67	void * symtab_addr = (void*) ((uintptr_t) mach_base + off);
aoqi@0	68	struct nlist_64 *cur_nlist = (struct nlist_64 *) symtab_addr;
aoqi@0	69	struct nlist_64 *last_nlist = cur_nlist; // no size stored in an entry, so keep previously seen nlist
aoqi@0	70
aoqi@0	71	int32_t found_strx = 0;
aoqi@0	72	int32_t found_symval = 0;
aoqi@0	73
aoqi@0	74	for (uint32_t i=0; i < nsyms; i++) {
aoqi@0	75	uint32_t this_value = cur_nlist->n_value;
aoqi@0	76
aoqi@0	77	if (addr_relative == this_value) {
aoqi@0	78	found_strx = cur_nlist->n_un.n_strx;
aoqi@0	79	found_symval = this_value;
aoqi@0	80	break;
aoqi@0	81	} else if (addr_relative > this_value) {
aoqi@0	82	// gone past it, use previously seen nlist:
aoqi@0	83	found_strx = last_nlist->n_un.n_strx;
aoqi@0	84	found_symval = last_nlist->n_value;
aoqi@0	85	break;
aoqi@0	86	}
aoqi@0	87	last_nlist = cur_nlist;
aoqi@0	88	cur_nlist = cur_nlist + sizeof(struct nlist_64);
aoqi@0	89	}
aoqi@0	90	if (found_strx == 0) {
aoqi@0	91	return false;
aoqi@0	92	}
aoqi@0	93	// write the offset:
aoqi@0	94	*offset = addr_relative - found_symval;
aoqi@0	95
aoqi@0	96	// lookup found_strx in the string table
aoqi@0	97	char * symname = mach_find_in_stringtable((char*) ((uintptr_t)mach_base + stroff), strsize, found_strx);
aoqi@0	98	if (symname) {
aoqi@0	99	strncpy(buf, symname, buflen);
aoqi@0	100	return true;
aoqi@0	101	}
aoqi@0	102	DEBUG_ONLY(tty->print_cr("no string or null string found."));
aoqi@0	103	return false;
aoqi@0	104	}
aoqi@0	105
aoqi@0	106	void* MachODecoder::mach_find_command(struct mach_header_64 * mach_base, uint32_t command_wanted) {
aoqi@0	107	// possibly verify it is a mach_header, use magic number.
aoqi@0	108	// commands begin immediately after the header.
aoqi@0	109	struct load_command *pos = (struct load_command *) mach_base + sizeof(struct mach_header_64);
aoqi@0	110	for (uint32_t i = 0; i < mach_base->ncmds; i++) {
aoqi@0	111	struct load_command *this_cmd = (struct load_command *) pos;
aoqi@0	112	if (this_cmd->cmd == command_wanted) {
aoqi@0	113	return pos;
aoqi@0	114	}
aoqi@0	115	int cmdsize = this_cmd->cmdsize;
aoqi@0	116	pos += cmdsize;
aoqi@0	117	}
aoqi@0	118	return NULL;
aoqi@0	119	}
aoqi@0	120
aoqi@0	121	char* MachODecoder::mach_find_in_stringtable(char *strtab, uint32_t tablesize, int strx_wanted) {
aoqi@0	122
aoqi@0	123	if (strx_wanted == 0) {
aoqi@0	124	return NULL;
aoqi@0	125	}
aoqi@0	126	char *strtab_end = strtab + tablesize;
aoqi@0	127
aoqi@0	128	// find the first string, skip over the space char
aoqi@0	129	// (or the four zero bytes we see e.g. in libclient)
aoqi@0	130	if (*strtab == ' ') {
aoqi@0	131	strtab++;
aoqi@0	132	if (*strtab != 0) {
aoqi@0	133	DEBUG_ONLY(tty->print_cr("string table has leading space but no following zero."));
aoqi@0	134	return NULL;
aoqi@0	135	}
aoqi@0	136	strtab++;
aoqi@0	137	} else {
aoqi@0	138	if ((uint32_t) *strtab != 0) {
aoqi@0	139	DEBUG_ONLY(tty->print_cr("string table without leading space or leading int of zero."));
aoqi@0	140	return NULL;
aoqi@0	141	}
aoqi@0	142	strtab+=4;
aoqi@0	143	}
aoqi@0	144	// read the real strings starting at index 1
aoqi@0	145	int cur_strx = 1;
aoqi@0	146	while (strtab < strtab_end) {
aoqi@0	147	if (cur_strx == strx_wanted) {
aoqi@0	148	return strtab;
aoqi@0	149	}
aoqi@0	150	// find start of next string
aoqi@0	151	while (*strtab != 0) {
aoqi@0	152	strtab++;
aoqi@0	153	}
aoqi@0	154	strtab++; // skip the terminating zero
aoqi@0	155	cur_strx++;
aoqi@0	156	}
aoqi@0	157	DEBUG_ONLY(tty->print_cr("string number %d not found.", strx_wanted));
aoqi@0	158	return NULL;
aoqi@0	159	}
aoqi@0	160
aoqi@0	161
aoqi@0	162	#endif
aoqi@0	163
aoqi@0	164