[apple/xnu.git] / osfmk / kern / symbols.c

/*
 * Copyright (c) 2006 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */

/*-
 * Copyright (c) 2004 Networks Associates Technology, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <mach/mach_types.h>
#include <mach-o/mach_header.h>
#include <mach-o/nlist.h>
#include <mach/kmod.h>
#include <libsa/stdlib.h>
#include <kern/misc_protos.h>

static const struct nlist *
syms_find(const struct nlist *syms, int nsyms, vm_offset_t addr,
    vm_offset_t *ofs)
{
	const struct nlist *best = 0;
	int                 i;

	for (i = 0; i < nsyms; i++) {
		int st = syms[i].n_type & N_TYPE;

		if (st == N_SECT || st == N_ABS) {
			if (syms[i].n_value == addr) {
				*ofs = 0;
				return (syms+i);
			}
			else if (syms[i].n_value < addr &&
				 (best == 0 ||
				  (syms[i].n_value > best->n_value))) {
				*ofs = addr - syms[i].n_value;
				best = syms+i;
			}
		}
	}

	return (best);
}

static const char *
syms_getname(const struct symtab_command *sc, const char *ss,
	     const struct nlist *sp)
{
	if (sp->n_un.n_strx == 0)
		return ("");
	else if ((unsigned)sp->n_un.n_strx > sc->strsize)
		return ("*bad string*");
	else
		return (ss + sp->n_un.n_strx);
}

/* Search for a symbol in the given object file, which must either
 * have a LINKEDIT segment or have been read directly into memory
 * and isload passed as 1.

 * If mh has a LINKEDIT segment, an object file loaded in the normal
 * way will have the symbol table available at the load address.
 */

static const char *
syms_nameforaddr1(const struct mach_header *mh, int isload,
    vm_offset_t addr, vm_offset_t *ofs)
{
	const struct symtab_command  *sc = NULL;
	const struct segment_command *le = NULL;
	const struct segment_command *p;
	const struct segment_command *sym = NULL;
	const struct nlist           *syms;
	const char                   *strings;
	unsigned int                  i;

	p = (const struct segment_command *) (&mh[1]);

	for (i = 0; i < mh->ncmds; i++) {
		if (p->cmd == LC_SYMTAB)
			sc = (const struct symtab_command *) p;
		else if (p->cmd == LC_SEGMENT &&
		    !strncmp(p->segname, "__LINKEDIT", sizeof(p->segname)))
			le = p;

		/* only try to find a name for an address that came from
		 * a text section.
		 */
		if (p->cmd == LC_SEGMENT &&
		    addr >= p->vmaddr && addr < p->vmaddr + p->vmsize) {
			unsigned int j;

			const struct section *sp = (const struct section *)
			    (((const char *) p) + sizeof(struct segment_command));

			for (j = 0; j < p->nsects; j++) {
				if (addr >= sp[j].addr &&
				    addr <  sp[j].addr + sp[j].size &&
				    !strncmp (sp[j].sectname, "__text",
					    	sizeof(sp[j].sectname))) {
					sym = p;
					break;
				}
			}
		}
		p = (const struct segment_command *)
			(((const char *) p) + p->cmdsize);
	}

	if (sc == 0 || sym == NULL)
		return (NULL);

	if (!isload) {
		syms = (const struct nlist *) (((const char *) mh) + sc->symoff);
		strings = ((const char *) mh) + sc->stroff;
	}
	else if (le) {
		syms = (const struct nlist *) le->vmaddr;
		strings = (const char *)
			(le->vmaddr + sc->nsyms * sizeof(struct nlist));
	} else
		return (NULL);

	const struct nlist *sp = syms_find(syms, sc->nsyms, addr, ofs);
	if (sp)
		return syms_getname(sc, strings, sp);

	return (NULL);
}

extern struct mach_header  _mh_execute_header;
extern kmod_info_t        *kmod;

/* Search for a symbol and return the name, offset, and module in which the
 * address was found. A null module means the kernel itself.
 */

const char *
syms_nameforaddr(vm_offset_t addr, vm_offset_t *ofs, kmod_info_t **km)
{
	const char  *name = NULL;

	name = syms_nameforaddr1(&_mh_execute_header, 1, addr, ofs);
	if (name) {
		*km = NULL;
		return (name);
	}

	return (NULL);
}


/* Format the results of calling syms_nameforaddr into a single string.
 * The buffer must be at least 13 bytes long; 80 is recommended.
 */

int
syms_formataddr(vm_offset_t addr, char *out, vm_offset_t outsize)
{
	vm_offset_t  ofs;
	kmod_info_t *k = NULL;
	const char  *name;

	name = syms_nameforaddr(addr, &ofs, &k);

	if (ofs > 0x100000)
		name = NULL;

	if (name != NULL) {
		if (k != NULL)
			snprintf(out, outsize, "0x%08X <%s:%s + %d>", addr, 
			    k->name, name, ofs);
		else
			snprintf(out, outsize, "0x%08X <%s + %d>", addr, name,
			    ofs);

		return (1);
	}
	else {
		snprintf(out, outsize, "0x%08X", addr);
		return (0);
	}
}
Commit	Line	Data
2d21ac55 A	1	/*
	2	* Copyright (c) 2006 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
	5	*
	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
	14	*
	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
	25	*
	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
	27	*/
	28
	29	/*-
	30	* Copyright (c) 2004 Networks Associates Technology, Inc.
	31	* All rights reserved.
	32	*
	33	* Redistribution and use in source and binary forms, with or without
	34	* modification, are permitted provided that the following conditions
	35	* are met:
	36	* 1. Redistributions of source code must retain the above copyright
	37	* notice, this list of conditions and the following disclaimer.
	38	* 2. Redistributions in binary form must reproduce the above copyright
	39	* notice, this list of conditions and the following disclaimer in the
	40	* documentation and/or other materials provided with the distribution.
	41	*
	42	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
	43	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	44	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	45	* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
	46	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	47	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	48	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	49	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	50	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	51	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	52	* SUCH DAMAGE.
	53	*/
	54
	55	#include <mach/mach_types.h>
	56	#include <mach-o/mach_header.h>
	57	#include <mach-o/nlist.h>
	58	#include <mach/kmod.h>
	59	#include <libsa/stdlib.h>
	60	#include <kern/misc_protos.h>
	61
	62	static const struct nlist *
	63	syms_find(const struct nlist *syms, int nsyms, vm_offset_t addr,
	64	vm_offset_t *ofs)
65	{
66	const struct nlist *best = 0;
67	int i;
68
69	for (i = 0; i < nsyms; i++) {
70	int st = syms[i].n_type & N_TYPE;
71
72	if (st == N_SECT \|\| st == N_ABS) {
73	if (syms[i].n_value == addr) {
74	*ofs = 0;
75	return (syms+i);
76	}
77	else if (syms[i].n_value < addr &&
78	(best == 0 \|\|
79	(syms[i].n_value > best->n_value))) {
80	*ofs = addr - syms[i].n_value;
81	best = syms+i;
82	}
83	}
84	}
85
86	return (best);
87	}
88
89	static const char *
90	syms_getname(const struct symtab_command sc, const char ss,
91	const struct nlist *sp)
92	{
93	if (sp->n_un.n_strx == 0)
94	return ("");
95	else if ((unsigned)sp->n_un.n_strx > sc->strsize)
96	return ("bad string");
97	else
98	return (ss + sp->n_un.n_strx);
99	}
100
101	/* Search for a symbol in the given object file, which must either
102	* have a LINKEDIT segment or have been read directly into memory
103	* and isload passed as 1.
104
105	* If mh has a LINKEDIT segment, an object file loaded in the normal
106	* way will have the symbol table available at the load address.
107	*/
108
109	static const char *
110	syms_nameforaddr1(const struct mach_header *mh, int isload,
111	vm_offset_t addr, vm_offset_t *ofs)
112	{
113	const struct symtab_command *sc = NULL;
114	const struct segment_command *le = NULL;
115	const struct segment_command *p;
116	const struct segment_command *sym = NULL;
117	const struct nlist *syms;
118	const char *strings;
119	unsigned int i;
120
121	p = (const struct segment_command *) (&mh[1]);
122
123	for (i = 0; i < mh->ncmds; i++) {
124	if (p->cmd == LC_SYMTAB)
125	sc = (const struct symtab_command *) p;
126	else if (p->cmd == LC_SEGMENT &&
127	!strncmp(p->segname, "__LINKEDIT", sizeof(p->segname)))
128	le = p;
129
130	/* only try to find a name for an address that came from
131	* a text section.
132	*/
133	if (p->cmd == LC_SEGMENT &&
134	addr >= p->vmaddr && addr < p->vmaddr + p->vmsize) {
135	unsigned int j;
136
137	const struct section sp = (const struct section )
138	(((const char *) p) + sizeof(struct segment_command));
139
140	for (j = 0; j < p->nsects; j++) {
141	if (addr >= sp[j].addr &&
142	addr < sp[j].addr + sp[j].size &&
143	!strncmp (sp[j].sectname, "__text",
144	sizeof(sp[j].sectname))) {
145	sym = p;
146	break;
147	}
148	}
149	}
150	p = (const struct segment_command *)
151	(((const char *) p) + p->cmdsize);
152	}
153
154	if (sc == 0 \|\| sym == NULL)
155	return (NULL);
156
157	if (!isload) {
158	syms = (const struct nlist ) (((const char ) mh) + sc->symoff);
159	strings = ((const char *) mh) + sc->stroff;
160	}
161	else if (le) {
162	syms = (const struct nlist *) le->vmaddr;
163	strings = (const char *)
164	(le->vmaddr + sc->nsyms * sizeof(struct nlist));
165	} else
166	return (NULL);
167
168	const struct nlist *sp = syms_find(syms, sc->nsyms, addr, ofs);
169	if (sp)
170	return syms_getname(sc, strings, sp);
171
172	return (NULL);
173	}
174
175	extern struct mach_header _mh_execute_header;
176	extern kmod_info_t *kmod;
177
178	/* Search for a symbol and return the name, offset, and module in which the
179	* address was found. A null module means the kernel itself.
180	*/
181
182	const char *
183	syms_nameforaddr(vm_offset_t addr, vm_offset_t ofs, kmod_info_t *km)
184	{
185	const char *name = NULL;
186
187	name = syms_nameforaddr1(&_mh_execute_header, 1, addr, ofs);
188	if (name) {
189	*km = NULL;
190	return (name);
191	}
192
193	return (NULL);
194	}
195
2d21ac55 A	196
	197	/* Format the results of calling syms_nameforaddr into a single string.
	198	* The buffer must be at least 13 bytes long; 80 is recommended.
	199	*/
	200
	201	int
	202	syms_formataddr(vm_offset_t addr, char *out, vm_offset_t outsize)
	203	{
	204	vm_offset_t ofs;
	205	kmod_info_t *k = NULL;
	206	const char *name;
	207
	208	name = syms_nameforaddr(addr, &ofs, &k);
	209
	210	if (ofs > 0x100000)
	211	name = NULL;
	212
	213	if (name != NULL) {
	214	if (k != NULL)
	215	snprintf(out, outsize, "0x%08X <%s:%s + %d>", addr,
	216	k->name, name, ofs);
	217	else
	218	snprintf(out, outsize, "0x%08X <%s + %d>", addr, name,
	219	ofs);
	220
	221	return (1);
	222	}
	223	else {
	224	snprintf(out, outsize, "0x%08X", addr);
	225	return (0);
	226	}
	227	}