1 /* $NetBSD: kern_ctf.c,v 1.8 2021/04/06 07:57:03 simonb Exp $ */
2 /*-
3 * Copyright (c) 2008 John Birrell <jb@freebsd.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * $FreeBSD: src/sys/kern/kern_ctf.c,v 1.1.4.1 2009/08/03 08:13:06 kensmith Exp $
28 */
29
30 #define ELFSIZE ARCH_ELFSIZE
31 #include <sys/proc.h>
32 #include <sys/module.h>
33 #include <sys/exec.h>
34 #include <sys/exec_elf.h>
35 #include <sys/kmem.h>
36 #include <sys/malloc.h>
37 #include <sys/kobj_impl.h>
38 #include <sys/kobj.h>
39 #include <sys/kern_ctf.h>
40
41 #define _KSYMS_PRIVATE
42 #include <sys/ksyms.h>
43
44 #include <net/zlib.h>
45
46 /*
47 * Note this file is included by both link_elf.c and link_elf_obj.c.
48 *
49 * The CTF header structure definition can't be used here because it's
50 * (annoyingly) covered by the CDDL. We will just use a few bytes from
51 * it as an integer array where we 'know' what they mean.
52 */
53 #define CTF_HDR_SIZE 36
54 #define CTF_HDR_STRTAB_U32 7
55 #define CTF_HDR_STRLEN_U32 8
56
57 static void *
z_alloc(void * nil,u_int items,u_int size)58 z_alloc(void *nil, u_int items, u_int size)
59 {
60 void *ptr;
61
62 ptr = malloc(items * size, M_TEMP, M_NOWAIT);
63 return ptr;
64 }
65
66 static void
z_free(void * nil,void * ptr)67 z_free(void *nil, void *ptr)
68 {
69 free(ptr, M_TEMP);
70 }
71
72 int
mod_ctf_get(struct module * mod,mod_ctf_t ** mcp)73 mod_ctf_get(struct module *mod, mod_ctf_t **mcp)
74 {
75 mod_ctf_t *mc;
76 struct ksyms_symtab *st;
77 void * ctftab = NULL;
78 size_t sz;
79 int error = 0;
80 int compressed = 0;
81
82 void *ctfbuf = NULL;
83 uint8_t *ctfaddr;
84 uint16_t ctfmagic;
85 size_t ctfsize;
86
87 /*
88 * Return the cached mc if there is one already.
89 */
90
91 extern specificdata_key_t fbt_module_key;
92
93 mc = module_getspecific(mod, fbt_module_key);
94 if (mc != NULL) {
95 *mcp = mc;
96 return (0);
97 }
98
99 /*
100 * Allocate and initialize a new mc.
101 */
102
103 mc = kmem_zalloc(sizeof(mod_ctf_t), KM_SLEEP);
104 st = ksyms_get_mod(module_name(mod));
105 if (st != NULL) {
106 mc->nmap = st->sd_nmap;
107 mc->nmapsize = st->sd_nmapsize;
108 }
109
110 if (mod->mod_kobj == NULL) {
111 /* no kobj entry, try building from ksyms list */
112 if (st == NULL) {
113 error = ENOENT;
114 goto out;
115 }
116
117 ctfaddr = st->sd_ctfstart;
118 ctfsize = st->sd_ctfsize;
119
120 mc->symtab = st->sd_symstart;
121 mc->strtab = st->sd_strstart;
122 mc->strcnt = 0; /* XXX TBD */
123 mc->nsym = st->sd_symsize / sizeof(Elf_Sym);
124 } else {
125 if (kobj_find_section(mod->mod_kobj, ".SUNW_ctf", (void **)&ctfaddr, &ctfsize)) {
126 error = ENOENT;
127 goto out;
128 }
129
130 mc->symtab = mod->mod_kobj->ko_symtab;
131 mc->strtab = mod->mod_kobj->ko_strtab;
132 mc->strcnt = 0; /* XXX TBD */
133 mc->nsym = mod->mod_kobj->ko_symcnt;
134 }
135
136 if (ctfaddr == NULL) {
137 error = ENOENT;
138 goto out;
139 }
140
141 /* Check the CTF magic number. */
142 memcpy(&ctfmagic, ctfaddr, sizeof ctfmagic);
143 if (ctfmagic != CTF_MAGIC) {
144 error = EINVAL;
145 goto out;
146 }
147
148 /* Check if version 2. */
149 if (ctfaddr[2] != 2) {
150 error = EINVAL;
151 goto out;
152 }
153
154 /* Check if the data is compressed. */
155 if ((ctfaddr[3] & 0x1) != 0) {
156 uint32_t *u32 = (uint32_t *) ctfaddr;
157
158 /*
159 * The last two fields in the CTF header are the offset
160 * from the end of the header to the start of the string
161 * data and the length of that string data. se this
162 * information to determine the decompressed CTF data
163 * buffer required.
164 */
165 sz = u32[CTF_HDR_STRTAB_U32] + u32[CTF_HDR_STRLEN_U32] +
166 CTF_HDR_SIZE;
167
168 compressed = 1;
169 } else {
170 /*
171 * The CTF data is not compressed, so the ELF section
172 * size is the same as the buffer size required.
173 */
174 sz = ctfsize;
175 }
176
177 /*
178 * Allocate memory to buffer the CTF data in its decompressed
179 * form.
180 */
181 if (compressed) {
182 if ((ctfbuf = malloc(sz, M_TEMP, M_WAITOK)) == NULL) {
183 error = ENOMEM;
184 goto out;
185 }
186 ctftab = ctfbuf;
187 mc->ctfalloc = 1;
188 } else {
189 ctftab = (void *)ctfaddr;
190 }
191
192 /* Check if decompression is required. */
193 if (compressed) {
194 z_stream zs;
195 int ret;
196
197 /*
198 * The header isn't compressed, so copy that into the
199 * CTF buffer first.
200 */
201 memcpy(ctftab, ctfaddr, CTF_HDR_SIZE);
202
203 /* Initialise the zlib structure. */
204 memset(&zs, 0, sizeof(zs));
205 zs.zalloc = z_alloc;
206 zs.zfree = z_free;
207
208 if (inflateInit2(&zs, MAX_WBITS) != Z_OK) {
209 error = EIO;
210 goto out;
211 }
212
213 zs.avail_in = ctfsize - CTF_HDR_SIZE;
214 zs.next_in = ctfaddr + CTF_HDR_SIZE;
215 zs.avail_out = sz - CTF_HDR_SIZE;
216 zs.next_out = ((uint8_t *) ctftab) + CTF_HDR_SIZE;
217 inflateReset(&zs);
218 if ((ret = inflate(&zs, Z_FINISH)) != Z_STREAM_END) {
219 printf("%s(%d): zlib inflate returned %d\n", __func__, __LINE__, ret);
220 error = EIO;
221 goto out;
222 }
223 }
224
225 /* Got the CTF data! */
226 mc->ctfcnt = ctfsize;
227 mc->ctftab = ctftab;
228 ctfbuf = NULL;
229
230 module_setspecific(mod, fbt_module_key, mc);
231 *mcp = mc;
232 mc = NULL;
233
234 out:
235 if (ctfbuf != NULL)
236 free(ctfbuf, M_TEMP);
237 if (mc != NULL)
238 kmem_free(mc, sizeof(*mc));
239
240 return (error);
241 }
242