1 /* $NetBSD: kern_ctf.c,v 1.7 2018/05/28 21:05:00 chs 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 * 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 67 z_free(void *nil, void *ptr) 68 { 69 free(ptr, M_TEMP); 70 } 71 72 int 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 size_t ctfsize; 85 86 /* 87 * Return the cached mc if there is one already. 88 */ 89 90 extern specificdata_key_t fbt_module_key; 91 92 mc = module_getspecific(mod, fbt_module_key); 93 if (mc != NULL) { 94 *mcp = mc; 95 return (0); 96 } 97 98 /* 99 * Allocate and initialize a new mc. 100 */ 101 102 mc = kmem_zalloc(sizeof(mod_ctf_t), KM_SLEEP); 103 st = ksyms_get_mod(module_name(mod)); 104 if (st != NULL) { 105 mc->nmap = st->sd_nmap; 106 mc->nmapsize = st->sd_nmapsize; 107 } 108 109 if (mod->mod_kobj == NULL) { 110 /* no kobj entry, try building from ksyms list */ 111 if (st == NULL) { 112 error = ENOENT; 113 goto out; 114 } 115 116 ctfaddr = st->sd_ctfstart; 117 ctfsize = st->sd_ctfsize; 118 119 mc->symtab = st->sd_symstart; 120 mc->strtab = st->sd_strstart; 121 mc->strcnt = 0; /* XXX TBD */ 122 mc->nsym = st->sd_symsize / sizeof(Elf_Sym); 123 } else { 124 if (kobj_find_section(mod->mod_kobj, ".SUNW_ctf", (void **)&ctfaddr, &ctfsize)) { 125 error = ENOENT; 126 goto out; 127 } 128 129 mc->symtab = mod->mod_kobj->ko_symtab; 130 mc->strtab = mod->mod_kobj->ko_strtab; 131 mc->strcnt = 0; /* XXX TBD */ 132 mc->nsym = mod->mod_kobj->ko_symcnt; 133 } 134 135 if (ctfaddr == NULL) { 136 error = ENOENT; 137 goto out; 138 } 139 140 /* Check the CTF magic number. (XXX check for big endian!) */ 141 if (ctfaddr[0] != 0xf1 || ctfaddr[1] != 0xcf) { 142 error = EINVAL; 143 goto out; 144 } 145 146 /* Check if version 2. */ 147 if (ctfaddr[2] != 2) { 148 error = EINVAL; 149 goto out; 150 } 151 152 /* Check if the data is compressed. */ 153 if ((ctfaddr[3] & 0x1) != 0) { 154 uint32_t *u32 = (uint32_t *) ctfaddr; 155 156 /* 157 * The last two fields in the CTF header are the offset 158 * from the end of the header to the start of the string 159 * data and the length of that string data. se this 160 * information to determine the decompressed CTF data 161 * buffer required. 162 */ 163 sz = u32[CTF_HDR_STRTAB_U32] + u32[CTF_HDR_STRLEN_U32] + 164 CTF_HDR_SIZE; 165 166 compressed = 1; 167 } else { 168 /* 169 * The CTF data is not compressed, so the ELF section 170 * size is the same as the buffer size required. 171 */ 172 sz = ctfsize; 173 } 174 175 /* 176 * Allocate memory to buffer the CTF data in its decompressed 177 * form. 178 */ 179 if (compressed) { 180 if ((ctfbuf = malloc(sz, M_TEMP, M_WAITOK)) == NULL) { 181 error = ENOMEM; 182 goto out; 183 } 184 ctftab = ctfbuf; 185 mc->ctfalloc = 1; 186 } else { 187 ctftab = (void *)ctfaddr; 188 } 189 190 /* Check if decompression is required. */ 191 if (compressed) { 192 z_stream zs; 193 int ret; 194 195 /* 196 * The header isn't compressed, so copy that into the 197 * CTF buffer first. 198 */ 199 memcpy(ctftab, ctfaddr, CTF_HDR_SIZE); 200 201 /* Initialise the zlib structure. */ 202 memset(&zs, 0, sizeof(zs)); 203 zs.zalloc = z_alloc; 204 zs.zfree = z_free; 205 206 if (inflateInit2(&zs, MAX_WBITS) != Z_OK) { 207 error = EIO; 208 goto out; 209 } 210 211 zs.avail_in = ctfsize - CTF_HDR_SIZE; 212 zs.next_in = ctfaddr + CTF_HDR_SIZE; 213 zs.avail_out = sz - CTF_HDR_SIZE; 214 zs.next_out = ((uint8_t *) ctftab) + CTF_HDR_SIZE; 215 inflateReset(&zs); 216 if ((ret = inflate(&zs, Z_FINISH)) != Z_STREAM_END) { 217 printf("%s(%d): zlib inflate returned %d\n", __func__, __LINE__, ret); 218 error = EIO; 219 goto out; 220 } 221 } 222 223 /* Got the CTF data! */ 224 mc->ctfcnt = ctfsize; 225 mc->ctftab = ctftab; 226 ctfbuf = NULL; 227 228 module_setspecific(mod, fbt_module_key, mc); 229 *mcp = mc; 230 mc = NULL; 231 232 out: 233 if (ctfbuf != NULL) 234 free(ctfbuf, M_TEMP); 235 if (mc != NULL) 236 kmem_free(mc, sizeof(*mc)); 237 238 return (error); 239 } 240