1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright (c) 1995, 2010, Oracle and/or its affiliates. All rights reserved. 23 */ 24 25 /* 26 * tpcom: Threaded Print Comment 27 * 28 * tpcom is a threaded version of the pcom program. It will create 29 * a new thread for each new ELF descriptor that it examines. It 30 * will then examine each elf descriptor and print the .comment section 31 * if found. 32 * 33 * This program demonstrates that libelf is MT-Safe and the usage 34 * of elf_begin(ELF_C_READ). 35 */ 36 37 #include <stdio.h> 38 #include <libelf.h> 39 #include <gelf.h> 40 #include <fcntl.h> 41 #include <unistd.h> 42 #include <stdlib.h> 43 #include <string.h> 44 #include <thread.h> 45 46 47 #define NUMLWPS 32 /* arbitrary number of LWPS */ 48 49 static const char *CommentStr = ".comment"; 50 51 /* 52 * arguments to be passed into process_elf(). 53 */ 54 typedef struct { 55 Elf *pe_elf; 56 char *pe_file; /* elf member name */ 57 int pe_fd; 58 short pe_member; /* is this an archive member? */ 59 } pe_args; 60 61 62 static mutex_t printlock = DEFAULTMUTEX; /* printlock used to */ 63 /* group output */ 64 /* of comment sections */ 65 66 static void 67 print_comment(Elf *elf, const char *file) 68 { 69 Elf_Scn *scn = NULL; 70 GElf_Shdr shdr; 71 Elf_Data *data; 72 size_t shstrndx; 73 74 if (elf_getshdrstrndx(elf, &shstrndx) == -1) { 75 (void) fprintf(stderr, "%s: elf_getshdrstrndx() failed: %s\n", 76 file, elf_errmsg(0)); 77 return; 78 } 79 80 while ((scn = elf_nextscn(elf, scn)) != NULL) { 81 /* 82 * Do a string compare to examine each section header 83 * to see if it is a ".comment" section. If it is then 84 * this is the section we want to process. 85 */ 86 if (gelf_getshdr(scn, &shdr) == NULL) { 87 (void) fprintf(stderr, "%s: elf_getshdr() failed: %s\n", 88 file, elf_errmsg(0)); 89 return; 90 } 91 92 if (strcmp(CommentStr, elf_strptr(elf, shstrndx, 93 shdr.sh_name)) == 0) { 94 int i; 95 char *ptr; 96 97 (void) mutex_lock(&printlock); 98 (void) printf("%s .comment:\n", file); 99 100 /* 101 * Get the data associated with the .comment 102 * section. 103 */ 104 if ((data = elf_getdata(scn, NULL)) == NULL) { 105 (void) fprintf(stderr, 106 "%s: elf_getdata() failed: %s\n", 107 file, elf_errmsg(0)); 108 (void) mutex_unlock(&printlock); 109 return; 110 } 111 /* 112 * Data in a .comment section is a list of 'null' 113 * terminated strings. The following will print 114 * one string per line. 115 */ 116 for (i = 0, ptr = (char *)data->d_buf; 117 i < data->d_size; i++) 118 if (ptr[i]) { 119 (void) puts(&ptr[i]); 120 i += strlen(&ptr[i]); 121 } 122 (void) putchar('\n'); 123 (void) mutex_unlock(&printlock); 124 } 125 } 126 127 } 128 129 static void 130 process_elf(pe_args *pep) 131 { 132 Elf_Cmd cmd; 133 Elf *_elf; 134 135 switch (elf_kind(pep->pe_elf)) { 136 case ELF_K_ELF: 137 print_comment(pep->pe_elf, pep->pe_file); 138 break; 139 case ELF_K_AR: 140 cmd = ELF_C_READ; 141 while ((_elf = elf_begin(pep->pe_fd, cmd, 142 pep->pe_elf)) != NULL) { 143 Elf_Arhdr *arhdr; 144 pe_args *_pep; 145 int rc; 146 147 if ((arhdr = elf_getarhdr(_elf)) == NULL) { 148 (void) fprintf(stderr, 149 "%s: elf_getarhdr() failed: %s\n", 150 pep->pe_file, elf_errmsg(0)); 151 } 152 cmd = elf_next(_elf); 153 _pep = malloc(sizeof (pe_args)); 154 _pep->pe_elf = _elf; 155 _pep->pe_file = malloc(strlen(pep->pe_file) + 156 strlen(arhdr->ar_name) + 5); 157 (void) sprintf(_pep->pe_file, 158 "%s(%s)", pep->pe_file, arhdr->ar_name); 159 _pep->pe_fd = pep->pe_fd; 160 _pep->pe_member = 1; 161 162 if ((rc = thr_create(NULL, 0, 163 (void *(*)(void *))process_elf, 164 (void *)_pep, THR_DETACHED, 0)) != 0) { 165 (void) fprintf(stderr, 166 "thr_create() failed, rc = %d\n", rc); 167 } 168 } 169 break; 170 default: 171 if (!pep->pe_member) { 172 (void) mutex_lock(&printlock); 173 (void) fprintf(stderr, 174 "%s: unexpected elf_kind(): 0x%x\n", 175 pep->pe_file, elf_kind(pep->pe_elf)); 176 (void) mutex_unlock(&printlock); 177 } 178 } 179 180 (void) elf_end(pep->pe_elf); 181 if (pep->pe_member) 182 free(pep->pe_file); 183 free(pep); 184 thr_exit(0); 185 } 186 187 int 188 main(int argc, char ** argv) 189 { 190 int i; 191 192 if (argc < 2) { 193 (void) printf("usage: %s elf_file ...\n", argv[0]); 194 return (1); 195 } 196 197 /* 198 * Initialize the elf library, must be called before elf_begin() 199 * can be called. 200 */ 201 if (elf_version(EV_CURRENT) == EV_NONE) { 202 (void) fprintf(stderr, 203 "elf_version() failed: %s\n", elf_errmsg(0)); 204 return (1); 205 } 206 207 /* 208 * create an arbitrary number of LWP's to run the 209 * threads that will be created. 210 */ 211 if (thr_setconcurrency(NUMLWPS) != 0) { 212 (void) fprintf(stderr, "thread setconcurrency failed\n"); 213 return (1); 214 } 215 216 for (i = 1; i < argc; i++) { 217 int fd; 218 Elf *elf; 219 pe_args *pep; 220 int rc; 221 char *elf_fname; 222 223 elf_fname = argv[i]; 224 225 if ((fd = open(elf_fname, O_RDONLY)) == -1) { 226 perror("open"); 227 continue; 228 } 229 230 /* 231 * Attempt to open an Elf descriptor Read/Write 232 * for each file. 233 */ 234 if ((elf = elf_begin(fd, ELF_C_READ, 0)) == NULL) { 235 (void) mutex_lock(&printlock); 236 (void) fprintf(stderr, "elf_begin() failed: %s\n", 237 elf_errmsg(0)); 238 (void) mutex_unlock(&printlock); 239 (void) close(fd); 240 continue; 241 } 242 pep = malloc(sizeof (pe_args)); 243 pep->pe_elf = elf; 244 pep->pe_file = elf_fname; 245 pep->pe_fd = fd; 246 pep->pe_member = 0; 247 if ((rc = thr_create(NULL, 0, (void *(*)(void *))process_elf, 248 (void *)pep, THR_DETACHED, 0)) != 0) { 249 (void) mutex_lock(&printlock); 250 (void) fprintf(stderr, 251 "thr_create() failed with code: %d\n", rc); 252 (void) mutex_unlock(&printlock); 253 return (1); 254 } 255 } 256 257 thr_exit(0); 258 return (0); 259 } 260