1 /*- 2 * Copyright (c) 1991, 1993, 1994 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #if 0 35 #ifndef lint 36 static char sccsid[] = "@(#)regular.c 8.3 (Berkeley) 4/2/94"; 37 #endif 38 #endif 39 40 #include <sys/cdefs.h> 41 __FBSDID("$FreeBSD$"); 42 43 #include <sys/param.h> 44 #include <sys/mman.h> 45 #include <sys/stat.h> 46 47 #include <err.h> 48 #include <errno.h> 49 #include <limits.h> 50 #include <signal.h> 51 #include <stdlib.h> 52 #include <stdio.h> 53 #include <string.h> 54 #include <unistd.h> 55 56 #include "extern.h" 57 58 static u_char *remmap(u_char *, int, off_t); 59 static void segv_handler(int); 60 #define MMAP_CHUNK (8*1024*1024) 61 62 #define ROUNDPAGE(i) ((i) & ~pagemask) 63 64 void 65 c_regular(int fd1, const char *file1, off_t skip1, off_t len1, 66 int fd2, const char *file2, off_t skip2, off_t len2) 67 { 68 u_char ch, *p1, *p2, *m1, *m2, *e1, *e2; 69 off_t byte, length, line; 70 int dfound; 71 off_t pagemask, off1, off2; 72 size_t pagesize; 73 struct sigaction act, oact; 74 75 if (skip1 > len1) 76 eofmsg(file1); 77 len1 -= skip1; 78 if (skip2 > len2) 79 eofmsg(file2); 80 len2 -= skip2; 81 82 if (sflag && len1 != len2) 83 exit(DIFF_EXIT); 84 85 sigemptyset(&act.sa_mask); 86 act.sa_flags = SA_NODEFER; 87 act.sa_handler = segv_handler; 88 if (sigaction(SIGSEGV, &act, &oact)) 89 err(ERR_EXIT, "sigaction()"); 90 91 pagesize = getpagesize(); 92 pagemask = (off_t)pagesize - 1; 93 off1 = ROUNDPAGE(skip1); 94 off2 = ROUNDPAGE(skip2); 95 96 length = MIN(len1, len2); 97 98 if ((m1 = remmap(NULL, fd1, off1)) == NULL) { 99 c_special(fd1, file1, skip1, fd2, file2, skip2); 100 return; 101 } 102 103 if ((m2 = remmap(NULL, fd2, off2)) == NULL) { 104 munmap(m1, MMAP_CHUNK); 105 c_special(fd1, file1, skip1, fd2, file2, skip2); 106 return; 107 } 108 109 dfound = 0; 110 e1 = m1 + MMAP_CHUNK; 111 e2 = m2 + MMAP_CHUNK; 112 p1 = m1 + (skip1 - off1); 113 p2 = m2 + (skip2 - off2); 114 115 for (byte = line = 1; length--; ++byte) { 116 if ((ch = *p1) != *p2) { 117 if (xflag) { 118 dfound = 1; 119 (void)printf("%08llx %02x %02x\n", 120 (long long)byte - 1, ch, *p2); 121 } else if (lflag) { 122 dfound = 1; 123 (void)printf("%6lld %3o %3o\n", 124 (long long)byte, ch, *p2); 125 } else 126 diffmsg(file1, file2, byte, line); 127 /* NOTREACHED */ 128 } 129 if (ch == '\n') 130 ++line; 131 if (++p1 == e1) { 132 off1 += MMAP_CHUNK; 133 if ((p1 = m1 = remmap(m1, fd1, off1)) == NULL) { 134 munmap(m2, MMAP_CHUNK); 135 err(ERR_EXIT, "remmap %s", file1); 136 } 137 e1 = m1 + MMAP_CHUNK; 138 } 139 if (++p2 == e2) { 140 off2 += MMAP_CHUNK; 141 if ((p2 = m2 = remmap(m2, fd2, off2)) == NULL) { 142 munmap(m1, MMAP_CHUNK); 143 err(ERR_EXIT, "remmap %s", file2); 144 } 145 e2 = m2 + MMAP_CHUNK; 146 } 147 } 148 munmap(m1, MMAP_CHUNK); 149 munmap(m2, MMAP_CHUNK); 150 151 if (sigaction(SIGSEGV, &oact, NULL)) 152 err(ERR_EXIT, "sigaction()"); 153 154 if (len1 != len2) 155 eofmsg (len1 > len2 ? file2 : file1); 156 if (dfound) 157 exit(DIFF_EXIT); 158 } 159 160 static u_char * 161 remmap(u_char *mem, int fd, off_t offset) 162 { 163 if (mem != NULL) 164 munmap(mem, MMAP_CHUNK); 165 mem = mmap(NULL, MMAP_CHUNK, PROT_READ, MAP_SHARED, fd, offset); 166 if (mem == MAP_FAILED) 167 return (NULL); 168 madvise(mem, MMAP_CHUNK, MADV_SEQUENTIAL); 169 return (mem); 170 } 171 172 static void 173 segv_handler(int sig) { 174 static const char msg[] = "cmp: Input/output error (caught SIGSEGV)\n"; 175 176 write(STDERR_FILENO, msg, sizeof(msg)); 177 _exit(EXIT_FAILURE); 178 } 179