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