2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1991, 1993, 1994
5 * The Regents of the University of California. All rights reserved.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 static char sccsid[] = "@(#)regular.c 8.3 (Berkeley) 4/2/94";
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
41 #include <sys/param.h>
45 #include <capsicum_helpers.h>
55 static u_char *remmap(u_char *, int, off_t);
56 static void segv_handler(int);
57 #define MMAP_CHUNK (8*1024*1024)
59 #define ROUNDPAGE(i) ((i) & ~pagemask)
62 c_regular(int fd1, const char *file1, off_t skip1, off_t len1,
63 int fd2, const char *file2, off_t skip2, off_t len2)
65 struct sigaction act, oact;
67 u_char ch, *p1, *p2, *m1, *m2, *e1, *e2;
68 off_t byte, length, line;
69 off_t pagemask, off1, off2;
80 if (sflag && len1 != len2)
83 pagesize = getpagesize();
84 pagemask = (off_t)pagesize - 1;
85 off1 = ROUNDPAGE(skip1);
86 off2 = ROUNDPAGE(skip2);
88 length = MIN(len1, len2);
90 if ((m1 = remmap(NULL, fd1, off1)) == NULL) {
91 c_special(fd1, file1, skip1, fd2, file2, skip2);
95 if ((m2 = remmap(NULL, fd2, off2)) == NULL) {
96 munmap(m1, MMAP_CHUNK);
97 c_special(fd1, file1, skip1, fd2, file2, skip2);
101 if (caph_rights_limit(fd1, cap_rights_init(&rights, CAP_MMAP_R)) < 0)
102 err(1, "unable to limit rights for %s", file1);
103 if (caph_rights_limit(fd2, cap_rights_init(&rights, CAP_MMAP_R)) < 0)
104 err(1, "unable to limit rights for %s", file2);
105 if (caph_enter() < 0)
106 err(ERR_EXIT, "unable to enter capability mode");
108 sigemptyset(&act.sa_mask);
109 act.sa_flags = SA_NODEFER;
110 act.sa_handler = segv_handler;
111 if (sigaction(SIGSEGV, &act, &oact))
112 err(ERR_EXIT, "sigaction()");
115 e1 = m1 + MMAP_CHUNK;
116 e2 = m2 + MMAP_CHUNK;
117 p1 = m1 + (skip1 - off1);
118 p2 = m2 + (skip2 - off2);
120 for (byte = line = 1; length--; ++byte) {
121 if ((ch = *p1) != *p2) {
124 (void)printf("%08llx %02x %02x\n",
125 (long long)byte - 1, ch, *p2);
128 (void)printf("%6lld %3o %3o\n",
129 (long long)byte, ch, *p2);
131 diffmsg(file1, file2, byte, line);
138 if ((p1 = m1 = remmap(m1, fd1, off1)) == NULL) {
139 munmap(m2, MMAP_CHUNK);
140 err(ERR_EXIT, "remmap %s", file1);
142 e1 = m1 + MMAP_CHUNK;
146 if ((p2 = m2 = remmap(m2, fd2, off2)) == NULL) {
147 munmap(m1, MMAP_CHUNK);
148 err(ERR_EXIT, "remmap %s", file2);
150 e2 = m2 + MMAP_CHUNK;
153 munmap(m1, MMAP_CHUNK);
154 munmap(m2, MMAP_CHUNK);
156 if (sigaction(SIGSEGV, &oact, NULL))
157 err(ERR_EXIT, "sigaction()");
160 eofmsg (len1 > len2 ? file2 : file1);
166 remmap(u_char *mem, int fd, off_t offset)
169 munmap(mem, MMAP_CHUNK);
170 mem = mmap(NULL, MMAP_CHUNK, PROT_READ, MAP_SHARED, fd, offset);
171 if (mem == MAP_FAILED)
173 madvise(mem, MMAP_CHUNK, MADV_SEQUENTIAL);
178 segv_handler(int sig __unused) {
179 static const char msg[] = "cmp: Input/output error (caught SIGSEGV)\n";
181 write(STDERR_FILENO, msg, sizeof(msg));